The economy of ground squirrel destruction

UNITED STATES PUBLIC HEALTH SERVICE
RUPERT BLUE, SuRGEON GENERAL

THE ECONOMY OF GROUND SQUIRREL
DESTRUCTION

BY

J. D. LONG
Surgeon, United States Public Health Service

REPRINT No. 238
FROM THE

PUBLIC HEALTH REPORTS

DECEMBER 11, 1914

WASHINGTON
GOVERNMENT PRINTING OFFICE
1915
lidonograph

or DOF
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THE ECONOMY OF GROUND SQUIRREL DESTRUCTION.'

By J. D. LoneG, Surgeon, United States Public Health Service.

Every farmer or rancher who has had to contend with ground
squirrels, gophers, or similar pests, has been aware for years that
these animals have caused great losses each year through damage
done by eating or destroying growing crops, such as hay, grain,
fruits, nuts, vegetables, etc.; through damage to young trees, vines,
and other nursery stock or seedlings; through damage to crops and
fields that has resulted from flooding of the land due to breaks in
irrigation ditches and canal banks, such breaks being due, in most
instances, to burrows made into the banks by ground squirrels or
gophers. Further, frequent interruptions to railroad traffic, and
sometimes loss of life, have occurred through cave-ins in railroad
cuts and washouts in embankments that have had their beginning
through flood or surface water finding its way through a ground-
squirrel burrow to a place where damage could result. In addi-
tion, even though washouts did not occur, subsidence of ties and
rails took place, due to individual burrows or colonies caving in,
with resulting increase in maintenance-of-way charges and repairs
to rolling stock and rails, due to pounding, and on rail ends and
joints. '

In California, from July 1, 1913, to November 1, 1914, the Public
Health Service has caused ground squirrels to be reduced about 90
per cent over an area of 3,373,146 acres, which includes about 2,009
miles of railroad right of way. The average cost for labor and
materials has been about 17.4 cents per acre, and the average infesta-
tion has been about 6.5 squirrels per acre. From the above it is
estimated that about 21,925,449 ground squirrels have been destroyed.
As a result of the above-described operations, it is believed that
bubonic plague has, for all practical purposes, been eradicated from
the State of California and that any further danger of its spread
has been removed.

During the progress of this work of squirrel destruction so many
comments were made by farmers, landowners, ranchers, and others

1 Reprint from the Public Health Reports, vol. 29, No. 50, Dee. 11, 1914.
73398°—15 (3317)

December 11, 1914 3318

as to the savings that had resulted, that it was decided to make
an attempt to collect data and see if any reliable conclusions could
be drawn from the replies sent in. To this end a circular letter was
addressed to supervising inspectors in charge of the various counties,
accompanied by a supply of blank forms to be filled out by farmers,
ranchers, and others. The circular letter and blank form are given

below:
[Cireular letter. ]

UNITED States PuBLic HEALTH SERVICE,
111 New MontTGoMeERY STREET,
San Francisco, Cal., September 24, 1914.
To Supervising Inspectors:

There are forwarded you, under separate cover, 250 blank forms, which you
are directed to apportion between yourself and your field inspectors.

These blanks are to be taken to those landowners in the various districts
who have effected practical squirrel destruction, with the request that for the
good of the work and in the interest of its future continuance the questions on
the blanks be filled out as accurately as may be possible and the blanks signed.

All the information furnished will be considered aS CONFIDENTIAL as far as
individuals are concerned, and only the total results of the investigation in each
county will be used. Names of individuals will not be given out except by
consent, as indicated on the blanks.

Signature is desired only as evidence of the authenticity of the TapOretE

Instruct your field inspectors to render such assistance in filling out the blanks
as may seem necessary or desirable, in order that the information obtained may
be as nearly accurate as possible.

Supervising inspectors are directed to forward all complete blanks to head-
quarters as soon as they are received, in order that the compilation of the
information may be proceeded with at once.

(Signed ) J. D..Lone,
Surgeon in Charge Field Operations and Laboratory.

[Blank form. ]

PO 3 CE ee je die

It is requested that landowners and others supply the following information
in order that the economic benefits of squirrel destruction may be more clearly
known and in order that actual data on this subject may be compiled.

