Occasional Papers

Museum of Texas Tech University

Number 253 25 April 2006

Mammals of the Harte Ranch Area of Big Bend National Park,

Brewster County, Texas

Franklin D. Yancey, II , Richard W Manning, and Clyde Jones

Abstract

A three-year study (1990-1992) on the mammals of the Harte Ranch area of Big Bend
National Park was conducted. Forty-two species of mammals were documented to occur in this
area. Descriptive accounts are presented for each species, which include comments regarding
distribution, relative abundance, habitat preference, and reproductive biology. The mammalian
diversity of the Harte Ranch area in comparison to other areas in the region is discussed.

Key words: Big Bend National Park, Harte Ranch, mammalian diversity, Rosillos Mountains.

Introduction and Methods

For a total of almost three years, we studied the
biodiversity of mammals on the Harte Ranch area of
Big Bend National Park. The Harte Ranch area is about
75,000 acres in size, and is located in the northwestern
portion of Big Bend National Park. It is situated west
of Persimmon Gap Ranger Station, north of the Pitcock-
Rosillos Ranch, and east of Terlingua Ranch.

This survey of mammals of the Harte Ranch area
was carried out in accordance with the work of a unique
Research Consortium organized by Dr. Milford Fletcher
(National Park Service) and Dr. David Schmidly (then
of Texas A&M University). We made every effort to
coordinate our field activities with those of the other
members of the Research Consortium, which included

surveys of invertebrates, amphibians, reptiles, birds,
and plant communities.

Our major objectives were to determine the kinds
of extant mammals on Harte Ranch, and to sample
and observe mammals in as many of the microhabitats
throughout the geographic area as possible. We em¬
ployed standard methods of capturing and monitoring
mammals as described by Jones et al. (1996). We con¬
centrated our efforts on the use of Sherman live traps
(over 10,000 trap-nights) which allowed for the release
of animals captured that were not needed as voucher
specimens. All field research activities were conducted
in the most discrete manner possible in consideration
of the sensitivities of the local human population in
the region.

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Occasional Papers, Museum of Texas Tech University

Results

During our field research, 66 specific localities
within the Harte Ranch section of Big Bend National
Park were sampled (Table 1). These sampling data,
supplemented with a variety of observational data, re¬
sulted in the documentation of 42 species of mammals
at Harte Ranch (Table 2).

In the accounts that follow, 42 species of mam¬
mals that are known to occur on the Harte Ranch sec¬
tion of Big Bend National Park are treated. Although
ordinal and familial headings are not utilized here, they
are presented in Table 2. Accounts are presented in
the currently accepted phylogenetic sequence through
genera; species are arranged alphabetically within
each genus. Scientific and vernacular names of taxa
follow Manning and Jones (1998) and Baker et at
(2003). Linear measurements in these accounts are
in millimeters. Specimens listed are deposited in the
Collection of Recent Mammals at the Museum of Texas
Tech University.

My otis yumanensis yumanensis
(H. Allen 1864)

Only two specimens of Yuma myotis were ob¬
tained during this study. Both bats were captured in
mist nets placed over water. According to Schmidly
(1991), this bat usually forages near open water in low¬
land habitats. Testes of these bats, captured on 8 and 10
November, measured 1 x 1 and 3x1, respectively.

Specimens examined (2).—Mountain Lodge,
Harte Ranch, 1,0.6 mi. S, 1.5 mi. E Key Place, Harte
Ranch, 1.

Pipistrellus hesperus maximus
Hatfield 1936

The western pipistrelle was the most common
bat encountered during this study. Although specimens
were obtained by use of mist nets set over water at
only two localities, these mammals were observed fly¬
ing about at dusk and dawn at numerous places in the
study area, especially along roads and adjacent to Chalk
Ridge. A female examined on 19 May contained two

embryos (crown-rump length, 11); lactating females
were collected on 19-21 July. Measurements of testes
of males obtained in July and August ranged from 2 x
2 to 4 x 4; in October and November, testes of males
measured from 1 x 1 to 3x2. Volant young-of-the-year
pipistrelles were captured on 19-21 July.

