BLM LIBRARY

TECHNICAL NOTE 350

U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT

SMALL MAMMALS OF THE BLACK CANYON AND SKULL VALLEY PLANNING UNITS

MARICOPA AND YAVAPAI COUNTIES, ARIZONA

by

William (8. 3{efi<nel,

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SMALL MAMMALS OF THE BLACK CANYON AND SKULL VALLEY PLANNING UNITS,
MARICOPA AND YAVAPAI COUNTIES, ARIZONA

by Wil liam G. Kepner
U.S. Bureau of Land Management
Phoenix District Office

October 1978

Bureau of Land Management

Library

B!dg. 50, Denver Federal Center

Denver, CO 8Q225

TECHNICAL NOTE 350

ABSTRACT

Traditionally, past wildlife habitat management on public lands has
been restricted to game species. Recent policy now dictates that all
BLM-administered lands are to be inventoried for nongame species. The
first nongame inventory was completed during the spring and summer of
1978 on two planning units in central Arizona comprising some 338,000
acres of public land. Vertebrate species were surveyed for relative
density, species diversity, and distribution. During the course of this
study a total of 50 mammal species were either collected or observed.
Trapping methods closely followed that of Calhoun (1951) and more than
18,000 trap nights were accumulated. Relative densities for 19 differ-
ent species collected along trap lines were determined within eight
plant communities of the Sonoran Desert. Distribution and density data
clearly demonstrate the ability of mammal species to overlap habitat and
reveal general trends as to habitat preference. Desertscrub and wash
communities were the most productive habitats for small mammals. They
supported the highest relative densities and the highest number of
species. In contrast, the more mesic habitats, such as riparian
woodlands and interior chaparral, were the least productive habitats
sampled.

ii

ACKNOWLEDGEMENTS

I wish to thank Rick Prigge for his assistance in collecting the
field data. I am extremely grateful to Dr. E. Lendel 1 Cockrum at the
University of Arizona (Tucson) for his aid in the identification of
mammals and for making the museum of mammals and certain literature
available to me. Rodney G. Engard and J. Harry Lehr, Director and
Herbarium Curator of the Desert Botanical Garden (Phoenix), respec-
tively, were responsible for the identification of many of the plants
which occurred on the planning units. Lauren M. Porzer assisted in
critically reviewing this report as it was compiled, and was responsible
for the figures included in the text. Finally, I give special thanks to
Bob Furlow, BLM Phoenix District Office, who first approached me with
the challenge of mammal inventories and allowed me the freedom to pursue
it.

in

TABLE OF CONTENTS

List of Tables v

List of Figures and Appendices vi

Introduction 1

Description of the Study Area 2

Location 2

Topography 2

Climate 2

Vegetation 2

Methods 10

Results 11

Discussion 22

Literature Cited 27

Appendices 30

iv

LIST OF TABLES

Table

1. Mean Daily Maximum and Minimum Temperatures for

the Months of April through August in °F 4

2. Monthly Temperature Extremes for Spring/Summer

1978 in °F 5

3. Precipitation Normal, Actual, and Departure from

Normal in Inches for Spring/Summer 1978 6

4. Mammal Species Collected April 1978 through

August 1978 12

5. Mammal Species Observed April 1978 through

August 1978, but not Collected 14

6. Small Mammal Densities for Each Major Vegetation

Community 15

7. Total Catch Percentages and Habitat Selection of

the Mammal Species Collected by Snap Trapping 16

8. Small Mammal Densities for the Sonoran Desert

scrub Communities 18

9. Small Mammal Densities for Desert Grassland

Communities 20

10. Total Relative Density and Habitat Utilization of

the Most Frequently Collected Species 25

LIST OF FIGURES AND APPENDICES

Figure

1. Location of Skull Valley and Black Canyon

Planning Units, Yavapai and Maricopa Counties 3

2. Comparison of Relative Densities and Number of
Species for the Eight Major Vegetative Communities

within the Black Canyon/Skull Valley Planning Units ... 23

3. Comparison of Relative Densities for the Four Most
Frequently Collected Species in Eight Standard Habitat
Sites within the Black Canyon/Skull Valley Planning

Units 24

Appendix

1. Locations and Elevations of Recording Stations Used

for Climatological Data 30

2. Black Canyon/Skull Valley Standard Habitat Sites .... 31

3. Black Canyon Planning Unit Mammal Transect

Localities 32

4. Skull Valley Planning Unit Mammal Transect

Localities 36

5. Mammal Species Potentially Inhabiting the Black
Canyon/Skull Valley Planning Units, but Unreported

During the Sample Period 37

VI

INTRODUCTION

The vertebrate fauna (excluding Osteichthyes) of the Black Canyon
and Skull Valley Planning Units was surveyed during the spring and
summer of 1978 for relative density, species diversity, and
distribution.

Traditionally, past wildlife habitat management on public lands has
been restricted to game species. Recent legislation dictates that all
BLM-administered lands are to be inventoried for nongame species. The
Integrated Habitat Inventory and Classification System (IHICS) is the
current wildlife data collecting and habitat analysis system for envi-
ronmental assessment of wildlife resources and management of public
lands. It is to serve as the baseline information source at the policy
maki ng level .

DESCRIPTION OF THE STUDY AREA

Location. The survey was conducted on two BLM-administered planning
units northwest of Phoenix in Maricopa and Yavapai counties. Together
the Black Canyon and Skull Valley Planning Units comprise 338,000 acres
of public land, 256,000 acres and 82,000 acres respectively (Fig. 1).

Topography. Topography within the two planning units varies from
desert flatlands, foothills, and mesas, to low elevation mountains.
These landforms are highly dissected by intermittent drainages
throughout the study area and many form narrow canyons of high relief.
Soils vary from fine alluvial sediments to large granite pegmatites.
Elevation ranges from approximately 1,200 to 5,800 feet.

Climate. The study area is characterized by a warm, arid climate
typical of the Sonoran Desert. Total annual precipitation is variable,
but generally follows the bimodal pattern of winter and summer
precipitation with spring and fall drought. Table 1 shows the mean
daily maximum and minimum temperatures for the months of April through
August from four recording stations located within the planning units.
Locations and elevations of climatological stations are given in
Appendix 1. Daily temperatures fluctuate greatly as exemplified in
actual monthly highs and lows recorded during the time of study and
1 isted i n Table 2.

Considerable disparity exists in comparing the monthly preci-
pitation during the 1978 study period to the mean monthly precipita-
tion records (Table 3). The 1978 hydrological cycle can best be des-
cribed as an atypical year with higher than normal winter and spring
precipitation. In contrast, summer precipitation recorded for the four
stations was well below the annual norm.

Vegetation. The Black Canyon and Skull Valley Planning Units
intergrade the Upper and Lower Sonoran Life-zones. Eight plant
communities and eleven standard habitat sites were encountered within
the two life-zones (Lowe and Brown 1973).

Upper Sonoran Life-zone
Chaparral Community
Desert Grassland Community

Lower Sonoran Life-zone

Sonoran Desertscrub
Lower Colorado Community
Arizona Upland Community

Fig. 1, LOCATION OF SKULL VALLEY AND BLACK CANYON PLANNING UNITS,
YAVAPAI AND MARICOPA COUNTIES.

