Skip to main content

Full text of "The beaver : its work and its ways"

See other formats

^ s^. ^# 


These monographs are a series of pubHcations 
similar in character to articles published in The 
Journal of Mammalogy, but not suitable for 
periodical publication because of their length or 
for other reasons. 

The plans for this Series are broad and compre- 
hensive, and contemplate the publication of 
works covering all phases of technical and popular 

The Monographs and The Journal of Mammalogy 
are issued under the auspices of the American 
Society of Mammalogists. 

Information regarding these monographs may 
be obtained from the Secretary of the American 
Society of Mammalogists, A. Brazier Howell, 
U. S. National Museum, Washington, D. C, or 
the Publishers, The Williams & Wilkins Com- 
pany, Baltimore, U. S. A. 

This series is edited by Hartley H. T. Jackson, 
Bureau of Biological Survey, Washington, D. C. 
Ethel M. Johnson and Emma M. Charters as- 
sisted in editing Monograph 2. 


1. Anatomy of the Wood Rat. A. Brazier 
Howell, U. S. Biological Survey, Washington, 
D. C. 225 pages. S5.00. 

2. The Beaver. Edward R. Warren, Colorado 
Springs, Colorado. 177 pages. S3.00. 

In Preparation 

3. Life of the Carlsbad Cavern. Vernon 
•Bailey, Washington, D. C. 

Other titles will be announced 
Prices are net postpaid 

The American Society of Mammalogists participates in the profits from 
the sale of monographs. These profits are used to assist in publishing 
such monographs that could not be undertaken unless undervvTitten. 



.,-., ».:sl • 


^ r a 






Collaborator, The Roosevelt Wild Life Forest 

Experiment Station, New York State College 

of Forestry, Syracuse, N. Y.; Late Director of 

the Museum, Colorado College. 




Copyright 1927 

Made in the United States of America 

Published February, 1927 

Composed and Pbinted at ths 


Baltimore, Md., U. S. A. 


S., M., R., and M, 


CO " 

List of Illustrations xiii 

Introduction xvii 

Acknowledgments xix 

Description 1 

Ancestry; The Giant Beaver; Races of the Beaver; Distribution; 
Beaver Place Names ; Historical 12 

Intelligence of the Beaver 24 

The Dam 28 

The Lodge 58 

Canals, Trails, and Landing Places 80 

Beaver Meadows 95 

Food and Tree-Cutting 104 

Breeding and Family Life 132 

Swimming and Walking 138 

Voice, Sign Heaps, Enemies, Disease, Parasites, Beavers and 
Fish, Beavers and Bird Life 145 



Fur; Castoreum; Beaver Meat; Beaver FARmNG 157 

Things That a Beaver Does Not Do 166 

Bibliography 170 

Index 175 


A fifty-five pound beaver frontispiece 

A beaver's tail 3 

Beaver swimming, showing conspicuous ears 3 

Side view of beaver's skull 4 

Side view of beaver's skull, with incisor teeth placed on 

outside 4 

Hind foot of beaver 9 

Skeleton of giant beaver 9 

Map of North America showing distribution of beaver and of 

the aspen 18 

Lower side of dam built of willows 31 

Beaver dam which had been cut through to drain the pond.. 31 

Dam with long poles on the face 32 

Map of dams deflecting current back to the side of the stream 

where the water was deepest 36 

The series of three dams 37 

A dam with two sharp angles 37 

14. A long, crooked dam on the North Fork of Elk Creek, Yellow- 
stone Park 38 

Fig. 15. Map showing two dams with many angles in them. North Fork 

of Elk Creek 39 

Fig. 16. Map of ponds on the North Fork of Elk Creek, Yellowstone 

Park, showing the changes which were made in two years. . 40 












































g. 17. A dam which covered an arc of 225 degrees 42 

g. 18. The diversion dam on Carnelian Creek 47 

g. 19. The ponds on Lost Creek, before draining 47 

g. 20. The ponds on Lost Creek, after draining 48 

g. 21. Beaver work in the Town of Manitou 53 

g. 22. Beaver dam under a railroad bridge 53 

g. 23. Pond with conifers killed by flooding 54 

g. 24. Pond with alders, etc., killed by flooding 54 

g. 25. Pond with willows, etc., killed by flooding 59 

g. 26. A typical beaver house 59 

g. 27. Interior of the lodge on Lost Creek 60 

g. 28. Drained pond on Lost Creek, showing the lodge 60 

g. 29. Floor plan of the lodge on Lost Creek 62 

g. 30. Plan of the large lodge near the Petrified Tree road 64 

g. 31. Open cut into the lodge on the Petrified Tree road 67 

g. 32. A lodge in Colorado before cutting open 68 



Fig. 33. A lodge in Colorado after cutting open 68 

Fig. 34. The Pine Tree lodge 75 

Fig. 35. A bank lodge, Carnelian Creek 75 

Fig. 36. A lodge after the snow came 76 

Fig. 37. A bank lodge, Cooke City road 85 

Fig. 38. A canal. Tower Creek 85 

Fig. 39. A beaver trail passing under several dead logs 86 

Fig. 40. A landing place 89 

Fig. 41. A landing place 90 

Fig. 42. A beaver's tracks in the mud 90 

Fig. 43. A beaver trail showing where logs have been dragged over it. . 91 

Fig. 44. A beaver trail in the snow 92 

Fig. 45. A hole on shore reached by an underground passage from the 

stream 97 

Fig. 46. The beaver meadow on Lost Creek 98 

Fig. 47. A beaver trail through willows 99 

Fig. 48. Pond in the ''Bench Colony," full of water, July 23, 1921 99 

Fig. 49. Pond in the "Bench Colony," partly drained, September 4, 

1921 100 

Fig. 50. Pond in the "Bench Colony," well advanced toward a meadow, 

August 17, 1923 100 

Fig. 51. A pond in Colorado, photographed October 8, 1913 101 

Fig. 52. The same place, October 18, 1922. All traces of a pond have 

disappeared. The change really took place in two years. . . . 101 
Fig. 53. A beaver meadow covered with a dense growth of willows. . . . 102 

Fig. 54. Chips cut from aspen 107 

Fig. 55. Chips cut from lodgepole pine 107 

Fig. 56. Toothmarks of beaver on aspen tree 108 

Fig. 57. A Cottonwood tree cut by beaver 108 

Fig. 58. Aspens cut by beaver Ill 

Fig. 59. Cottonwoods cut by beaver Ill 

Fig. 60. Aspen stumps cut twice 112 

Fig. 61. Tangled trees 112 

Fig. 62. The record stump 113 

Fig. 63. A stump six feet high 114 

Fig. 64. Pine with bark removed by beaver 115 

Fig. 65. Pine with a spiral notch 116 

Fig. 66. Pine much cut into 119 

Fig. 67. A piece of aspen caught between two stumps 120 

Fig. 68. Willow brush stored in a pond 120 

Fig. 69. Willow brush stored at lodge 125 

Fig. 70. Pine with bark removed by beaver 126 

Fig. 71. Douglas fir with bark removed from trunk and roots 129 

Fig. 72. Piece of aspen much gnawed by beaver 130 


Fig. 73. Young beavers in the lodge 130 

Fig. 74. A beaver swimming 143 

Fig. 75. A beaver floating 143 

Fig. 76. A beaver resting 144 

Fig. 77. The beaver which combed its hair after being taken from the 

trap and tethered 144 

Fig. 78. Sign heap or mud pie made by beaver 147 

A t 


There are other books about the beaver, one of which, 
Morgan's ^The American Beaver and His Works," will 
always be a classic on the subject. Morgan's studies were 
the first attempt to assemble really accurate information 
as to the habits of the animal, the size and construction of 
its dams, house and other structures, although Hearne 
had contributed a great deal to our knowledge, some of 
which was quoted by Morgan. He WTote, however, al- 
most exclusively about the beavers of the Northern Penin- 
sula of Michigan, and the book w^as pubHshed more than 
fifty years ago. 

Since that time much more has been learned about the 
animal, and a few books published, but as in Morgan's case, 
treating mainly of the animal as found in a certain region. 
Mills's ' 'Beaver World" is on the Longs Peak region, and 
Dugmore's ' 'Romance of the Beaver" is largely about the 
Canadian and Newfoundland beaver. Both contain much 
valuable information. 

I have given much time to studying the beaver, mostly 
in Colorado and the Yellowstone National Park, as well 
as in such other places as I happened to be and w^here the 
animal was to be found. In doing this work I secured 
considerable information concerning the beaver's habits, 
and especially about dams and houses, much of which has 
been published elsewhere. In the course of my studies I 
came to reahze that there was no one book about the beaver 
which was as comprehensive in its scope as such a book 
should be, and it seemed to me that such a book was de- 
sirable. Hence the attempt to supply this w^ant. 



The present book is in no sense a scientific monograph 
of the beaver. My desire has been to produce something 
for the lay reader, for the one who cares nothing about 
subspecies and such matters, but who wants to learn some- 
thing about the most interesting wild animal on the North 
American continent, for such the beaver seems to me to be, 
and judging from my experience with the tourists in the 
Yellowstone, I am not alone in that opinion. At Camp 
Roosevelt the visitors were more interested in the beavers 
than they were in the bears, and that is saying much. 

In writing this book I have drawn freely from all the 
sources of information at my command, books, various 
scientific papers, my own personal notes, and from cor- 
respondence. I have tried to tell the truth about my sub- 
ject, without humanizing it, but not without acknowledging 
the wonderful intelligence or specialized instinct, which- 
ever it may be, often displayed in the things it does. If I 
have been at least partly successful I shall be pleased, es- 
pecially if I have avoided any serious errors. It would 
be presumptuous to think there are no errors whatever. 


I wish to acknowledge my indebtedness to the following 
persons for assistance of various kinds in the preparation 
of this book: 

To Dr. Chas. C. Adams, lately Director of the Roosevelt 
Wild Life Forest Experiment Station, N. Y. State College 
of Forestry, Syracuse, now Director of the New York 
State Museum, Albany, for permission to use notes made 
when studying the beaver in the Yellowstone National 
Park, and in the Longs Peak Region, Colorado. It was 
while making these studies that I first thought of writing 
this book, so that it is in part a by-product of that work, 
and Doctor Adams has given me every encouragement 
while I have been preparing the manuscript. He also 
gave me permission to use the photographs reproduced in 
figures 2, 14, 18, 19, 20, 23, 24, 25, 27, 28, 31, 34, 35, 37, 
38, 39, 40, 41, 45, 48, 49, 50, 54, 55, 56, 58, 60, 61, 62, 
63, 64, 65, 66, 67, 70, 71, 72, 74, 75, 76 and 78. Also to 
use the maps and plans reproduced in figures 15, 16, 17, 
29 and 30. 

Joseph Dixon, of the jMuseum of Vertebrate Zoology, 
Berkeley, California, has kindly suppUed me with much 
helpful information concerning the breeding habits of the 
beaver in California. 

Dr. Wilham Lyman Underw^ood, of the Massachusetts 
Institute of Technology, has given me information about 
the influence of beaver ponds on fish. 

The Rocky Mountain News, Denver, Colorado, gener- 
ously gave permission to use the picture of the young 
beavers in the lodge. 



The Biological Survey, U. S. Department of Agriculture, 
gave permission to reproduce the map showing the distri- 
bution of the beaver and aspen. 

Vernon Bailey of Washington, presented the beautiful 
photograph of a beaver used as the frontispiece, and gave 
his consent to the use of the cut of the beaver's hind foot, 
first published in the Journal of Mammalogy, May, 1923. 

Dr. OHver P. Hay, Associate of the Carnegie Institution 
of Washington, was very helpful in his suggestions concern- 
ing the ancestry of the beaver, and kindly read the manu- 
script of that section of the book. 

David C. Mills, General Director of the National Asso- 
ciation of the Fur Industry, was good enough to have 
prepared and to send me a graph showing the range of 
prices of beaver fur for several years, which was of the ut- 
most aid in preparing my statement of that matter. 

The authorities of Colorado College gave permission to 
photograph the stick cut by beaver and shown in figure 72. 


With the exception of the South American capybara, 
the beaver is the largest hving representative of the order 
of Rodents, the Gnawers, to which the squirrels, rats, mice 
and sunilar animals belong. They are characterized by 
the large chisel-shaped front teeth or incisors. 

In external appearance a beaver is not so very unlike a 
huge, overgrown muskrat, with a rather short, wide, scaly 
tail, instead of a long, narrow, thin one, carried edgewise. 
Adults will run in total length from 40 to 45 inches, possibly 
more at times, of which length the tail will occupy from 12 
to 15 inches. 

The color above is a dark brown, with a dusky underfur 
of a considerably darker shade. The underparts are of a 
somewhat lighter color, inclining toward a pale chocolate 
brown. This color of the upper parts is that of the long, 
coarse outer or guard hairs, which are usually plucked out 
in preparing the skins for market. The color varies much 
in different parts of the animal's geographic range, and 
black, or almost black, examples are not unknown, usually, 
if not always, from northern or western Canada, while 
the majority, if not all, of the paler-colored skins come from 
the southern portion of the beaver's habitat. Vernon 
Bailey states: ^^So far as is at present known, the darkest, 
richest colored, and handsomest beaver fur is found native 
along the south shore of Lake Superior, in Northern Michi- 
gan and Wisconsin. In this region of heavy forests and 
deep snows the outer hairs of the animals are very dark 
brown, and the underfur is almost black. When tanned 



and plucked the skins are very beautiful, and .... they 
almost equal sea otter in depth of fur and richness of color." 

Speaking of the fur of the beaver of the Colorado River 
region, Arizona, Pattie says: ''In accommodation to the 
climate, [it] is becoming short." 

Albinos are occasionally found, though they appear to 
be very rare. MacFarlane thought he had seen perhaps 
ten during his long period of service with the Hudson^s 
Bay Company. Maximilian said that in 1833 yellowish 
white and pure white beavers were not infrequently caught 
in the Yellowstone. Martin, in ''Castorologia," states 
that about 1872 nine pure white beaver skins were secured 
in one parcel in the neighborhood of Little Slave Lake. 
R. E. C. Stearns stated that he had seen at Olympia, Wash- 
ington, a pure white beaver, without the least trace of the 
usual color. It was taken at or near Goldsborough, 25 
miles from Olympia. He also mentioned another speci- 
men, not as pure a white. Both were mounted. 

The tail merits a somewhat detailed description. It is 
of an oval shape, rather thick in the middle and next the 
body, and thins out both laterally and longitudinally, and 
there is evidently little or no fleshy matter at the sides and 
end. Except at the junction with the body, it is covered 
with a hard, scaly skin, which is very dark, almost black. 
One examined by me, and which is figured here, was If 
inches thick where it had been cut off, at the beginning of 
the scaly part, and was 3f inches wide at this place. It 
measured 6 by lOf inches. There were about eighty-five 
transverse rows of scales on this tail. There are a few short 
hairs projecting from between the scales on both sides, 
though perhaps more abundant on the upper. The part 
next the body is densely furred. The ratio of the width of 
the scaly portion to its length varies in different subspecies, 
and also among individuals of these groups. The width is 


Upper: Fig. 1. A Beaver's Tail 
Lower: Fig. 2. Beaver Swimming, Showing Conspicuous Ears 

Upper: Fig. 3. Side View of Beaver's Skull 

Lower: Fig. 4. Side View of Beaver's Skull, with Incisor Teeth 

Placed ox Outside 


from 41 to 48 per cent of the length, and the Carolina 
beaver, according to the data at my command, has much 
the broadest tail, that of the type-specimen being 10.8 by 
6 inches in size. The connection with the body is com- 
paratively broad and thick, and very muscular while the 
tail itself is largely composed of fatty tissue. The muscles 
are powerful and the animal has complete control over them, 
being able to turn the tail in almost any direction, even 
completely underneath the body, so that it can sit upon it. 
An old trapper informed me that a pet beaver owned by 
him used its tail as a table, placing food upon it. The 
tail serves as a brace when the owner is standing up cutting 
down a tree, when it would seem likely that those strong 
muscles would come in good play. It is used as a rudder 
when swimming, and at times as a scull to give increased 
speed, or possibly as a change from using the hind feet. 
Mills states that he occasionally saw a pet beaver carry mud or 
other building material clasped between the tail and the body. 
In diving when alarmed, a beaver often gives an alarm by 
slapping the water with its tail, making a loud noise, and 
incidentally splashing water in every direction (Fig. 1). 

The eyes are small, and the range of vision is probably 
limited, though they are quick to detect a moving object. 
The ears are comparatively short, an inch and a half high, 
lined with fur, closed when under water, while the hearing is 
keen. Even though short, the ears are really quite noticea- 
ble and prominent when the animal is swimming, or at rest 
on the surface of the water, being carried erect and standing 
(Fig. 2) clearly defined against the head. The small nostrils 
are valvular, like the ears, with large nasal cavities behind 
them, and the sense of smell is very acute. The mouth has 
hairy lips closing back of the incisors so as to exclude water 
when the animal is working below the surface. 

The fore paws are small, with fairly long claws, and are 


used as hands and for digging. The toes are not webbed. 
They are not used at all in swimming. 

Like the tail the beaver's hind foot deserves a quite de- 
tailed description. It is large and webbed, looking some- 
thing like the foot of a goose, with long, strong toes, each 
with a good-sized nail. This web extends to the base of 
the toes. The foot from which this description was made 
was seven inches long, and could be spread out to a width 
of more than five. It was thinly haired, mainly of a dark 
slaty or chocolate color, with some brownish, especially on 
the part nearest the body. The third and fourth nails 
were the longest, over an inch in length, while the outer 
nail was five-eighths of an inch long. The two inner nails 
are greatly specialized, and have been called the ^ ^comb- 
ing claws.'' 

The claw on the inner toe is formed of two well defined 
parts. The upper is a quite normally formed and shaped 
nail, } inch wide and f inch long. Opposed to this, and 
smaller, is the other portion, which is not really a nail, 
but rather a soft lobe, though it does appear to have a 
little horny substance in it, this being especially noticeable 
along the edge. The surface opposed to the upper part is 
somewhat roughened or corrugated. These two parts of 
the nail are movable and close upon one another, so that if 
hair is drawn between them it will be thoroughly combed 
and cleaned. 

The second double claw is quite different from the first. 
It is a double claw, this feature being very noticeable. It 
has always been known to those who have had anything 
to do with beavers, while the double character of the outer 
claw has usually been overlooked. Both parts of this 
double claw or nail are of typical horny substance, the 
inner being the upper, and somewhat the longer, and more 
normally shaped. It is decidedly curved. It measured 
J by f inch in the specimen examined. 


Below and at the outside is the other half, which is placed 
edgewise with reference to the first described, with what we 
may call the underside turned toward the body of the 
animal. It is thin and rounded at the end, and thick at 
the base. The dimensions were J by tV inch. These two 
portions of the claw are movable, and like those of the first 
claw, can be closed tightly together (Fig. 5). 

Vernon Bailey gives the following excellent description 
of the way in which these claws are used : 

''Never until I had tame beavers to study did I fully 
understand the use and structure of these pecuUar nails 
nor the reason for the incurving form of the two inner toes. 
My young beavers would sit and comb their fur for a half 
hour at a time, making elaborate toilets when they had 
nothing else to do. The curved finger nails of the hands 
were used on certain parts of the body, around the breast 
and head, the base of the tail, and especially in the short 
hair around the anus where the oil from the two oil glands is 
caught and held for distribution. These finger nails were 
simply raked through the fur in a coarse combing and oil 
distributing process, preliminary to the final, thorough 
combing with the hind feet. Then with one foot at a time 
the sides, shoulders, and belly were systematically gone 
over with inward, rotary strokes of the two double claws, 
until every kink and snarl of the fur was straightened out 
and not improbably, as Seton suggests, any mites or insect 
parasites combed out and off.'' 

The hind feet are the chief means of propulsion in swim- 

The two large incisor teeth in each jaw are the tools with 
which the beaver does his woodcutting, and are excellently 
adapted to the purpose. The front sides of these teeth are 
composed of a thin layer of very hard enamel, with a thick 
layer of comparatively soft dentine behind it. As the 


tooth is used the dentine wears away much faster than the 
enamel, with the result that there is always a chisel edge at 
the front of the tooth. During the life of the animal these 
teeth continue growing, and if by any chance there is an 
injury to a tooth so that it no longer opposes the one in the 
opposite jaw, the latter may keep on growing until it is of 
such a length as to be a source of great trouble to the owner 
even if it does not cause death from starvation from inabil- 
ity^ to feed. The color of the front of the incisors is a 
bright orange-red. They are long, and the concealed por- 
tions are much curved in the skull and lower jaw. IXIorgan 
gives the radius of the curve of the upper incisors as one 
inch, and of the lower If inches. I obtained somewhat 
different results in the case of the teeth I measured, these 
radii being 0.6 and 1.6 inches respectively. Very likely my 
specimens were from a smaller animal than Morgan's (Figs. 
3 and 4). 

There are four teeth in the molar series on either side of 
each jaw, formed of alternate vertical layers of enamel and 
dentine, which by their unequal wear always afford a good 
grinding surface. 

The muscles on the side of the head which actuate the 
jaws are thick and powerful, as they need to be to enable 
the animal to do the work it does with its teeth, such as 
gnawing wood, tearing out chips, and dragging sticks and 

Adult beavers range in weight from forty pounds up- 
ward. A sixty-pound one is an unusually heavy one, while 
seventy pounds is very rare, though Bailey states there are 
records of old and very fat beavers weighing 100 to 110 
pounds. He gives the weight of two two-weeks old beavers 
at If and 2 pounds respectively. 

The genital organs are beneath the skin, protected from 
the water, and open into the anal cloaca, hence one cannot 

Upper: Fig. 5. Hind Foot of Beaver 
Lower: Fig. 6. Skeleton of Giant Beaver 



easily determine the sex of a beaver, except in the case of 
adult females, which have four teats, two between the fore 
legs, and two three inches farther back. 

There are two pairs of large glands under the skin in 
front of the rectum. The anterior and larger pair of these 
are the castoreum sacs, containing castoreum, and the 
smaller, posterior pair are the oil sacs. More will be said 
about the castoreum later. 


Ancestry; The Giant Beaver; Races of the Beaver; 
Distribution; Beaver Place Names; Historical 


It is rather difficult to write anything definite concerning 
the ancestry of the beaver, or the genus Castor, of which 
several fossil species have been described in Europe and 
America. Steneofiber, a genus which made its appearance 
shortly before the middle of the Tertiary Period, in the 
Middle Oligocene Epoch of Europe, has been said to be the 
first known ancestor of the beaver. It was about the size 
of a marmot. 

Certain maromals whose remains are found in North 
America in somewhat later formations were at one time 
placed in the genus Steneofiber, but are now referred to 
other genera, and are, moreover, placed in different families 
from Castor. Steneofiber is therefore not known from 
North America, and if Castor is descended from it, then this 
latter genus is not really a native of this continent, but an 
immigrant from Eurasia via the land bridge across Bering 

Castor first appeared in the Pliocene of Europe. I do not 
know what the forms intermediate between it and Steneo- 
fiber are, but Castor has persisted as a genus to the present 

An allied genus, Trogontherium of Europe, first appeared 
in the Upper PUocene, and T. cuvieri of the Pleistocene was 
about one-fifth larger than the modern beaver. It is 
placed in the family Castoridce with the beaver. In the 



First Fauna! Subzone the Heidelberg man {Homo heidel- 
hergensis) was contemporary with Trogontherium, and of 
course with Castor fiber, the European beaver, which 
existed at the same time. Trogontherium survived until 
the lower part of the Middle Pleistocene. 

Castor is widespread in North American Pleistocene, 
but is lacking from the Pliocene and earlier formations of 
that continent. It occurs in deposits which are very early 
Pleistocene, as at Fossil Lake, near Christmas Lake, Ore- 
gon; on the Niobrara River, 15 miles from Hay Springs, 
Nebraska; and the Port Kennedy Cave, Pennsylvania. 

Dipoides was a rodent about the size of a marmot whose 
remains have been found in western North America from 
the Upper Miocene up to the Pliocene. Matthews and 
Cook have remarked that Dipoides shows a marked ap- 
proach to Castoroides. It may be an ancestor of that genus. 


The giant beavers, belonging to the genus Castoroides, 
though closely related to the beaver, are placed in a dif- 
ferent family, Castoroididw. They were exclusively North 
American animals. 

The geological range of this genus is from deposits which 
belong very near the beginning of the Pleistocene, upward 
all through that epoch, while numerous specimens have 
been found overlying the last or Wisconsin Drift, showing 
that the animal existed long after the glacial ice had dis- 
appeared. In the lower deposits it is found associated 
with horses and camels, and also with remains of the true 
beavers of the genus Castor. Specimens have been found 
in many parts of the country from central New York to 
the Great Plains, and also at Fossil Lake, near Christmas 
Lake, Oregon; and from Florida to Minnesota. A. G. 


Maddren, of the United States Geological Survey, col- 
lected part of a femur in Yukon Territory, nearly up to the 
Arctic Ocean. 

The finest specimen of the giant beaver ever discovered 
is at Earlham College, Richmond, Indiana. It was found 
in a swamp in Randolph County, Indiana, and was reported 
to have been discovered ^ ^standing in the natural position." 
It was not quite grown. Though some of the bones were 
missing it was more nearly complete than any other speci- 
men. The fore feet were missing, and have never been 
found with other specimens. The specimen was mounted, 
and a cut is presented herewith, copied from Hay. The 
fore feet were modeled after those of the beaver, and other 
missing parts restored from other known specimens. 

The total length, measured along the curve of the back 
as mounted, is seven feet, two inches, about twice the length 
of a good-sized beaver, but the animal probably was not 
quite full-grown. Large specimens very likely reached a 
length of eight or nine feet, more than twice the length of 
the beaver, "and therefore more than eight times the bulk 
of the latter." (Hay.) A skull from Iowa was fourteen 
inches long (Fig. 6). 

The incisors were enormous. The upper ones formed 
about a semicircle, and in the Earlham specimen were 8.14 
inches long, measured along the outer curve. On this curve 
they project forward and downward beyond the bone al- 
most four inches. The width was 0.93 inches, and the 
thickness from front to back almost as* much. These teeth 
are relatively much larger than in the beaver. 

The lower incisors were much longer than the upper; 
in the Earlham specimen 9.69 inches. 