Specimens examined (49). Mountain Lodge,
Harte Ranch, 48; Cedar Creek, 0.75 mi. E Twin Peaks,
Harte Ranch, 1.

Eptesicus fuscus pallidus
Young 1908

A lactating female was captured on 20 July in a
mist net placed over water. In the Big Bend of Texas,
female big brown bats inhabit lowland areas during the
summer months (Schmidly 1991).

Specimens examined (1).—Mountain Lodge,
Harte Ranch, 1.

Lasiurus cinereus cinereus

(Palisot de Beauvois 1796)

On two occasions during the night of 10 Novem¬
ber, a hoary bat was observed in a mist net set over
water; the bat escaped before it could be retrieved.
According to Schmidly (1991) this species is restricted
mostly to wooded, montane areas of the Big Bend.

Specimens examined (0).

Corynorhinus townsendiipallescens
(Miller 1897)

Two specimens of Townsend’s big-eared bat were
obtained during this study. A male, taken from inside
a building on 8 November, had testes that measured 4
x 2. A non-gravid female was netted over water on 8
November.

Specimens examined (2).—Key Place, Harte Ranch,
1; 0.6 mi. S, 1.5 mi. E Key Place, Harte Ranch, 1.

Yancey et al.-Mammals of the Harte Ranch Area of Big Bend National Park

3

Table 1 .— Gazeteer of geographic localities, Harte Ranch , Big Bend National Park.