1 inch = 50 miles

TABLE 1. MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURES FOR THE MONTHS
OF APRIL THROUGH AUGUST IN °F. *

STATION

MAXIMUM

Cordes

April

72.5

May

81.5

June

90.6

July

95.4

August

92.3

Castle Hot Springs

April

80.7

May

90.2

June

98.7

July

103.3

August

100.4

Wickenburx

April

80.8

May

90.1

June

99.0

July

103.6

August

100.6

Hillside

April

74.4

May

80.1

June

89.8

July

94.5

August

93.3

MINIMUM

42.

,0

49.

,0

56,

,9

65.

,7

64.

.6

51,

.1

59.

.0

68,

,2

76,

.4

74,

.5

43.

.3

49,

.9

57,

,9

69,

,7

68,

.3

39,

.3

43

.8

52,

.8

62,

,4

60

.3

* Arizona Climate 1931-1972, 2nd Edition. William D. Sellers and

Richard H. Hill. University of Arizona Press; Tucson, Arizona 1974.

TABLE 2. MONTHLY TEMPERATURE EXTREMES FOR SPRING/SUMMER 1978 IN °F. *

STATION

MAXIMUM

Cordes

April
May

80
97

June

103

July

104

August

101

Castle

Hot Springs

April

87

May

102

June

108

July

113

August

109

Wickenburg

April

92

May

106

June

113

July

115

August

108

Skull Valley

April

77

May

90

June

97

July

102

August

96

MINIMUM

32
36
50
54
54

39
46
58
67
68

34
42
45
50
50

27
32
40
44

47

* Arizona Climatological Data, Monthly Summaries, National Oceanic and
Atmospheric Administration, Environmental Data Service, National
Climatic Center; Asheville, North Carolina 1978.

TA3LZ 3. PRECIPITATION NORMAL, ACTUAL, AND DEPARTURE FROM NORMAL IN INCHES
FOR SPRING /SUMMER 1978.

NORMAL ACTUAL DEPARTURE AVERAGE PPT /YEAR

Ccrdes

April

.68

May

.30

June

.29

July

1.77

August

2.54

Castle Hot

Springs

April

.49

May

.17

June

.22

July

1.06

August

2.87

Wickenbure

April

.50

May

.15

June

.17

July

1.21

August

2.24

Skull Valley

April

May

June

July

August

Hillside

April

.97

May

.22

June

.06

July

1.04

August

2.09

.80 +.12

.24 -.06

T -.29 13.54

.99 -.78

1.70 -.84

.72 +.23

.33 +.16

-.22 15.07

1.02 -.04

1.57 -1.30

.89 +.39

.25 +.10

-.17 10.77

.36 -.85

.28 -1.96

1.35
.54
T

1.46
.95

13.52

Riparian Deciduous Woodland

Mesquite/Acacia Bosque Community
Mixed Broadleaf Community
Cottonwood/Willow Community
Mixed Riparian Scrub Community

Standard habitat sites are given in Appendix 2.

Chaparral Community. Chaparral generally occurs between 4,000 and
6,000 feet in elevation and where precipitation ranges between 13 and 23
inches annually (Lowe 1964).

Chaparral communities are generally characterized by dense shrubby
growth of low uniform height. Grasses are scarce, except in broken
areas, and plant diversity is low. Scrub oak (Quercus turbinella) is
the most frequently encountered dominant within this community. It
accounted for 28% cover along a representative transect, followed by
buckbrush (Ceanothus greggii) 18%, wait-a-minute bush (Mimosa
biuncifera) 17%, and skunkbush (Rhus trilobata) 14%.

Desert Grassland Community. Desert grassland in Arizona is
generally a mixed grass/shrub type of community that occurs on shallow,
rocky soils between 3,500 and 5,000 feet in elevation. It is one of the
most highly diverse plant communities and often represents a grass-
dominated transition between chaparral above and the desertscrub below.
As a transitional area, desert grassland receives between 10 and 15
inches of precipitation annually. Snakeweed (Gutierrezia sarothrae)
often comprises the highest percentage of cover. For example, in one
transect it represented 29% cover followed by tobosa grass (Hi 1 aria
mutica) 27%, curly mesquite grass (Hilaria belangeri) 17%, and catclaw
(Acacia greggii) 5%.

Sonoran Desertscrub. At lower elevations, desert grassland grades
into the desertscrub of the Lower Sonoran Life-zone. In Arizona, total
annual precipitation and elevation within this zone range from 3 to 11
inches precipitation and from 100 to approximately 4,000 feet in
elevation (Lowe 1964).

Sonoran desertscrub can be further subdivided into two distinct
communities: (1) Lower Colorado desert community, and (2) the Arizona
Upland desert community (Lowe and Brown 1973).

Lower Colorado Community. Lower Colorado desert communities are
most clearly represented by creosote bush (Larrea tridentata) flats in
which trees are usually lacking and shrubs are dominant and widely
scattered. Representative cover values found creosote bush comprising
55% cover and triangle-leaf bursage (Ambrosia deltoidea) at 16%. This
is a climax community which is characterized by alkaline soils of fine
texture within low desert basins.

Arizona Upland Community. Arizona Upland is best represented by
palo verde-saguaro (Cercidium-Cereus) desertscrub. In this community,

plants are comprised of small-leaved trees, as well as shrubs and numer-
ous cacti. Best development is attained on rocky hills and coarse-
soiled slopes, i .e. the bajada, where the substratum is on or near the
parent bedrock material. Plant morphology is highly diverse with leaf-
less, drought deciduous, and evergreen species, thereby making it the
most structurally diverse vegetational community encountered. Community
biomass and productivity are greater here than in the creosote bush
communities on the valley fill of the plains below. Shrubs are more
varied than the trees, and although the foothill understory may be pre-
dominantly of a single species, e.g. triangle-leaf bursage or brittle-
bush (Encelia farinosa), it is often comprised of a mixture of 5 to 15
or more shrub species in the form of a layered understory. Some
representative cover values for a south-facing foothill include the
following: brittlebush 33%, creosote bush 13%, triangle-leaf bursage
11%, foothill palo verde (Cercidium microphyllum) 9%, and saguaro
(Cereus giganteus) at 0%. The low cover value for the saguaro is due to
its vertical growth form and therefore results in low percent cover
values by the line intercept method. Actual importance of saguaro is
probably greater than these low values would indicate.

Riparian Deciduous Woodland. Riparian habitats are distinct biotic
communities associated with perennial or intermittent watercourses.
They are unique reservoirs of plant and animal diversity which extend
from the desertscrub of the Lower Sonoran to the fir forests of the
Canadian Life-zone. These habitats consist of different life-forms or
species other than those of the immediately surrounding nonriparian
climax.

Because riparian communities generally exhibit a predictable
vertical zonation where composition and form of the riparian woodland
changes with elevation, this biome can be subdivided into four major
communities: (1) mesquite/acacia bosque, (2) mixed broadleaf community,
(3) cottonwood/wil low community, and (4) the mixed riparian scrub
community.