Give figures as nearly accurate as possible on property controlled by you.
Location of property: T_---, Rese Seclerake Ol 2-2 see grant.
Ls afoy erai) UCN) sts eam 9 ee ee ee eae eee
Number of acres under cultivation === eee
INumbeniof acres inspastune 22S
Number ofvacres ‘wooded iss2e2 2) 2 aulte eee ee oe ee eee

KANdeO fiCl0 De ee
Method) usedstovdestroysQUILne] S52 = ne ee ee

3319 December 11, 1914

Amount of money expended in squirrel destruction (labor and material) $_-_____
Estimated increase in crops due to the destruction of squirrels, as compared to
PLevVioUusEyecaLsE@nstons- OF Pounds) Of Crops)/-22—2- 22s es

PASTURE LAND.

Methodeuseds toga eStroy, SQUILTel sie hse 2 a ee
Amount of money expended in squirrel destruction (labor and material) $_____-
How much has your pasture land increased in yalue, due to the destruction of

REMARKS.

Under this heading give any other benefits that may have resulted from the
destruction of squirrels, such as saving on repairs to canals or irrigation-ditch
banks, savings on young trees or nursery stock, or on grain or other products
that may have been stored for future use.

My name may be referred to in connection with this report, if deemed neces-

sary.
(If it is desired that the name of the signer is not to be referred to, cross out

the preceding sentence.)
(Sione heres) es ae eee Ce ee ee ee

From September 24, 1914, to November 1, 1914, 497 replies had
been received. The information given had apparently been care-
fully compiled, and is believed to be as accurate as can be obtained.

Only the increase in crop is taken into consideration, this increase
being figured on the basis of the average crop for preceding years,
when ground squirrels were present and taking their annual toll.

The 497 replies received represent a total area of 321,233 acres;
the total sum reported as expended for squirrel destruction over this
area amounted to $36,091.85, or an average of 11.2 cents per acre;
the value of the savings realized over this area from the destruction
of ground squirrels amounted to $109,301.50, or an average saving
of 34 cents per acre, which represents a return of 303.5 per cent in
the first year.

To illustrate the savings on each particular type of crop or in-
dustry, the following figures, taken from the returns as compiled,
are given:

December 11, 1914 3320

Cultivated Lands.

ii(dspersons saved: 1:746 tons: Of shays= =o aaa ee value__ $15, 890. 50
249) persons*saved 2415.4 tonstof grain ats eee do__.. 50, 144.50
(Oepersons= saved! 208)" tOnS Of y fhUi tse es eee ee do__.. 5, 338: 50
1D: Persons: saved! =18;395" pounds of mutts === saa aa eee eee do-.._ 1,882.00
36 persons saved 287 tons of vegetables____________________ do_--- 4,026.00

Three hundred and seventy of the above persons estimated that
their land had increased in value $2.74 per acre as a direct result of
squirrel destruction. (This figure of $2.74 per acre increase in value
has not been included in the total savings of $109,301.50 given above.)

Pasture Lands.

One hundred and fifty-two persons reported that 2,163 more head
of cattle could be pastured on 150,845 acres of pasture land than
could be pastured before squirrels were destroyed, or 1 additional
horse or cow to each 69.7 acres of pasture. This saving alone, esti-
mated at the usual figure of $1 per month per head, represents a
saving of $25,976.

One hundred and sixty-eight persons estimated that their pasture
land had increased in value $1.17 per acre as a direct result of squirrel
destruction. (This figure of $1.17 per acre has not been included in
the total savings of $109,301.50 previously given.)

Various Savings.

Twenty-one persons reported savings of $2,331 in repairs to irri-
gation canal banks, but made no estimate as to losses due to flooding
in previous years. Average saving per person, $111.

Thirty-six persons reported “great savings on repairs to ditch
and canal banks,” but made no estimate of the amount saved.

Twenty-two persons reported savings of $2,188 on young trees, an
average of $99 per person.

Nine persons reported savings of $1,525 on grain and other prod-
ucts that were kept in storage in granaries, etc.; average saving,
$169.44 per person. r

The great majority, under the heading of remarks, expressed their
satisfaction with the results obtained and hoped that the work would
be continued until ground squirrels were entirely eliminated.

It is thoroughly realized by all interested parties that, to obtain
good and satisfactory results of a permanent nature in work of this
character, the Federal, State, and county governments and the people
themselves must work in complete and harmonious cooperation
through some such organization as has been at work during the past
year.

SEyAl December 11, 1914

Summary.
ee liCseBeCe ly Chmeemeen na en oe Se ek Se 497
Amount expended in squirrel destruction on 321,283 acres_________ $36, 091. 85
AMO UM isexpenged: PCr. PersOMs ass 2 ees Tae ee $72. 61
Amount saved as a direct result of squirrel destruction___________ $109, 301. 50
: AGOULLISAVeG) ela DCLSON 2 2 ses ent. Sen nee eee ae. ee es $201. 81
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