1. Mountain Lodge, Harte Ranch

2. 1 mi. N Mountain Lodge, Harte Ranch

3. 0.75 mi. N Mountain Lodge, Harte Ranch

4. 0.25 mi. N, 2.25 mi. W Mountain Lodge, Harte Ranch

5. 0.5 mi. N, 2 mi. W Mountain Lodge, Harte Ranch

6. 0.3 mi. N, 2 mi, W Mountain Lodge, Harte Ranch

7. 0.5 mi. N, 1.5 mi. W Mountain Lodge, Harte Ranch

8. 0.5 mi. N, 0.1 mi. W Mountain Lodge, Harte Ranch

9. 1.75 mi. N, 2.75 mi. E Mountain Lodge, Harte Ranch

10. 2.1 mi. N, 3.2 mi. E Mountain Lodge, Harte Ranch

11. 1.75 mi. N, 1.5 mi. E Mountain Lodge, Harte Ranch

12. 1.5 mi. N, 2 mi. E Mountain Lodge, Harte Ranch

13. 1.5 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch

14. 1.5 mi. N, 0.75 mi. E Mountain Lodge, Harte Ranch

15. 1.25 mi. N, 1 mi. E Mountain Lodge, Harte Ranch

16. 1 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch

17. 2.5 mi. W Mountain Lodge, Harte Ranch

18. 0.5 mi, S Mountain Lodge, Harte Ranch

19. 0.5 mi, S, 2.5 mi. W Mountain Lodge, Harte Ranch

20. 1 mi. S, 2.5 mi. W Mountain Lodge, Harte Ranch

21. 1.25 mi. S, 2.5 mi. W Mountain Lodge, Harte Ranch

22. 1.25 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch

23. 1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch

24. 2 mi. S, 0.5 mi. E Mountain Lodge, Harte Ranch

25. 1.3 mi. N Mountain Lodge, Harte Ranch

26. 1.5 mi. N, 0.4 mi. E Mountain Lodge, Harte Ranch

27. 0.4 mi. N, 1 mi. W Mountain Lodge, Harte Ranch

28. 2.5 mi. N, 4 mi. W Mountain Lodge, Harte Ranch

29. 1.3 mi. N, 4 mi. W Mountain Lodge, Harte Ranch

30. LI mi. S, 3.8 mi. W Mountain Lodge, Harte Ranch

31. Key Place, Harte Ranch

32. 1.5 mi. N, 2.6 mi. E Key Place, Harte Ranch

33. 0.4 mi. N, 0.8 mi. E Key Place, Harte Ranch

34. 0.4 mi. N, 1.2 mi. E Key Place, Harte Ranch

35. 0.25 mi. N Key Place, Harte Ranch

36. 0.25 mi. N, 0.25 mi. E Key Place, Harte Ranch

37. 0.5 mi. S, 1.5 mi. E Key Place, Harte Ranch

38. 0.6 nu. S, 1.5 mi. E Key Place, Harte Ranch

39. Headquarters, Harte Ranch

40. 2.5 mi. N, 1 mi. W Headquarters, Harte Ranch

41. 0.25 mi. N, l mi. W Headquarters, Harte Ranch

42. 0.25 mi. N, 1 mi. E Headquarters, Harte Ranch

43. 1.25 mi. W Headquarters, Harte Ranch

44. 1.25 mi. E Headquarters, Harte Ranch

45. 0.75 mi. S Headquarters, Harte Ranch

46. 0.5 mi. N, 1.4 mi. W Headquarters, Harte Ranch

47. 0.1 mi. W Airstrip Lodge, Harte Ranch

48. 2.2 mi. N, 7,25 mi. W Persimmon Gap Ranger Station,
Harte Ranch

49. 4 mi. S Persimmon Gap Ranger Station. Harte Ranch

50. 4 mi. S, 0.5 mi. E Persimmon Gap Ranger Station, Harte
Ranch

51. 4 mi. S, 1 mi. E Persimmon Gap Ranger Station, Harte
Ranch

52. 4 mi. S, 2 mi. W Persimmon Gap Ranger Station, Harte
Ranch

53. 4 mi. S, 0.5 mi. W Persimmon Gap Ranger Station, Harte
Ranch

54. 4.25 mi. S, 1.75 mi W Persimmon Gap Ranger Station,
Harte Ranch

55. 4.25 mi. S, 1.25 mi. W Persimmon Gap Ranger Station,
Harte Ranch

56. 5 mi. S, 2.5 mi. W Persimmon Gap Ranger Station, Harte
Ranch

57. 2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger Station,

Harte Ranch

58. Coyote Tank, 0.25 mi. N, 6.6 mi. W Persimmon Gap
Ranger Station, Harte Ranch

59. Northwest Windmill, 1 mi. N, 7 mi. W Persimmon Gap
Ranger Station, Harte Ranch

60. Crazy Windmill, 0.7 mi. S, 3.2 mi. W Mountain Lodge,
Harte Ranch

61. Southeast Windmill, 5.1 mi S, 0.5 mi. E Persimmon Gap
Ranger Station, Harte Ranch

62. Buttrill Spring, Harte Ranch

63. 0.1 mi. N, 1.5 mi. E Twin Peaks, Harte Ranch

64. Cedar Creek, 0.75 mi. E Twin Peaks, Harte Ranch

65. Cedar Creek, 0.8 mi. S, 0.4 mi. E Twin Peaks, Harte Ranch

66. Rosillos Peak, Harte Ranch

Checklist of mammals known to occur on the Harte Ranch section of Big Bend National Park.

Table 2 —

Order Chiroptera f4 Bats

Family Vespertilionidae (vespertilionid bats)
Myotis yumanensis (Yuma myotis)

Pipistrellus hesperus (western pipistrelle)
Eptesicus fnscus (big brown bat)

Lasiurus cine reus (hoary bat)

Corynorhintis townsendii (Townsend’s big-
eared bat)

Antrozous pallidus (pallid bat)

Family Molossidae (free-tailed bats)

Tadarida brasiliensis (Brazilian free-tailed bat)

Order Lagomorpha — Lagomorphs
Family Leporidae (hares and rabbits)

Sylvilagus audubonii (desert cottontail)

Lepus californicus (black-tailed jackrabbit)
Order Rodentia — Rodents

Family Sciuridae (squirrels and allies)