Mesquite/Acacia Bosque Community. Mesquite (Prosopis
velutina)/catclaw bosques are vegetated by thick, forest-like stands of
winter deciduous microphylls. Bosques in Arizona are largely restricted
to elevations below 3,500 feet where they attain maximum development on
the alluvium of old flood plains.

Historically, riparian stands were once extensive throughout the
state but have since been reduced or eliminated by past and present land
management. It is estimated that riparian areas in Arizona comprise
only 179,600 acres, of which 100,700 acres are adjacent to the Gila
River (Babcock 1968).

Cover values from a transect located within a mesquite bosque found
mesquite representing 35% cover and catclaw 20%.

Mixed Broadleaf Community. Mixed broadleaf communities are usually
found in Arizona along perennial or seasonally intermittent streams

8

between 3,500 and 6,500 feet in elevation (Brown et al_. 1977). It is
the riparian community that transects chaparral and" is composed of
broadleaf species such as Arizona walnut (Juglans major) , Emory oak
(Quercus emoryi), white oak (Quercus arizonica), and velvet ash
(Fraxinus pennsyl vanica). Cover values obtained from a transect located
along Arrastre Creek were representative for the community. It was
found here that velvet ash represented more than 25% cover, followed by
canyon grape (Vitis arizonica) 17%, Arizona walnut 12%, and Emory oak
11%.

Cottonwood/Willow Community. At elevations below 3,500 feet,
riparian habitats adjacent to desert grassland are generally dominated
by cottonwood (Populus fremontii), Goodding willow (Salix gooddingii),
sycamore (Plantanus wrightii), and net-leaf hackberry (Celtis
reticulata), thereby forming a distinct climax community. A represen-
tative example of cover values obtained from this type of community
found sycamore to be dominant at 18%, followed by velvet ash 15%, and
net-leaf hackberry 11%.

Mixed Riparian Scrub Community. Riparian scrub is the vegetational
community limited to the desert washes or arroyos. Life-form is vari-
able between deciduous microphylls such as members of the leguminosae
(palo verde, mesquite, ironwood, and catclaw) to broader leaved species,
e.g. canyon ragweed (Ambrosia ambrosioides). These communities occur
over a variety of sand to rubble-bottomed substrata along intermittent
drainages. Some representative cover values obtained from a low-desert
wash found wolf berry ( Lye i urn sp.) most frequently encountered at 35%
followed by catclaw 17%, blue palo verde (Cercidium floridum) 10%, and
ironwood (Olneya tesota) 6%.

METHODS

General distribution information on small mammals is available
(Burt and Grossenheider 1952, Hall and Kelson 1959, and Cockrum 1960),
but specific information on densities and distribution of species is
virtually nonexistent for the Black Canyon and Skull Valley Planning
Units.

Small mammals were sampled at 64 separate localities during the
season of highest activity, late spring through summer. Locational
descriptions of the transects are given in Appendix 3 and 4 by section
number and map coordinates. Densities were determined by extensive grid
trapping in the eight major vegetative communities that occur within the
study area. Each grid consisted of two parallel lines 50 feet apart with
15 trapping stations per line. On each line, stations were located 50
feet apart with 3 traps at each station (two museum specials and one rat
trap) totalling 90 traps per grid (modified after Calhoun 1951). Each
grid was trapped three consecutive nights and traps were baited with a
mixture of peanut butter, oatmeal, and dimethyl pthalate, an ant
repellent (Anderson and Ohmart 1977).

Because the area trapped cannot be accurately determined for snap
trapping, small mammal densities for transects are expressed in terms of
captures per trap night, calculated as the number of each species caught
per 270 trap nights (3 consecutive nights x 90 traps set per night).
Relative abundance was estimated from frequency of occurrence for
mammals observed but not trapped along transects, e.g. game animals,
bats, and large-bodied animals which do not lend themsel ves readily to
this method of trapping or size of traps. Additional information on
mammals was obtained through museum records, sight records, observation
of sign, shooting, mist netting, can traps, and selective trapping
either of special habitat features or with special traps, e.g. macabee
gopher traps.

A representative collection of skins and skulls prepared as voucher
specimens from the animals trapped are on deposit at the Phoenix
District Office of the Bureau of Land Management, Museum of Northern
Arizona (Flagstaff), and the University of Arizona, Department of
Ecology and Evolutionary Biology, Collection of Mammals (Tucson).
Identifications followed Jones et al . 1975.

10

RESULTS

Arizona displays a diverse assemblage of southwestern vertebrates;
it supports 134 different mammal species which represent 41.6% of the
total North American mammalian fauna north of Mexico (Hubbard 1977).
During the sampling period of April through August, 1978, a total of 38
species were collected and an additional 12 were observed for the Black
Canyon and Skull Valley Planning Units (Tables 4 and 5).

A total of 64 trapping grids was utilized in the survey (52 on
Black Canyon and 12 for Skull Valley) in which 444 small mammals com-
prising 19 species were collected. Species composition and relative
abundance of the small mammals collected by snap trapping are summarized
in Table 6 for each major plant community. Relative densities were
determined from 16,020 of the accumulated 18,270 trap nights. Trapping
success for the habitat sites considered was estimated at 2.77%.

The most abundant rodent was the white-throated woodrat (Neotoma
albigula) which comprised 23% of the total mammals trapped and was
present in nine out of the eleven standard habitat sites (Table 7).
Other significantly abundant species were the rock pocket mouse
(Perognathus intermedius) which accounted for 20.9%, Merriam's kangaroo
rat (Dipodomys merriami) 13.7%, and the cactus mouse (Peromyscus
eremicus) 11.2%. The remaining 15 species collected from trap lines
were less abundant with percentages ranging from 0.2 to 7.4%.

It should be noted that density values per 270 trap nights listed
in Table 6 and percentage totals in Table 7 are not representative for
the sciurids and leporids. These two families are more abundant than
the figures would indicate, but have been included here for completeness
of data.

Sciurids are diurnal ly active animals and, although snap traps were
set throughout the day, periods of high temperature and low moisture may
have forced the large-bodied rodents into aestivation to reduce heat
stress and water loss. This is already well documented for other
Sonoran Desert rodents where depressed summer activity patterns were
correlated with increased body weight (Reichman and Van de Graaff 1973).
The fact that snap trapping was conducted during an extended period of
elevated air temperatures in an arid habitat, coupled with the fact that
some species because of their size, were not highly vulnerable to snap
traps, may account for the reduced density figures.

Hares and rabbits are active throughout the summer and are
extremely abundant in number, although the relative density figures
would not suggest this. A compound problem exists where preference for
herbaceous and succulent forage may render the bait unattractive to
members of this family in addition to reduced capture due to large body
size.

Mixed riparian scrub displayed the highest total relative density
among all communities sampled (Table 6). Eleven species were collected

11

'aKl ©

MAMMAL SPECIES COLLECTED APRIL 1978 THROUGH AUGUST 1978.