The enamel was not confined to the front of the incisor, 
as is the case with the beaver, but passed around its whole 
outer face. It was missing on the other faces. The enamel 


was longitudinally grooved, with the grooves separated by 
sharp ridges. At the tips the incisors were not worn off 
to a chisel edge, as in the beavers "but in such a way that 
there is formed between and in the two a deep pit which 
received the tips of the lower incisors." (Hay.) 

Such bones of the hind feet as are known indicate a foot 
greatly like that of the beaver, though shorter in proportion 
to the length of the body. Hay makes some comparisons 
between the leg bones of this animal and those of the 
beaver which show that the giant beaver was relatively 
the shorter-legged animal of the two. 

"As to the habits of this animal we can make inferences. 
We may be sure that it was a vigorous gnawer of hard sub- 
stances. It was almost certainly an aquatic animal. 
Probably like the beavers it was addicted to cutting down 
trees and building dams and lodges for the protection of 
itself and young from cold and enemies. The tail was less 
expanded than that of the beaver, and possibly the animal 
had not learned j^et to slap the water with it for sport and 
as a signal of danger. It may have been more flexible, 
and therefore a better aid in swimming than that of the 
beaver." (Hay.) 

What was supposed to be the house of a giant beaver was 
discovered near New Knoxville, Ohio, in 1889. It was 
about eight feet square and between three and four high, 
and built of willow poles about three inches in diameter, 
"laid in the manner in which beaver houses are constructed 
at the present time." The bones of the former owner were 
found in the house. As bones of deer and other animals 
were also found there it was supposed that wolves or other 
carnivorous animals had taken possession after the builder's 



As practically always occurs when an animars habitat 
includes a considerable territory, especially when the cli- 
mate and other features are greatly varied, as is the case 
with the beaver, this animal has developed into a number of 
geographic races, whose names, with their type localities^ 
are given below. No attempt is made to give descriptions 
of these forms. It is sufficient to say here that they differ 
in size, proportions, color, and in the characteristics of the 

Castor canadensis canadensis Kuhl, Canadian Beaver. Hudson Bay. 
Castor canadensis leucodonta Gray, Pacific Beaver. Vancouver Island. 
Castor canadensis frondator Mearns, Sonora Beaver; Broad-tailed Beaver. 

San Pedro River, Mexico, near Mexican Boundary Monument No. 98. 
Castor canadensis carolinensis Rhoads, Carolina Beaver. Dan River, near 

Danbury, Stokes County, North Carolina. 
Castor canadensis pacificus Rhoads, Washington Beaver. Lake Kichelus or 

Kecheelus, Kittitas County, Washington. 
Castor canadensis texensis Bailey, Texas Beaver. Cummings Creek, 

Colorado County, Texas. 
Castor canadensis phaeus Heller, Admiralty Beaver. Pleasant Bay, 

Admiralty Island, Alaska. 
Castor canadensis mexicanus Bailey, Rio Grande Beaver. Ruidoso Creek, 

6 miles below Ruidoso, New Mexico. 
Castor canadensis michiganensis Bailey, Woods Beaver. Tahquamenaw 

River (5 miles above falls), Luce County, Michigan. 
Castor canadensis belugas Taylor, Cook Inlet Beaver, Beluga River, Cook 

Inlet region, Alaska. 
Castor subauratus suhauratus Taylor, Golden Beaver. Grayson, Stanislaus 

County, San Joaquin River, California. 
Castor subauratus shastensis Taylor, Shasta Beaver. Cassel, (Hat Creek) 

Pit River, Shasta County, California. 
Castor cacaetor Bangs, Newfoundland Beaver. Near Bay St. George, 


^ The type locality is the locality from which came the specimen from 
which the first description of a species was made. 


The European Beaver 

The European beaver, Castor fiber, is very similar in 
appearance to the American animal, but is slightly smaller. 
There are some differences in the characters of the skull, 
that of the European animal being the narrower, and having 
slightly proportionally longer nasal bones. 


Once the American beaver occupied a vast area on the 
North American continent. This area may be broadly 
stated as the whole of the United States, overlapping a short 
distance south into northern JNIexico, and in Canada extend- 
ing north to the limit of the deciduous trees, really to that 
of the aspen; at the mouth of the ]^vlackenzie River this 
brings the animal north of the Arctic Circle. Within this 
range it is absent from the desert regions of southern 
California, and parts of Utah and Nevada, and most of 
Florida, Georgia, and North and South Carolina. 

The accompanying map (fig. 7), reprinted by courtesy 
of the United States Biological Survey, shows the former 
distribution of the beaver and the distribution of the 
aspen. Taking together the ranges of the various species 
of birch, these trees cover much the same ground as the 
aspen, but apparently do not extend quite as far to the 

Over much of this great area the animal has been exter- 
minated, and probably in much of the remaining part its 
numbers are greatly diminished. As an offset to this the 
beaver has been reintroduced in a number of localities, and 
is doing Vv^ell in most of these places — too well in some, 
according to the opinions of some people whose property 
they have been damaging. 

It recently has been reported as having voluntarily re- 



Fig. 7. Map op North America Showing Distribution of Beaver and of 

THE Aspen 

Showing the range of the beaver and of the aspen,:it8 principal f9od tree The ^eavyj,kc^ line 
shows th?originallange of the t^aver Though now extermmated m much ^^ f^JJ,^l^f/^ty^^trib- 
hne probably still shows quite correctly the limits of its range. It f^°^^ ° J ^^Vie shaded area of the 
uted animals in North America. The distribution of the aspen i^ shown by ^^|jf ^^^^JJf^^i °^ Jj^e 
map. It is the most widely distributed tree m North America. The |«^^^^f l^l b'ir °h^« a^^^^^ 
various species of birch, is found over most of this same area acd some of the b^c^ 
bly found farther south than the aspen, though not extending as far nto \\ej^^^ Jf Jj^-^^^^^^^^ 
certain species of birch are important food trees of the beaver, but m tHe KocKy Mounwim a 
Pacific Coast regions are of no importance whatever. Dpnartment of Agriculture. 

This map is reproduced by courtesy of the Biological Survey, U. S. Department oi iigricu lui 


turned to one or two places in West Virginia, in which state 
it had been considered as extinct for fifty years or more. 
I have a private letter saying that three colonies have es- 
tablished themselves in New Jersey. 

According to Barret-Hamilton and Hinton's British 
Mammals, the Old World beaver once occupied the ^'WHiole 
of the forested region of Eurasia, from Lapland and northern 
Russia southwards to Spain, Italy, and the Euphrates, 
and from Great Britain eastwards at least as far as the 
Lena. The Asiatic limits of its distribution are, however, 
still imperfectly known." While the beaver lived in Great 
Britain, it never was an inhabitant of Ireland. 

The same authors state that at the present time, the 
beaver is found only in southw^estern Norway, in the Elbe, 
and in the delta of the Rhone, in each of which localities 
it is supposed to enjoy complete protection. The Nor- 
wegian colony is the most important. Nothing is said by 
these authors about the present day distribution in eastern 
Europe or in Asia. 

It is remarked that the colony in the Rhone delta must 
be one of the most interesting in the world, '^for since there 
is little or no timber at hand, the beavers must lead what is 
practically the life of a huge water rat." 

James 0. Pattie's Narrative gives us an excellent concep- 
tion of the number of beavers to be found in some parts of 
the West a hundred years ago. Trapping on the Gila 
River and some of its tributaries in Arizona, from the middle 
of December, 1824, through March, 1825, his party of seven 
took four hundred and fifty beavers. In one night thirty- 
seven were taken. In February, 1826, he found the Salt 
River in Arizona to abound with beaver. In the spring 
and summer of that year he reported beavers scarce on the 
South Platte and on the main Platte, owing to continual 
trapping. The winter of 1827-28 he made another expedi- 


tion into Arizona with a party of eight, and took plenty of 
beavers on the lower Gila in late November. In December 
he was on the Colorado River, floating down in canoes con- 
structed by his party from logs. The river seems to have 
had a large beaver population, and he says there were many 
on the islands in the river. The outfit must have been well 
supplied with traps, for he says they sometimes took sixty 
beavers of a morning. One night forty traps were set, and 
the next morning thirty-six beavers had been captured, 
^^an excellent night's hunt." In fact they caught so many 
of the animals that they were soon obliged to make another 
canoe to carry their fur. They already had eight, fastened 
together in pairs by means of platforms across them. 

Franchere reported beavers as common in the country 
of the Willamette, Oregon, in 1811 to 1814, and Townsend 
said there were many on the Malade River in 1833. 


As a natural consequence of its former wide distribution 
in America the beaver has given its name to many streams, 
lakes and other natural features, to say nothing of towns. 
The following list, which includes names of which the word 
"beaver" forms a part, is taken from the index to maps in 
the Century Dictionary, edition of 1911. The number 
following a name signifies that, if more than one, there are 
so many of that name. 

Beaver, 24 Beaver Dam 

Beaver Bank Beaverdam Bald, 2 

Beaver Brook, 3 Beaverdam Creek 

Beaver Center Beaver Dam Creek, 2 

Beaver City, 2 Beaver Dam Lake, 2 

Beaver Cove Beaver Dam Mountains 

Beaver Creek, 29 Beaver Dam Pond 

Beavercreek, 4 Beaver Dams 

Beaver Crossing Beaverfalls 

Beaverdam, 7 Beaver Falls, 2 


Beaver Harbor, 2 Beaver Meadows 

Beaverhead County Beaver Mouth 

Beaver Head River Beaver Pond 
Beaver Head Rocks * Beaverpond, 2 

Beaver Hill Beaver River, 10 

Beaverhill Beaver River Corner 

Beaverhill Lake Beaver River Range 

Beaver Island, 2 Beaver Run 

Beaver Kill Beaver Springs 

Beaverkill Beaver Tail Point 

Beaver Lake, 7 Beaverton, 5 

Beaverlick Beavertown 

Beaver Lick Mountains Beaver Valley 

Beaver Lodge Mountains Beaverville 
Beaver Meadow 

A total of forty-four different names, which would be 
greater if I counted separately such names as Beaverdam and 
Beaver Dam, which are really the same, and one hundred 
and forty places. These names are scattered all over the 
United States and Canada, and show of themselves how 
widely distributed the beaver must have been in the past. 
The list is doubtless incomplete, for in "A Gazetteer of 
Colorado,'' published by the United States Geological 
Survey in 1906, I find fourteen Beaver Creeks, two Beavers 
(settlements), Beaver Ridge, Beaver Brook (stream), 
Beaver Brook (station), these last two in different counties, 
Beaver Creek (postoffice), Beaverdam Creek, Beaver 
Station, Little Beaver Creek, North Beaver Creek, and I 
know of a Big Beaver Creek and a Beaver Lake in this 
state. No doubt the other western states are equally well 
supplied with beaver place-names. 

In England there are various beaver place-names, such 
as Beverley, Bevercoates, Beversbrooks, Beverstone, Beaver- 
bourne, Beaver Island, Beverege, and Beverley Brook. 

In my old home, ten miles out from Boston, is a Beaver 
Brook, where I used to go fishing when a boy, and a Beaver 
Brook Station on the railroad. 



The word ' 'beaver' ' in one form or another is common 
to Indo-Germanic languages, and is traceable to the Old 
Aryan hehhrus. The old Persian hadvara was used to signify 
the beaver between 300 and 400 B.C. Some, at least, of the 
ancient Greek writers had a personal knowledge of the 
animal. Dante, writing in 1310, refers to the beaver in 
the Inferno. In fact the animal lived in the Po as late as 
the sixteenth century. 

'The beaver was undoubtedly a very common British 
mammal in the later prehistoric periods, and to its activities 
we may owe some very striking features of the present 
British landscape.' '^ The fens may have been due to the 
destruction of the natural drainage by dams and fallen 
tree trunks. The destruction of the Pennine woodland and 
the formation of the peat mosses of Lancashire, were the 
work of the beaver. 

"Apart from human persecution, it is perhaps doubtful 
whether a small island like Britain could have long con- 
tinued to support a large population of beavers. "^ It prob- 
ably did not become extinct on that island before the 
thirteenth century. 

Gerald deBarri, better known as Geraldus Cambrensis, 
traveled in Wales in 1188 and wrote of the beaver there, 
describing the construction of their houses. He speaks of 
their making communications from floor to floor, as if there 
were more than one story to the structures. The houses are 
said to be built of willows and other kinds of wood, and differ- 
ent kinds of leaves. Mud is not mentioned in the translation. 
"In the coiu"se of time, their habitations bear the appear- 
ance of a grove of willow trees, rude and natural without, 
but artfully constructed within." 

* A History of British Mammals, Barrett-Hamilton and Hinton. 


The early history of Canada is full of allusions to the 
beaver, for the French, from almost the very beginning of 
the settlement of that region, began the acquisition of 
beaver skins, either by trading with the Indians, or by other 
methods. The Jesuit fathers, in their intercourse with the 
savages, seem to have acquired many skins, and to have had 
much difficulty in disposing of them. The rules of the 
order appear to have prohibited any sort of commerce for 
profit. The company chartered by the king of France had 
the sole right to trade in any sort of furs, and the Jesuits 
were obliged to sell to this company for any price it chose to 

The first parish church of Quebec was built by a contri- 
bution of beaver skins from the governor. The carpet 
around the altar was paid for by beaver skins. 

Beaver skins seem also to have had some s>Tiibolical 
significance among the Indians, apart from their ordinary 
uses. In some of the Jesuit accounts mention is made of 
presents of beaver skins being made to different tribes when 
adjusting disputes between them. The value of the skins 
themselves was not great, but the sentiment conveyed by 
them meant much, and served to bind a treaty. 

I have said nothing in regard to the traditions and legends 
of the Indians concerning the beaver. They had many, 
varying with the different tribes. I think most of the 
tribes had legends connecting the beaver in some way with 
the creation of the world. Some tribes possessed the medi- 
cine bundle known as the '^beaver bundle,'^ which was sup- 
posed to have supernatural attributes. The individual 
possessors or holders of these bundles had special powers 
due to this ownership. The various Blackfoot tribes seem 
to have set much store by them. 


The Intelligence of the Beaver 

It is not easy to write of the intelligence of the beaver 
or of that of any other of the lower animals. The opinions 
of the various writers on the subject vary widely, some 
crediting the animal with a high degree of intelligence, and 
others denying that it is possessed of anything more than a 
highly developed and speciahzed instinct. Right here we 
come to the difficulty of defining the difference between 
instinct and intelligence, or perhaps it might be better to 
say where one begins and the other ends. Intellectually 
the beaver is human-hke in that it does some very clever 
things, and it also does some very stupid ones, and it should 
not be judged solely by either. 

The rodents, of which order the beaver is a member, are 
rather low in the scale, and the brain is smooth, wanting in 
convolutions, these facts apparently indicating a low mental 
capacity. The beaver does not dift'er from other rodents 
in respect to the structure of the brain. 

I find it somewhat difficult to define my own position in 
the matter. Perhaps it might be well for me to say that I 
have never made any study of psychology, and whatever 
opinions I may have are based upon observations made 
upon animals at various times. I do believe that animals 
have a certain amount of intelfigence, as distinguished from 
instinct, very likely varying with the different orders, and 
of course with different individuals. 

My studies of the beaver have led me to the conclusion 
that it does act intelligently, not with the human intelfi- 
gence some v/riters would ascribe to it, but that it does do 



things in which it is guided by something more than in- 
stinct alone. Such things as the selection of the best loca- 
tions for dams, of which I later give one or two instances, 
the building of canals with two or more water levels, 
making a ditch around a rough place in a stream so as to 
take its logs down with the least trouble, all seem to me to 
point to the possession of some degree of intelligence. An 
instinct which tells an animal to do any or all of these 
things comes so near being intelligence that it may as well 
be called that. 

On the other hand, in the felling of trees, the animals 
seem often to proceed in an unintelligent manner, and to 
have no notion as to making a tree fall in the most suitable 
direction, and especially so as to prevent its entanglement 
with other trees. \Miere trees have become entangled 
with others in falling, the beavers seldom seem to take 
very obvious methods of freeing them. Mills says that 
he knew beavers to stop cutting on the windward side of a 
grove on a windy day, and to go around to the lee side; also 
not to cut trees whose tops were entangled in the branches 
of other trees. 

Mills firmly believed that the beaver was an intelligent, 
reasoning animal, and gave various reasons for his belief. 
Morgan was very much of the opinion that the beaver is 
possessed of a free intelligence, as he termed it, mentioning 
especially in this connection the interrelation of dams, 
lodges, and water level. He also thought that while a 
canal was simpler to construct than a dam, it required 
more inteUigence to plan, which is quite true. 

In connection with canals Dugmore says: "These canals, 
I venture to say, are a demonstration of the highest skill 
to be found in the work of any animal below man. It is 
even doubtful whether man in his lowest form does such 
extraordinary constructive work and with such remarkable 


success." He also cites the fact that beavers will turn 
other streams into their own in order to add to the water 
supply as something requiring thought. 

G. J. Romanes expressed the following opinion: "Most 
remarkable among rodents for instinct and intelligence, 
unquestionably stands the beaver. Indeed, there is no 
animal — not even excepting the ants and bees^ — whose 
instinct has risen to a higher level of far-reaching adapta- 
tion to certain conditions of environment, or where facul- 
ties, undoubtedly instinctive, are more puzzlingly wrought 
up with faculties no less undoubtedly intelligent." 

On the other side Johnson considers the beaver acts 
entirely from instinct. "But in the course of the ages it 
has evolved a set of instincts, highly complex, at which we 
can not but marvel just as we marvel at the instincts of the 
ant and the bee. These instincts are inherited and at just 
the right time in their life history, when the proper stimuli 
prompt them, the young beaver will do certain things, and 
do them in the same way and just as well as their parents, 
without first having to be shown or taught how." 

Seton says: "While of a low general mentality, the beaver 
has a wonderfully developed instinct for the building of 
dams and waterways. A quickness to take advantage of 
little things and a ready adaptability to change of sur- 
roundings that in this special department puts it in the 
highest class of low animal intelligence. A case parallel 
with that of the ants indeed; which, though so low in or- 
ganization, have acquired extraordinarily complex instincts, 
whose history affords one of the most wonderful ^fairy tales 
of science.' " 

I think Seton puts the case very well when he says that 
after the beaver had been considered on a par with man 
intellectually and most wonderful tales were told about it, 
there was a reaction, and it was put in the same class as the 


rabbit and porcupine, as to intelligence. Later, thanks to 
the work of such observers as Hearne and IMorgan, we find, 
as usual, that the truth is between the two extremes. 

That the beaver is adaptable no one who has studied 
its work will deny. In adapting itself to or taking ad- 
vantage of circumstances it does just what a human engineer 
does when, before beginning the construction of a dam, for 
instance, he studies the surroundings, investigates the pro- 
posed site and the character of the underlying rocks or soil, 
and having gained this knowledge, plans his work accord- 
ingly, more elaborate and thorough than what the beaver 
does, and more consciously done than the beaver's work, 
perhaps. But the main point is that each adapts itself 
to circumstances, and if in the case of the man this shows 
intelligence, why not also in the case of the beaver? 


The Dam 

Unless the animals happen to be living in natural ponds or 
lakes, the dam is almost sure to be the first structure made 
by the beaver. It is necessary to their existence in many 
cases, and absolutely essential to their welfare. Therefore 
in the founding of a new colony dam-building is the first step, 
and once built, the dam requires constant attention and 
repair to keep it in condition. 

The method of construction appears to be always practi- 
cally the same at the beginning. Branches of willows, 
alders, or whatever brush is most available, and this is usually 
one or both of the two just named, are cut and placed on the 
bottom with the butt ends upstream, and often forced into 
the bottom. Mud and gravel, and frequently stones, are 
put on these branches, this material being obtained from the 
bottom just above the dam. Other layers of brush are 
placed upon the first, each in turn weighted down with mud, 
until the dam reaches the desired height. At first the water 
leaks through the loosely constructed affair, but the stream 
brings down sediment which helps to make the dam water- 
tight, more mud is placed on the upper side and on the crest, 
and soon the dam is holding water, and the pond has filled. 
A drained beaver pond usually, if not always, has a ditch 
or trench immediately above the dam from which the earth 
used in the latter was taken. 

Such, in a few words, is the construction of the usual dam. 
But a dam is never finished as long as the pond is occupied, 
for it not only requires continual attention to keep it in 
ordinary repair, but the pond tends to fill up with silt brought 



in by the stream, which naturally lessens the depth of the 
water, and hence the dam must be raised in order to retain 
the water at the desired depth. Raising the height of the 
dam almost invariably means lengthening it, and thus a dam, 
which was originally straight, comes to have a curve up or 
down stream, or, if it be a long one, may have several 
angles in it. 

In constructing the dam the beaver brings up such mate- 
rials as mud and stones from the bottom by carrying them 
held against its chin by its fore feet, w^hich are pretty effi- 
cient hands in such work. Mills speaks of seeing his young 
pet beaver carry mud and sticks clasped between the tail 
and belly. The branches used are conveyed by holding them 
in the mouth and letting them trail alongside on the ground 
or in the water until the dam is reached, where the paws may 
be used to place them properly. In building dams beavers 
will often take advantage of any natural elevations which 
may be of use to them. At one place in Colorado, where a 
low dam was extended across a wide flat or meadow, and 
where numerous clumps of willows stood a little higher than 
the surrounding surface, the animals built their dam from 
one of these clumps to another, saving themselves consider- 
able labor, though I must confess I thought their work was 
wasted, for only a very shallow pond was created, of which I 
was unable to see the use. It was one of those cases where 
it seemed as if the beaver had made a mistake and failed to 
accompHsh anything. 

I have little doubt that at the beginning of the construc- 
tion of a dam most of the brush used is laid longitudinally 
with the current, not transversely. Some dams may pos- 
sibly have all the material laid in this manner. In many 
cases, however, where dams have been cut through by man 
or a stream, the ends at the banks remaining, one sees the 
ends of sticks projecting from the break as if they had been 


laid across the stream (Fig. 9). I have seen several instances 
where this appeared to be quite evident. The sticks here 
were usually rather small. It also seems possible that some 
movement may occur in the inevitable setthng of a dam 
which shifts some of the sticks, causing them to take this trans- 
verse position. When a dam is completed sticks and brush 
are often seen lying lengthwise on the top, and the peeled 
sticks carried there after the bark has been eaten from them 
lie in various positions, criss-cross, as one writer expresses it. 
Many sticks of this sort drift to the dam and lodge there. 
Sticks carried to the lower face of a dam after its completion 
seem to be dropped there in almost any manner. I have 
seen one dam in Colorado which had long pine poles placed 
along its face so that their ends projected quite high above 
the dam (Fig. 10). 

One dam which I found in Colorado, built upon a bench a 
few feet above the stream, had willow brush laid horizon- 
tally between clumps of willows which were along the course 
of the dam. As the water in the pond came from springs 
there was practically no current to resist, and this somewhat 
w^eak form of construction was of no detriment to the dam. 

Dams consisting wholly of mud or sods are sometimes 
built. The one or two which I have seen were in swampy 
ground where there was no current, and were made by 
excavating the material from above the dam and pihng it up 
along the desired location. In one case in the Yellowstone 
the whole pond was thus excavated in building the dam. 
This pond was apparently constructed for water storage. 

It is sometimes stated that trees are felled across a stream 
in beginning a dam, but it is exceedingly doubtful if this is 
ever the case. Morgan mentions one instance where a 
large fallen pine formed part of a dam, but he was in doubt 
as to w^hether the tree had fallen before the beginning of the 
dam, and thus suggested the site to the beavers, or had fallen 
on the dam after it was built. 

^*«>i:-, ^^fe 

Upper: Fig. 8. Lower Side of Dam Built of Willows 
Lower: Fig. 9. Beaver Dam Which had been Cut Through to 

Drain the Pond 


*^ h 




Fig. 10. Dam with LuNu Toll- ux the Face 



I saw two or three small dams in a group on Tower Creek, 
Yellowstone Park, where half -decayed pine logs formed part 
of the dam. I think it probable that the beavers intention- 
ally made use of these fallen logs as part of their dams, 
which belonged to a series of storage ponds. It certainly 
seems rather unlikely that several logs should have fallen 
across so many dams in the same group after the building 
of the dams. A. H. Howell, in the Biological Survey of 
Alabama, states that beaver built small dams across Catoma 
Creek in that state, generally utilizing '^trunks of fallen 
trees (not of their own cutting) for a foundation, filling in 
the space between the logs with sticks, cane stalks, leaves 
and mud." 

In Gunnison County, Colorado, I found a dam twenty 
feet long and eight feet wide on top, built across a slough 
having little or no current. This appeared to be constructed 
largely of mud, though a certain percentage of sticks was 
also visible. It was evidently quite old at the time of 
my examination, but a Kttle work had recently been done 
on it. 

In 1899 a surveyor named John Harrold was running sec- 
tion hues in the Little jNlissouri Badlands, immediately west 
of the Killdeer Mountains, North Dakota, and discovered 
three or four beaver dams built of coal. The face of one of 
these was six feet high. The coal came from a nearby bluff. 
Taylor, who is the authority for the above, also mentions 
dams on the Upper ^\niite Earth River, North Dakota, built 
entirely of stones, some of which would weigh as much as 
fifty pounds.^ Mills speaks of a dam in the Sawtooth Moun- 
tains, Idaho, constructed of logs from a snowshde. I have 
myself seen a few sticks from a snowshde utihzed in a dam. 

Morgan speaks of three dams discovered in ]\Iontana 
which were in a petrified state. ^They were not in that 

* Taylor, Beavers, Their Ways. 


complete and final state of petrifaction which involves the 
change of every particle of the original woody materials, and 
the substitution of solid substances; but rather incrusted 
with lime, which, penetrating and solidifying the entire 
structures, had given them a permanently durable form/^ 
These dams were fifty to sixty feet long, and had a fall of 
water over them of from one to four feet. 