Ammospermophilus interpres (Texas antelope
squirrel)

Spermophilus spilosoma (spotted ground

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Occasional Papers, Museum of Texas Tech University

Table 2. (coni.)

squirrel)

Spermophilus vanegalus (rock squirrel)

Family Geomyidae (pocket gophers)

Cratogeomys castanops (yellow-faced pocket
gopher)

Family Heteromyidae (pocket mice and kangaroo
rats)

Perognathus flavus (silky pocket mouse)
Chaetodipus eremicus (Chihuahuan Desert
pocket mouse)

Chaetodipus nelsoni (Nelson’s pocket mouse)
Dipodomys merriami (Merriam’s kangaroo rat)
Dipodomys ordii (Ord’s kangaroo rat)

Family Muridae (mice and rats)

Reithrodontomys megalot is (western harvest
mouse)

Peromyscus boy Hi (brush mouse)

Peromyscus eremicus (cactus mouse)
Peromyscus leu Copus (white-footed mouse)
Peromyscus maniculatus (deer mouse)
Peromyscus pectoralls (white-ankled mouse)
Onychomys arenicola (Mearns’ grasshopper
mouse)

Sigmodon hispidus (hispid cotton rat)

Neotom a mexicana (Mexican woodrat)

Neotom a micropus (southern plains woodrat)
Family Erethizontidae (New World porcupines)

Erethizon dorsatum (porcupine)

Order Carnivora — Carnivores
Family Canidae (canids)

Can is latrans (coyote)

Urocyon cinereoargenteus (common gray fox)
Family Procyonidae (procyonids)

Bassariscits astntus (ringtail)

Procyon lotor (common raccoon)

Family Mustelidae (mustelids)

Mustela frenata (long-tailed weasel)

Family Mephitidae (skunks)

Mephitis mephitis (striped skunk)

Family Felidae (cats)

pel is concolor (mountain lion)

Lynx rufus (bobcat)

Order Artiodactyla — Even-toed Ungulates
Family Dicotylidae (peccaries)

Tayassu tajacu (collared peccary)

Family Cervidae (cervids)

Cervus elaphus (elk)

Odocoileus hemionus (mule deer)

Family Antilocapridae (pronghorn)

Antilocapra americana (pronghorn)

Family Bovidae (bovids)

Ammotragus lervia (Barbary sheep)

Antrozous pallidus pallidus

(Le Conte 1856)

The pallid bat was found commonly from March
through September during this study, especially in as¬
sociation with man-made structures and open water.
Before the collapse of the structure, the old adobe
house at the former headquarters of the Harte Ranch
was an important night roost for these bats. Pregnant
females (embryo crown-rump length, 23-26) were
obtained on 19 and 22 May, respectively. Lactating
females were present on 19-21 July. Testes of a male
captured in March measured 5x3; bats obtained in
May had testes that ranged in size from 2 x 1 to 6 x 2.
A male examined in August had testes that measured 9
x 5. Volant young-of-the-year pallid bats were present
in July and August.

Specimens examined (22).—Mountain Lodge,
Harte Ranch, 17; Key Place, Harte Ranch, 2; Head¬
quarters, Harte Ranch, 3.

Tadarida brasiliensis mexicana

(Saussure 1860)

Brazilian free-tailed bats were captured in mist
nets set over water from March through November.
As a result of the well-known segregation of sexes in
these bats, females were obtained only in March (3),
October (2), and November (1). Measurements of tes¬
tes of males ranged from 2 x 1 to 6 x 3; animals with
the larger testes were obtained in September, October,
and November.

Specimens examined (59).—Mountain Lodge,
Harte Ranch, 59.