INSECTIVORA, Insectivores
SCRICIDAE, Shrews

Notiosorex crawfordi

:h:?.C?TERA, Bats

PHYLLOSTOMATIDAE, Leaf -nosed bats

Macrotus waterhousi

7ESPERTILI0NIDAE , Plain-nosed bats

Myotis yumanensis
Myotis ve lifer
Myotis thysanodes
Myotis calif ornicus
Pipistrellus hesperus
Eptesicus fuscus
Plecotus townsendi
Antrozous pallidus

MOLOSSIDAE, Free tail bats

Tadarida femorosacca

LAGOMORPHA, Hares and Rabbits

LEPORIDAE, Hares and Rabbits

Lepus calif ornicus
Sylvilagus floridanus
Sylvilagus auduboni

HODENTIA, Rodents

SCIURIDAE, Squirrels and Allies

Spermophilus variegatus
Spermophilus tereticaudus
Ammospermophilus harrisi
Eu tarn las dorsalis

GEOMYIDAE, Pocket gophers

Thorn omys bottae

HETEROMYTDAE , Kangaroo Rats and Pocket Mice

Perognathus longimembris
Perognathus amplus
Perognathus baileyi
Perognathus penicillatus
Perognathus intermedius
Z i ooc omys mernami
Litooorcys oroi

Desert shrew

California leaf^nosed bat

Yuma myotis
Cave myotis
Fringed myotis
California myotis
Western pipistrelle
Big brown bat
Townsend's big-eared bat
Pallid bat

Pocketed free-tailed bat

Black-tailed jack rabbit
Eastern cottontail
Desert cottontail

Rock squirrel

Round-tailed ground squirrel
Yuma antelope squirrel
Cliff chipmunk

Valley pocket gopher

Little pocket mouse
Arizona pocket mouse
Bailey's pocket mouse
Desert pocket mouse
Rock pocket mouse
Merriam's kangaroo rat
Ord's kangaroo rat

12

Table A continued

MURIDAE, Introduced Rats and Mice
Mus mus cuius

CRICETIDAE , Native Rats and Mice

Rei throdontomys megalotis
unycnomys leucTogaster

Onychomys torridus
Peromyscus eremicus
Peromyscus mani cu la tus
Peromyscus leucopus
Peromyscus boy lei
Neotoma albigula
Neotoma lepida
Neotoma stephensi

CARNIVDRA, Carnivores

CANIDAE, Dogs and Allies

Urocyon cine re oar gen teus

MUSTELIDAE, Weasels, Skunks, and Allies

Spilogale gracilis

House mouse

Western harvest mouse
Northern grasshopper mouse

Southern grasshopper mouse

Cactus mouse

Deer mouse

White-footed mouse

Brush mouse

White-throated wood rat

Desert wood rat

Stephen's wood rat

Gray fox

Western spotted skunk

13

larle 5. MAMMAL SPECIES OBSERVED APRIL 1978 THROUGH AUGUST 1978,

but not collected.

CARNIVORA . Carnivores

CANIDAE, Dogs and Allies

Canis latrans

URSIDAE, Bears

Ursus americanus
PROCYONIDAE, Raccoons and Allies

Bassariscus astutus

Procyon lotor

MUSTELIDAE, Weasels, Skunks, and Allies

Taxidea taxus
Mephitis mephitis

FELIDAE, Cats

Felis concolor
Felis rufus

ARTIODACTYLA , Even-toed Ungulates
TAYASSUIDAE, Peccaries

Dicotyles tajacu
CERVTDAE, Deer and Allies

Odocoileus hemionus
ANTILOCAPRIDAE , Antelope

Antilocapra americana
PEP.ISSODACTYLA, Odd-toed Ungulates
BQUIDAE, Horses and Asses

Eauus asinus

Coyote

Black bear

Ringtail
Raccoon

Badger
Striped skunk

Mountain lion
Bobcat

Javelina

Mule deer

Pronghorn antelope

Burro

14

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15

Table 7. TOTAL CATCH PERCENTAGES AND HABITAT SELECTION OF THE MAMMAL SPECIES COLLECTED
BY SNAP TRAPPING.

Species

Percentage caught in all
habitats with total number
trapped in parentheses.

Habitat Utilization
(Number of habitats the
species was found in
versus total number of
habitats).

Dipodomys merriami
Dipodomys ordi
Perognathus amplus
Perognathus baileyi
Perognathus intermedius
Perognathus longimembris
Perognathus penicillatus
Peromyscus eremicus
Peromyscus leucopus
Peromyscus maniculatus
Onychomys torridus
Neotoma albigula
Neotoma lepida
Neotoma stephensi
Ammospermophilus harrisi
Spermophilus tereticaudus
Eutamias dorsal is
Syl vilagus auduboni
Sylvilagus floridanus

13.7% (61)

0.7% (3)

3.4% (15)

7.4% (33)

20.9% (93)

2.0% (9)

4.0% (18)

11.2% (50)

0.5% (2)

0.7% (3)

0.5% (2)

23.0% (102)

4.5% (20)

0.5% (2)

5.4% (24)

0.2% (1)

0.2% (1)

0.7% (3)

0.5% (2)

8/11
2/11
2/11
4/11
6/11
2/11
2/11
9/11
2/11
2/11

1/11
9/11

7/11
2/11
5/11
1/11

1/11
3/11

2/11

16

and the highest densities for Merriam's kangaroo rat, Bailey's pocket
mouse (Perognathus baileyi), little pocket mouse (Perognathus
longimembris), deTert pocket mouse (Perognathus penicillatus), and Yuma
antelope squirrel (Ammospermophilus harnsi ) were recorded here. The
most significant species, in terms of relative densities, appear to be
the Merriam's kangaroo rat (2.44), Yuma antelope squirrel (2.44), and
white-throated woodrat (2.25). In addition, two lagomorphs, the
black-tailed jack rabbit (Lepus californicus) and especially, the desert
cottontail (Sylvilagus auduboni) were observed to be abundant in their
utilization of this habitat.

Small mammals are able to take full advantage of the variety this
community provides in the form of substrate types and cover. Substrate
varies from alluvial sand to loose talus on rocky shelves. Cover is
provided from both the riparian desertscrub and the debris of inter-
mittent flooding. Collectively, differences in life-form of the
vegetation and topography form a structurally diverse community that
supports the greatest number of species at the greatest population
numbers.

The vegetational structure of Arizona Upland is similarly diverse
and was found to support an equal number of species as mixed riparian
scrub, but at reduced densities. The highest reported densities for the
rock pocket mouse and desert woodrat (Neotoma lepida) were in desert-
scrub. In this community the highest recorded relative densities were
for rock pocket mouse (2.75), white-throated woodrat (1.64), and
Merriam's kangaroo rat (1.21). Black-tailed jack rabbits and desert
cottontails were common in desertscrub habitat of Arizona Upland, and
rock squirrels (Spermophilus variegatus) were locally common among rock
outcrops. Round-tail ground squirrels (Spermophilus tereticaudus) were
infrequently encountered as local populations on desert flatlands where
mesquite and creosote bush occurred over sandy soils. None were
collected by snap trapping. Coyotes (Cam's latrans) were observed as
being most numerous here than in any other vegetational community,
presumably in response to the jack rabbit and cottontail populations.
They usually occurred as isolated individuals whereas javelina
(Dicotyles tajacu) formed small bands that were generally found in areas
laden with prickly pear (Opuntia phaeacantha). Mule deer (Odocoileus
hemionus) were occasionally sighted in open, more broken desertscrub
where browse plants such as jojoba (Simmondsia chinensis) were abundant.
Feral burros (Equus asinus) were only encountered in desertscrub
communities. They occur as small herds in areas proximal to water
sources, e.g. cattle tanks and springs, and were most numerous near Lake
Pleasant Regional Park.