The beaver has been credited with having the intelUgence 
to build its dam with an upstream curve, the better to 
withstand the force of the current. Just another of the 
legends about the animal. Sometimes the dams are built in 
a straight line across the stream, sometimes curved up and 
sometimes down, and in a long dam often bent both ways 
indiscriminately. I think they do this without any special 
reasoning, unless special circumstances force a particular 
construction. The most pecuUar example of a downstream 
curve which I have seen was on a dam on a small stream in 
Colorado. T\Tien I first saw it I called it a '^mule-shoe 
curve." I examined and measured it. The total length 
was seventy-one feet. From the end at the right bank of 
the stream it extended down parallel with the current 
twenty-four feet. At this point high water had torn a 
gap five feet wide and swung the broken-out portion down- 
stream in line with the other part. It was twelve feet across 
at right angles to the stream to where the dam turned up 
again, and it was about twenty-five feet across between the 
two ends of the dam. I could see no reason for this manner 
of construction. There did not appear to have been any 
obstacle to building a dam directly across the stream, and 
it seemed possible that the dam had been originally thus 
built and afterward broken by flood, parts perhaps forced 
down stream, as I had seen, and their ends later connected 
to close the gap. 

Beaver dams are of all lengths, from the trifling ones a 


foot or two long, made to head off a side flow of water, to 
the one mentioned by Mills, on Jefferson River, near 
Three Forks, Montana. This was 2140 feet long, most of 
it old; more than half was under six feet high; two short 
sections were twenty- three feet wide at the base, five on top, 
and fourteen feet high. This is, of course, extremely 
unusual, and unfortunately Ivliils gives no further details 
which might explain the reason for this extraordinary length. 
Undoubtedly it was the work of many generations of beavers, 
and probably constructed intermittently. 

Shiras gives a picture of a dam forming the western end of 
Echo Lake, which occupies a mile in the center of Grand 
Island, Lake Superior. The legend under the picture says: 
'^The bank on the left, covered with second growth trees, 
is an ancient beaver dam 1500 feet long, probably 400 
years old, and forming the lake, originally.'^ 

I think it doubtful if dams are ever of any great length 
when first constructed. The great majority are under fifty 
feet long at first, though I have seen a dam in Colorado 
which was nearly a hundred feet long as first built, it being 
necessary for it to be of this length in order to cross the 
stream. Another below it was seventy-six feet in a straight 
line from end to end, but curved twice, first down, then 
upstream, starting from the right bank and ending short of 
the left. Below this dam, and setting out diagonally into 
the stream from the left bank, was a short one twenty feet 
long. The water flowed around the end of the long upper 
dam, and thence around the free end of the short lower one, 
thus throwing the main body of water back to the right bank 
where it would naturally have been if undisturbed by any 
obstruction, and where it was much deeper than on the oppo- 
site side, and therefore keeping the water deep below the dam 
as well as above. When I first described this place I made 
the statement that the downward curve of the dam near 



the right bank created an eddy and backwater above the dam 
and threw the swifter current over to the other side into the 
shallow water. Doubtless this was the case, but from what 
I have since seen of beaver work I am in doubt as to whether 
or not that downstream curve was made intentionally. 

It may be as well to mention here three dams on the same 
stream some little distance above those just described. The 
upper one extended about halfway across the river from the 
left bank; twenty-five feet below, and on the opposite side. 

^c/? -f. £: 

Fig. 11. Map of Dams Deflecting Current Back to the Side of the 
Stream Where the Water was Deepest 

was another dam also extending halfway across; sixty-five 
feet below that and on the same side was a third dam, like- 
wise going halfway over. Twenty-five feet below was a 
small dam about eight feet long. The upper dam backed 
up considerable water, but, as the stream had too much fall, 
not to any great depth. The other two dams, while not 
increasing the depth of the water so very much, did make 
quiet pools, perhaps more to the beavers' liking than the 
swift water (Fig. 12). 

Upper: Fig. 12. The Series of Three Dams 
Lower: Fig. 13. A Dam with Two Sharp Angles 


Fig. 14. A. Long, Crooked Dam ox the >,orth Fork of Elk Creek, 

Yellowstone Park 




To return to the dimensions of dams. I measured the 
dam which formed Beaver Lake in Yellowstone Park, and 
found it to be 1054 feet long, this without following accu- 
rately all the bends of the dam, which was quite crooked. 

The longest dam still used by beavers which I have per- 
sonally measured was one on the North Fork of Elk Creek, 
Yellowstone Park. This was three-hundred and fifty feet 




Fig. 15. Map Showing Two Dams with Many Angles in Them, North 

Fork of Elk Creek 

from end to end, and very crooked. In spite of its length 
it made only a narrow pond, one hundred feet wide, because 
of the topography (Fig. 14), the ground being comparatively 
level in the direction of the dam but rising faster up stream, 
most of the water entering and leaving towards one side of the 
pond. This conformation of the surface doubtless explains the 
irregularities of this and similar dams. The beginning is a 



short dam across the stream which forms a pond. The water 
rises in this, and presently begins to flow around one or both 
ends of the dam. The beavers extend the dam to cut off the 
escaping water, and these extensions point up or downstream 
according to the lay of the land, thus producing an up or 
downstream curve in the dam, which is thus purely an 

Fig. 16. Map of Ponds on the North Fork of Elk Creek, Yellowstone 
Park, Showing the Changes Which Were Made in Two Years 

accident and not intentional. The varying curves in such 
a long dam as the one I have just mentioned are undoubtedly 
caused by variations in the surface of the ground across 
which the dam was made, the builders carrying the dam 
along from point to point as necessary to stop the overflow. 
Something over a hundred yards upstream from the above 
described dam is one which in 1921 was 115 feet long. In 


1923 it was 250 feet, more than double its former length, 
and the pond was proportionately increased in area, and con- 
tained a lodge. This increase in size was probably made by 
beavers which moved up from the large pond below in order 
to be nearer the aspens, and also possibly because they were 
crowded out of the other place (Fig. 16). 

The height of beaver dams is of course variable. I think 
a large majority are under five feet high, measuring per- 
pendicularly from the crest to the stream bottom below. 
Johnson gives the heights of two dams in the Adirondacks 
as 8 feet 8 inches and 11 feet 1 inch, respectively. These 
are really very much out of the common, if not extraordi- 
nary. One sometimes sees dams but two or three feet high 
which back the water up for considerable distances. This 
depends, naturally, upon the fall of the stream; the greater 
the fall, the higher the dam must be to make a pond of any 
size and depth. Sometimes comparatively short dams will 
make large ponds. One dam in the Yellowstone, 103 feet 
long, was placed at the lower end of a wide, shallow valley, 
below which the gulch fell off rather abruptly, forming a 
pond 350 feet long by 225 feet in its greatest width. At 
Crescent Hill the largest pond, 340 by 800 feet, was formed 
by a dam 165 feet long. Of course in both cases the locations 
of the dams were exceptionally favorable for the formation of 
such large ponds. Frequently it is the other way about, long 
dams ha\dng narrow ponds above them, sometimes not more 
than a half or a third of the length of the dam in width. 

In a stream with a gentle fall a short dam between the 
banks may make a pond several hundred feet long. I have 
seen a dam sixty feet long back the water up 475 feet, and 
another thirty-five feet long make a pond 350 feet in length, 
and a third dam fifty feet long made a 375 foot pond, all on 
the same stream. At Little Trappers Lake I found a dam 
three feet long which backed water up for 75 feet. Johnson 


mentions a dam 75 feet long and three feet high on Salmon 
Brook in the Adirondacks, which made a flow about a mile 

Beavers sometimes display excellent judgment in locating 
a dam at the most suitable point to get the best results. 
At Crescent Hill, Yellowstone Park, the dam making the 
large pond previously mentioned was placed at the lower 
end of a gulch between Crescent Hill and a ridge to the east, 

O /O 2.0 30 <fO -^O/TTiS' -T- 

FiG. 17. A Dam Which Covered an Arc of 225 Degrees 

at a point where the two slopes came closest together; the 
gulch widened above where the pond was formed, while 
below the valley spread out and became flatter; this was the 
place an engineer would have selected for the same purpose. 
This dam appeared to be rather an old one. Several 
hundred feet below, along the gulch, the beaver had, in 1921, 
begun another dam at a similar spot, where the two slopes 
approached and a comparatively short dam would flood a 


good-sized area. In 1923 I found the place in the same con- 
dition as when last visited in 1921. Evidently the beavers 
had decided they did not wish a pond there. 

Beavers make mistakes at times in building dams, some- 
times because the stream is too turbulent for them to make a 
permanent structure, or because there is not material for 
them to work with, or the dam does not make a pond of 
sufficient size or depth. 

Mills mentions a dam wliich by successive additions came 
to extend three-fourths of the way around the pond. I 
saw a small abandoned pond near Yancey^s, the dam to which 
partially encircled the pond and described an arc of 225 
degrees, though far from circular. The pond was situated 
where the North Fork of Elk Creek entered the valley. 
The pond was so filled up with gravel that but little could be 
learned about the history of the dam. 

Dugmore says that alders are most frequently used in 
building dams. I presume that refers to the regions where 
most of his observations were made, Canada and Newfound- 
land. If I were to go according to my own work, I should 
say willow, and as a matter of fact I think the animals use 
the materials which are most available. He states that a 
week of steady work on the part of a family will see a thirty 
or forty foot dam raised two feet or more. 

Ponds are often abandoned because the supply of food 
trees has become exhausted. After a new crop has grown 
the beavers may return and repair the dam and reestablish 
the colony, but very likely the newcomers may be entirely 
unrelated to the previous residents. 

Dugmore says that spillways are often made on dams to 
take care of the overflow, though I have never seen anything 
of the sort myself. He mentions an instance of a dam under 
construction being threatened by a flood. The beavers 
made a large enough opening in the dam to permit the flood 


waters to escape, and after the storm had passed and the 
water subsided they closed the gap and completed the dam. 

Morgan distinguished two types of dams, the ''stick dam" 
and the ''solid bank dam;" the former of interlaced stick and 
pole work on the lower face, with mud and earth on the water 
or upper face; the latter usually found lower down on streams 
and containing much more earth and mud, probably much 
older structures than the first. Personally I have never 
been able to make any such distinctions. He thought 
curvature of dams was purely accidental. 

He estimated the amount of material in Grass Lake dam, 
which was 260 feet 10 inches long, greatest height 6 feet 
2 inches, to be upwards of 7,000 cubic feet. 

Morgan knew of no instance in the area studied by him 
of a dam being constructed across a stream having a greater 
depth than two feet at the lowest water level. 

Practically all dam building is done in the fall, in prepara- 
tion for winter. 

Beavers will build dams wherever a supply of water can 
be had to make a pond, and where a supply of food is at hand. 
They will build them across the outlets of natural ponds in 
order to raise the water level. The greater number are built 
on running streams. The previously mentioned dam at 
Crescent Hill was seemingly built to hold the water from 
springs in the gulch above, which are now covered by the 
pond, for there was no visible water supply, though in the 
spring melting snow must supply considerable water for a 
short time. On Tower Creek, also in Yellowstone Park, an 
extensive series of ponds utilized the water from a large 
spring on the creek bottom some distance away from the 
stream, and at the foot of the mountainside which rises 
above the creek valley. There were other series of ponds 
on the same stream which obtained their water supply in 
the same manner from other springs. The stream itseK 


was really too rapid and rough to be favorable for dam build- 
ing, though I saw where the beavers were beginning one and 
had the foundation laid part way across. This had disap- 
peared two years later. 

Perhaps the most pecuKar location for a dam which has 
come to my notice is one that I was told about. A number 
of years ago my informant had occasion to visit a mining 
tunnel on a mountain several miles southwesterly from 
Colorado Springs. This mountain, while of no great eleva- 
tion itself, is much higher than the region immediately 
surrounding it. The tunnel was near the top of the moun- 
tain, and was about one-hundred and fifty feet long. The 
first twenty-five feet was in earth, and had been timbered 
with posts and caps, with lagging overhead and part way 
down the sides to hold up the ground. Aspen trees grew all 
about, evidently the attraction for the beavers. There was a 
good spring at the tunnel and the latter was wet, with 
enough water dripping from the roof to make a small stream 
which flowed from the mouth. All the water disappeared 
in the ground a couple of hundred feet or so below the tunnel 

Beavers had built a circular dam about ten feet from the 
mouth of the tunnel in such a fashion as to impound the 
water from both the spring and the tunnel. The dam was 
about eighteen inches high, built of mud, aspen sticks and 
brush, and backed the water up in the tunnel for some dis- 
tance. Inside the tunnel holes had been dug in the earth at 
the sides of the timbered portion, and the earth from them 
apparently used in the dam. 

Many peeled aspen sticks were in the pond formed by this 
dam, and at the breast of the tunnel were more. The bark 
had been pulled from these last in strips, and used to make a 
nest or bed, which was about four feet in diameter and three 
high . It was hollowed out on top. 

46 THE BEA\^K 

While no beavers were there at the time of the examination 
the work looked fresh, and certainly had been done within a 
year. The visit was made in early autumn and the tunnel 
had been worked the preceding fall. The nearest stream is 
four or five miles away and that not suitable for beavers. 

On CarneUan Creek in Yellowstone Park the beavers had 
done an interesting piece of engineering. On the flat on the 
left bank was a series of four good-sized ponds, which re- 
ceived their water supply from the creek in the following 
manner: An old dam, or its remains, extended part way 
across the stream, which was quite wide at this point, and 
which also made a considerable bend; from the end of this 
old dam an extension had been carried part way to the 
right bank in such a manner as to divert a portion of the 
stream into the upper pond, whence of course it went on 
down through the others. The creek had so much fall that 
the last of the ponds was several feet above its level (Fig. 18). 

At times beavers drain the water from their ponds, either 
partially or entirely. Why, I do not know. Mills expressed 
the opinion that it might be for sanitary reasons, to permit 
the sun and air to purify the bottom of the pond and interior 
of the lodge, if one was present. Later the pond would be 
filled again by closing the opening in the dam. I know of 
one pond which was full in February, empty the following 
October (no visit made between those dates), and full again 
in November. 

In the Yellowstone a pond with two good-sized lodges had 
been drained by a hole through the dam at the stream chan- 
nel. The pond bottom was full of devious channels which, 
presumably, the former occupants had dug. The pond 
was apparently abandoned because all the aspens on either 
side had been harvested. The beavers were living in another 
pond a short distance upstream, and possibly in another 
below (Figs. 19 and 20). 

Liter: Fig. 18. The Diversion Dam on Carnelian Lkj:.ilk 
Lower: Fig. 19. The Ponds on Lost Creek, before Draining 


* ** 

Fig. 20. The Ponds ox Lost Creek, after Draixixg 



On another stream in the same region two connecting 
ponds were drained some time between July 23 and 28. 

I have thought possibly the first mentioned pond had been 
drained to prevent the water in it from becoming stagnant 
before reaching the ponds below. Being of good size the 
current through it was slow and the water might need 
aerating. This theory, however, hardly seems apphcable to 
the last mentioned ponds, where the conditions were quite 

Beavers are frequently very bold when not molested, 
and will build their dams surprisingly close to inhabited 
houses, and even within the limits of a town. Several years 
ago a small dam was constructed in Ruxton Creek, in the 
town of Manitou, a thriving summer resort at the foot of 
Pikes Peak, with a permanent winter population of several 
thousand. One could look from the sidewalk down into the 
gulch where the stream was, and all along on the opposite 
side were houses. Even in the dull winter season people 
were constantly passing, yet the beavers had built this dam 
and had been cutting trees and bushes close by, even at the 
top of the bank close to the sidewalk (Fig. 21). 

The following autumn a colony established itself on Foun- 
tain Creek, a mile below Manitou, not far, however, from 
houses, and built a dam near a railroad track, and cut 
down forty or more trees. This work was washed out by 
high water the following simimer, and the animals moved 
upstream a short distance and built a new dam four feet 
high, under the bridge by which the railroad crossed the 
creek, making a pond one hundred feet long. They had 
felled a number of cottonwood trees here. I think these 
beavers moved away the following year and never returned 
(Fig. 22). 

A somewhat remarkable instance is that of a couple of 
beavers which estabhshed themselves in an artificial lake at 
the summer resort of Green Mountain Falls, in the Ute 


Pass, Colorado. To prevent the animals from destroying 
the few trees about the lake the townspeople carried green 
brush to them, which supphed food and also material for a 
lodge which they built beside an island in the lake. In 
1926 they were still Uving there and had increased in number 
to four. 

Such occurrences as the washing away of dams by floods 
are common happenings on our western streams, if not 
elsewhere. In the mountains these floods are usually due 
to melting snow in spring, which often raises a stream several 
feet above its ordinary level, and at lower altitudes cloud 
bursts in summer may send down large volumes of water at 
one time which tear out almost any obstructions which may 
be in their path. The floods in Colorado, in June, 1921, 
carried out every dam on a long stretch of one stream with 
which I am famiUar, and changed the channel in many 
places. What the beavers did during the high water I do 
not know, but after the flood receded they evidently re- 
turned and built new dams, and there are still flourishing 
colonies on the stream. 

Mills, speaking of the "Moraine Colony'^ at a time when 
it was deserted, said that the stream had cut deeply through 
the old main dam, and this showed that it had been built on 
top of an older and filled-up pond; this second dam was on 
top of a still older one. In the sediment of the oldest pond 
were found a spear head, charred logs, and a buffalo skull. 

Dugmore says: "Agassiz, speaking of the age of beaver 
work, mentions the building of a milldam which required 
some excavating. ^This soil was found to be peat bog. A 
trench was dug into the peat 12 feet wide, by 1200 feet long, 
and 9 feet deep; all the way along this trench old stumps of 
trees were found at various depths, some still bearing marks 
of having been gnawed by beaver teeth'." By calculating 
the growth of the bog as about a foot a century there is 


fairly good evidence that the dam built by the beavers must 
have existed about one thousand years ago. 


Beavei's build dams for various reasons. The primary 
purpose for which one is made is to provide a sufficient 
depth of water in which the animals can move about in safety 
and to which they can retreat from their enemies, and in 
which they can transport their food supplies; deep enough 
to protect the entrances to the lodge, when there is a lodge, 
and the burrows in the banks. The pond must also be of 
such depth that when frozen in winter there will still be 
water enough to enable the inhabitants to move about under 
the ice and to pro\dde a place for the winter storage of food. 
Such is a brief statement of the requirements of a pond 
intended for residential purposes. 

But there are other uses to which a pond is put, and not 
every pond in a colony is inhabited by the beavers. They 
are often built to pro\'ide water in which food supphes may 
be floated to the main pond. Thus the ^'Deadwood Dam 
Pond" in the Moraine Colony near Longs Peak, described 
by Mills, was made to enable the builders to cut aspens in a 
grove on the shore of the pond and float them across, and 
thence carry them to the pond where they lived. This 
Deadwood Dam Pond was not on the stream but was filled 
by means of a canal dug for that purpose. 

On a stream we often find dams above and below the main 
pond. These have several uses. All of them may be 
used for carrying food to the principal pond; those upstream 
from the latter are serviceable in controlling flood waters 
and preventing them from rushing in too great a volume into 
the latter and perhaps endangering it. Incidentally atten- 
tion should be called to the fact that the whole series of 
beaver dams on a stream may be of great service to man in 


preventing floods in the stream below them, holding back a 
surplus of water and permitting it to escape only gradually. 
These dams are of ser\dce not only for preventing floods, but 
also for storing water which may be used for irrigation. 

The dam next below the main one is often, if not always, a 
protection to the latter by backing water up against its base, 
enabling it to resist increased pressures from water or ice. 
Of course all the dams of a series may protect one another in 
this manner. 

Another use of beaver dams and ponds to man is that in 
those sections where canoes and light boats are used for 
travel sufficient water is found in the beaver ponds on 
streams where it might otherwise be impossible to proceed. 
Ponds and dams check silt coming down in the stream, and 
prevent it getting into reservoirs, ditches and fields farther 
down. One writer states that stock are now using several 
ranges in the National Forests of Colorado which formerly 
could not be used for lack of water. Beavers made ponds in 
the small streams, conserved the water, and made it avail- 
able to stock during the siunmer. Beaver dams and flows 
along a stream often prove to be excellent firebreaks, pre- 
venting the spread of forest fires, which are checked by the 
flooded spaces. 

A report of the Supervisor of the Gunnison National For- 
est, Colorado, gives an example of the value of beaver 
ponds as storage reservoirs. He says: 

'^During the protracted drought of the season just passed 
(1924), the water supply for the Minnesota reservoir ran 
low and it was evident that sufficient water for the late 
irrigation run would not be available. Fourteen large 
beaver ponds near the head of Deep Creek and just above 
the Minnesota canal were tapped and the water turned into 
the small stream bed and carried to the company^s canal, 
thence to their reservoir, which was filled by this additional 

Upper: Fig. 21. liEAVj^u Work in^ the Towx of AiAxiiuu 
Lower: Fig. 22. Beaver Dam Under a Railroad Bridge 






Upper: Fig. 23. Pond with Conifers Killed by Flooding 
Lower: Fig. 24. Pond With Alders, etc. Killed by Flooding 



supply. The president of the company stated that he esti- 
mated the value of this water to fruit growers along the 
jNIinnesota and North Fork valleys at not less than $15,000, 
as it practically saved the fruit crop on every orchard that 
was depending on this irrigation project for water. This 
meant a little over $1,000 for each of the fourteen dams 


I have mentioned the uses of beaver dams, and it is only 
fair to look at the other side and say something about 
the damage caused by beavers. The damage to lands by 
flooding is probably slight as a rule, though sometimes 
western farmers complain of their meadows being flooded 
by beaver work (Figs. 23, 24 and 25). 

Possibly the most serious damage is that caused to timber 
by flooding, of which Johnson has made a study in the 
Adirondacks, and this in spite of the complaints which were 
made, does not appear to be as serious as some of those op- 
posed to the beavers claimed. It so happens that my own 
observations show comparatively little of this damage. 
While I have seen many trees thus killed, by far the greater 
portion have been aspens, alders and willows, which are not 
considered of any particular value. The commercial value 
of the pines, firs and spruces which I have seen destroyed by 
beaver ponds would be small, though they sometimes made 
a rather conspicuous showing when standing in a pond with 
their brown tops contrasting with the green living trees 
about them. Besides flooding there is also the damage 
which may be done by cutting down trees or girdling them, 
though this is little compared with that done by flooding. 

Dr. C. E. Johnson has made what is probably the closest 
study of such damage with the object of arriving at some- 


where near a correct estimate of the amount. This was in 
Hamilton and Herkimer counties of the Adirondacks, New 
York. He quotes from the New York Conservation Com- 
mission's report that in 1919 forest rangers estimated that 
8,681 acres had been flooded by beavers in the Adirondacks, 
and the estimated value of merchantable timber thereon 
was $51,425. In 1920 this damage had been increased by 
$3,410, making a total of about $55,000. 

Johnson expresses the opinion that the damage to timber 
due to beavers is much less than that caused by windfalls 
and by fire, to say nothing of the waste by man in lumbering 
operations and otherwise. 

The owners of private property in the Adirondacks, 
especially those having summer homes there, are those who 
most keenly feel the depredations of the beaver. This is 
naturally the case, considering that the destruction of the 
trees results in marring the beauty of their property. Where 
beavers are near houses they may do harm by cutting fruit 
or shade trees which have been planted. In a public park in 
Colorado Springs wandering beavers occasionally cut some 
of the shade trees and shrubs. These beavers apparently 
come down a stream which flows through the park, enter one 
of the ponds, of which there are several in the park, and of 
course do some tree cutting in order to obtain food. 

Dugmore considered that the damage to timber by 
beavers is hardly worth mentioning. In this connection, 
Fins, Feathers, and Fur, the Bulletin of the Minnesota 
State Game and Fish Department, says some small timber is 
killed by beavers as a result of the flooding of low lands, but 
usually this is not of great value, and the damage is not 
extensive. This Bulletin agrees with Johnson that losses by 
wasteful lumbering, forest fires, and attacks by insects are 
far greater than those caused by beavers. 


It has been claimed that deer die of thirst in the Adiron- 
dacks in winter because they can find no open water where 
they can drink, the beavers damming the streams so that 
they freeze entirely over. The deer eat snow for a while 
but finally give up. It is stated that forest rangers have 
found deer that have thus died. 

The Lodge 

The beaver's lodge, house, or hut, is the second of those 
structures which have given the animal a reputation as a 
builder. The image which usually forms in a person's 
mind when one is mentioned is that of a beehive-shaped 
affair standing in the pond away from the shore, entirely 
surrounded by the water. \Yhile this is the common form, 
it is not the only one. There are all gradations from it, 
from that built in the water, with one side against the bank, 
to the one partly in the water and partly in the bank, and 
finally we have the lodge wholly in the bank away from the 
water, sometimes several feet. The latter are called '^bank 
lodges," while iMorgan called the first kind '^island lodges." 
They intergrade so that it is impossible to draw a hard and 
fast line between them (Fig. 26). 

It seems to me that probably the bank lodge was the first 
structure of the sort, and that the island lodge evolved from 
that. Just which variation of the bank lodge was the 
first to appear one can only guess. There are arguments in 
favor of each, and it seems quite probable that ancestors of 
our present day beavers may have begun building lodges of 
the different t}^es in separate localities, and independently 
of one another, and that the habit gradually spread to all 
the beavers, with the consequent adoption of all the varia- 
tions. Not all beavers build houses. Some never do, but 
live in burrows in the banks of streams and lakes. Of these 
burrows more will be said later. Others may sometimes live 
in lodges, and at other times in burrows, according to cir- 
cumstances, and as a matter of fact, I doubt if, even when 


Upper: Fig. 2o. Poxd with Willows, etc. Killed by Flooding 
Lower: Fig. 26. A Typical Bea^-er House 



-•n*- .,,rf- 

Upper: 1ig. 27. Interior of the Lodge on Lost Creek 
Lower: Fig. 28. Drained Pond on Lost Creek, Showing the Lodge 



the animals have lodges, they are ever without burrows in 
the banks of the pond whenever it is practicable to make 
them, these being used as places of refuge. 

The island lodge, being the best known, and, after all, 
being regarded as the type of these structures, will be de- 
scribed first. The t}^ical lodge of this sort is a round, 
conical or beehive-shaped structure of mud and sticks in the 
pond at varying distances from the shore, sometimes but a 
step or two, and again many feet. It has a solid foundation 
of some sort, a small natural island, a shallow spot in the 
pond which gives an opportunity to begin building, or the 
beavers may make a foundation by carrying mud and brush 
to the desired spot, or more likely digging the former up from 
the bottom around the chosen spot and depositing it where 
needed. The house is built by piling mud and brush upon 
the foundation. 

Beavers are bound by no hard and fast rules in building 
their houses. Their sticks do not have to be laid just so, 
and trued and plumbed so that the building will not fall 
down. Nothing of the sort. They lay the sticks across 
one another in any way convenient, piling mud on them as 
they go along, only taking care that little or no mud is put 
in the middle, so that an air space is left between the sticks. 
This is their ventilator. 