Yancey et al.-Mammals of the Harte Ranch Area of Big Bend National Park

5

Sylvilagus auduhonii minor

(Mearns 1896)

On the Harte Ranch, the desert cottontail is found
primarily in xeric lowlands, especially in Nine Point
Draw and its tributaries. It seems that these mammals
are especially wary in the area; they are not found far
from cover. Desert cottontails were rare during the
first two years of this study. However, in May and
June of 1992, they were abundant, and many young
animals were observed. Lactating females were taken
in March, May, and August. A female with six fe¬
tuses (crown-rump length, 35), one with three fetuses
(crown-rump length, 12), and a female with two fetuses
(crown-rump length, 55) were collected in March, May,
and August, respectively. Testes of males collected in
March through November measured from 27 x 17 to
50 x 20. A male taken on 8 November exhibited fresh
winter pelage,

Specimens examined (12).—Mountain Lodge,
Harte Ranch, 2; 1 mi. N Mountain Lodge, Harte Ranch,
2; 1.3 mi. N Mountain Lodge, Harte Ranch, 1; 0.5 mi.
N, 1.5 mi. W Mountain Lodge, Harte Ranch, 1; 1.25
mi. N, 1 mi. E Mountain Lodge, Harte Ranch, 1; 1.5
mi. N, 0.4 mi. E Mountain Lodge, Harte Ranch, 1; 1.5
mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch, 1; 1.75
mi. N, 1.5 mi. E Mountain Lodge, Harte Ranch, 1; 0.25
mi. N Key Place, Harte Ranch, 1; 4 mi. S Persimmon
Gap Ranger Station, Harte Ranch, 1.

Lepus californicus texianus
Waterhouse 1848

The black-tailed jackrabbit is a widespread and
often common inhabitant of the study area, especially in
open creosote bush and mesquite grasslands. Although
no precise census data are available, it seems that this
hare was increasing in numbers in the area during the
last year of our study. Reproductive data gathered on L.
californicus included a female with one fetus (crown-
rump length, 28) collected in July, one with three fetuses
(crown-rump length, 40) obtained in August, and a
female containing two fetuses (crown-rump length,
38) examined in September. Lactating females were
collected in March, July, and August. Testes of adult
males measured in June were 42 x 19, whereas males
collected in August had testes that were 25 x 10, 28 x
8, and 50 x 18, respectively.

Specimens examined (18).—Mountain Lodge,
Harte Ranch, 1; 1 mi. N Mountain Lodge, Harte Ranch,
2; 0.25 mi. N, 2.25 mi. W Mountain Lodge, Harte
Ranch, 1; 1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte
Ranch, 1; 1.5 mi. N, 2 mi. E Mountain Lodge, Harte
Ranch, 1; 1.75 mi. N, 2.75 mi. E Mountain Lodge, Harte
Ranch, 1; 0.5 mi. S, 1.5 mi. E Key Place, Harte Ranch,
1; 0.25 mi. N Key Place, Harte Ranch, l; 1.5 mi. N, 2.6
mi. E Key Place, Harte Ranch, 1; Headquarters, Harte
Ranch, 3; 0.7 mi. N Headquarters, Harte Ranch, 1; 4.25
mi. S, 1.25 mi. W Persimmon Gap Ranger Station, Harte
Ranch, 1; 4 mi. S, 2 mi. W Persimmon Gap Ranger Sta¬
tion, Harte Ranch, 1; 4 mi. S Persimmon Gap Ranger
Station, Harte Ranch, 1; 4 mi. S, 0.5 mi. E Persimmon
Gap Ranger Station, Harte Ranch, 1.

Ammospermophilus interpres
(Merriam 1890)

The Texas antelope squirrel is not common on
the Harte Ranch. Animals were observed on several
occasions along the road in the vicinity of Key Place,
and near the western boundary of the area, but none
were collected. As with several other kinds of mam¬
mals in the area, we were impressed with the wariness
exhibited by this species.

Specimens examined (0).

Spermophilus spilosoma marginatus
Bailey 1890

Spotted ground squirrels occur predominantly
in habitats on coarse, sandy-gravelly soils in the area.
These animals also are wary; they seldom ventured far
from cover of shrubs and grasses. Information obtained
on reproduction in this species includes females col¬
lected in September with four and seven placental scars,
respectively. A male obtained in May had testes that
measured 22 x 13; measurements of testes of an animal
collected in September were 13x7. A male examined
on 21 May exhibited distinct molting of the pelage.
Some of these ground squirrels taken in September and
October had extensive deposits of fat.