Arizona Upland was further subdivided into three standard
habitat sites based on gradient. They included desertscrub flatlands,
foothills, and hillsides. Many species key to the degree of inclination
and the subsequent substrate types, rather than specific vegetational
species. This is clearly illustrated in Table 8 where relative den-
sities indicate that the Merriam's kangaroo rat shows habitat preference
for areas of low relief with substrate consisting of loosely compacted

17

le B.

SMALL MAMMAL DENSITIES FOR THE SONORAN DESERTSCRUB COMMUNITIES.
DATA ARE SHOWN AS NUMBER OF ANIMALS CAPTURED PER 270 TRAP NIGHTS AND
PARENTHESES INDICATE TOTAL NUMBER TRAPPED.

Species

Dipodomys merriami
Perognathus amp"! us
Perognathus baileyi
Perognathus intermedius
Perognathus longimembris
Perognathus penicil latus
Peromyscus eremicus
Neotoma albigula
Neotoma lepida
Ammospermophilus harrisi
Syl vilagus auduboni

Flatland

2.6 (26)

1.5 (15)
0.5 (5)
1.0 (10)
0.3 (3)

1.6 (16)
0.6 (6)
0.7 (7)

Foothill

0.69 (8)
0.43 (5)
1.63 (19)
3.86 (45)

0.26 (3)
1.80 (21)
0.60 (7)
0.17 (2)
0.09 (1)

Hillside

0.79 (5)
2.69 (17)

2.53 (16)
1.42 (9)

Totals

3.29 (34)
0.43 (5)
2.42 (24)
8.05 (77)
0.50 (5)
1.00 (10)
3.09 (22)
4.82 (46)
1.20 (13)
0.87 (9)
0.09 (1)

TOTALS

Relative density

8.8

9.53

7.43

Number of trap nights

2,700

3,150

1,710

7,560

Number of animals caught

88

111

47

246

Number of speci es

8

9

4

11

18

alluvial outwash. Its numbers were reduced in foothill situations and
nonexistent on hillsides. In contrast, the rock pocket mouse was found
at higher densities in desert foothills where rock talus was prevalent,
and the cactus mouse exhibited habitat preference for the rock outcrops
present on desertscrub hillsides.

Simple monotypic vegetation types, such as creosote flats of the
Lower Colorado community, typically support a small number of abundant
species. Creosote flat habitat accounted for the third highest total
relative density, but only four species were collected. The highest
density for Arizona pocket mouse (Perognathus amplus) and the second
highest density for Merriam's kangaroo rat were recorded in creosote
communities.

Eight species were snap trapped in desert grasslands. The highest
densities for white-throated woodrat, cactus mouse, deer mouse
(Peromyscus maniculatus) , and southern grasshopper mouse (Onychomys
torridus) were recorded here. This indicates a trend where cricetid
rodents appear to displace the heteromyid rodents and occur at higher
densities in more mesic habitats, such as grasslands. Bradley and Mauer
(1973) report that food habits of desert rodents tend to be generalized,
i.e. small mammals utilize basic food types such as seeds, forbs, and
arthropods depending upon seasonal availability. However succulence,
usually in the form of green forbs or insects, is necessary in the diet
of sciurid and cricetid species in contrast to the heteromyids, which
only resort to succulence during the reproductive season (Bradley and
Mauer 1973). Supplementary water may be important to most cricetids but
another factor governing the distribution and abundance of small mammals
in desert grasslands may be the availability of cover. Life-form of the
vegetation dictates the amount and type of cover and food available and
may be more important than the mere presence or absence of certain plant
species. It was on this assumption that desert grassland was split into
two standard habitat sites. It was thought that in a habitat where a
vegetational canopy is lacking, that more may be provided in the way of
cover from rock outcrops. This is better illustrated in Table 9 where
densities for cactus mouse were found to be higher in areas with rock
outcrop, than those without. Densities were also significantly higher
for white-throated woodrat in rock outcrop associations due to the
increased availability of suitable nesting sites. In addition, the
eastern cottontail (Sylvilagus floridanus) was first observed in desert
grasslands. It is sympatric with desert cottontail here, but occurs in
greater numbers. It is generally found to be abundant from 2,600 feet
to higher elevations of 5,200 feet in chaparral.

The highest densities for Ord's kangaroo rat (Dipodomys ordi) and
Stephen's woodrat (Neotoma stephensi ) were recorded in chaparral habi-
tat. Six other species were snap trapped in this community with white-
throated woodrat being the most abundant (1.80). Additionally, the
white-footed mouse (Peromyscus leucopus) was found only in chaparral and
its riparian counterpart of mixed broadleaf. Also, the brush mouse
(Peromyscus boylei ) and northern grasshopper mouse (Onychomys
leucogaster) were only collected here and it was the only sight locality
for mountain lion (Felis concolor).

19

Table 9. SMALL MAMMAL DENSITIES FOR DESERT GRASSLAND COMMUNITIES.

DATA ARE SHOWN AS NUMBER OF ANIMALS CAPTURED PER 270 TRAP NIGHTS AND
PARENTHESES INDICATE TOTAL NUMBER TRAPPED.

Species

Desert Grassland

Dipodomys merriami
Peromyscus eremicus
Peromyscus maniculatus
Onychomys torridus
Neotoma albigula
Neotoma lepida
Neotoma stephensi
Syl vilagus floridanus

0.20 (1)
0.80 (4)
0.40 (2)

1.80 (9)

Desert Grassland
With Rock Outcrop

0.33 (1)

3.33 (10)

0.67 (2)

6.67 (20)

0.33 (1)

0.33 (1)

Totals

0.20 (1)

(2) 4.13

(14) 0.40

(2) 0.67

(2) 8.47

(29) 0.33

(1) 0.33

(1) 0.20

(1) 0.53

TOTALS

Relative density
Number of trap nights
Number of animals caught
Number of species

3.4

1,350

17

5

11.66

810

35

6

2,160
52

8

20

Many small mammals, heteromyid rodents in particular, may live out
their entire life span without ever drinking free water. They have
evolved to meet water requirements through metabolism of carbohydrates.
Water conservation in these rodents is enhanced by an efficient renal
system which can concentrate urine, a lack of sweat glands, and their
nocturnal habits. It is these factors which render riparian areas
insignificant to most small mammals. The three remaining habitats
considered, mixed broadleaf, cottonwood/wil low, and mesquite bosques,
all reported low density values and reduced species numbers. However,
these areas are important for one of the smallest mammals present in the
state, the desert shrew (Notiosorex crawfordi). All nine locality
records were obtained from the use of can traps in mixed riparian scrub
at 1,680 feet up to mixed broadleaf communities at 5,100 feet. Pocket
gophers (Thomomys bottae) also heavily utilized riparian areas. Their
burrows were frequently encountered along stream banks and over many of
the flood plains adjacent to both perennial and intermittent drainages.
This type of habitat was also observed to be significant to bats and
larger mammals such as mustelids, procyonids, deer and javelina which
periodically visit perennial water sources.