The entrances are begun deep enough below the surface 
of the water to be safe from freezing. They are made by 
burrowing up from or near the bottom of the pond, gnawing 
off the ends of the sticks which interfere, and when above the 
water level making the living-room or chamber by a con- 
tinuation of the process, fonidng a space suited to the size of 
the family. Dugmore says there are two floors, one a few 
inches lower than that of the main room, and this is the one 
on which the occupants come up from the pond, and where 
they stop to permit the water to drain from their bodies, thus 



keeping the sleeping room dry. I have not happened to run 
across any arrangenaent which conformed exactly to this 

It was my good fortune, however, to find a lodge in a 
drained pond on Lost Creek, Yellowstone Park, which had 
one entrance so large that I could enter the house without 
having to destroy any part of it for the purpose. The out- 
side dimensions of the house were about 13| by 16J feet 

Fig. 29. Flook Plan of the Lodge on Lost Creek 

on the bottom, and about seven feet high. The owners 
evidently believed in preparedness, for they had no less than 
eight doors or entrances, all at the pond bottom. Nor did 
they think it wise to have them all come to the interior at 
the same place. The diagram shows how they arranged 
matters. One came up through the floor of the living-room, 
possibly for a sudden departure in case an unwelcome caller 
arrived. Another, opening outside near the above, passed 
clear under the chamber, and came out on the first floor or 


level. This latter was about a foot above the pond bottom, 
and eighteen inches below the chamber floor. No doubt it 
was under water when the pond was filled, so could not serve 
any of the purposes Dugmore mentions (Figs. 27, 28 and 29). 

The entrance by which I gained access to the interior was 
forty-two inches wide — wider than many a front door in 
our own houses. TVTiy it had such a width I do not know, 
but it showed no evidence of having been widened by any 
animal intruder. On either side of and above it could be 
seen the ends of the sticks of which the house was built, 
all showing the marks of the builders' teeth made in cutting 
them off. These sticks were from less than an inch up to 
over three inches in diameter, and many appeared to have 
had the bark eaten from them before being used as building 
material. Thus they served a double purpose. 

The first floor was two feet wide and four feet long. The 
li\'ing-room was of a somewhat triangular shape, six feet in 
its greatest length and width, and eighteen inches high. It 
also showed the cut-off ends of sticks all about its interior, 
with mud between them. The occupants had either dis- 
pensed with bedding or taken it with them when they moved. 
None was found. Flash powder was burned in an attempt 
to photograph the interior, and the smoke poured freely 
from the top, showing good ventilation, no doubt better 
than when the house was surrounded by water, cutting off 
the draft. A beaver has low respiration and circulation, 
and does not need as much air as some other animals. 

The chamber was of such size that a man could get into 
it, and did. In fact, two of us did so. It was said that 
John Colter, the first white man to visit the Yellowstone 
Park, was once pursued by Indians, and escaped by diving 
into the water and entering a beaver lodge. The house just 
described shows that the story is not improbable, and it was 
not an unusually large house. 



The remaining five entrances all came to the lower floor, 
either directly or indirectly, for two of them connected with 
entrances which led to this floor. 

Another lodge close by, in the same pond, had one of its 
entrances out in the pond bottom six feet away from the 
base of the lodge. 


I J. 3 a. ^ 


^ ruitet 

Fig. 30. Plan op the Large Lodge near the Petrified Tree Road 

An attempt was made to open a lodge in an abandoned 
pond near the road to the petrified tree, in the same region 
as the one just described. This attempt was not as success- 
ful as it might have been, thanks to a good-sized log which 
interfered with the work and could not very well be removed. 
This lodge was thirty feet in diameter, and 8| feet high 
above the pond bottom. It had ten entrances, or what 


appeared to be such, most of them being at the pond bottom. 
On our first visit we crawled into one which was eighteen 
inches above the bottom, and succeeded in getting in far 
enough to discover that it branched into two passages or 
rooms. Retiurning a few days later wath tools this entrance 
was converted into an open cut extending to the point where 
the rooms separated. Here the log barred further progress. 
I could, however, wriggle into the rooms, and obtained suffi- 
cient data to make the accompanying plan. The rooms were 
scarcely a foot high, and I had to lie flat on either my back 
or abdomen to make the necessary measurements. Return- 
ing a few days after this I found the roof had settled so 
much that it was impossible to get in. The house was evi- 
dently an old one and the sticks composing it were very much 
decayed. A long wire introduced into the various entrances 
always came against some obstruction wliich interfered with 
its further progress (Figs. 30 and 31). 

From the size of the lodge we expected larger chambers or 
more of them. As the plan shows, there was space for 
another room south of that found on that side, and one may 
have been there. There were trails over the top of the 
house, and in the right hand room were found porcupine 
quills and dung. Woodchucks or marmots also frequented 
the place, sunning themselves on the top. 

The first lodge which I ever opened was in Colorado. 
This was built of willow brush mixed with mud. It was 
easily cut across with an axe so as to expose the room. 
This lodge had been abandoned for some time. Before 
opening it measured ten feet across from east to west, and 
eight feet across the section from north to south, along the 
line where the cutting was done. The room was two feet 
wide and extended back 4^ feet. It was ten inches high, 
but the roof had undoubtedly settled. The latter was 
twenty-two inches thick, and the walls on either side three 


feet thick. The floor appeared to have been just above the 
water level, and had a bed of coarse swamp grass on it. 
The single entrance w^hich I discovered came into the room 
from under a mass of brush which lay to the east of the house, 
and extended a distance of fifteen feet out from the latter. 
This brush had been stored there as winter food, and never 
used. It was a very efficient vestibule to the front door, 
and doubtless afforded protection to the animals when they 
entered the lodge (Figs. 32 and 33). 

Audubon said that a lodge examined by him had an 
entrance 2| feet in diameter, through which three of his 
companions entered but found nothing. He gives no 
other details as to the size of the lodge. 

Dugmore sa^^s that of the two levels he mentions the 
inhabitants enter on the lower and remain to permit the 
water to drain from their fur and to dry themselves. On 
the second floor, a few inches higher, is the bedding material. 
The lower floor is also supposed to be a dining-room. He 
gives the interior dimensions of one house as: 4 feet 10 
inches long; 4 feet 5 inches wide; 2 feet 1 inch high; lower 
floor 4 inches above water; bed floor 6 inches higher. He 
also says that some of the interiors may be as much as twelve 
feet in diameter. This seems very possible, for in the case of 
the large lodges mentioned by him and Johnson, and the 
one on Tower Creek, allowing but six feet thickness for the 
walls on either side, which seems to me more than ample, 
there would still be left 25, 23, and 27 feet for the respective 
greatest lengths of the rooms inside, that is, supposing there 
to be but one room to the lodge. These large lodges often 
have two or more unconnected rooms, and all the lodges which 
I hav^e opened had irregularly shaped chambers. 

Morgan opened a lodge the outside measurements of 
which were 16 feet 4 inches by 19 feet 9 inches; height 4 
feet 6 inches above waterline; chamber 7 feet by 7 feet 8 

Fig. 31. Open Cut into the Lodge on the Petrified Tree Road 


Upper: Fig. 32. A Lodge in Colorado before Cutting Open 
Lower: Fig. 33. A Lodge in Colorado after Cutting Open 



inches; height of chamber 1 foot to 1 foot 4 inches. Size 
of entrances through floor 15 inches square, and length of 
entrances 7 and 10 feet. 

A used lodge on the margin of a slough near Palo Verde, 
on the Colorado Desert, in southeastern California, not far 
from the Colorado River, was opened. It was three feet 
high and twelve feet across the base, built of branches and 
small saphngs cut when in full leaf, by the beavers and laid 
compactly. It was eight inches thick over the nest cavity. 
The chamber was 2J feet high by four to five feet across. 
"At one side the bank had been cut away to make the floor 
comparatively level, as the house was built on a sloping 
bank near its top. There was an underwater entrance at 
one side, and an opening through the wall above ground. 
A fresh willow sapHng had been hauled through this opening 
butt first. The beds were merely hollows in the earth 

In the good old daj^s when fiction had precedence over 
fact in writing about the beaver, it was said that some lodges 
were di\dded into several rooms, for eating, sleeping, store- 
rooms, and the like, but of course such is not the case. 
Hearne says concerning this: 'Tt frequently happens that 
some of the large houses are found to have one or more 
partitions, if they deserve that appellation; but that is no 
more than a part of the main building, left by the sagacit}^ 
of the beaver to support the roof. On such occasions, it is 
common for these different apartments, as some are pleased 
to call them, to have no communication with each other but 
by water; so that in fact they may be called double or treble 
houses, rather than different apartments of the same house. 
I have seen a large beaver house built in a small island, that 
had nearly a dozen apartments under one roof; and, two or 
three of these only excepted, none had any communication 

1 Grinnell, Birds and Mammals of the Colorado Valley, p. 226. 


with each other but by water. As there were beaver enough 
to inhabit each apartment it is more than probable that each 
fanaily knew its own and always entered at its own door.'^ 

Hearne said that his Indians took thirty-seven beavers 
from this house, and many others escaped. His observa- 
tions were made in the latter third of the eighteenth century. 

A lodge is usually small at first, and grows by additions to 
the outside and enlarging the chamber as these additions 
are made. Just how separate rooms are made I do not 
know, though I have had a hint as to one possible method. 
In 1921 a small lodge and a larger one stood close together 
in a pond on Lost Creek. In 1923 the two apparently had 
been merged, and it would seem probable that here the two 
rooms were kept separate. 

Morgan states that the number of lodges m a pond rarely 
exceeds four, though in some cases six and eight have been 
found. I have never seen more than three in a pond myself. 

Good-sized logs and poles are often, if not usually, placed 
on the top of a lodge, presumably for protection. It is a 
favorite place for leaving sticks after the bark has been 
eaten from them. Dugmore speaks of logs eighteen feet 
long and six inches through at the butt as often used, but I 
have never seen any of such a size. He also says that shorter 
pieces a foot or more long are not uncommon. I have at 
times seen poles ten or twelve feet long on houses. Perhaps 
this heavy stuff may be of service in weighting and holding 
down the exterior materials of the house. 

It is essential that there be water about the lodge suffi- 
ciently deep to protect the entrance from freezing. Often 
this is provided by the animals in excavating the material to 
build their home, and perhaps sometimes for a dam. This 
deep water is also often used for storing the winter supply 
of food. 

In autumn the lodges are usually plastered well with fresh 


mud, at least in those regions where there is severe cold. 
Hearne makes a statement to this effect concerning the 
beavers in northwestern Canada. Mills gives the statistics 
of lodges of which he made notes in Colorado and INIontana, 
and these show that the great majority were well plastered 
before the coming of winter. Dugmore also makes state- 
ments to the same effect. Without keeping any special 
notes on this point I also have noticed the occupied lodges 
usually are plastered in October. Morgan says that in some 
cases the outside of the lodge is plastered with mud late in 
the fall. 

I have never seen any data as to how long it takes to build 
a lodge. The only note I have bearing on the subject is of a 
pond which had no lodge in it on August third, and on Sep- 
tember third there was a small one with a heap of brush in 
the water beside it. 

A house is often built about a bunch or clump of bushes or 
small trees, such as willows or alders, which frequently 
have several stems growing from one root. The roots 
e\ddently furnish the necessary foundation for the lodge, the 
building material being piled upon them and about the stems 
of the brush, which, when outside the confines of the cavity, 
often continue to grow and bear leaves. A somewhat un- 
usual example of this kind was a lodge in the Longs Peak 
region, Colorado, which had no less than sixteen living alder 
trunks coming up through the outer portion, ranging from 
2| to 5 inches through, being evidently outside the bound- 
aries of the chamber. 

Another lodge which I saw in the same region had a lodge- 
pole pine standing in the center, and the structure was 
obviously built about it. Being out in the pond it was inac- 
cessible to me and I could not make a close examination. 
Though dead, the pine still had brown needles on its 
branches. I was told that the house had been built four or 
five years previously (Fig. 34). 


Frequently, if not always, lodges have smooth slides or 
trails from their tops down to the water. They have the 
appearance of being used for sliding only, as they are smooth 
mud and lacking in footmarks or other indications that the 
animals have climbed up them. Presumably the beavers 
make the ascent elsewhere on the house and descend over 
the sUdes, a speedy way of getting down if an enemy appears. 
Perhaps they do it just for fun, as an otter does on its 

Lodges naturally vary much in size. Some are small. I 
have seen one only six feet in diameter, w^hile others very 
much larger exist. In 1921 a lodge on Tower Creek was 
21 by 24 feet, and 7 feet 3 inches above water level. In 
1923 the same lodge was found to be 33^ by 39 feet at the 
water level, the largest of which I have any record. It 
was then GJ feet high. Possibly the top may have settled, 
but I think the water level in the pond had been raised. 
The house had five entrances in 1921. Dugmore mentions 
one in Newfoundland which was 37 feet in its greatest di- 
ameter, and Johnson gives a pictm'e of one in the Adiron- 
dacks 35 feet in its greatest diameter and 28 feet in the short- 
est, and 7 feet high. A house in Gunnison Count}^, 
Colorado, was of an oval shape, 17 by 22 feet on the ground, 
and 12 feet along the ridge on top. 

The number of inhabitants to a lodge of course varies; 
the normal beaver family consists of two adults, the young 
of the year, and the young of the preceding year, or kits and 
yearhngs, as we may call them. Morgan says the Lake 
Superior trappers estimated seven to the lodge, and the 
Rocky Mountain trappers eight; this was in the middle of 
the eighteen sixties. Johnson based his estimate of the 
number of Adirondack beavers on ten to the lodge. I 
noted eight hving in one lodge in Yellowstone Park. 

The bedding material may be either grass or shredded 


wood. Dugraore says the latter is more frequently used, 
and that may be the case where wood is easily obtainable, 
but many beaveis live where there are only small willows or 
other bushes and are practically forced to use grass. 

The following remarkable description of beaver lodges is 
taken from Fauna Am.ericana, by Richard Harlan, published 
in Philadelphia in 1825: 

''The huts are estabhshed on these dams, and formed of 
nearly the same material as the dikes; the huts are two stories 
high, each story eighteen inches in height; logs composing 
these cells have been observed two feet in length, sixteen 
inches in circumference, and weighing fourteen pounds; it 
is evident from the marks on the ends of these logs, that they 
have all been cut through with the teeth, and notched at 
the end, so as to interlock with each other in the same 
manner as logs fashioned by human industry for the purpose 
of constructing the common log houses. The base of the 
lower chamber is under water, as is also the hole by which 
they enter. '^ 

An old book in which is what purports to be an account 
of the beaver has a picture of a lodge with doors and windows 
in it, quite like a real house. 


As I have already remarked, bank lodges vary in the man- 
ner of their construction. Some are built wholly outside the 
bank, but against it ; others partly outside and partly in the 
bank; and still others wholly in the bank, perhaps several 
feet away from the water. One can not help wondering 
which type was the first to be developed from the burrow, 
undoubtedly the primitive habitation of the beaver. Per- 
haps it was the last named, for it would be a simple miatter, 
if the ground above a burrow happened to cave in, for the 
owners to pile sticks and earth over the opening, enlarge 
the chamber if necessary, and they would have a lodge. 


The lodges built against the bank, of either sort, are prob- 
ably also a development of the burrow, originally begun by 
placing sticks in the water before the entrance as a protec- 
tion, and afterwards developing these accumulations into 
houses. Even now one not infrequently sees small piles of 
sticks before the entrances to burrows, and it may have been 
from such as these that bank lodges originated, and later the 
island lodge. Morgan speaks of burrows on the Upper Mis- 
souri as protected by a "false lodge," evidently just such 
piles of sticks as I have just mentioned. In some cases the 
winter store of food may possibly be placed at the burrows, 
and also the discarded sticks may accumulate there. 

Shiras- speaks of locating a beaver burrow deep within 
a bank by a lake. 'The next year it broke through the 
surface soil, which was then covered with a mass of sticks." 
Such occurrences as this might well have been the beginnings 
of bank lodges, at least of the kind in the bank away from 
the water. It seems very likely that where the bank is not 
high enough to permit of the excavation of a chamber suffici- 
ently elevated above the water level, the opening is made 
to the surface and then covered with brush and mud, or 
possibly the covering may be put on first and then the earth 
removed from below. There are many things of this sort 
which we have yet to learn about the beaver. 

An abandoned bank lodge in the Yellowstone Park was 
built over a burrow, beginning close to the old shoreline of 
the pond. It was twelve feet long, six wide, and the highest 
part 5| feet above the bottom. The burrow continued into 
the hill back of the lodge. This consisted of sticks piled 
over the burrow, mixed with the usual mud. The burrow 
must have been widened to make a room, but the affair 
was so old that not much could be learned about it. 

2 Wild Life of Lake Superior, p. 196, 

Upper: Fig. 34. The Pixe Tree Lodge 
Lower: Fig. 35. A Bank Lodge, Carneliax Creek 


Fig. 36. A Lodge After the Snow Came 



A bank lodge at a pond by the Cooke City road had a 
cavity extending into the bank. This was divided into two 
parts by a large rock. The longer portion was some six or 
eight feet long, two wide, and a foot high. The other was 
about two feet shorter. There was some shredded bark 
on the bottom of the longer cavity, apparently the bedding 
(Fig. 37). 

I examined two abandoned bank lodges on the samie 
stream in Colorado, each of which had the living-room just 
below the surface of the ground. These had each been a foot 
or more high and covered with a roof of sticks a foot or more 
in thickness. Owing to age this had settled so that the 
original thickness could not be told. Each of these lodges 
was several feet from the stream bank. 

H. A. English, in a letter, describes a beaver house which 
he found in Saskatchewan, Canada, and which seems to show 
that at times the beavers may make very serious mistakes 
in locating their lodges. It was in a long, narrow muskeg. 
There was no open water, and while it was muskeg, grass 
and moss grew all about the lodge, and the animals had 
dug canals to willow thickets about sixty yards from it. 
''In thinking it over I am unable to see how the beaver got 

their food or kept the passages open I have 

never before or since seen a lodge which looked more out of 

place It was November and of course there was 

heavy ice on lakes and creeks. I would not like to say the 
beaver were in the lodge, but think they were, in which case 
they might starve or come out very poor, where they are 

usually very fat and sleek While trapping in 

Manitoba I have come across muskrat houses that were 
built in shallow water and the rats had been able to keep a 
very limited space from freezing and were very poor and 
nearly starved, while rats that had their houses in the same 
marsh but in deep water were fat and prime." 

G. B. Grinnell, in 'The Cheyenne Indians," tells an 


interesting story of some Indian children entering what 
apparently was a bank lodge. Three little girls, ten or 
twelve years old, were sent to the river by their mothers to 
get water. When they reached the stream they decided 
to take a swim before returning. Removing their clothes 
they went out on a fallen tree projecting over the water. 
One of them noticed a hole in the bank under water and 
suggested they see where it went, so they dived and swam 
under water up the hole. They felt something large and 
soft pass by them, going out. A beaver, of course. They 
went a few feet and saw a little light, and discovered they 
were inside a beaver house. A little frightened by the 
beaver which had passed them as they were going in, they 
did not dare go back, and therefore broke a hole in the 
roof where the light came in, and emerged from this. They 
found themselves in a thicket of wild rose bushes and were 
much scratched before they made their way through them. 


The beaver was perhaps naturally a burrowing animal 
from the very beginning; at any rate, it still is, and as 
before remarked, many beavers never build houses but live 
in burrows in the banks of streams and lakes. In many cases 
a stream may be too rough or swift for a dam to be built, 
or so wide and deep as to be beyond the beaver's engineering 
skill, and yet have a plentiful food supply upon its banks, and 
here the animals make their homes in holes. In such cases 
they are called "bank beaver" and are often said to be a dif- 
ferent sort from those living in lodges. Such is not the case, 
however. They are merely adapting themselves to circum- 
stances, and, as a matter of fact, the lodge builders usually, 
if not always, have burrows in the banks of their ponds in 
which they can take refuge if disturbed in their houses, or if 
pursued by an enemy and unable to reach the lodge. On a 


little stream in the Yellowstone a lodge in one pond was 
inhabited by a family of eight beavers, and three others were 
living in a burrow a few ponds below. It is said that the 
male beaver, as the time approaches for the annual addition 
to his family, removes to a burrow and remains there several 

I have been unable to obtain much information as to the 
length of burrows. One w^hich I examined in the Yellow- 
stone had a total length of thirty feet, but that struck me as 
unusual, though Bailey says they are sometimes forty to 
fifty feet long, and large enough for a man to crawl into. 
Various burrow^s examined by Morgan terminated under the 
roots of trees. Those which he described were from ten to 
over thirteen feet long, some leading from ponds, and one 
from a canal. He gives a diagram of the latter showing at 
the end a chamber 2 feet 6 inches by 3 feet 2 inches, and 
about ten inches high. ''The roof of the latter came near 
to the surface, and w^as formed chiefly of the roots of the 
clump of trees under which it was excavated." 


Canals, Trails, and Landing Places 


The canal is the third of the structures of the beavers which 
have made them noted among four-footed animals. It is 
the least known, though the one which might, in many 
respects, be considered as showing the most intelligence, on 
the part of the builders. Not that they do not make mis- 
takes at times, and dig canals which fail to carry the water 
where desired. Sometimes an engineer of the genus Homo 
surveys a ditch in which the water will not run! Whether 
guided by intelligence or by a highly specialized instinct the 
beaver does construct some remarkable works in the form 
of canals. Morgan very well says that the canal of itself 
is simpler than the dam to construct, but requires more 
intelligence to plan. 

The ordinary canal is built for the purpose of transporting 
logs from the place where they were cut to the pond, and 
also to afford a water way in which the builders may pass 
back and forth in more security than when traveling on 
land. Morgan gives an instance where beavers cut a canal 
across a narrow neck of land to save going around a bend in 
the stream, this being purely for the purpose of traveling 
and not for transport. 

Canals vary much in length, from those but a few feet 
long, hardly worthy of the name, to those several hundred 
feet long, and built with two or more levels in them, the 
first or lowest being the only one to receive water from the 
pond or stream, the upper ones getting their supply from a 



spring or stream at a higher elevation, or, as in the case of 
some examined on Tower Creek, from the swampy ground 
in which the upper levels w^ere dug. One of these was ninety 
feet long, the other one hundred and fifty feet, and they 
represented somewhat different engineering problems. The 
first mentioned was seventeen feet long at the pond level 
to the lower side of the dam, and tw^enty-three feet to the 
upper side, and above this was the remainder of the ditch. 
The lower level of course obtained its water from the pond 
and was fifteen inches deep ; the upper level was nine inches 
deep and was supplied by seepage from the marshy ground 
about it. The canal varied in width from fifteen to eighteen 
inches. The face of the dam had a long gradual slope which 
must have greatly facilitated dragging logs over it. Aspens 
were being cut on the hillside above this canal. 

The second canal was about half a mile upstream from 
the other, and its lower end was twenty-three feet away 
from the creek, being connected with it by a trail, and at 
the* time of the examination this was two feet above the 
water level. There w^as but one level to the canal, which 
was from three to four feet wide, and twelve to eighteen 
inches deep, the water supply being derived from a spring 
at the landward end. The westerly bank of this canal was 
considerably lower than the other and was being raised by 
means of mud dug from the bottom. Aspens were being 
cut near the end of this canal (Fig. 38). 

Morgan described one canal 523 feet long leading from a 
natural pond, 450 feet from which was a short dam across 
the canal; 25 feet above that was another dam extending 27 
feet on one side and 75 feet on the other side of the ditch; 
and 47 feet farther up, at the head of the canal, was a third 
dam 55 feet long on one side of the ditch and 87 feet on the 
other. There were pools of water above the head of the 
canal, and the long dams collected the drainage from these 


and deflected it into the canal, besides collecting the rain- 
fall and using that. This canal was from two to four feet 
wide, and 1 J to 2| feet deep, the greater portion being of the 
first named width. The first 450 feet was cut through level 
ground and received water from the pond. 

Another canal from the same pond divided into two 
branches at the end of 150 feet, these being 100 and 115 
feet long respectively, and extending along ground covered 
with deciduous trees, giving access to a large food supply, 
for which water transportation was thus furnished. This 
ditch was from three to five feet wide and eighteen inches 
deep. It had several burrows dug from it under knolls 
covered with trees, apparently for refuges. 

Morgan also describes another three level canal from the 
Carp River which was 579 feet long, 3 to 4J feet wide, IJ 
to 2^ feet deep. The first dam was 111 feet from the river, 
the second 289 feet. The ground all about was swampy 
and the ditch was filled by filtration from this. At the 
mouth of the canal the river was not deep enough for a 
beaver to swim below the surface out into the stream, so the 
beavers dug a channel twenty-five feet long and a foot deep 
in the river bed, giving the desired depth. 

In the region described by Morgan tamarack trees were 
nearest the water and on quite level ground. The deciduous 
trees desired as food were farther back, and therefore the 
beavers were obliged to make these canals in order to reach 

If I have been somewhat tedious in going into all these 
details and figures it is because I wished to show the remark- 
able nature and what we may call the magnitude of the work 
thus done by the beaver, for surely these long canals de- 
serve the term when we consider the tools with which they 
are made. The two and three level canals are of course the 
most remarkable. It is easy enough and natural to dig a 


ditch at the pond level so that the water will fill it, but quite 
another thing to make one at a level above this and build a 
dam to retain the water derived from some other source, 
and thus avoid digging the pond level portion to an imprac- 
ticable depth. 

Speaking of a certain canal Mills says that the mud dug 
out in making it was piled evenly along the lower side, and 
looked more like the work of a careful man with a shovel 
than of beavers without tools. He also mentions a canal 
begun at the Moraine colony and then abandoned because 
the beavers discovered they could not make it carry the 
water where they wished. He describes a series of canals 
dug in the bed of Lily Lake, Estes Park, at a time when the 
water had fallen so low that there w^as not sufficient left for 
the use of the beavers. It finally receded so much that the 
only water left was in the ditches, which must have been the 
work of years. For a detailed description I refer my readers 
to his book. It must suffice to say here that these canals 
varied in length from quite short ones up to one 750 feet 
long. Mills states that he has known of beavers extending 
canals in the bottom of a pond and making submarine 
tunnels when the pond was ice-covered. 