Specimens examined (8).—0.5 mi. S, 2.5 mi. W
Mountain Lodge, Harte Ranch, 1; 2.1 mi. N, 3.2 mi.
E Mountain Lodge, Harte Ranch, l; 0.25 mi. N, 0.25

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Occasional Papers, Museum of Texas Tech University

mi. E Key Place, Harte Ranch, 3; 0.4 mi. N, 0.2 mi. E
Key Place, Harte Ranch, 1; 0.4 mi. N, 0.8 mi. E Key
Place, Harte Ranch, 1; 0.4 mi. N, 1.2 mi. E Key Place,
Harte Ranch, 1.

Spermophilus variegatus grammurus

(Say 1823)

Rock squirrels were observed in the vicinity of
Buttrill Spring and on rocky outcrops on the western
slopes of the Rosillos Mountains, however no speci¬
mens of this taxon were collected. In addition to being
uncommon in the area, these squirrels were extremely
wary.

Specimens examined (0).

Cratogeomys castanops clarkii

(Baird 1855)

Yellow-faced pocket gophers were found in deep,
sandy soils of the lowlands in the western portion of the
study area. In addition these animals were located in
shallow, rocky soils in the vicinity of Mountain Lodge.
Schmidly (1977) reported that these gophers require
topsoils of a depth of seven to eight inches, suggesting
that C. castanops should be distributed more widely in
the area than our records indicate. A female obtained in
September contained three fetuses (crown-rump length,
49). Measurements of testes of a male collected in No¬
vember were 7x5. Animals taken in May, September,
and November exhibited evidence of molting.

Specimens examined (5).—Mountain Lodge,
Harte Ranch, 2; 0.75 mi. N Mountain Lodge, Harte
Ranch, 1; 1 mi. S, 2.5 mi. W Mountain Lodge, Harte
Ranch, 1; 1.25 mi. S, 2.5 mi. W Mountain Lodge,
Harte Ranch, l.

Perognathus flavus gilvus

Osgood 1900

The silky pocket mouse was one of the more com¬
mon small rodents encountered throughout the study
area. Although not especially abundant in any given
place at any given time, this heteromyid was obtained in
numerous habitats on both sandy and rocky substrates
during the course of this study. Our perceptions of the

habitat preferences of this rodent coincide with those
determined by Porter (1962). Pregnant females were
taken in March (4 fetuses, crown-rump length, 7),
July (3 fetuses, crown-rump length, 4), and August (6
fetuses, crown-rump length, 3; 3 fetuses, crown-rump
length, 5; 4 fetuses, crown-rump length, 10; 3 fetuses,
crown-rump length, 11; 4 fetuses, crown-rump length,
12; 2 fetuses, crown-rump length, 18). Lactating fe¬
males also were collected in August. Measurements of
testes of males taken in various months were recorded
as follows: March, 4x2; May, 6x3; July, 2 x 2, 3
x 2, 5 x 4, 7 x 4; August, 2 x 1, 2 x 2, 4 x 2, 4 x 3;
November, 2x1. Animals undergoing seasonal molt
were examined in July and August.