Arizona has more different kinds of bats than any other state in
the union, 26 species within three families (Cockrum 1960). In sampling
with mist nets and .22 cal. birdshot, we were able to account for 10
species over both planning units (Table 4). Abandoned dwellings, rock
crevices, cattle tanks, trees, caves, and especially abandoned mines
were important forage and roosting sites. Numerous mine shafts and
tunnels occur throughout the planning units. These apparently represent
significant habitat and were heavily utilized by bats. Large colonies,
with up to several different species, were discovered in almost every
mi ne tunnel sampled.

21

DISCUSSION

In summary, mixed riparian scrub and Arizona Upland appear to be
the most productive habitats for small mammals in the Black Canyon and
Skull Valley Planning Units. The highest relative densities and the
highest number of species for all communities considered were found here
(Fig. 2). Presumably, this is in response to the diversity of habitat,
where life-form of the vegetation and substrate vary greatly. The
majority of the 338,000 acres surveyed over both planning units con-
sisted of desertscrub foothills that were highly braided by intermittent
washes. Mixed riparian scrub and Arizona Upland scrub therfore repre-
sent considerable habitat for the endemic small mammals. This is
consistent with the results of Schwartzmann et_ aj_. (1975). They
reported similar high mammal diversity and density values for desert-
scrub in their study of the Proposed Salt-Gila Aqueduct Site in
central-Arizona.

Desert grassland and creosote communities were intermediate in
their utilization by small mammals. Creosote flats were found to
support few species at high population numbers. This was comparative to
the results of Bradley and Mauer (1973) in their study of similar
habitat in southern Nevada.

Riparian communities such as mixed broadleaf and mesquite bosques
were the least productive habitats sampled. The lowest relative
densities and number of species were recorded here. Perennial waters
are of little consequence to many of the small mammals which have the
ability to obtain their water metabolical ly. As a result, riparian
areas do not represent significant habitat to these mammals and in terms
of diversity and relative density, they typically support depauperate
populations.

The white-throated woodrat, Merriam's kangaroo rat, rock pocket
mouse, and cactus mouse were the four most frequently collected species
on both planning units and therefore reported the highest relative den-
sities (Fig. 3). Their total relative densities and habitat utilization
are listed in Table 10. Information from this study revealed that
mammal species are not restricted to given habitats, but overlap to form
a continuum of distribution and should be managed accordingly. Coexis-
tence of species depends on the ability of each population to delineate
and segregate niche space. This may be achieved by different activity
patterns (either diurnal or seasonal), by subdivision of the habitat, or
by subdivision of the community resources. All tend to reduce shared
habitat and resource utilization between species.

A listing has been compiled in Appendix 5 for mammal species known
to occur within the Black Canyon and Skull Valley Planning Units, but
whose presence was not substantiated by capture or observation through-

22

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24

Table 10. TOTAL RELATIVE DENSITY AND HABITAT UTILIZATION OF THE MOST FREQUENTLY

COLLECTED SPECIES. DATA ARE SHOWN AS NUMBER OF ANIMALS CAPTURED PER 270 TRAP
NIGHTS AND PARENTHESES INDICATE TOTAL NUMBER TRAPPED.

Total Relative No. of Habitats Found in
Density Versus Total No. of Habitats

Neotoma albigula 11.32 (102) 9/11

Dipodomys merriami 7.56 (61) 8/11

Perognathus intermedius 6.36 (93) 6/11

Peromyscus eremicus 6.15 (50) 9/11

25

out the present course of study. Of the 50 total mammal species either
collected or observed during the sample period, none were either feder-
ally or state listed as being threatened or endangered. Only one
species, the pocketed free-tailed bat (Tadarida femorosacca), exhibited
a major range extension. It is normally found in Baja and northern
Mexico and in southern California and Arizona (Hall and Kelson 1959).
Locality records for Arizona are primarily from Pima, Santa Cruz, and
part of Cochise County, but one specimen was collected approximately
eight miles northwest of Lake Pleasant in Yavapai County. Whether this
represents a population trend or an isolated instance is unknown at this
time.

As a final note, population estimates are based on the probability
of capture remaining constant for removal as well as mark and release
trapping (Hayne 1949). Several parameters are involved which can make
trapping selective and affect trapping success. They include the
number, kind, size, and placement of traps; type of bait; weather;
moonlight; inadvertent snapping of traps by cows and burros; unavail-
ability of snapped traps; and age, sex, size, reproductive condition,
and activity pattern of the species involved.

In regards to seasonal activity, most small mammals exhibit a
bimodal pattern of spring and fall peaks separated by periods of
dormancy and aestivation (Lewis 1972, M'Closkey 1972, Reichman and
Van de Graaff 1973, Anderson, et al_. 1977). Evaluation of habitat in
terms of densities and diversities for various mammal populations should
be made relative to the seasonal activity periods of the species
i nvol ved.

26

LITERATURE CITED

Anderson, B.W., J. Drake, and R.D. Ohmart. 1977. Population

fluctuations in nocturnal rodents in the Lower Colorado River
Valley. j_n Proc. Symp. on the Importance, Preservation, and
Management of the Riparian Habitat. USDA Forest Service, Fort
Collins, Colo. Gen. Tech. Report RM-43 : 183-192.

Anderson, B. W. and R. D. Ohmart. 1977. Rodent bait additive which
repels insects. Jour. Mammalogy 58:242.

Babcock, H.M. 1968. The phreatophyte problem in Arizona. Ariz.
Watershed Symp. Proc. 12:34-36.

Barbour, R. W. and W. H. Davis. 1969. The bats of America. The
University Press of Kentucky, Lexington, Kentucky.

Beatley, J. C. 1969. Dependence of desert rodents on winter annuals
and precipitation. Ecology 50:721-724.

Bradley, W. G. and R. A. Mauer. 1973. Rodents of a creosote bush

community in southern Nevada. Southwestern Naturalist 17:333-344.

Brown, D. E. and C. H. Lowe. 1974a. A digitized computer-compatible
classification for natural and potential vegetation in the South-
west with particular reference to Arizona. Jour. Ariz. Acad. Sci.
9, Suppl. 2.

. 1974b. The Arizona system for natural

and potential vegetation - illustrated summary through the fifth
digit for the North American Southwest. Jour. Ariz. Acad. Sci. 9,
Suppl. 3.

Brown, D. E., C. H. Lowe, and J. F. Hausler. 1977. Southwestern

riparian communities: their biotic importance and management in
Arizona. J_n Proc. Symp. on the Importance, Preservation, and
Management of the Riparian Habitat. USDA Forest Service, Fort
Collins, Colo. Gen. Tech. Report RM-43 : 201-211.

Calhoun, J. B. 1951. North America census of small mammals. Release
No. 4, Jackson Memorial Lab. Bar Harbor, Michigan, Release No. 1,
Rodent Ecology Project, John Hopkins Univ., Baltimore, Maryland.

Cockrum, E. L. 1960. The recent mammals of Arizona, their taxonomy and
distribution. The University of Arizona Press, Tucson, Arizona.

27

Hall, E. R. and K. R. Kelson. 1959. The mammals of North America. 2
Vol. Ronald Press, New York, New York.