In another book,^ describing the struggle of a colony for 
existence during winter. Mills states that a ditch two feet 
wide and nearly as deep was dug from the house in the center 
of the pond to the upper portion, which had been swampy 
before being flooded, and where they were able to secure 
enough roots of various sorts to ward off starvation. This 
was, of course, after ice had covered the pond. 

Mr. Mills called my attention to a canal on the Roaring 
Fork which differed from the usual type in having a very 
steep grade. The beavers were harvesting aspens some 

1 Famine in Beaver Land, in Watched by Wild Animals. 


distance upstream from their pond, and found difficulty in 
floating the logs down the bouldery creek bed at the then 
low water stage. Therefore they went off a little distance 
to one side of the stream, and taking water from a pond 
there above the bad water, led it doAvn so that it rejoined the 
creek at a pond below the rough places, much simplifying the 
transportation problem. It is not clear to me just how 
much ditch was actually constructed, but I think probably 
only enough to start the water on the right course, for the 
slope down which it flowed was steep enough for the water to 
cut its own channel easily. To do this certainly showed good 
sense on the part of the animals, for in attempting to use 
the stream one or two of their number had been killed by a 
mountain lion, and they had been able to get only a few logs 
down after much labor. 

S. Stillman Berry has given an account of a beaver canal 
in Montana which seems to be the longest on record. A 
portion of it was carried through a slough, or perhaps it 
would be better to say that the builders utilized the slough 
as part of the canal, though they seem to have done some 
bank building in it to confine the water. A portion of the 
canal was cut through a swampy place and the mud thrown 
up on either side to make the banks. The length of the 
waterway was 745 feet, and the total length of the whole 
stretch used for conveying logs, including a waterless sec- 
tion at the further end, 1145 feet. 

Dugmore states that the canals are completed before 
wood-cutting operations are begun. But this would be true 
in only a limited sense, for the very long canals I have m.en- 
tioned were doubtless constructed by degrees, extended as 
became necessary to reach additional supplies of food. 

Seton says the longest canal he ever examined was an 
old one in the Adirondacks, which was 654 feet long, and 
nearly four feet wide. It was well marked after fifty years 
of abandonment. 

Upper: Fig. 38. A Canal, Tower Creek 
Lower: Fig. 37. A Bank Lodge, Cooke City Road 


Fig. 39. A Beaver Trail Passing Under Several Dead Logs 



In studying some beaver work on a stream in Colorado 
where the food supply was small willows, which grew thickly 
over the bottom land, I was quite surprised to find several 
canals leading from various of the ponds out among the 
willows, being from fifty to nearly a hundred feet long. The 
beavers apparently found it advantageous to have water 
transportation even for willow brush. Trails led from two 
of these canals across to another pond a short distance away, 
on a side channel from the creek, indicating that probably 
the canals were also used for traveling. 

On the South Fork of Elk Creek, not far from Yancey's, 
was a canal leading northw^esterly from the end of the lowest 
pond of the series, which was 104 feet long, 4 to 6 feet wide, 
and 27 inches deep. The material dug from this was thrown 
up on the lower or northeasterly side. Two years later this 
canal was found to be abandoned. From another pond in 
the same group a ditch extended 48 feet. It was a foot wide, 
and the first 27 feet were 18 inches deep, while the remaining 
portion was merely a shallow run, at the end of which was a 
dam extending 20 feet in an easterly direction from the ditch. 
The pond formed by this dam was only about six feet wide, 
into which a mere trickle of w^ater came, also a trail. The 
purpose of this dam was probably to collect and conserve 
whatever water drained or seeped in from above so that it 
might be conveyed by the canal to the pond below. In 
summer, at the time of my visit, there did not seem to be 
much tree cutting going on at this place. 

At another colony in the Yellowstone some of the smaller 
ponds of the series were connected by canals thirty to forty 
feet long, sixteen to eighteen inches wide, and eight to four- 
teen inches deep, leading from below the dam of one pond 
down to the next, and invariably there was a trail and slide 
over the dam into the canal, showing evidence of constant 
use in traveling back and forth, and probably for carrying 


Dugmore suggests that canals may have had their origin 
in the use of short natural openings in the shore of a pond, 
which were gradually extended, and finally the beavers 
learned to build canals wherever the^^ wished, if feasible. 

It will be seen from the foregoing that there are many 
variations in the construction of canals, and some in their 
uses. Not all colonies have canals, for of course they are 
not always necessary, but when made they are adapted to 
their intended purposes, whether to bring logs some dis- 
tance from the pond, or to serve as a connection between 
two ponds. They are so notable that one can not refrain 
from expressing surprise at such things being done by animals 
having no tools but their fore paws, and the mental faculties 
of which, according to some, are no more than a highly 
specialized instinct. 


In pursuing their activities on shore, beavers often make 
well defined paths or trails, which, when in use for a con- 
siderable length of time, may become deeply worn. As 
many, if not all the trails, are used by the beavers in carrying 
logs and brush, this material is probably responsible for 
most of the cutting down of the path. While I think it 
somewhat doubtful if the animals really lay out a road and 
clear it before beginning to use it, though some have stated 
that such is the case, they do cut out any roots, branches or 
logs which may interfere with their work. I have seen a 
four inch stick which had been cut through and part of it 
pulled to one side of a trail. Rotten logs lying across a 
trail are broken and worn by the sticks dragged over them. 
Conversely, trails sometimes pass under fallen logs which 
are lying high enough above ground not to interfere with the 
beaver going beneath. I saw one trail which went under 
eight logs in a distance of twenty feet (Fig. 39). Johnson 

Fig. 40. A Landing Place 














Fig. 43. A Beaver Trail Showing Where Logs Have Been Dragged 

Over It 


Fig. 44. A Beaver Trail in the Snow 



figures a trail, or ''tote road" as he calls it, cut through the 
crest of a bank in the Adirondacks about a hundred feet 
above the water. 

Where there is, as is often the case, tall rank grass growing 
on the shore of a stream or pond, trails through it are de- 
cidedly noticeable. The beavers crush the grass down on the 
ground, and often bring mud out on their feet, making a 
very well defined road. Often at these trails a considerable 
space is trampled down on the shore, apparently where the 
beavers have landed. I have called such spots ''landing 
places." From the fact that peeled sticks are often found at 
them they may be used as feeding places (Figs. 40 and 41). 

Here may be mentioned the "forms" described by Johnson 
as seen by him in Minnesota. They were located close to 
the bank, so that the occupant could get into the water 
quickly, and were used by the beavers in the daytime, 
either as sunning or resting places. He says they were 
more or less shallow depressions in the ground, roughly oval 
in outline. Sometimes they had a Httle bedding, of either 
sm.all chips or dry twigs and grass. As a rule they were free 
from peeled sticks. None of the places which I have ex- 
amined myself answers this description, though I have seen 
a place where the grass was crushed down as if an animal 
had been lying there. 

Many trails will show the marks where logs have been 
dragged over them, the end of the log having left a distinct 
furrow in the ground. In other cases where brush has been 
dragged alongside the beaver, the scratches made by the 
ends of the twigs are plainly visible. I have seen this not 
only in gravel and sand, but also in snow when it has fallen 
early in the season when the animals were still harvesting 
their winter food. The mark made by a log is somewhat 
similar to that made w^hen a log is drawn over the ground by 
a man or horse (Fig. 43) . 


Seton, in his description of the beaver ponds near Yancey's, 
in the Yellowstone, mentions what he calls docks or landing 
places. These were short canals with raised mud or sod 
wharfs at the end. ^^ These are either lookouts or sunning 
places." Usually there were paths leading away from 
them. At Yancey's, Seton says many short trails ended 
at anthills occupied by small black ants. He suggests the 
beavers may have gone to these to let the ants pick off 

Paths are frequently found along streams which are 
detours around a rock}^ or steep portion of the channel 
avoiding rough traveUng, and possibly are not necessarily 
used for transport. I have seen some which appeared to 
be much traveled and yet showed no indications of anything 
being dragged over them. 

Beavers sometimes have underground passages from the 
bank, coming to the surface some distance from the shore. 
One was found in the Longs Peak region the exit of which is 
shown in the cut. This was some twenty feet from the 
bank of the stream. The grass about it was matted down 
and much covered with mud over a space 2§ by 6 feet, and 
from the hole a trail led up the hill toward an aspen grove. 
This hole was 54 inches long by 26 inches in greatest width 
(Fig. 45). 


Beaver Meadows 

Beaver meadows have played a very important part in 
the development of North America from the earliest days 
of its settlement. This is because they provided level 
land, good soil, usually covered with grass, sometimes also 
vath bushes. The grass provided pasturage and hay, and 
the meadows, when cultivated, produced good crops, so that 
it was but natural that when available these were the first 
lands to be taken. 

^Tins, Feathers and Fur" sa^^s '^Most of the forest 
meadows where the pioneer settler is able to obtain hay for 
his stock have been caused by the killing off of small timber 
by beaver flooding many years ago, and in this way the 
beaver have contributed to the convenience of the farmer." 

^\Tiile presumably the above quotation is intended to 
apply especially to present conditions in Minnesota, doubt- 
less it is also applicable to the conditions found by the earli- 
est settlers in the Atlantic States, who must gladly have 
availed themselves of any open spaces which did not involve 
clearing the timber from the land. 

Building the dam can well be said to be the first step taken 
toward making a beaver meadow, for as soon as the pond is 
made silt begins to settle in it and fill it. This forces the 
owners, as explained in the chapters on the dam, to continue 
raising the dam to keep the water deep enough for their pur- 
poses. The fxlling-in process continues indefinitely, but a 
pond never becomes a meadow as long as the beavers con- 
tinue to occupy it. Let them abandon it, however, and a 
meadow may be formed in a surprisingly short time. 



It has not been easy to obtain any definite information 
as to the length of time required to form a beaver meadow, 
and we are fortunate in having some data concerning the 
meadow on Lost Creek, above Yancey's, Yellowstone Park. 
In 1897 there were at this place long dams and large ponds 
which Seton mapped and described, and which were in- 
habited by a flourishing colony of beavers. In 1912 Seton 
revisited the place and found the colonj^ abandoned and the 
meadow pretty well formed. The beavers, according to M. 
P. Skinner, formerly park naturalist, began to desert the 
place about 1903 or 1904. In 1921 I examined the ground 
and found most of it solid, and the dams, except the two 
upper longest ones, so nearly obliterated that it was difficult 
to locate their sites. Thus in perhaps twelve or fifteen years 
these meadows assumed their present form. 

There is a wide valley here, bounded by hills, and traversed 
by Lost and Elk Creeks, which is one large beaver meadow. 
The old Yancey place is situated at the forks of these 
streams, and Yancey used to cut hay near his place twenty- 
five or thirty years ago. Since 1920 the National Park 
Service has been cutting hay here for its own use. Some of 
the ground is still too soft for the use of a mowing machine. 
I have information that in 1907 there was a beaver colony 
on Lost Creek toward the northeasterly part of this area. 
This is now like the rest of the meadow. Thus it would 
appear that this meadow is not all of the same age, but was 
formed at different times, the portion at the junction of the 
streams being the oldest (Fig. 46). 

Another instance in Yellowstone Park is the case of the 
lowest pond in what I called the ^^Bench Colony." When I 
first examined this July 23, 1921, it was full of water (Fig. 
48) . This gradually receded during the summer, and when 
I saw the pond for the last time that year, September 4, 
it was more mud flat than pond (Fig. 49). Figure 50, 

Fig. 45. A Hole ox Shore Reached by ax Uxdergrouxd Passage from 

THE Stream 






Upper: Fig. 47. A Beaver Trail Through Willows 

Lower: Fig. 48. Pond ix the "Bench Colony," Full of Water, 

July 23, 1921 


•4 ^ 


Upper: Fig. 49. Pond in the "Bench Colony," Partly Drained, 

September 4, 1921 

Lower: Fig. 50. Pond in the "Bench Colony," Well Advanced 
Toward a Meadow, August 17, 1923 



Upper: Fig. 51. A Pond in Colorado, Photographed October 8, 1913 

Lower: Fig. 52. The Same Place, October 18, 1922. All Traces op 

A PoxD Have Disappeared. The Change Really Took 

Place in Two Years 












taken August 17, 1923, shows the pond practically all 
covered with coarse grass. There were still soft muddy 
places here and there, and the channel which can be seen was 
very soft mud, as my assistant discovered when he stepped 
on it and went in above his knees. 

In a case which came under my observation in Colorado 
I found on a small stream a good-sized pond containing a 
lodge. This pond was formed by a dam one hundred and 
thirty feet long. This was in 1913. The following year the 
dam was broken through at the stream channel, and the 
pond drained, and in 1915 it was overgrown with grass. 
When examining the place in the autumn of 1922 I found 
that the stream channel had been very much deepened, 
presumably by a flood the previous year, and a new dam 
built between the banks, forming a pond over two hundred 
feet long. The old dam, though almost obliterated in 
places, could be traced on either bank above, more than four 
feet higher than the new water level. The old pond was 
now a meadow covered with grass and the old lodge a ruin 
(Figs. 51 and 52). 

The character of the material with which a beaver pond 
may be filled is variable. Sometimes it is a fine silt which 
makes an excellent soil, and probably this is the first material 
to be deposited. On the other hand I saw some ponds in 
the Yellowstone which were being filled, or were already 
filled, with a coarse gravel. At Longs Peak Inn, Colorado, 
the site of an old beaver pond was excavated to make an 
artificial pond, and here I found a fine gravel or coarse 
sand resulting from the grinding up or disintegrating of the 
granite country rock. This seemed to be devoid of humus 
or vegetable matter which might serve as plant food. On 
top of this, however, there appeared to be a layer of black 
mould in which grass and willows grew. 

Many beaver meadows become covered with a dense 
growth of willows, almost impenetrable at times (Fig. 53). 


Food and Tree Cutting 

The beaver's food is exclusively of a vegetable nature, and 
no matter how the ponds and streams in which the beaver 
lives may abound with fish it never harms them. The pre- 
ferred food would appear to be the bark of trees, and it is the 
inner or cambium layer, the one between the outer bark and 
the wood, which is mostly eaten, not the tough outer bark. 
In the case of small twigs, however, or stems like those of 
small willows, it would seem likely that all the bark is eaten, 
the outside layer being too thin to be conveniently discarded. 
While deciduous trees are almost universally used, coni- 
fers are also sometimes utilized. The thick bark of large 
trees is unfit for food, though I have seen large aspen logs 
from which the bark had been eaten and none of the outer 
bark discarded. 

The following trees are mentioned by different authors as 
being used for food by beavers: Aspen or poplar, cotton- 
wood, willow, alder, box elder, different species of birch, 
yellow birch being preferred (Morgan), wild cherry, pin 
cherry, viburnum or witch hopple, black and white ash, 
soft and bird's-eye maple. 

These food trees vary with the locality, but almost every- 
where the aspen seems to be preferred above all others, and 
in the Rocky Mountain region it is the food tree of the ani- 
mal, for, aside from cottonwoods, willows and alders, the 
other species are mostly noticeable by their absence. 

In the summer beavers would appear to be less dependent 
on bark for food, and eat many other things, perhaps for a 
change in diet, and perhaps as a conservation measure to 



avoid drawing too heavily on a food supply which must be 
used in winter. 

The following plants have been mentioned or have been 
noted as being used in summer: Raspberry bushes, various 
sorts of roots and grasses (Morgan) ; roots of water lily and 
spatterdock (Dugmore) ; berries, mushrooms, sedge (Mills) ; 
wild rose bushes, cow parsnip, thistles (Warren); hazel, 
cornel, service berry (Bailey). 

I also noticed that other plants such as wdld geranium 
had been cut where a beaver was feeding, but have no evi- 
dence that they were eaten, though presumably they were. 
In the case of the bushes, as well as the seedling aspens which 
are often cut at this season, leaves, wood, and bark all 
appear to be eaten. 

Howell, in the Biological Survey of Alabama, says that in 
one locality in that state, wherever cornfields bordered the 
lake deeply worn trails were found leading into the fields, 
and it was stated that in summer beavers resorted regularly 
to the corn patches and consumed a considerable quantity 
of corn. A planter told of finding one standing up in a corn- 
field and reaching for an ear of corn. This is the only men- 
tion I have seen of beavers destroying farm crops. 

Much has been said and written about the tree-cutting 
activities of the beaver. First I wish to say that it is 
extremely rare, if ever, that a beaver cuts a tree with the 
idea of having it fall in a certain definite direction. Enos 
Mills told me that he had seen one or two instances where 
such might have been the case, but he did not know if it 
was so. As a matter of fact, most, if not all, beaver-cut 
trees fall in the direction towards which they happen to 
lean. Wind may occasionally influence the direction in 
which a tree falls. 

The powerful incisor teeth are the tools with which a 
beaver does his tree cutting, and most efficient tools they are. 


One or two bites are sufficient to cut a bush a half-inch or 
so through. In cutting trees of any size chips are taken out 
by first cutting at either end and then prying out sideways 
with the teeth. In trees of such a size that a wide scarf has 
to be cut good-sized chips are often removed, especially from 
soft woodS; such as aspen. I have seen chips of the latter 
wood seven inches or more long. On an aspen seventeen 
inches in diameter, which was cut evenly all around, the 
width of the notch in the wood was 9^ inches. In a lodge- 
pole pine twenty-one inches in diameter, on which all the 
cutting was done from one side, the notch had been made 
seventeen inches high. Pine wood being harder than aspen 
the chips are smaller, four inches being the longest I have 
found, and this pine must represent relatively much more 
work than the aspen mentioned (Figs. 54 and 55). 

Judging from my own observations and from what others 
have written, the great majority of trees are cut through 
from one side, especially in the case of the smaller ones, and 
the side from which the cutting is done is selected more 
for its convenience than for any other reason. On a hill- 
side nearly all the trees will be cut either from the up-hill 
side, or from one side or the other, and only a few from the 
lower side. Now a man in cutting a tree makes his deepest 
cut on the side toward which he wishes the tree to fall, but 
the trees which a beaver cuts on a hillside will nearly all 
fall down hill, no matter from what side the cutting is done. 
This is because most of the trees naturally lean down-hill, 
and therefore fall that way. Similarly trees growing along 
a stream tend to lean toward the water, and when cut, fall 
in that direction. It should perhaps be mentioned that 
Dugmore says that most trees are cut all around the trunk, 
and that may have been the case where he made his studies, 
in Canada and Newfoundland. It is the larger trees stand- 
ing on level ground which are most likely to be cut evenly 


IP f 



*. ^ 

K V' 



. -v 


• / 


Upper: Fig. 54. Chips Cut From Aspen 
Lower: Fig. 55. Chips Cut From Lodgepole Pine 




all around. This of course makes the work somewhat easier, 
for then not as wide a notch has to be cut as when the cut- 
ting is all done from one side. Figures illustrating this 
point have already been given, in the cases of the large aspen 
and pine. 

On a steep bank by Tower Creek I found two aspen stumps 
close together, about three feet high. Each had a notch 
cut on the lower side, but the cuts which felled the trees 
were made on the up-hill side several inches above. Evi- 
dently the beavers had decided it was unsafe to continue 
cutting below, and had gone to the upper side to finish the 
job (Fig. 60). 

A beaver does not always work continuously to cut down a 
tree. Thus the seventeen inch aspen was first seen July 
20, when it had a notch cut around it, not especially recent 
work though evidently done somie time the previous spring 
or early summer. The tree was seen quite frequently during 
the succeeding weeks, and was still standing August 28. 
On September 4 it was found to have been felled during the 
week preceding. In the Colorado Museum of Natural 
History, Denver, is a cottonwood stump 29^ inches in di- 
ameter, concerning which Director J. D. Figgins wrote me 
that there was evidence of long intervals between cuttings. 

Shiras states that a colony, estimated to contain eight 
beavers, had from tw^enty-five to thirty trees in the process 
of felling at one time, showing that they did not always work 
at a tree until it was felled. '^On an average it took from 
ten to fifteen days before large trees w^ere felled by reason of 
this intermittent cutting.'^ He also shows a picture of a 
beaver cutting on a black ash ninety-one inches in circum- 
ference. Beavers worked at this tree in three different 
years and never cut it down. 

There is much variation in the height of beaver-cut 
stumps. I have found a few two or three inches high, or 


even less, invariably of very small trees, an inch or two 
through. I found a group of half a dozen aspen stumps, 
three to four feet high; the trunks were lying there unused. 
Possibly they were cut when the snow was deep, and the 
woodcutters were caught by some enemy, cougar, wolf 
or coyote. Sometimes a stump, which at first glance appears 
unusually high, is seen on a little closer examination really 
not to be out of the ordinary, due to the circumstances under 
which it was cut. In the Longs Peak region, Colorado, I 
found an aspen stump forty-nine inches high. It stood 
beside a large rock, and it was very plain that the beaver 
stood on the rock when it cut it. The trunk was still at- 
tached to the stum.p, and green leaves were on the tree, 
though its tip was resting on the ground. Many a tree is 
cut by a beaver working from a fallen log, and stumps cut 
on a hillside where the work is mostly done from above 
will average higher than those cut on level ground. 

By the Lewis River, thirteen miles below the Thumb, I 
came across a group of most unusually high stumps, all 
lodge-pole pines. They varied from 4J up to 8 feet 8 inches 
in height. I think the last must be a record. I have seen 
no reference elsew^here to one as high. The tree was six 
inches in diameter. The other trees ranged in size up to 
nearly twenty inches through. Evidently they had been 
cut when the snow was deep, three feet and upward, pre- 
sumably in the spring. Other trees around had patches 
of bark gnawed off at about the same heights. Still others 
had been attacked close to the ground. One tree had a spiral 
notch, beginning 51 inches above the ground, and going more 
than completely round the trunk (Figs. 62 to 66). 

By far the greater number of trees felled by beavers are 
small; possibly eight inches in diameter would cover the 
majority, but that does not prevent them from attacking 
much larger trees at times. The large cottonw^ood, and ash 

r«%% j'spajj-ji! j>v-^ ■ 

Upper: Fig. 58. Aspens Cut by Bea\'er 
Lower: Fig. 59. Cottonwoods Cut by Beaver 


^v*srf ^ 

Upper: Fig. 60. Aspen Stumps Cut Twice 
Lower: Fig. 61. Tangled Trees 


Fig. 62. The Record Stump 


Fig. 63. A Stump Six Feet High 


Fig. 64. Pine with Bark Removed by Beaver 




Fia, 66. Pine with a Spiral Notch 



trees mentioned above are examples of this. Mills records 
a stump 3 feet 6 inches in diameter, on Jefferson River, 
Montana, near the mouth of Pipestone Creek. In the 
^ ^Nature Room" at Longs Peak Inn is a cottonwood stump 
having diameters of 32 and 28 inches at right angles to one 
another. Vernon Bailey, in the Mammals of the Glacier 
National Park, figures a cottonwood stump 46 inches across. 
Judging from the picture this was quite irregular in shape. 
This is the largest of which I have any knowledge. 

Considering the tools with which it works a beaver can 
fell trees quite quickly. Mills states that a four-inch aspen 
can be cut in about an hour. Dugmore says that a single 
beaver will cut down a tree eight to ten inches through in one 
night. Morgan makes the statem^ent that with three beavers 
working on a tree at once, two nights at most would be 
ample to bring down a tree a foot in diameter. Bailey says 
that an old beaver will fell a three or four inch aspen, cut it 
into sections four to eight feet long, and drag it to the water 
in one night. 

There is a difference of opinion among observers as to 
how many beavers work upon a tree at the same time. I 
think most doubt if more than two ever do, and: that number 
infrequently. Another point on which opinions vary is as 
to whether, when a tree is about to fall, the beaver doing the 
cutting gives a signal by striking the ground with its tail 
as a warning to other beavers nearby. I suspect that the 
signal is sometimes given and sometimes not, just as a beaver 
often dives without slapping the water with its tail, even 
when alarmed. I have seen a beaver which I came upon 
unexpectedly as it was swimming in a pond, slip quietly 
below the surface without a sound. 

In cutting trees the beaver usually stands on its hind feet 
with the wide, heavy tail stretched out behind as a balance, 
but some trees are cut so close to the ground that the animal 


must have been on all fours, and others may be cut when the 
beaver is standing up and working as high as it can reach. 
One or both fore feet are placed on the trunk while the work 
is being done. 

There are many mischances connected with tree felling. 
The top of a tree may lodge in the branches of an adjoining 
tree so that it does not fall to the ground (Fig. 61) . Once in a 
while it may be released by cutting the obstructing tree, but 
not often. Sometimes part of the trunk can be cut off. I 
found an aspen four inches through whose top had lodged in 
another tree a short distance away. Evidently it had been 
leaning considerably, and the beavers had cut off so much 
that the end of the suspended part was only about half the 
size of the stump and was nine feet away from it, and over 
two feet from the ground. Attempts to release an entangled 
tree are usually made by cutting the trunk a second, and even 
a third time, presumably with the hope that as the tree 
settles after the new cutting it will clear itself of entangle- 
ments and fall to the ground. This it does at times, and, 
I suspect, just as often does not. I found in the Longs Peak 
region twin aspen stumps, two feet high and two inches in 
diameter. Another aspen had been felled and caught 
between them, and all of it cut off and carried away except 
a piece eight inches long and 1| inches in diameter which 
still remained between the two stumps. Of course there 
was nothing to show which tree had been felled first, but 
presumably the entangled one, for it could hardly have 
caught between the stumps if the other trees had been cut 

The next step after the felling of a tree is the trimming 
of the branches, and then the cutting of the trunk into 
lengths suitable for transportation to the food pile. The 
length of the pieces into which a log will be cut naturally 
varies with its diameter. Morgan states that logs five inches 

Fig. 66. Pine Much Cut Into 


Upper: Fig. 67. A Piece of Aspen Caught Between Two Stumps 
Lower: Fig. 68. Willow Brush Stored in a Pond 



in diameter are cut into one-foot lengths, four inch logs into 
eighteen-inch and three inch into two-foot lengths. This 
hardly seems correct to me, for I have seen good-sized logs 
cut from eight to twelve feet long. I consider it most 
likely that the ease with which a log can be carried to the 
water has much to do with the matter. Where brush, 
fallen logs, or other obstructions interfere with getting the 
harvest to the water the animals may clear the way some- 
what by cutting out bushes or roots. These trails often 
pass under fallen logs, as mentioned elsewhere. Much of 
the smaller brush, or its bark, is eaten when cut. 