Specimens examined (64).—Mountain Lodge,
Harte Ranch, 7; 2.5 mi. N, 4 mi. W Mountain Lodge,
Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain Lodge,
Harte Ranch, 1; 1.25 mi. S, 2.75 mi. W Mountain
Lodge, Harte Ranch, 9; 1.5 mi. S, 2.75 mi. W Mountain
Lodge, Harte Ranch, 1; 1.1 mi. S, 3.8 mi. W Mountain
Lodge, Harte Ranch, 6; 1 mi. N, 0.5 mi. E Mountain
Lodge, Harte Ranch, 4; 0.5 mi. S, 1.5 mi. E Key Place,
Harte Ranch, 2; Headquarters, Harte Ranch, 1; 0.25
mi. N, 1 mi. E Headquarters, Harte Ranch, 1; 0.5 mi.
N, 1.4 mi, W Headquarters, Harte Ranch, 1; 4 mi. S
Persimmon Gap Ranger Station, Harte Ranch, 1; 4
mi. S, 1 mi. E Persimmon Gap Ranger Station, Harte
Ranch, 2; 4 mi. S, 0.5 mi. E Persimmon Gap Ranger
Station, Harte Raneh, I; 4.25 mi. S, 1.25 mi. E Persim¬
mon Gap Ranger Station, Harte Ranch, 9; Southeast
Windmill, 5 mi. S, 0.5 mi. E Persimmon Gap Ranger
Station, Harte Ranch, 1; 0.1 mi. N, 1.5 mi. E Twin
Peaks, Harte Ranch, 4; Cedar Creek, 0.75 mi. E Twin
Peaks, Harte Ranch, 10; Cedar Creek, 0.8 mi. S, 0.4
mi. E Twin Peaks, Harte Ranch, 1.

Chaetodipus eremicus

(Mearns 1898)

In accordance with the preferences of habitats of
these pocket mice reported by Porter (1962), we found
the Chihuahuan Desert pocket mouse in all kinds of
vegetation in habitats on rock-free, sandy soils (and
occasionally on gravel) where we sampled mammals
during this study. This mouse was the most abundant
heteromyid collected during our fieldwork at Harte
Ranch. Females carrying fetuses were obtained in

Yancey et al-M ammals of the Harte Ranch Area of Big Bend National Park

7

March (3 fetuses, crown-rump length, 1.5; 5 fetuses,
crown-rump length, 6), May (6 fetuses, crown-rump
length, 4), June (8 fetuses, crown-rump length, 2; 6
fetuses, crown-rump length, 7), July (2 fetuses, crown-
rump length, 3), August (4 fetuses, crown-rump length,
5; 4 fetuses, crown-rump length, 12; 3 fetuses, crown-
rump length, 21), September (4 fetuses, crown-rump
length, 10), and November (3 fetuses, crown-rump
length, 13). Ranges of measurements of testes of
males were recorded as follows: March, 7 x 4 - 11 x
6; June, 3 x 2 - 8 x 4; July, 3x1 -7x3; August, 6x4
- 10x4; September, 4 x 2 - 6 x 3; November, 3x1,4
x 1. Molting was noted in specimens obtained during
July and August.

Specimens examined (179).—Mountain Lodge,
Harte Ranch, 5; 1.5 mi. S, 2.75 mi. W Mountain
Lodge, Harte Ranch, 51; 0.5 mi. N, 2 mi. W Mountain
Lodge, Harte Ranch, 1; 2.5 mi. N, 4 mi. W Mountain
Lodge, Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain
Lodge, Harte Ranch, 4; 2.5 mi. W Mountain Lodge,
Harte Ranch, 3; Crazy Windmill, 0.7 mi. S, 3.2 mi. W
Mountain Lodge, Harte Ranch, 2; 1 mi. N, 0.5 mi. E
Mountain Lodge, Harte Ranch, 2; 1.5 mi. N, 0.5 mi. E
Mountain Lodge, Harte Ranch, 1; 1 mi. N, 0.5 mi. E
Mountain Lodge, Harte Ranch, 3; Headquarters, Harte
Ranch, 4; 0.25 mi. N Headquarters, Harte Ranch, 2;
0.75 mi. N Headquarters, Harte Ranch, 6; 1.25 mi. E
Headquarters, Harte Ranch, 14; 2.5 mi. N, 1 mi. W
Headquarters, Harte Ranch, 6; Buttrill Spring, Harte
Ranch, 3; 0.1 mi. W Airstrip Lodge, Harte Ranch, 1;
Key Place, Harte Ranch, 1; 0.5 mi. S, 1.5 mi. E Key
Place, Harte Ranch, 7; 1.4 mi. S, 3.4 mi. E Key Place,
Harte Ranch, 5; Bone Spring, Harte Ranch, l; 4 mi.
S Persimmon Gap Ranger Station, Harte Ranch, 6;
4 mi. S, 0.5 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 1; 4.25 mi. S, 1.25 mi. W Persimmon
Gap Ranger Station, Harte Ranch, l; 4.25 mi. S, 1.75
mi. W Persimmon Gap Ranger Station, Harte Ranch,
8; 5 mi. S, 2.5 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 8; 2.2 mi. N, 7.25 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 6; North Windmill, 1
mi. N, 7 mi. W Persimmon Gap Ranger Station, Harte
Ranch, 2; 2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger
Station, Harte Ranch, 4; Coyote Tank, 0.25 mi. N, 6.6
mi. W Persimmon Gap Ranger Station, Harte Ranch,
7; 4 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
Harte Ranch, 2; 4 mi. S, 1 mi. E Persimmon Gap
Ranger Station, Harte Ranch, 5; Southeast Windmill,