Hayne, D. W. 1949. Two methods for estimating population from trapping
records. Jour. Mammalogy 30:399-411.

Hubbard, J. P. 1977. Importance of riparian ecosystems: biotic con-
siderations. In Proc. Symp. on the Importance, Preservation, and
Management of tn~e Riparian Habitat. USDA Forest Service, Fort
Collins, Colo. Gen. Tech. Report RM-43:14-18.

Jones, J. K. , D. C. Carter, and H. H. Genoways. 1975. Revised

checklist of North American Mammals north of Mexico. Occasional
Papers. The Museum of Texas Tech. University, Lubbock, Texas.

Kearney, T. H. and R. H. Peebles. 1960. Arizona flora. The University
of California Press, Berkeley, California.

Lehr, J. H. 1978. A catalogue of the flora of Arizona. Desert
Botanical Garden, Phoenix, Arizona.

Lewis, A. W. 1972. Seasonal population changes in the cactus mouse,
Peromyscus eremicus. Southwestern Naturalist 17:85-93.

Lowe, C. H. (ed.). 1964. The vertebrates of Arizona. The University
of Arizona Press, Tucson, Arizona.

Lowe, C. H. and D. E. Brown. 1973. The natural vegetation of

Arizona. Arizona Resources Information System, Phoenix, Arizona.
Coop. Pub. #2.

M'Closkey, R. T. 1972. Temporal changes in populations and species
diversity in a California rodent community. Jour. Mammalogy
53:657-676.

Reichman, 0. J. and K. M. Van de Graaff. 1973. Seasonal activity and
reproductive patterns of five species of Sonoran Desert rodents.
Amer. Mid. Nat. 90:118-126.

Schwartzmann, J. L., W. F. Laudenslayer, R. D. Ohmart, and R. W. Smith.
1975. Field studies of the nongame mammals, birds, herpetofauna,
and vegetation analysis of the proposed Salt-Gil a Aqueduct.
Prepared for the Bureau of Reclamation.

Sellers, W. D. and R. H. Hill (eds.). 1974. Arizona climate:

1931-1972, 2nd ed. The University of Arizona Press, Tucson,
Arizona.

Stamp, N. E. and R. D. Ohmart. 1975. Final report on the field studies
of the nongame birds and small mammals of the proposed Orme Dam
site. Bureau of Reclamation Contract No. 14-06-300-2541.

28

Stephenson, R. L. and R. D. Ohmart. 1973. the vertebrate fauna of
Spider and Cross U Ranches in Santa Maria Mountains, Arizona:
A summer and winter survey.

Turkowski , F. J. and J. R. Vahle. 1977. Desert rodent abundance in
southern Arizona in relation to rainfall. USDA Forest Service,
Fort Collins, Colo. Research Note RM-346.

U.S. Department of Commerce. 1978. Arizona climatological data,
monthly summaries. National Oceanic and Atmospheric Adminis-
tration, Environmental Data Service, National Climatic Center;
Asheville, North Carolina.

29

Appendix 1. LOCATIONS AND ELEVATIONS OF RECORDING STATIONS USED FOR
CLIMATOLOGICAL DATA.

Cordes Yavapai County

34° 18' latitude
112° 10' longitude
Elevation - 3773'
means for period 1941-1970

Castle Hot Springs Yavapai County

33° 59' latitude
112° 22' longitude
Elevation - 1990'
means for period 1959-1970

Wickenburg Maricopa County

33° 58' latitude
112° 44' longitude
Elevation - 2095'
means for period 1941-1970

Skull Valley Yavapai County

34° 30' latitude
112° 41' longitude
Elevation - 4254'

Hillside Yavapai County

34° 25' latitude
112° 55' longitude
Elevation - 3845'
means for period 1941-1954

30

Appendix 2. BLACK CANYON/SKULL VALLEY STANDARD HABITAT SITES (Numbered)

Upper Sonoran Life-zone

1. Chaparral

2. Desert Grassland

3. Desert Grassland with Rock Outcrop

Lower Sonoran Life-zone
Sonoran Desertscrub

4. Lower Colorado
Arizona Upland

5. Desertscrub Flatland

6. Desertscrub Foothill

7. Desertscrub Hillside

Riparian Deciduous Woodland

8. Mesquite/Acacia Bosque

9. Mixed Broadleaf

10. Cottonwood/Will ow

11. Mixed Riparian Scrub

31

Appendix 3. BLACK CANYON PLANNING UNIT MAMMAL TRANSECT LOCALITIES,

Mammal Grid #1

AZ., Maricopa Co. T5N R1E NW1/4 Sec. 30, elev. 1400'

Mammal Grid #2

AZ., Maricopa Co. T5N R1W SE1/4 Sec. 21, elev. 1450'

Mammal Grid #3

AZ., Maricopa Co. T5N R1E SW1/4 Sec. 19, elev. 1560'

Mammal Grid #4

AZ., Maricopa Co. T5N R1W NW1/4 Sec. 25, elev. 1400'

Mammal Grid #5

AZ., Maricopa Co. T6N R1W SW1/4 Sec. 23, elev. 1800'

Mammal Grid #6

AZ., Maricopa Co. T7N R1W NE1/4 Sec. 35, elev. 1840'

Mammal Grid #7

AZ., Maricopa Co., French Creek flood plain
T7N R1W NE1/4 Sec. 13, elev. 1800'

Mammal Grid #8

AZ., Yavapai Co. T7N R2E NW1/4 Sec. 33, elev. 2080'

Mammal Grid #9

AZ., Maricopa Co. T6N R1E NW1/4 Sec. 35, elev. 1660'

Mammal Grid #10

AZ., Yavapai Co., Agua Fria River flood plain
T7N R1E SW1/4 Sec. 12, elev. 1680'

Mammal Grid #11

AZ., Maricopa Co. T8N R2E SE1/4 Sec. 32, elev. 1760'

Mammal Grid #12

AZ., Yavapai Co. T7N R1E SW1/4 Sec. 4, elev. 2080'

Mammal Grid #13

AZ., Maricopa Co. T6N R2W SW1/4 Sec. 35, elev. 1840'

Mammal Grid #14

AZ., Maricopa Co. T6N R1W SW1/4 Sec. 18, elev. 2300'

Mammal Grid #15

AZ., Maricopa Co., Morgan City Wash
T7N R2W SE1/4 Sec. 25, elev. 2520'

32

Mammal Grid #16

AZ., Maricopa Co. T6N R2W SW1/4 Sec. 22, elev. 2300'

Mammal Grid #17

AZ., Maricopa Co., Picacho Wash
T6N R2W NE1/4 Sec. 9, elev. 2300'

Mammal Grid #18

AZ., Maricopa Co. T6N R1W NE1/4 Sec. 34, elev. 1800'

Mammal Grid #19

AZ., Maricopa Co. T6N R2W SW1/4 Sec. 7, elev. 2180'

Mammal Grid #20

AZ., Maricopa Co. T7N R3W NW1/4 Sec. 35, elev. 2440'

Mammal Grid #23

AZ., Yavapai Co. T7N R1E SW1/4 Sec. 10, elev. 1780'

Mammal Grid #24

AZ., Maricopa Co., New River flood plain
T6N R2E NW1/4 Sec. 20, elev. 1750'