Most of the tree cutting is done in the late summer and in 
autumn in preparation for winter, and the wood so cut is 
stored in the pond for the winter's food, usually close to the 
lodge or conveniently accessible to it. The fact that this 
material is stored under water has given rise to some absurd 
fables to account for its remaining beneath the surface. 
Thus it was said, and I have seen it repeated quite recently 
in a sportman's magazine, that the beaver sucks the air out 
of the wood in order to cause it to sink ! Certainly a remark- 
able performance when one considers the size of a beaver's 
mouth and the size of some of the logs. The real explana- 
tion is that the green wood is so heavy that it soon becomes 
waterlogged and sinks. The lowest layer probably is 
forced into the bottom and the other stuff piled on it, very 
likely in such a manner as to entangle it with that below, 
and soon absorbs enough water to keep it down. 

Mills says that the first portions of the foodpile consist 
of entire trees, limbs and all, which are usually placed in a 
rude circle with the butts inward and the tops outward, and 
this forms an entangling foundation which holds in place the 
succeeding material. Morgan states that freshly cut yellow 
birch will barely float. 

The size of some of these foodpiles is sometimes quite 


extraordinary. Mills gives the size of one in the Moraine 
colony as three feet deep and 124 feet in circumference. 
To make this 732 aspen saplings were gathered, also several 
hundred willows. Another harvest pile mentioned by him 
was four feet high and ninety feet in circumference. One 
foodpiie which I saw in Gunnison County, Colorado, con- 
sisted entirely of willows, the large ends of which were stuck 
into or against the bank of the pond. The stuff was from 
three to seven or eight feet long, placed in water four feet or 
more deep, from the bottom up to the surface, and extending 
along the shore of the pond for over a hundred feet. Another 
brush heap which I saw not far away must have contained 
over eight hundred cubic feet of willow boughs, which appar- 
ently were never used, for when I saw them the pond had 
been drained, though I am sure no beavers had lived in it 
for a year or two, and the bark was rotting from the brush. 
Presumably the beavers were trapped before they could use 
their store. If the stored food is not used during the winter 
it is abandoned, never used at all, the animals evidently 
preferring fresh provender in the spring (Figs. 68 and 69). 
In moving logs to the pond or canal the beaver adopts 
such methods as are best suited to the circumstances. It 
may push or roll them over the ground until the water is 
reached, or if their size permits, take hold with the teeth 
and drag them alongside itself, or drag them along while 
walking on its hind legs, supporting the stick with the hands. 
Sometimes the stick is throw^n over the shoulder while held 
by the teeth. I have seen marks on the ground as if a stick 
three or four inches thick had been dragged down a hill from 
one pond to another. I think branches and brush are always 
carried by being dragged alongside, certainly the marks 
which I have seen in trails would indicate that such is the 
case. At Camp Roosevelt we used to walk down the Cooke 
City road in the evening to watch the beavers at a colony 


there. The animals did not mind spectators and came out of 
the water and went up the opposite hillside to gather food. 
Wild rose bushes, w^hich grew in profusion, seemed to be 
especial favorites, and a beaver would be seen cutting these, 
seemingly taking hold of the end of each, as fast as cut, with 
its mouth, until it had accumulated as many as it could 
hold. Then it would waddle down the hill dragging the mass 
of green beside it, this often looking as large as the beaver 
itself. Little aspens, a foot or two high, were cut and carried 
in the same manner. 

Once in the water the food is transported by holding with 
the teeth and letting it float beside the animal as it swims 
to the foodpile, on reaching which it dives down and forces 
its load into the stuff already there. Then it will remain 
until it absorbs enough water to stay do\\Ti even though 
it may become disentangled. Such food as the rose bushes 
or small aspens was either eaten on shore, occasionally in 
shallow water, or taken into the lodge. 

The logs are not always taken aw^ay as soon as cut, though 
the branches and limbs may be disposed of very soon. 
The beaver does not always see the need of hurry, or of work- 
ing all the time, and logs may be seen l^dng on the ground 
for some time after felling, and then removed gradually as 
needed, or at least in time for storage. Mills mentions two 
colonies in the Longs Peak region not far apart which had 
somewhat different methods of working. In one colony it 
was the custom to move the felled trees promptly to the 
storage pile, while in the other most of the harvest was cut 
down before the moving began. I have seen both of these 
colonies and could see nothing about their respective situa- 
tions which might account for this. Possibly one or both 
have changed their methods in the years which have elapsed 
since Mills made his observations, perhaps adopting modern 
ideas of efficiency. 


When unusually large trees are felled only the branches 
and upper portions of the trunks are used. The bark on 
the remainder is eaten from the log as it lies on the ground, 
or sometimes left and allowed to go to waste. The casual 
observer seeing this may perhaps blame the beaver for 
wanton destruction of the timber, when really the animal 
has used all that was of any service to itseK. What more 
can we ask? Does man do any better, or as well? I must 
admit, however, that in the case of several large pines which 
I have found, cut by beavers and never used, I am at a 
loss for any explanation of such work. Some of these trees 
were so large that it must have been difficult work and taken 
much time to bring about their downfall. 

Speaking of pines brings me to the use of the bark of coni- 
fers as food. All the authorities say this is rare, and appear 
to think it may result from necessity, due to the scarcity 
of other food. The more one studies an animal, the more 
occasion he is apt to find to modify his preconceived ideas, 
and so it proved with me in this case. In the Longs Peak 
region in 1922 I found numerous lodgepole pines from 
which the beavers had removed some of the bark, even when 
other food was close at hand. The trees were not cut 
down, but the bark had been taken off in triangular patches 
or strips, the apex of the triangle above, as if the animal 
had cut across the lower end, then loosened it and torn the 
bark upward, causing it to come off in this form. Occa- 
sionally oblong patches were found and once or twice a 
girdled tree. The trees from which the bark had been re- 
moved were from five to ten inches through. I found few or 
no chips at the bases of the trees, and never any of the bark. 
Some saplings were found which had practically all the bark 
eaten from them. Sometimes I found the tips of pine 
boughs in the water close to the shores of ponds, showing 
beaver toothmarks on their ends. While I have no proof 

Fig. 69. Willow Brush Stored at Lodge 


Fig. 70. Pine with Bark Removed by Beaver 



that this bark was eaten, I have but Kttle doubt that it was, 
for I know of no other use to which it would be put. The 
beavers would hardly be likely to use it for bedding, no 
matter how fond they might be of the piney odor, for the 
pitch would soon soil their fine fur coats (Fig. 70). 

In 1923, in the Yellowstone Park, I gathered much more 
evidence as to the use of conifer bark by beavers. Visiting 
the Crescent Hill colony for the first time in two years, and 
with much curiosity as to what developments had taken 
place during that tim.e, I found that the inhabitants were 
obtaining part of their food from Douglas firs. On very 
large trees they were cutting away the thick outer bark, 
which lay strewn about on the ground, and were eating the 
inner bark to a height of two feet from the ground. One 
tree was almost girdled in this way, and the beavers had 
also scraped the earth away from the roots and eaten the 
bark from them. Smaller trees had been cut down, tops 
and branches cut off and carried away, and the logs remained 
practically denuded of their bark. At one place beside the 
Yellowstone River several firs were found which had been 
attacked in the same way. At another place by the Yellovv^- 
stone I found where Engelmann spruces had been cut several 
years ago (Fig. 71). 

At the above mentioned locality on the Lewis River 
several lodgepole pines had had the bark removed in much 
the same manner as in the Longs Peak region. 

At various other colonies near Camp Roosevelt I found 
w^here beavers had used small firs and spruces. 

I have therefore come to the conclusion that the beaver 
makes much more use of conifer bark than it has been 
supposed to do. 

Dugmore says that he has been told by trappers and In- 
dians that about the time the young are to be born the 
pregnant female eats a small quantity of conifer bark, 


which is supposed to have some medicinal quahty. I can 
not help wondering how the trappers happened to discover 
this interesting fact. 

J. S. Newberry, speaking of the beaver in the Cascade 
Mountains, one hundred and fifty miles south of the Colum- 
bia River, said they cut off whole groves of young pine trees 
and carried them away bodily. 

It is almost invariably stated that the bark is the food 
which is obtained from the trees cut by the beaver, and 
doubtless this is true to a great extent, if not entirely so. 
Morgan, however, was of the opinion that wood itself formed 
a considerable portion of the beaver's food. He mentions 
instances where trees had been cut into apparently for 
the express purpose of eating the wood, as no chips remained 
about the trees, which were not entirely cut down. He 
also refers to the sticks and logs so often seen about beaver 
work which have apparently unnecessary notches cut into 
them, and thinks this was done to get the wood. I have 
often wondered myseK why this was done, and the thought 
had entered my mind that the wood had been eaten, and 
yet it seemed so unlikely when there was plenty of bark 
that I hardly gave the idea serious consideration. Sticks 
three to five inches in diameter are often found having cuts 
in several places close together, going all around the stick 
but not quite severing it. If the wood was not eaten the 
only other likely use of it would be for bedding. Other- 
wise the beavers were just whittling (Fig. 72). 

Morgan gives somewhat more convincing evidence with 
regard to this in the stomach contents of three beavers taken 
in February and March and sent out for dissection. Doctor 
Ely, who made the dissections, ''found their stomachs 
filled with lignine, with a slight intermixture of the tendrils 
of forest trees, and no perceptible remains of bark. The 
comminuted particles were so clearly of wood as to leave no 
doubt upon the question.'' 




Fig. 71. Douglas Fir with Bark Removed from Trunk and Roots 


Upper: Fig. 72. Piece op Aspen Much Gnawed by Beaver 
Lower: Fig. 73. Young Beavers in the Lodge 



In the Longs Peak region I found in two different ponds 
on the same stream dead lodgepole pines some of the roots 
of which had recently been cut off by beavers, and some 
of them quite close to the trunk. At one of the ponds a 
piece of a root was floating in the water by the tree. I saw 
no indications as to what use, if any, had been made of the 
portions cut off. I also saw a pine in Tower Creek the 
ends of the roots of which had been cut off in this way. 

We have little information as to how far away from 
the water a beaver will go in order to cut trees. The great- 
est distance which I have found was at Lily Lake, Estes 
Park. Here trees had been felled more than four hundred 
feet from the shore and dragged down the hill to the water. 
At Crescent Hill, Yellowstone Park, trees had been cut 
two hundred and twenty feet from the pond, but there were 
no aspens growing farther away, and never had been. 
Vernon Bailey says '^ trees have been cut as far back as 
ten or twelve rods from the shore, but track, trace, or 
trail of beaver is rarely if ever found farther from water y 
Italics mine. 

In summer beavers seem to make grass a portion of their 
food. I have seen grass floating in ponds where there was 
no indication of muskrats, and have sometimes seen where 
it had been cut on shore. In the Yellowstone I saw beavers 
carrying grass in their mouths dive down into the lodge, 
where it may have been eaten or used for bedding. Observ- 
ers in other places mention seeing where grass had been cut 
along shore. It is evident the animals use a goodly variety 
of food during the summer, perhaps as a relief from the 
enforced monotony of the winter diet of bark. 

In connection with beavers eating grass Taylor speaks of 
what he calls "grass beaver.' ' These lived where there was 
little or no brush and fed on grass, and were never as large 
and sleek looking as those living on bark. 

Breeding and Family Life 

The family life of the beaver would appear to be quite a 
model one. With an exception to be noted below all ob- 
servers and writers seem to be agreed that the beaver is 
monogamous and mates for life. The young remain in the 
lodge or burrow until they are fully grown, when they 
leave the old home, but often set up a new one for them- 
selves in the same pond. This might be likened to a human 
family where the old folks remain in the homestead while 
the children build new homes nearby, and all unite in work- 
ing together for the common good. 

When we come to look into the matter not as much 
appears to be known of some of the breeding habits of the 
beaver as we might have a right to expect after all the years 
we have known the animal. The creature's habits are in 
themselves obstacles to gaining information as to some 
things. Thus the rutting season does not seem to be 
definitely known. MacFarlane thought it was in January 
and February, but in those months over much of its range 
the beaver is living in ice-covered waters and not to be seen, 
much less studied. The same writer thought the period of 
gestation was about three months and the young were born 
in April and May. This last fact seems pretty well estab- 
lished. He states that the young are born blind and help- 
less, while Dugmore says the eyes are open at birth, basing 
his statement on what he had been told b}^ trappers and 

The number in a family seems to be quite variable. Per- 
haps the usual number is about four. As few as one has 



been noted in a litter, while MacFarlane says seven and 
eight were not uncommon on Peace River, and an Indian 
told him of finding nine embryos in a female killed on lower 
Peace River. It should be mentioned that Hearne, who 
spent several years in the northwest fur country, found as 
many as six foetuses in a female in but two instances. Mor- 
gan mentions a trapper who found eight in a female caught 
by him, and who also found eight in a lodge. Earl Theron 
Engle says that two beavers taken in South Boulder Canon, 
Colorado, February 23, 1924, each contained three embryos, 
7 mm. and 9 mm. in length. The government trapper who 
procured the animals said that the record is the earliest 
observed in several years trapping. 

One spring Mills visited several colonies to see if he could 
find out the number of children in a family. He saw one 
family of eight, and one mother had but a single baby. 
The average number was five. On May twelfth he saw 
six youngsters sunning themselves on top of a house. The 
fact that a beaver has but four teats might seem to indicate 
that four was the normal number of young. 

I have previously stated that there was an exception to 
the almost universal belief that beavers take but a single 
mate. Vernon Bailey makes the following statement: 
^^Like all rodents, beavers are polygamous, and the fact that 
fights among the males take place indicates that the older 
ones strive for supremacy." He also says that in August he 
found two females, one male, and six good-sized young in 
one house. As the sexes seem to be about equal in number 
polygamy appears rather doubtful to me. 

The male apparently leaves the home lodge or burrow 
about the time the young are to be born and takes up his 
abode in a burrow elsewhere. When the family are a 
few weeks old he returns to the lodge. Morgan states 
that at the age of six weeks the young will wean themselves 


and take to eating bark, while Bailey says that young 
beavers may be weaned at two months of age. Dugmore 
says that they come out of the house less than three weeks 
after birth. 

Joseph Dixon, Museum of Vertebrate Zoology, University 
of California, has very kindly given me some notes concern- 
ing the breeding of beavers in California. In that state the 
majority of young are born in April, chiefly in the first 
half of the month, though a few litters make their appearance 
during the latter part of March. Mr. Dixon also has record 
of small young, not more than a few days old, having been 
found as late as the first of May. He found, April 15, 1921, 
that the young were fourteen inches long and not more than 
a week old. They made no attempt to escape when the 
house was dug into, and were picked up and handled as 
though they had been kittens. The following season a 
number of houses were visited which contained young 
two or three weeks old, and these could not be captured, 
as they dove into the water through the entrances when an 
attempt was made to dig cautiously into the side of the 
house. In this case the youngsters were admittedly 
frightened from the house. However, even when, so far as 
was known, there had been no disturbance to cause the 
baby beavers to leave the house, it was found by muddy 
tracks at the margin of the pond that young beavers left 
the lodge when from three to four weeks old. In another 
instance a mother beaver and her three young, all about the 
size of large cottontails, were seen to ramble about in the rank 
grass some twenty feet back from the margin of the pond. 
This was late in June, probably six weeks after the other 
baby beavers had been born. This may have been a second 
litter. Mr. Dixon concludes his letter by saying: 'Ter- 
sonally, I have every reason to believe that in California 
youngsters begin to venture out, normally, when they are 
about three to four weeks old." 


In this connection I wish to record the observations I 
made in Yellowstone Park. A lodge was under observation 
continuously from the early part of July, and though we 
saw two adults and three yearlings on nearly every visit, 
we saw, though watching for them, no young of the year 
until August 22, when three made their appearance, the size 
of large muskrats. I estimated the length of one which I 
was able to observe very closely for some time at eighteen 
inches. If Dixon is correct in giving the age of young four- 
teen inches long as a week these could not have been more 
than two weeks old. After that day they were often seen. 
It seems strange that they should have attained such a size 
before showing themselves, especially when the others of the 
family showed no particular fear of the spectators who stood 
on the shore of the pond practically every evening. This 
was in 1921. 

In 1923, at another pond in the same region, we spent 
several evenings watching the beavers, which were quite 
indifferent to our presence on a dam at the upper side of the 
pond. They swam about close to us, also going away to the 
farther end of the pond and there gathering young aspens, 
rose bushes and willows. The lodge was but a short dis- 
tance from where we were, and another lodge was also built 
in the dam above mentioned, which seemed to be honey- 
combed with tunnels and passages. Young could be heard 
in both lodges, into which food was taken, but the young- 
sters never appeared outside, though we had observations as 
late as August 25. We saw both adult and yearling beavers 
on every visit. 

My Yellowstone notes seem to be much at variance with 
the above observations of others, unless, indeed, the young 
observed there were second litters. The later season in the 
Yellowstone might possibly make some difference in the 
breeding as compared with California, but hardly enough to 


account for such great discrepancies. The subject is a 
puzzle to me with the data at hand at present. Vernon 
Bailey says there seems to be no evidence of more than one 
litter in a season. 

In the Yellowstone I noted something which I never have 
seen mentioned an^^^here. It was the feeding of the year- 
lings by the adults. One of the latter would be seen to go on 
shore and return with a load of green food, with which it would 
swim to a certain part of the pond. Here a yearling or two 
would join it and take part or all of the food and eat it. 
If only a portion was taken the old one carried the remainder 
into the lodge. This was seen several times on different 
evenings. No yearlings were seen to go ashore where the 
adults did, though a few times one did go out at other places 
for a little willow brush. I can not help wondering if these 
'Yearlings'' may not really have been the first litter of the 
year, which probably would grow to a good size in three 

Foster parentage is not unknown among beavers. Mills 
gives specific instances, and Dugmore also speaks of the 
matter, possibly following Mills. 

On the whole the home life of the beaver appears to 
be a not unhappy one — when man leaves him alone. The 
beaver works when necessary to obtain food, or to build 
dams, canals or houses. But that does not occupy all its 
time. No building operations are carried on in spring or 
early summer, the season of high water, nor is much tree 
cutting done until late summer. From this time on, over 
much of the animal's range, it is busy preparing for cold 
weather, repairing dams and lodges, and gathering food. 
When winter comes and everything is frozen up, all there is 
for it to do is to eat and sleep. In the summer some beavers 
like to wander about. These are the males, and possibly 
yearling females. Mother beavers must stay at home and 


look after the family. These wanderers sometimes stray 
far from home and even from water, for I have been told of 
one having been seen on a dry divide in the Yellowstone 
a long distance from the nearest water. The purpose of this 
wandering is not quite clear. Perhaps in some cases it is 
to find a new location, in others just to get away to new 
scenes for a while. It is not even clear whether the travelers 
ever return home, though they are supposed to do so. In 
the case of two-year old beavers they may be looking for 
mates, or pairs may be prospecting for homesteads. In 
this connection it may be mentioned that while the female 
beaver probably does not usually begin to breed before the 
age of two years, Bailey says that instances are known of 
single foetuses being found in year-old females. 

Like all animals, wild or domesticated, young beavers 
are playful. Their play, so far as I have myself observed, 
and I think also others, is in the water, and seems to consist 
mostly of pushing and pulling one another about. Yearlings 
which I saw playing appeared to get their heads against one 
anothers' shoulders and push until one went over. I have 
seen a youngster thus rolled completely over in the water. 
Probably there is but little play on land. They are too 
awkward in their movements there for this to be safe. 

Beavers are said to live from twelve to fifteen years. 
Mills had glimpses of a beaver he called 'Tlat-top" during a 
period of eighteen years, and thinks it was at least four 
years old when first seen, making its age at least twenty-two 

The trappers told Father DeSmet that those beavers 
which were lazy and unwilling to work w^ere exiled from the 
colony, and forced to live apart at a distance in a state of 
starvation in the winter because they had not put up food. 
They were easily caught, but their fur was not as good as 
that of other beavers because of lack of food. This tale has 
been current with variations for many years. 


Swimming and Walking 


It is of course in the water that the beaver is most at home, 
and naturally with the structure and aquatic habits of the 
animal, it is a far better swimmer than walker. It swims 
easily at or beneath the surface, usually at a rather slow or 
moderate speed, using its hind feet for propulsion, for 
which their size and webbed structure are admirably 
adapted. Bailey says that when alarmed beavers can 
swim under water as fast as an otter or a seal, while Seton 
thinks they rarely swim faster than two miles an hour. 
Bailey says that the tail is effectively used as a propeller 
when speed is desired. 

Dugmore says that in swimming the hind feet are used, 
and to a very limited extent the tail, chiefly for sudden 
starts or turns. In this it differs from the muskrat, which 
swims chiefly with its tail, which it uses as a scull. In 
comparing beavers and muskrats Shiras says ^^Unhke the 
muskrat, with its body well out of water, the beaver swims 
nearly submerged, with only the head showing. At a 
distance it is sometimes hard to tell one from the other when 
swimming, except by the greater speed and wake of the 

Dugmore says that upon the speed at which the animal is 
going depends the amount of the back which is visible. 
He says that he has never been able to make absolutely 
sure that the tail is employed as a propeller, except for a 
few strokes on a sudden burst of speed. 



Johnson says the propelling organs are the hind feet. 
He has never seen the tail used as a scull, and believes that 
it is principally used as a rudder. When the animal is 
swimming straight away the hind feet strike out together, 
and when it is turning the strokes may alternate. 

Beavers which I watched closely when they were swim- 
ming by daylight in Yellowstone Park of course used their 
hind feet for propelling, but not exclusively. Though the 
tail was usually carried motionless behind, I sometimes 
saw it used with a sculling motion. As at such times the 
animal went straight ahead the tail was not then being used 
for steering, though I did see it used for that purpose on 
other occasions. Sometimes the swimmers turned without 
using the tail for a rudder, evidently doing it by means of 
the hind feet. 

The fore feet are not used at all in swimming, being then 
folded against the body. 

A beaver can remain under water for a considerable 
period. Bailey says commonly four or five minutes at a 
time, but that they can swim half a mile or more without 
coming to the surface, and have been timed for 15 minutes 
under water in traps. When moving about under the ice in 
winter they may get air from bubbles under the ice or from 
open holes. Mills says they can swim two hundred yards 
under water without coming to the surface, and can remain 
under water five to ten minutes. On one occasion one 
stayed under water more than eleven minutes. Dugmore 
says (p. 77) eight to nine minutes, and (on p. 13) six to seven 

The above-mentioned Yellowstone beavers did but little 
slapping with the tail. They often dived without apparent 
reason, usually quietly, but sometimes noisily. Even small 
sticks thrown into the water near the animals did not trouble 
them. Something which did cause one to slap its tail was a 


camera which I had set on a tripod on the dam near the 
trail where the animals crossed, hoping to obtain a picture. 
One came near this, evidently intending to land, but on see- 
ing the camera dived with a great splash, and it and another 
afterward swam about, occasionally diving with slaps as if 
to manifest their displeasure. 

Dugmore says that his photographs show that when a 
beaver slaps the water with its tail in diving the head and 
shoulders are held high out of the water as the tail is raised. 
This slapping with the tail is a well known habit of the 
beaver, and one which is made a good deal of by some 
writers. The slapping appears to be a danger signal, but 
even when alarmed the beaver does not always give it. I 
once came suddenly upon a beaver as it was swimming in a 
pond in midday, and though it must have been frightened 
at my unexpected appearance it dove quietly and without 
the least noise. One day at the Crescent Hill colony in the 
Yellowstone Park we were eating our lunch on the opposite 
side of the pond from the lodge. A beaver kept coming 
out, swimming around and then disappearing until I could 
stand it no longer, and picking up my graflex, I crossed on 
the dam and stationed myself at a favorable point. Pres- 
ently I was able to make an exposure. The beaver dived 
at the sound of the shutter without any disturbance. En- 
couraged by my success I went somewhat nearer the lodge, 
and presently my subject reappeared. Evidently I was too 
close this time, for as the shutter went the beaver dived with 
a tremendous splash which threw water all over me, though 
I was some twenty feet or more away. At another colony 
in the Yellowstone I was watching a beaver feeding one 
afternoon, when it suddenly disappeared, and a few minutes 
afterward I discovered it quite close to me, floating motion- 
less in the water, with only the head out. Then it returned 
to its feeding place. This was repeated two or three times, 


the animal always moving so quietly under water that it 
made no surface disturbance. 

This floating quietly is something which the beaver seems 
fond of doing. The animal rests easily with the upper part 
of the head and back out of water, and the tail on the sur- 
face. Sometimes it appears to be done for purposes of obser- 
vation, at other times the animal seems to be resting, or 
perhaps loafing. 

Sheldon, in 'The Wilderness of the Upper Yukon," says 
he twice saw beavers dive when they were unsuspicious, 
and in both cases they slapped their tails. Selous men- 
tions two instances of beavers on the bank which were not 
alarm^ed by the tail slaps of others, even when close-by. 
Sheldon thinks some other interpretation of the habit than 
an alarm must be attempted, that perhaps it is a muscular 
contraction to assist in sudden diving. 

A somewhat similar use of the tail is that of thumping the 
ground with it when a tree is about to fall, as a supposed 
signal to the other beavers around to look out. As stated 
elsewhere there is a difference of opinion about this. 


Walking is far from being one of the beaver's strong points. 
On the contrary it is a method of progression for which its 
build does not adapt it, therefore its walk is decidedly 
awkward, at times very much like a waddle as it moves 
about over the ground on its various errands, cutting trees, 
or gathering bushes for food. Quite different is the ease 
with which it moves in the water, its real native element. 

For a faster gait a beaver uses a clumsy lope or gallop, 
not very fast, for it is said that a man can easily outrun an 
adult, and any of its four-footed enemies could do so without 
trouble. I once had a rather amusing experience with a 
beaver, though it was in the water instead of on land. The 


animal was swimming in the pond almost directly below 
where I stood on the bank several feet above and I made an 
exposure with a graflex camera. The noise of the shutter 
startled the beaver, which ordinarily would have dived. 
Unfortunately for it, however, the water was very shallow 
and several fallen trees intervened between the place and 
deeper water. Over these logs the beaver loped and gal- 
loped with a great splashing until it reached a place where it 
could get beneath the surface. The negative obtained 
showed with what quickness a beaver can get into motion, 
for the shutter had been set for a very short exposure in 
order to allow for the movement in swimming, but the nega- 
tive shows a rather unrecognizable blur, and the position 
of the animal shows that it began to jump the very instant 
the shutter was released, certainly quick response to an alarm. 

Upper: Fig. 74. A Bea'V'er Swimaung 
Lower: Fig. 75. A Beaver Floating 


Upper: Tig. 76. A Bea^ter Resting 

Lower: Fig. 77. The Beaver Which Combed Its Hair after Being 
Taken from the Trap and Tethered 



Voice; Sign Heaps; Enemies; Disease; Parasites; 
Beavers and Fish; Beavers and Bird Life 


Different writers vary much in their descriptions of the 
beaver's voice. Morgan says that the cry of a young beaver 
very closely resembles that of a child a few days old. Mills 
says that sometimes a strange, shrill whistle is given. Some- 
times, when alarmed a young beaver gives a shrill and 
frightened cry not unlike that of a lost human child. He 
has heard near a beaver house in early summer a subdued 
concert going on inside, a purring, rhythmic melody. He 
says that the beaver also has a love ditty, a rhythmic mur- 
mur and sigh, very appealing, and it seems strangely ele- 
mental as it floats across the beaver pond in the twiUght. 

Dugmore likens the voice of the young to the muffled 
whining of very young babies. My assistant in 1921 said 
that the noise made by the yearling beavers when playing 
was like that of a young kitten, only sharper. Seton says 
that young beavers wail like a crying child; older ones hiss 
in menace or utter a querulous ^^churr." 

In 1923, some companions who were watching the beavers 
with me in the Yellowstone Park, where we could hear the 
young in the lodge, were well agreed that the voice of the 
young in the lodge was most hke the whimpering of young 
puppies, without any whining or squealing note. One 
gentleman compared it to the grunting of young pigs, ten 
to fourteen days old. None of these people could detect 
any resemblance to the cry of a human child. 




A means of communication used by the beaver, perhaps 
more especially if it is traveling about the country and wishes 
to leave some indication of its presence, is what we may 
call for want of a better name, the ^'sign heap." Seton 
calls these things mud pies. 

Sign heaps are little cakes or piles of mud near a stream or 
pond on which the castoreum is deposited. One which it 
was my good fortune to find on Lost Creek, Yellowstone 
Park, was placed in shallow water close to the shore, and 
was a little more than a foot in diameter and three inches 
thick. It had been made either the preceding night, or 
the night before that, as we had been there two days pre- 
viously. It was merely a round cake of mud, but so placed 
that it stood apart from its surroundings and was really 
quite conspicuous and easily seen. I could detect no odor 
about it. 

Morgan gives an account of something similar: ^^ After 
selecting a suitable place upon dry ground near the pond or 
stream, they void their castoreum here and there upon the 
grass, and, in the musky atmosphere thus created, spend 
some hours at play or basking in the sun. The trappers 
call these playgrounds ^musk bogs."^ 

Nuttall, in speaking of trapping beavers, says: ^^Scarcely 
anything is now employed for bait but the musk or cas- 
toreum of the animal itself. As they live in community, 
they are jealous and hostile to strangers of their own species 
and following the scent of the bait, are deceived into the 
trap'^ (Fig. 78). 


The arch-enemy of the beaver, as of all other wild life, 
is of course man. The list of other enemies is short. Cou- 
gars, bobcats, lynxes, wolves, coyotes, bears, wolverenes. 


Fig. 78. Sign Heap or Mud Pie 2^1ade by Beaver 



otters, and possibly foxes and fishers, seem to be the four- 
footed enemies with which a beaver has to reckon. Some 
of the larger hawks, such as the goshaw^k, as w^ell as the 
eagles and great horned owl, may occasionally pick up a 
small youngster. Dugmore, in his story of the life of a 
beaver family, tells of a goshawk capturing a beaver kit 
as it was playing on the shore. As Dugmore was very 
careful in what he wTote I take it for granted he based his 
story on facts known to him. He seems to be the only 
author who mentions birds killing beaver, but I see nothing 
improbable about such an occurrence as he relates. 

Of the other enemies mentioned, all, excepting the otter, 
probably kill beavers by surprising them when on land, 
or perhaps occasionally when in very shallow water. They 
may steal upon a victim when it is at work cutting do^vn a 
tree, or trimming one after it has been felled, or traveling 
across country from one water to another. Mills gives 
several instances where a number of beavers were thus 
killed by cougars and coyotes. I found in the Longs Peak 
region in late August, what w^as left of a beaver which had 
been killed a few days before by a coyote or coyotes, drop- 
pings of which were found close-by. All that could be found 
of the beaver were a few scraps of fur and of the scaly 
part of the tail, and part of the intestines. These were but 
a few feet from the lodge, which was a bank lodge, and 
presumably at or near the place where the victim had 
been surprised and killed. 

Mills also mentions an instance of a bear tearing open a 
beaver house, a proceeding which to me looks like a waste 
of time. While Bruin was trying to break through the thick 
walls the inmates would quietly leave and all he would have 
for his trouble would be an opportunity to observe the do- 
mestic arrangements of his intended prey. 

Comparatively little seems to be known as to the rela- 


tions between the beaver and the otter. The latter is fully 
as much at home in the water as the former, and surely 
would be a most formidable enemy. In ^Tins, Feathers 
and Fur/' March, 1922, James Harris, a Minnesota game 
warden, reported that in February, on the Superior Game 
Refuge, he saw where an otter had made a hole through a 
beaver dam and drained the water off. He said: ^^Trappers 
claim that otters do this so as to make an air space to 
swim around in under the ice and look for food; they will 
also attack beaver if they find one alone. A local trapper 
informed me that he had seen a beaver dam in the game 
refuge where an otter had drained it and had a fight with 
the beaver, they had driven him out and wounded him as 
there were blood stains on the trail where he came out.'' 
Audubon says that the otter is the worst enemy the beaver 

Mills, in ^'Watched by Wild Animals," chapter V, "The 
Otter Plays on," tells of a battle between an otter and 
beavers in the latter's pond. Most of the fighting was under 
water. Several beavers were in the fray against the single 
otter, which finally broke away and made its escape, and 
seemingly was badly bitten. 

A beaver is essentially a peace-loving animal, and such 
as I have seen caught in traps made absolutely no fight. 
One which was caught by a hind toe only, permitted me to 
pull it by the tail out from under the bank where it was 
hiding, attach a long wire to a hind foot, and remove the 
trap. I then dragged it along to an open space on the shore 
where I could photograph it (Fig. 77) . The animal made not 
the slightest resistance, and appeared quite resigned to its fate. 
When once on the shore and securely tethered, it began to 
comb and dry its hair with its claws. And all the time I 
had been in fear of a nip from those teeth which easily could 
have made serious cuts if their owner had been inclined to 


use them. Male beavers are said to fight among themselves 
during the rutting season, and scars are found on the hides, 
made by the teeth of the combatants. 

In contrast to my experience is the account by George 
G. Goodwin, in Nature Magazine, of a fight he had with a 
trapped beaver. The latter freed itself from the trap just 
as the man, who was waist deep in the water, caught hold of 
a hind leg. The beaver turned on its captor, biting at his 
face, but unsuccessfully. Goodwin had no weapon and 
defended himself with his fist, but without effect. Finally 
the beaver gave up the attack on the face, swung around, 
and bit through the top of the man's thigh, making a w^ound 
large enough to put the little finger in. This last attack 
gave the man an opening to get in a blow which laid out the 
animal until it could be dragged ashore and finished with a 
knife. This beaver was said to weigh over sixty pounds. 
This is the first account I have ever seen of a beaver attack- 
ing a man, even when it was trapped. 

Mills stated that he knew of two instances of bobcats 
being killed by beavers, but does not give any particulars. 
If a beaver did choose to make a fight it might easily kill 
an animal the size of a bobcat by a lucky bite in the neck 
severing the jugular vein. 

Grinnell, in the ^^ Cheyenne Indians," gives some account 
of the method used by this tribe many years ago to capture 
beavers. They used the meat for food and the skins for 
clothing, and trained dogs to hunt them. These dogs were 
small enough to enter the hole in the bank or lodge, and 
still were of fair size. A beaver dam would be broken so 
as to drain the water from the pond. The entrances to the 
lodges or burrows would be located, and a dog sent in. He 
would find the beaver, bark at it and worry it until it was 
angered and fought back, and follow^ed the dog out. The 
latter gradually backed away, inducing the beaver to follow 


by making short dashes at it, and finally backed clear out 
of the hole, followed by the beaver, which would promptly 
be knocked on the head with a club by an Indian waiting 

D. S. Stanley, in the American Naturalist for June, 1868, 
mentions a half-breed at Fort Sully, South Dakota, who 
owned a female bull terrier which followed beavers into 
their lodges and pulled them out, having sometimes a severe 
fight and being badly bitten. ''The Indians offer a big 
price (a large buffalo horse) for the dog." He also states 
that the wolverene lies in wait for beavers by their trails and 
kills them. 

In the original Journals of Lewis and Clark it is related 
that on May 19, 1805, somewhere on the Missouri River, 
Lewis wounded a beaver which was in the water. His dog 
went in to fetch it out, when the beaver bit the dog in the 
hind leg, severing an artery, and it was feared the dog would 


MacFarlane says that beavers are sometimes found dead 
of disease in their houses, and on the authority of Descham- 
bault, that in such cases the mouth and nostrils are generally 
infested by small white worms. 

FroUE Seton, page 476: ''Like others of our beasts this 
species has its years of increase and decrease, and also is 
subject to diseases that are as yet not understood. Tanner 
says of the beaver of the Upper Red River about 1800 
[quoted by Coues in Henry's Journal, p. 256]: ^Some kind 
of distemper was prevaihng among the animals which de- 
stroyed them in vast munbers. I found them dead and 
dying, in the water, on the ice, and on the land; sometimes 
I found one that, having cut a tree half down had died at its 
roots; sometimes one who had drawn a stick of timber half- 


way to his lodge was lying dead by his burden. Many of 
them which I opened were red and bloody about the heart. 
Those in large rivers and running waters suffered less; al- 
most all of those which lived in ponds and stagnant waters 
died. Since that year the beaver have never been as plenti- 
ful in the country of Red River and Hudson Bay as they 
used to be.'" 

None of the other authors whom I have consulted have 
anything to say about disease of the beaver. 


Beavers are afflicted, like most other mammals, with 
parasites, but these appear to be unique in that they belong 
to the order Coleoptera, which is that to which all beetles 
belong, not to the Mallophaga, which includes the biting 
lice of mammals and birds. 

Platypsyllus castoris is the name given to the better known 
of these parasites, and it has been found on both American 
and European beavers. It has been recorded from Alaska, 
Colorado, Dakota, Texas, Nebraska and California n 
America. Riley (Castorologia, Appendix C, p. 238) says 
that Leptinillus validus Horn, is an associate parasite of 
Platypsyllus on the beaver, a number of both having been 
taken from beaver skins brought from Alaska. 

Prof. T. D. A. Cockerell writes me that this is all that is 
known of its habits. L. testaceus occurs in nests of bumble- 
bees and field mice. L. aplodontia was found in California 
on Aplodontia, or mountain beaver, a mammal whose habits 
are very different from the real beaver. 

Vernon Bailey says that two specimens of L. validus were 
the only parasites found on four old beavers taken for 
specimens in Wisconsin. None was found on six young 
beavers kept in captivity. 



There seems to be much difference of opinion as to the 
influence of beaver dams and ponds on fish and fishing. 
Johnson, in his investigations in the Adirondack region, 
found great diversity in the ideas of the people in regard to 
this matter. Some claimed that the beaver ponds ruined 
the fishing, others that it improved it. It is possible that 
both opinions were correct, different physical conditions 
accounting for the discrepancies. 

Regarding beaver ponds and fish. Dr. W. Lyman Under- 
wood writes me that he knows of two instances where beaver 
ponds attracted trout. ^^One was in Maine on the head- 
waters of the St. Croix River. Here a small brook flowed 
through a meadow. A great many years ago there was a 
dam upon this stream and a sawmill beside it. The whole 
thing went into ruins forty or fifty years ago. Several 
years ago the beavers constructed a dam where the old lum- 
ber mill's dam once stood. There had been no fish in the 
brook in this meadow, but within a short time it became well 
stocked with trout and good fishing could be had there. 
Five or six miles below where the old mill had stood entered 
quite a large headwater stream. Here there had always been 
a goodly number of trout of fair size, but they never seemed 
to go up the small brook where the beavers finally made their 

'^The other instance of beavers being responsible for the 
stocking of ponds occurred in New Brunswick at the head of 
the Nepisguit River, some eighty miles from any habitation. 
Here were a number of beaver ponds where my guides told 
me that years ago, before the beavers had made the dams, 
there were no trout. When I visited them there was excel- 
lent fishing to be had and I frequently caught trout by 


standing on top of the dam and casting my flies into the 
water above it."^ 

Mills says that after a severe winter in the Longs Peak 
region the only trout left in certain streams were those in 
the beaver ponds. I saw trout in those ponds myself. In 
other parts of Colorado where I have been I have seen trout 
in beaver ponds, even in some which were connected with 
the main stream by a mere rivulet. 

Dugmore says the beaver ponds afford deep, cool retreats 
for trout in hot weather, and even though the dams may 
restrict the movements of the fish at times, there are always 
opportunities during the year for them to pass up or down. 

'Tins, Feathers and Fur" does not think trout fishing in 
Minnesota is affected in any way by beaver dams and ponds, 
the temperature of the water always remaining low enough 
in summer for the trout's needs.^ 


Not much has been said or written as to the influence of 
beaver ponds upon bird life. Possibly they have com- 
paratively little, but such as it is, it probably is beneficial. 
As one would naturally expect, various species of ducks are 
found about the ponds, especially in migration. In the 
Yellowstone I saw mallards about some of the ponds in 
summer, including a brood of young on one pond. The 
same species was also seen on ponds, in the Longs Peak 
region. In the Adirondacks, Johnson saw broods of black 
ducks which probably were locally hatched, also occasional 
hooded mergansers and American golden-eyes. He says 
the great blue heron was common and the solitary sand- 

1 From letter from Doctor Underwood. 
* December, 1922, p. 3. 


piper fairly common. In the Yellowstone I saw both the 
solitary and spotted sandpipers, the former late in the sum- 
mer, after the fall migration had begun. The latter was a 
summer resident, and seen not only at the beaver ponds, 
but along all the streams. 

Beaver ponds are likely to create along their shores 
conditions which will attract some of the swamp or marsh- 
loving w^arblers and sparrows, and induce them to nest 


Beaver Fur; Castoreum; Beaver Meat; Beaver 


beaver fur 

Almost from the very beginning of the settlement of 
North America the trade in beaver skins played a most im- 
portant part in the development of the country, especially 
of Canada and the western United States, where the search 
for the coveted furs sent the trappers into practically every 
nook and corner of the Rocky Mountains. 

The French, when in possession of Canada, were inde- 
fatigable in their pursuit of the animal, and the Hudson's 
Bay Company, when it came into being, likewise devoted 
much attention to the gathering of beaver skins. For a 
long series of years beaver fur furnished the material for 
hats, until in the nineteenth century the manufacture of 
silk for hats, and the use of the fur of the South American 
nutria or coypu combined to force the beaver from its place 
as a hatter's material, and one may say compelled its use 
exclusively for wearing apparel, a purpose for which it is 
eminently well adapted, being one of the best furs we have. 

In Canada trading began in 1603 under a Royal Charter 
(French), and about twenty-five years later the ^^Company 
of 100 Partners" was formed, which took over and developed 
the trade until 1663. After some changes Montreal became 
the capital of the Canadian fur trade. 

May 2, 1669, Charles II of England granted Royal 
Charter to the Governor and Company of Hudson's Bay, 
which granted exclusive rights in commerce and trading in 
that whole vast region. 



While of course many other furs were taken the beaver 
was of such prime importance that everything, both other 
kinds of furs and articles of merchandise, was valued in 
terms of beaver skins. Beaver tokens were issued by the 
fur companies for use in trading. Beaver skins in the early 
days of the trade began to be sold by the pound, and the cus- 
tom survived to a comparatively few years ago. The 
average weight of a beaver skin is 1^ to If pounds (Cas- 
torologia) . 

From 1853 to 1877, inclusive, the Hudson's Bay Company 
sold 2,965,389 beaver skins in London, the average being 
118,615 skins annually. The maximum, 172,042, was in 
1867, probably the m^ost productive year of the com.pany. 
The numbers fell off, and in 1897 the company sales were 
about 50,000, in 1900 about 43,000, 46,000 in 1902, and 
49,190 for 1903. The above figures are from MacFarlane. 

Seton says that in the last quarter of the eighteenth cen- 
tury about 150,000 skins were exported annually by 
American fur companies, and the Hudson's Bay Company 
marketed about 50,000 yearly. 

In 1891 the American output was reduced to 11,693, 
and the Hudson's Bay Company's was 57,260, while in 
1887 it had exported 102,745, and in 1871, 171,461 skins. 
In 1905 the Hudson's Bay Com^pany's returns were 54,119. 

Dugmore says that in 1859 there were 509,000 sold in 
London and Edinburgh. 

At the London fur sales in March, 1906, prices were $7.20 
to S8.40 for first-class skins, grading down to $3.60. Forty- 
one first-class black skins brought $14.88 each. Since that 
date prices have greatly advanced. 

Thanks to the kindness of David C. Mills, general director 
of the National Association of the Fur Industry, I have 
very complete data of the sales of beaver skins of the New 
York Fur Sales Corporation for the five years 1919-1923, 


inclusive. Sales are held three times in each year (the 
autumn sale was omitted in 1920). The lowest average 
price for all grades of skins was S12.03 at the sale of Janu- 
ary 17, 1921. The highest average price was S40.70, Feb- 
ruary 25, 1920. They dropped to S31.28 at the sale of 
April 27, 1920, and then to the above mentioned minimum, 
$12.03, the following January. 

The highest price at which any skins were sold was S64.00 
each for forty of the highest grade skins, at the February, 
1920, sale, while at the same sale fifty-two of the lowest 
grade pelts brought S8.50 each, dropping to $2.50 at the 
sale of the following April. 

Prices in 1923 averaged between $15 and $16, with a 
maximum of $27.75 for 76 skins, and a minimum of $1.00 
for 162, both of these prices being obtained at the September 

As a matter of fact, after the drop of Januarj^, 1921, and 
the subsequent moderate recovery at the following sales, 
prices have been fairly steady, averages ranging from $14.46 
to $21.09, with a maximum for the best of $35.50. 

The skins were sold in lots, and labeled I, II, III, IV and 
Cubs (and often also, large, medium, small and dark). 

The total number of beaver skins sold during these five 
years was 115,097, an average of 23,019.4 skins annually. 

The fur traders, in the early part of the nineteenth century, 
put the beaver skins in packs weighing one hundred pounds 
each. James, in the account of Long's Expedition, says 
there were seventy to eighty skins in a pack. He says the 
usual price per pound in St. Louis was $3.00. This was 
about 1820. Maximilian says there were generally sixty 
large pelts in a pack, and the usual price was $4.00 a pound. 

Some of the early writers on the Far West tell us what the 
traders paid for beaver skins. Alexander Ross, one of the 
party sent out by J. J. Astor on the expedition which founded 


Astoria, mouth of the Columbia River, in 1811 to 1814, 
says that at Fort Kamloops he bought one hundred and ten 
beavers for leaf tobacco at the rate of five leaves per skin, 
and at the last, when he had but one yard of white cotton 
remaining, a chief gave him twenty prime beaver skins for it. 

Father DeSmet tells us that in 1843 the beaver skin sold 
for nine or ten dollars worth of provisions, the real value of 
which was less than a single dollar. ^Tor a gill of whiskey, 
which has not cost the trader more than three or four cents 
is sometimes sold for three or four dollars, though the chief 
virtue it possesses is to kill the body and soul of the buyer." 

Farnham related that at Pueblo, Colorado, in 1839, 
a pint of whiskey was paid for a beaver skin, value S4.00. 
Townsend said they traded trifles costing 12J cents for 
beaver skins, worth in Boston S8 to $10. This was in 1833. 

The possibihties of developing the supply of beaver fur by 
enforcing a close season and the permitting of a limited 
amount of trapping under license, are shown by the follow- 
ing figures from the Minnesota Department of Conservation : 

1919-20, 361 pelts @ $35.00 $12,635.00 

1920-21, 1200 pelts @ 20.00 24,000.00 

1921-22, 3533 pelts @ 18.00 63,594.00 

Total $100,229.00 

The estimated catch for 1922-23 was eight thousand pelts, 
valued at $200,000, which appears to me to be too high an 

Previous to the enforcement of a close season beavers 
were practically extinct in many localities in Minnesota. 

In most of the states the beaver is protected, and trapping 
either forbidden, or allowed under restrictions. This has 
resulted in an increase in the numbers of the animal, and 
provides a supply which might be drawn upon for fur. If 
this matter is handled intelligently we should have a con- 
stant supply of beaver fur. 


At the present time fourteen states have an open season 
for the trapping of beaver. In twenty-five, including every 
one of the Rocky Mountain States, the animal is protected 
at all times, excepting that in most of the western states 
permits may be issued for the taking of beavers injuring or 
destro^dng property. In Minnesota and New York beavers 
may be trapped under special license; in a part of Oregon 
they may be trapped, and in the other part trapping is for- 
bidden. The beaver is not mentioned in the game laws of 
seven states, all of them old communities where the creature 
was long ago exterminated. 

In Canada five provinces permit the taking of beaver 
during open seasons, and it is protected at all times in five 
others. There is an open season in the northern part of 
Manitoba, and none in the southern. 

The Northern District of Lower Cahfornia has an 
open season on male beavers only. The law does not specify 
how the sex may be determined before the animal is captured. 
MacFarlane says that for more than a decade subsequent 
to 1821 each beaver district in the territories of the Hudson's 
Bay Company was restricted to the annual collection of a 
fixed number of beavers. This eventually proved to be of 
much benefit. After the beavers were known to have in- 
creased much in numbers the rule was gradually relaxed. 
'Tt may be here mentioned that the Company never en- 
couraged the hunting of beaver or an}^ other pelt out of 
season. On the contrary they strictly prohibited the killing 
of beaver in summer, and would only reluctantly accept the 
skins of such animals as they were assured had been abso- 
lutely necessary for food purposes." 

MacFarlane also says that skins taken by natives of 
Quebec who resort to Bersimis Post in the Gulf of St. Law- 
rence are among the very finest. Labrador, East Main, 
and other Hudson Bay posts also furnish a small number of 


similar pelts. '^As a rule, those which frequent clear- 
water streams have a better color than is the case with the 
summer inhabitants of very muddy rivers having their 
source in or beyond the Rocky Mountains and flowing 
through a sandy clay soil. The skins of such beaver are 
usually of a rusty brown color, with the inner fur of a lighter 
hue, and are certainly in appearance inferior to their cleaner- 
furred brethren and must therefore realize lower prices in 


While of course it is not a fur, castoreum has always been 
traded in by the fur buyers, and the amounts handled may 
well be treated in this chapter. The following figures taken 
from MacFarlane show the amounts handled by the Hud- 
son's Bay Company in part of its territories: 


Mackenzie River District (1863 to 1881) 6,251 

Old Athabasca (1858 to 1884) 18,904 

Average of Mackenzie River (1886, 1887 and 1889) 54 

Average of Athabasca (1885 to 1889) 211 

There was much falling off in the eighties, the result of 
^'free trade." 

David Mills informs me that there has been no market 
for beaver castors since 1914. In December, 1923, 1800 
pounds were offered in London by Lampson's, and about 100 
taken. In New York absolutely no movement has taken 
place. Ten years ago they brought SIO to $20 a pound at 
London, but now (March, 1924) the owners are holding for 
but $4 to $6 per pound. It is possible a few small sales 
might be made at $2.50. Really no ^^price" exists and fur 
buyers quote no prices for beaver castors. There are about 
six pairs of castors to the pound. 

A book called ''Castorologia" was published in 1685, 
which was a treatise on the medico-chemical uses of the 


beaver. Castoreum apparently cured many things, and 
the fat and blood also were used, the latter for epilepsy. 
The teeth were attached to the necks of children to facilitate 
the cutting of teeth. 

The following analyses of Castoreum are from Watt's 
Dictionary of Chemistry: 

Russian Canadian 

castoreum castoreum 

Volatile oil 1.00 2.00 

Castoreum resin 13.85 58.60 

Cholesterin 1.20 

Castorin 0.33 2.50 

Albumin 0.05 1.60 

Glutinous substance 2 . 30 2 . 00 

Extract soluble in water and alcohol 0.20 2.40 

Carbonate of ammonium 0.82 0.80 

Phosphate of calcium 1 . 44 1 . 40 

Carbonate of calcium 33 . 60 2 . 60 

Sulphates of potassium, calcium and magnesium 0.20 

Gelatinous substance extr. by potash 2.30 8.40 

Gelatinous substance extr. by potash soluble in 

alcohol 1.60 

Membranes, skin, etc 20.03 3.30 

Water and loss 22.83 11.70 

98.95 100.10 


Beaver meat is said to be very good eating, and the tail 
is a traditional delicacy among trappers and hunters. 
Never having tasted either I can not say anything from per- 
sonal experience. Bailey says the body meat has rather a 
gamey flavor, and was generally preferred by trappers to 
any other meat, even in early days when other game was 
abundant. He says the liver is as good as that of a chicken 
or goose. The tail is fatty tissue, very rich. Seton likens 
the tail to calf's head with marrow dressing, decidedly rich 
and heavy, but delicious eating. He says: ''In a vast por- 
tion of the Mackenzie Vallev the beaver serves the Indians 


as the buffalo did those of the plains. It is their staff of 
life, it feeds and clothes them, as well as supplies the neces- 
sary peltry to barter with traders for other things desired. 
These tribes are very naturally known as the ^Beaver 

Howell says that in Alabama the flesh of the beaver is 
eagerly sought for food, especially by negroes on the planta- 
tions. Johnson considers the meat very good. A cor- 
respondent writes that beaver meat is very good, but very 
rich and that the saddle of a yearling roasted is ''pretty 

Bailey suggests that beaver farmers could make the meat a 
source of income, selling that of the animals killed for fur. 

I have been told that years ago in Colorado somxe people 
used to cook beaver tails, then soak them in vinegar, and 
thus prepared they were excellent eating. 