Mammal Grid #25

AZ., Maricopa Co. T7N R2E NE1/4 Sec. 16, elev. 2360'

Mammal Grid #26

AZ., Maricopa Co. T6N R2E NE1/4 Sec. 7, elev. I860'

Mammal Grid #27

AZ., Yavapai Co. T7N R1E NE1/4 Sec. 11, elev. 2000'

Mammal Grid #28

AZ. , Yavapai Co., Humbug Creek flood plain
T7N R1E SE1/4 Sec. 17, elev. 1680'

Mammal Grid #29

AZ. , Yavapai Co., French Creek flood plain
T7N R1W NW1/4 Sec. 24, elev. 1700'

Mammal Grid #30

AZ., Yavapai Co. T7N R1E NW1/4 Sec. 19, elev. 1800'

Mammal Grid #31

AZ., Yavapai Co. T8N R1W NW1/4 Sec. 36, elev. 2240'

Mammal Grid #32

AZ., Yavapai Co. T8N R1W NE1/4 Sec. 28, elev. 2480'

Mammal Grid #33

AZ., Yavapai Co. T8N R1W SE1/4 Sec. 30, elev. 2400'

33

Mammal Grid #34

AZ. , Yavapai Co., Cedar Basin
T7N R2W SW1/4 Sec. 12, elev. 2640'

Mammal Grid #35

AZ., Yavapai Co. T8N R1W NE1/4 Sec. 11, elev. 2760'

Mammal Grid #36

AZ., Yavapai Co., Silver Creek
T9N R1W NE1/4 Sec. 16, elev. 4260'

Mammal Grid #37

AZ., Yavapai Co. T9N R1W SW1/4 Sec. 28, elev. 3800'

Mammal Grid #38

AZ., Yavapai Co. T7N R2W NE1/4 Sec. 9, elev. 3040'

Mammal Grid #39

AZ., Maricopa Co. T7N R2W NE1/4 Sec. 19, elev. 3120'

Mammal Grid #43

AZ., Yavapai Co. TUN R2E SE1/4 Sec. 17, elev. 3960'

Mammal Grid #44

AZ., Yavapai Co. T11N R2E NE1/4 Sec. 34, elev. 3840'

Mammal Grid #48

AZ., Yavapai Co. TUN R3E SW1/4 Sec. 19, elev. 3600'

Mammal Grid #49

AZ., Yavapai Co., Agua Fria River
T10N R3E NE1/4 Sec. 17, elev. 3240'

Mammal Grid #53

AZ., Yavapai Co. T11N R3W SW1/4 Sec. 6, elev. 4480'

Mammal Grid #61

AZ., Yavapai Co. T10N R3E NW1/4 Sec. 22, elev. 3740'

Mammal Grid #62

AZ., Yavapai Co., Indian Creek
T10N R3E NE1/4 Sec. 4, elev. 3360'

Mammal Grid #63

AZ., Yavapai Co. T10N R2E NE1/4 Sec. 2, elev. 3600'

Mammal Grid #64

AZ., Yavapai Co., Agua Fria River/Ash Creek flood plain
TUN R3E SW1/4 Sec. 17, elev. 3510'

Mammal Grid #65

AZ., Yavapai Co. T13N R2E SW1/4 Sec. 6, elev. 4920'

34

Mammal Grid #66

AZ. , Yavapai Co., Chaparral Gulch
T13N R1E SE1/4 Sec. 19, elev. 5120'

Mammal Grid #67

AZ., Yavapai Co. T12N R1E NE1/4 Sec. 23, elev. 4560'

Mammal Grid #68

AZ., Yavapai Co. T12N R2E NE1/4 Sec. 29, elev. 4120'

Mammal Grid #69

AZ., Yavapai Co. T12N R2E SW1/4 Sec. 4, elev. 4440'

Mammal Grid #70

AZ., Yavapai Co. T13N R1E SW1/4 Sec. 24, elev. 4880'

35

Appendix 4. SKULL VALLEY PLANNING UNIT MAMMAL TRANSECT LOCALITIES,

Mammal Grid #54

AZ., Yavapai Co. TUN R4W NE1/4 Sec. 27, elev. 4880'

Mammal Grid #55

AZ., Yavapai Co. T9N R5W NW1/4 Sec. 19, elev. 2800'

Mammal Grid #56

AZ., Yavapai Co. T10N R5W SW1/4 Sec. 30, elev. 3140'

Mammal Grid #57

AZ. , Yavapai Co. T10N R5W NW1/4 Sec. 24, elev. 4000'

Mammal Grid #58

AZ., Yavapai Co. T9N R5W NW1/4 Sec. 24, elev. 2985'

Mammal Grid #59

AZ., Yavapai Co. T8N R4W SE1/4 Sec. 19, elev. 2480'

Mammal Grid #71

AZ., Yavapai Co. T8N R5W SE1/4 Sec. 10, elev. 2540'

Mammal Grid #72

AZ., Maricopa Co. T7N R4W NW1/4 Sec. 15, elev. 2320'

Mammal Grid #73

AZ., Yavapai Co. T8N R4W SW1/4 Sec. 1, elev. 3040'

Mammal Grid #74

AZ. , Yavapai Co., Martinez Creek
T9N R6W NE1/4 Sec. 1, elev. 2900'

Mammal Grid #75

AZ., Yavapai Co. T8N R7W SE1/4 Sec. 14, elev. 2520'

Mammal Grid #76

AZ., Yavapai Co., Arrastre Creek flood plain
TUN R4W NE1/4 Sec. 26, elev. 4640'

36

Bureau of Land Management

Library

Bldg. 50, Denver Federal Center

Denver, CO 8Q225

Appendix 5. MAMMAL SPECIES POTENTIALLY INHABITING THE BLACK CANYON/SKULL

VALLEY PLANNING UNITS, BUT UNREPORTED DURING THE SAMPLE PERIOD,

CHIROPTERA

VESPERTILIONIDAE

My otis lucifugus subsp. occultus
My otis volans
Lasionyctens noctivagans
Lasiurus boreal is
Lasiurus cinereus
Euderma maculata

MOLOSSIDAE

Tadarida brasiliensis
Eumops perotis

RODENTIA

SCIURIDAE

Cynomys gunnisoni
HETEROMYIDAE

Perognathus flavus
CRICETIDAE

Sigmodon hispidus
ERETHIZONTIDAE

Erethizon dorsatum
CARNIVORA

MUSTELIDAE

Conepatus mesoleucus
ARTIODACTYLA
BOVIDAE

* Ovis canadensis

Little brown bat
Long-legged myotis
Silver-haired bat
Red bat
Hoary bat
Spotted bat

Brazilian free-tailed bat
Greater mastiff bat

Gunnison's prairie dog

Silky pocket mouse

Hispid cotton rat

Porcupine

Hog-nosed skunk

Desert bighorn sheep

* Historically known to occur within both planning units, but currently
extirpated from the area.

37

Please Request TN 350
YA-BLM-PT-81-13-6602

. 0 GOVERNMENT PRINTING OFFICE: 1981 - 781-354/488 Region No 8

Bureau of Land r nt

Denver, CO 8Q225

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