Pattie speaks of carrying dried beaver meat for provisions 
when on the Colorado River in southwestern Arizona. 
DeSmet said that the feet were the most dainty parts, and 
that the tail afforded a substitute for butter. 


Beaver farming is a subject of which I must confess a lack 
of personal knowledge, nor do I know of anyone who has 
had any experience, at least for any length of time, in the 
occupation of raising beavers for their fur. 

It is at least theoretically possible to procure some beavers, 
place them in an enclosure where there is water, also trees 
or bushes suitable for food, allow them to multiply, and 
when the time comes, kill a number and market their 
pelts. Whether this can be done profitably remains to be 

The Biological Survey of the United States Department of 
Agriculture has published a bulletin by Vernon Bailey in 


which the subject of beaver farming is taken up, and in which 
helpful suggestions are given. 

The important thing in establishing a beaver farm is to 
have a sure supply of water, a pond, lake or stream which can 
be enclosed in some way so as to prevent the escape of the 
animals. The water should be of such a depth naturally, 
or the situation such that the beavers can, by damming, 
make the water deep enough to prevent freezing to the 
bottom. Growing trees or bushes for a food supply would 
be a great advantage, though perhaps not essential. Brush 
might be cut elsewhere and placed in the enclosure, and also 
other food supplied. Willows grow fast, and quickly re- 
place themselves after cutting. 

The matter is one which is well worth trying out in an 
intelligent manner, but whoever undertakes it must be 
prepared to w^ait several years, very possibly as many as ten, 
before he will really know whether or not he has embarked in 
a profitable enterprise. 

Things That a Beaver Does Not Do 

The beaver has been credited with — or shall I say accused 
of? — doing many preposterous things, and other things 
which, while not preposterous, it would be rather foolish 
to believe. All sorts of queer stories have been told about 
the animal, some without anything in the way of a reason 
for their being. 

It is a popular notion that a beaver works all the time. 
No such thing. He is too wise to do anything so foolish. 
He works when he has to, and works hard then. But he 
hkes to loaf and play, and I suspect spends a lot of time doing 
so. Perhaps this goes to show^ his intelligence. 

The tail is not used as a trowel, to drive stakes with, or as 
a sled to carry mud or other materials upon. 

He is not a weather prophet, he can not foretell whether 
or not next winter will be a hard one. 

He does not suck the air from wood in order to make it 
sink. Anyone who would take the trouble to observe the 
size of a beaver's mouth would at once see how ridiculous 
such a notion is. 

He does not fell trees across a stream in order to construct 
dams against them. In a certain book for young folks about 
the beaver, one chapter has an entertaining account of how 
a pair of young beavers started out to make a home for 
themselves. How they traveled up the stream looking for 
a place where a dam could be built and a pond formed, is 
graphically told. At last they came to a place which suited 
the bridgegroom, who apparently was the more experienced 
of the couple. He first felled a tree on one bank so that it 



dropped across the stream, its branches hanging in the water. 
Then he went over to the other side and cut another tree so 
that it fell into the water just above the first, when it drifted 
down against the latter, and their branches became en- 
tangled, making a fine beginning for a dam. All very nice, 
but I suspect the author made liberal drafts upon his imag- 
ination in wTiting that story, for it is just the way a beaver 
does not go about building a dam. 

Beavers eat no fish or other animal food. 

When caught in a steel trap a beaver does not gnaw its 
foot off, but twists it round and round in its struggles to 
escape until it finally pulls the foot off. It is always the 
fore foot which is thus amputated, and the act is accidental, 
not intentional. 

Beavers do not gnaw a tree partly through, and then wait 
for the wind to blow it down. 

A beaver does not sleep in the lodge with its tail in the 
water so as to have warning of a break in the dam by the 
consequent drop in the water level. Yet I have seen a 
statement to this effect in a paper of large circulation. 

John Bradbury, an Englishman who traveled in the west 
in 1809, 1810 and 1811, in speaking of the knowledge of the 
hunters of the various animals concerning their habits, says : 
^^They state that an old beaver, who has escaped from a 
trap, can scarcely ever afterwards be caught, as traveling in 
situations where traps are usually placed, he carries a stick 
in his mouth, with w^hich he probes the sides of the river, 
so that the stick may be caught in the trap.'' 

The hunters also said that the young beavers are educated 
by the old ones. "It is well known that in constructing 
their dams, the first step the beaver takes is to cut down a 
tree that shall fall across the stream intended to be dammed 
up.'' Same old story! The hunters said they often found 
trees partly cut and abandoned, and these would not have 


fallen across the creek. Tooth-marks on the stumps showed 
the work was done by young beavers. The old ones made 
them stop because the tree would not fall over the water. 
The trappers showed Bradbury. 

Father DeSmet in 1843 said: When they are about con- 
structing a dam, they examine all the trees on the bank, 
and choose one that is most bent over the water on the side 
where they want to erect their fort. If they find no tree of 
this kind they repair to another place, or patiently wait 
until a violent wind gives the requisite inclination to some 
of the trees. 

If one wishes he can find opportunities for nature faking 
stories as he studies the beaver's work and chooses to tmst 
what he sees to suit his own purposes. 

I happened on a chance of the sort in the Yellowstone 
one day. Two aspen trunks growing from one root had 
been cut partly through from opposite sides and had fallen 
in opposite directions. Not far from them another aspen 
had also been partly cut and had fallen. An unusually 
large aspen had fallen so that it lay over the single stump 
and between the other two. This large aspen had been so 
much decayed that only a shell of green wood was left on 
one side, and when this was cut the tree had fallen, and had 
happened to drop as I have described. An examination of 
the various logs showed that the large tree had not fallen 
until after the others, for these showed no marks which the 
large tree would undoubtedly have made if it had fallen 
first and brought the others down with it. 

Now if I were a real good nature faker I might tell about 
it in this fashion: 

Old Paddy Beaver was taking a look about his premises 
one day and came across these two aspens groT\dng from one 
root, noticed the other, also the big one. He saw how httle 
work it would take to fell the latter and that it leaned in 


just the right direction to fall upon the other three. He said 
to himself, ^'Well, here's a chance to make a good killing 
with mighty little work. All I have to do is to cut those 
three trees partly through, a few bites will drop that big 
one right on them, and down they will come. That's dead 

So Paddy hustled out his gang of lumberjacks and put 
them to work while he stood around, bossed the job, and 
looked wise. The boys cut a little into one side of each of 
the smaller trees, then a little work on the proper side of the 
big one, and down it came just as Paddy had figured it would, 
and carried the other three with it in its downfall. 

Paddy strutted around, looked almost as big as he felt 
and remarked, ''You see, boys, it pays to have a good head 
on your shoulders. Now get busy and trim those trees and 
cut them into lengths." 

All of which is just what did not take place. 


Following is a list of books and articles relating to the beaver, most of 
which have been referred to in the preceding pages. It makes no pretence 
of being complete. 

Audubon, Maria R. Audubon and his Journals. With Zoological and 
other notes by Elliott Coues. New York : Charles Scribner's Sons. 

Bailey, Vernon. Two New Subspecies of North American Beavers. 
Proc. Biol. Soc. of Washington, vol. 16, Oct. 23, 1913. 

Wild Animals of Glacier National Park. The Mammals. U. S. 

Dept. Interior, National Park Service. 1918. 

Beaver Farming. Journal of Heredity, vol. 13, no. 7, pp. 315- 

318. July, 1922. 

Beaver Habits, Beaver Control, and Possibilities in Beaver Farm- 
ing. U. S. Dept. of Agriculture, Bulletin no. 1078. 1922. 

— The Combing Claws of the Beaver. Journal of Mammalogy, 

vol. 4, no. 2. May, 1923. 

— ■ — ■ • How Beavers Build Their Houses. Journal of Mammalogy, vol. 

7, no. 1. February, 1926. 

Bailey, Vernon, and Florence Merriam Bailey. Johnny and Paddy, 
Two Baby Beavers. Nature Magazine. January, 1923. 

Barrett-Haaolton, Gerald E. H., and Martin A. C. Hinton. A His- 
tory of British Mammals. Part 20, pp. 670-678. History and past 
distribution of the beaver. 1921. 

Berry, S. Stillman. Observations on a Montana Beaver Canal. Journal 
of Mammalogy, vol. 4, no. 2, pp. 92-104, May, 1923. Also reprinted 
in Smithsonian Report for 1922, pp. 297-308 (pub. No. 2735). 1924. 

Bradbury, John. Travels in the Interior of America, in the Years 1809, 
1810 and 1811, including a Description of Upper Louisiana, to- 
gether with the States of Ohio, Kentucky, Indiana and Tennessee, 
with the Illinois and Western Territories. Second Edition. 
London: Sherwood, Neeley and Jones. 1819. 

Brooks, A. B. Reappearance of Beavers in West Virginia. Journal of 
Mammalogy, vol. 4, no. 3. August, 1923. 

Chittenden, Hiram Martin. The American Fur Trade of the Far West. 
A History of the Pioneer Trading Posts and Early Fur Companies 
of the Missouri Valley and the Rocky Mountains and of the Over- 
land Commerce with Santa Fe. Map and Illustrations. New 
York: Francis P. Harper. 1902. 



DeSmet, p. J. Letters and Sketches: with a Narrative of a Year's Resi- 
dence among the Indian Tribes of the Rocky Mountains. Phila- 
delphia: M. Fithian. 1843. 

DoMMiNK, G. Some Impressions of Ranger Life in Winter. Nature Notes 
from Yellowstone Park [Mimeographed serial], vol. 3, no. 1. 
January 2, 1926. (A page on the activity of beaver on Hellroaring 

DuGMORE, A. Radclyffe. The Romance of the Beaver, being the History 
of the Beaver in the Western Hamisphere. Philadelphia: J. B. 
Lippincott Co. 1914. 

Farnham, Thomas J. Travels in the Great Western Prairies, with the 
Anahuac and Rocky Mountains, and in the Oregon Territory. 
London : Richard Bentley. 1843. 

Franchere, Gabriel. Narrative of a Voyage to the Northwest Coast of 
America, in the Years 1811, 1812, 1813 and 1814, or the First Ameri- 
can Settlement on the Pacific. Translated and edited by J. V. 
Huntington. New York: Redfield. 1854. 

Goodwin, George G. The American Beaver. Nature Magazine, vol. 5, 
no. 4, pp. 217-219. April, 1925. 

Grinnell, George Bird. Jack, the Young Trapper. New York: Stokes. 

■ The Cheyenne Indians, Their History and Ways of Life. New 

Haven: Yale University Press. 1923. 

Grinnell, Joseph. An Account of the Mammals and Birds of the Lower 
Colorado Valley, with especial Reference to the Distributional 
Problems involved. Univ. of California Pub. in ZooL, vol. 12, 
no. 4, pp. 51-294. 1914. 

Harris, James. Report of Warden James Harris on Winter Conditions in 
"Lake Superior Game Refuge." Fins, Feathers and Fur. March, 

Hawkins, Chauncey J. Little Builders of the Stream. Country Life in 
America, vol. 24, no. 5. September, 1913. 

Hay, Oliver P. The Pleistocene Mammals of Iowa. Iowa Geological 
Survey, vol. 23 (Annual Report, 1912). 1914. 

Hearne, Samuel. A Journey from Prince of Wales's Fort, in Hudson's 
Bay, to the Northern Ocean. Undertaken by order of the Hud- 
son's Bay Company. For the Discovery of Copper Mines, a North- 
west Passage, &c. In the Years 1769, 1770, 1771, & 1772. 1795. 

Henry, Alexander. The Manuscript Journals of Alexander Henry, Fur 
Trader of the Northwest Company, and of David Thompson, 
Official Geographer and Explorer of the same Company. 1799- 
1814. Edited by Elliott Coues. New York: Francis P. Harper. 
1897. (Vol. 1, Footnote on disease among beaver.) 


HiNTON, Martin A. C, and Geeald E. H. Barrett-Hamilton. A History 
of British Mammals. See reference under Barrett-Hamilton. 

HoLDEN, F. H. Osteological Relationships of Three Species of Beavers. 
Univ. of California Publ. in Zool., vol. 17, no. 8, pp. 75-114. 1917. 

Howell, Arthur H. A Biological Survey of Alabama. North American 
Fauna no. 45. Part I, Physiography and Life Zones. Part II, 
The Mammals. U. S. Dept. Agriculture, Biological Survey. 1921. 

Johnson, Charles E. An Investigation of the Beaver in Hamilton and 
Herkimer Counties of the Adirondacks. Roosevelt Wild Life Bul- 
letin, vol. 1, no. 2, pp. 117-186. 1922. 

Lange, D. The Forest Where the Mississippi Begins. American Journal 
of Forestry, vol. 28, no. 348. 1922. 

Leet, E. D. New York's Beaver Problem. American Forestry, April, 
1923, p. 199. 1923. 

Lewis and Cla.rk. Original Journals of the Lewis and Clark Expedition, 
1804-1806. Edited by Reuben Gold Thwaites. In 7 volumes. 
New York: Dodd, Mead & Co. 1904. (Vol. 2, account of Lewis's 
dog being bitten by beaver.) 

MacFarlane, Roderick. Notes on IMammals collected and observed in 
the Northern Mackenzie River District, Northwest Territories of 
Canada, with Remarks on Explorers and Explorations of the Far 
North. By R. MacFarlane, Chief Factor, Hudson's Bay Co. 
Proc. U. S. Nat. Mus., vol. 28, pp. 673-764. Washington. 1905. 

Martin, Horace T. Castorologia, or the History and Traditions of the 
Canadian Beaver. London: Edward Stanford; Montreal: Wm. 
Drysdale & Co. 1892. 

Maximilian, Prince of Wied. Travels in the Interior of North America. 
With Nimaerous Engravings on wood, and a large map. Trans- 
lated from the German by H. Evans Lloyd. London: Ackerman 
and Co. 1843. 

Mills, Enos A. The Spell of the Rockies. Boston: Houghton Mifflin Co. 

In Beaver World. Boston & New York: Houghton Mifflin Co. 


— The Rocky Mountain Wonderland. Boston & New York: 

Houghton IMifflin Co. 1915. 
•— Waiting in the Wilderness. New York: Doubleday, Page & Co. 


Watched by Wild Animals. New York and Toronto: Double- 
day, Page & Co. 1922. 

Wild Animal Homesteads. New York: Doubleday, Page & Co. 

Morgan, Lewis H. The American Beaver and His Works. Philadelphia: 

J. B. Lippincott & Co. 1868. 


Newberry, John S. Report on Zoology. Pacific R. R. Report, vol. 6, 

pp. 58-59. 1856. 
NuTTALL, Thomas. A Journal of Travels into the Arkansa Territory, 

during the Year 1819. With occasional observations on the man- 
ners of the aborigines. Illustrated by a map and other engravings. 

Philadelphia: Thos. H. Palmer. 1821. 
Pattie, Jaivies O. The Personal Narrative of James 0. Pattie of Kentucky, 

during an Expedition from St. Louis through the Vast Regions 

between that place and the Pacific Ocean, and thence back through 

the City of Mexico to Vera Cruz, during journeyings of six years. 

Edited by Timothy Flint. Cincinnati: John R. Wood. 1831. 
Riley, Smith. Fur Culture in the National Forests. Journal of Forestry, 

vol. 19, no. 6. October, 1921. 
Rose, Frank H. Colorado Beaver. Bulletin of the Colorado Fish & 

Game Protective Association, vol. 3, no. 3. Denver. August, 1923. 
Ross, Alexander. Adventiu-es of the First Settlers on the Oregon or 

Columbia River: Being a Narrative of the Expedition fitted out 

by John Jacob Astor to establish the "Pacific Fur Company;" 

With an account of some of the Indian tribes on the coast of the 

Pacific. London: Smith, Elder & Co. 1849. 
Sawyer, Edmund J. Beaver. Nature Notes from Yellowstone Park 

[Mimeographed serial], vol. 2, no. 2. April 29, 1925. (Remarks 

on the beaver in the park.) 
Seton, Ernest Thompson. Life Histories of Northern Animals. Two 

volumes. New York: Charles Scribner's Sons. 1909. 
■ Wild Animals at Home. New York: Doubleday, Page & Co. 

Sheldon, Charles. The Wilderness of the Upper Yukon. New York: 

Charles Scribner's Sons. 1911. 
Shiras, George, 3rd. The Wild Life of Lake Superior, Past and Present. 

National Geographic Magazine, vol. 40, no. 2. August, 1921. 
SFtanley], D. S. The Wolverene. American Naturalist, vol. 2, no. 5, 

p. 215. June, 1868. (Notes on beaver.) 
Taylor, Joseph Henry. Beavers: Their Ways and Other Sketches. 

Washburn, North Dakota. 1904. 
Taylor, Walter P. The Beaver of West Central California. Univ. of 

California Publ. in Zoology, vol. 10, no. 7. pp. 167-169. 1912. 
The Status of the Beavers of Western North America, with a 

Consideration of the Factors in their Speciation. Univ. of Calif. 

Publ. in Zoology, vol. 12, no. 15, pp. 413-495. March 20, 1916. 
TowNSEND, John K. Narrative of a Journey across the Rocky Mountains, 

to the Columbia River, and a Visit to the Sandwich Islands, Chili, 

&c. With a Scientific x\ppendix. Philadelphia: Henry Perkins; 

Boston: Perkins & Marvin. 1839. (Journey made in 1833-34.) 


Warren, Edward R. Some Interesting Beaver Dams in Colorado. Proc. 
Washington Acad. Sciences, vol. 6, pp. 429-437. 1905. 

The Life of the Yellowstone Beaver. Roosevelt Wild Life Bulle- 
tin, vol. 1, no. 2, pp. 187-221. Syracuse, New York. August, 1922. 

The Beaver in the Yellowstone National Park. Notes on the 

Beaver in Estes Park, Colorado. Roosevelt Wild Life Annals, 
vol. i, nos. 1-2, pp. 1-231. Syracuse, N. Y. October, 1926. 

Williams, Ira A. — An Unusually fine Example of Beaver Industry. Nat- 
ural History, vol. 25, no. 6, pp. 593-601. 1925. 


age of beaver work, 50. 

age when leaving lodge, 134. 

albinos, 2. 

ancestry, 12. 

Aplodontia, 153. 


bait, 146. 

bank beaver, 78. 

beaver, bank, 78. 

derivation of word, 22. 

distribution in North America, 17. 

distribution in Old World, 19. 

European, 13, 17. 

extinction in Great Britain, 22. 

history, 22. 

place names, 20. 

weight, 8. 
beaver farming, 164. 
beaver skins, 157. 

early trade, 157. 
number sold, 158. 
price, 159. 

number sold at New York sales, 

prices in recent years, 158. 

symbolical significance, 23. 

weight, 158. 
bobcats killed by beaver, 151. 
breeding habits, 132. 
burrows, 78. 

length, 79. 


Cambrensis, Geraldus, account of, 

canals, 80. 

different levels, 82. 

length, 80, 84. 

origin, 88. 

uses, 80. 
Capybara, 1 . 
Castor, 12, 13. 

geological age, 40. 
Castor cacaetor, 16. 
Castor canadensis belugae, 16. 
Castor canadensis canadensis, 16. 
Castor canadensis carolinensis, 16. 
Castor canadensis frondator, 16. 
Castor canadensis -leucodonta, 16. 
Castor canadensis mexicanus, 16. 
Castor canadensis michiganensis, 

Castor canadensis pacificus, 16. 
Castor canadensis phaeus, 16. 
Castor canadensis texensis, 16. 
Castor fiber, 13, 17. 
Castor subauratus shastensis, 16. 
Castor subauratus subauratus, 16. 
castoreum, 146, 162. 

analyses, 163. 

production, 162. 

sacs, 11. 
Castoridae, 12. 
Castoroides, description, 14. 

geological age, 13. 

habits, 15. 

where found, 13. 
clav/s, 6. 

close seasons, 160, 161. 
Coleoptera, 153. 
color, 1. 
corn eaten 105. 





dam, 28. 

agricultural value, 52. 

construction, 28. 

curvature, 34, 43. 

diversion, 46. 

fallen logs, 33. 

height, 41. 

length, 35. 

location, 44. 

materials used, 33, 43. 

petrified, 33. 

solid bank dam, 44. 

spillways, 43. 

stick dam, 44. 

uses, 51. 
damage, 55. 

to timber by flooding, 55. 

cutting timber, 56. 
deBarri (see Cambrensis), 22. 
Dipoides, 13. 
disease, 152. 
disposition, 150. 
distribution in North America, 17. 

in Old World, 19. 
draining ponds, 46. 


ears, 5. 
enemies, 146. 
European beaver, 17. 
eyes, 5. 


farming, beaver, 164. 
flooding, 50, 55. 
food, 104. 

bark, 128. 

conifer bark, 124, 127. 

grass, 131. 
food piles, 121. 

how collected, 122. 
fore paws, 5. 
forms, 93. 

foster parentage, 136. 
fur, 157. 


genital organs, 8. 
gestation, 132. 
giant beaver, 12, 13. 
glands, 11. 

castoreum, 11. 

oil, 11. 


hind foot, 6. 
home life, 136. 

Indian legends, 23. 

Indian method of capturing beaver, 

intelligence, 24. 

landing places, 93. 
length of life, 137. 
Leptinillus aplodontia, 153. 
Leptinillus testaceus, 153. 
Leptinillus validus, 153. 
lodge, 58. 

bank, 58, 73. 

bedding material, 72. 

burrows, 78. 
length, 79. 

construction, 61, 69, 70, 71, 

covering in autumn, 70. 

false, 74. 

interior, 62. 

island, 61. 

kinds, 58. 

number of beavers in, 72. 

number to pond, 70. 

size, 66, 72. 

slides, 72. 




Mallophaga, 153. 
meadows, beaver, 95. 

materials, 103. 

time of formation, 96. 
meat, use as, 163. 
Moraine colony, 50. 
mud pies, 146. 
musk bogs, 146. 


nostrils, 5. 


open season, 161. 

parasites, 153. 
petrified dams, 33. 
plant food, 105. 
Platypsyllus castoris, 153. 
polygamy, 133. 
popular beliefs, 166. 


races, 16. 

relation to fishing, 154. 

to bird life, 155. 
rutting season, 138. 


sign heaps, 146. 
spillways, 43. 

Steneofiber, 12. 
stumps, 109, 110. 
swimming, 138. 

floating, 141. 

speed, 138. 

use of tail, 139. 

tail, 2. 

as trowel, 166. 

description, 2. 

slapping water, 139. 

use, 5. 
teeth, 7. 
toes, 4. 
trails, 87, 88. 

markings by brush, 93. 
tree cutting, 104. 

size of trees cut, 110, 117. 

time required, 117. 

when done, 121. 
trees as food, 104. 
Trogontherium, 12. 
Trogontherium cuvieri, 12. 


underground passage, 94. 


voice, 145. 


walking, 141. 

water conservation, 51. 

weight, 8. 

Sans Tache 

Sans Tache 

IN THE ^^elder days of art" each artist or craftsman 
enjoyed the privilege of independent creation. He 
carried through a process of manufacture from begin- 
ning to end. The scribe of the days before the printing 
press was such a craftsman. So was the printer in the da^^s 
before the machine process. He stood or fell, as a crafts- 
man, by the merit or demxerit of his finished product. 

Modern machine production has added much to the worker's 
productivity and to his material welfare; but it has deprived 
him of the old creative distinctiveness. His work is merged 
in the work of the team, and lost sight of as something 
representing him and his personality. 

Many hands and minds contribute to the manufacture of a 
book, in this day of speciahzation. There are seven dis- 
tinct major processes in the making of a book: The iy^Q 
must first be set; by the monotype method, there are two 
processes, the "keyboarding" of the MS and the casting of 
the t}T)e from the perforated paper rolls thus produced. 
Formulas and other intricate work must be hand-set; then 
the whole brought together (^^composed") in its true order 
made into pages and forms. The results must be checked by 
proof reading at each stage. Then comes the ^ ^make- 
ready' ' and press-run and finally the binding into volumes. 

All of these processes, except that of binding into cloth or 
leather covers, are carried on under our roof. 

The motto of the Waverly Press is Sans Tache. Our ideal 
is to manufacture books ^^ without blemish' ' — worthy books, 
worthily printed, with worthy typography — books to which 

we shall be proud to attach our imprint, made by crafts- 
men who are wilhng to accept open responsibility for their 
work, and who are entitled to credit for creditable 

The printing craftsm^an of today is quite as much a crafts- 
man as his predecessor. There is quite as much discrimina- 
tion between poor work and good. We are of the opinion 
that the individuality of the worker should not be wholly 
lost. The members of our staff who have contributed their 
skill of hand and brain to this volume are : 

Composing Room: William Sanders, Edgar Simmons, Anthony Wagner, 
Andrew Rassa, Austin Uhland, Ernest Salgado, Nathan Miller, Arthur 
Baker, Herbert Leitch, Edward Rice, Richard King, Theodore Nilson, 
George Moss, V*^alter Phillips, Henry Shea. 

Proof Room: Sarah Katzin, Alice Reuter, Mary Reed, Ruth Treischman, 
Ethel Strasinger, Lucille Bull, Angeline Eifert, Audrey Tanner, Dorothy 
Strasinger, Lillian Gilland, Geraldine Browne, George Southworth, Ida 
Zimmerman, Catharine Miller. 

Press: Clarence Ridgeway, Robert S. Gallagher, Raymond Gallagher, 
Fred Lucker. 

Cutter: William Armiger. 

Keyboard: Anna Rustic, Harry Suseui^hl, Eleanor Luecke, Vera Taylor. 

Casters: Ernest Wann, Kenneth Brown, Mahlon Robinson, Charles 
Aher, George Smith, Frank Malanosky, Martin Griffen, Henry Lee, 
Charles Fick, George Buliinger. 

Folder: Laurence Krug, Shipley Bellinger. 



of the Wood Rat 



U. S. Biological Survey 

The comparative anatomy of Genus Neotoma pre- 
sents a complete study, concisely and simply of a 
common mammal; made comparative in order that 
it may be of greater technical value, and that more 
might be learned regarding anatomical variation to 
be expected mthin the closely related groups of 
mammals which are termed sub-genera. A de- 
tailed comparative treatment is provided, and the 
book is copiously illustrated with drawings and 
cuts, some in colors. 

Clothy gold stamped. 6x9. 225 pages. 

Eight color plates. Thirty illustrations. 

Bibliography. Index. 

Price $5.00 

Publishers of Scientific Books and Periodicals