5.1 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
Harte Ranch, 3; Cedar Creek, 0.8 mi. S, 0.4 mi. ETwin
Peaks, Harte Ranch, 2.

Chaetodipus nelsoni canescens
(Merriam 1904)

Nelson’s pocket mouse occurs in habitats on
gravelly and rocky substrates within the study area.
Precise habitats of this heteromyid in the Big Bend area
were described in detail by Porter (1962). We found
pregnant females of this species only in June (3 fetuses,
crown-rump length, 5; 4 fetuses, crown-rump length, 8)
and August (5 fetuses, crown-rump length, 8). Testes of
males taken through the year were measured as follows:
March, 8x4; May, 12x6; June, 8x4; July, 11 x 4, 9 x

4, 8 x 3; August, 3 x l, 4 x 2, 5 x 2; September, 5x2;
November, 4 x 2, 6 x 3, 6 x 4. Young-of-the-year were
collected in July and August. Based on examination of
specimens obtained, molting of pelage seemingly takes
place in late summer (July, August).

Specimens examined (121).—Mountain Lodge,
Harte Ranch, 25; 0.5 mi. N, 0.1 mi. W Mountain Lodge,
Harte Ranch, 10; 0.3 mi. N, 2 mi. W Mountain Lodge,
Harte Ranch, 7; 1 mi. N Mountain Lodge, Harte Ranch,
1; 2.5 mi. N, 4 mi. W Mountain Lodge, Harte Ranch,
1; 2 mi. S, 0.5 mi. E Mountain Lodge, Harte Ranch, 7;
Buttrill Spring, Harte Ranch, 33; 0.5 mi. S, 1.5 mi. E
Key Place, Harte Ranch, 11; 1.4 mi. S, 3.4 mi. E Key
Place, Harte Ranch, 5; 0.5 mi. N, 1.5 mi. W Headquar¬
ters, Harte Ranch, 7; 4.25 mi. S, 1.25 mi. W Persimmon
Gap Ranger Station, Harte Ranch, 1; 4 mi. S, 0.5 mi. E
Persimmon Gap Ranger Station, Harte Ranch, 1; 4 mi.

5, 1 mi. E Persimmon Gap Ranger Station, 1; 0.1 mi.

N, L5 mi. ETwin Peaks, Harte Ranch, 4; Cedar Creek,

O. 75 mi. E Twin Peaks, Harte Ranch, 3; Cedar Creek,
0.8 mi. E, 0.4 mi. S Twin Peaks, Harte Ranch, 4.

Dipodomys merriami ambiguus
Merriam 1890

Merriam’s kangaroo rat was associated most
commonly with gravelly and rocky soils, but with a
wide array of types of vegetation. Reproductive data
gathered on this species included pregnant females
taken in March (3 fetuses, crown-rump length, 12),

8

Occasional Papers, Museum of Texas Tech University

May (2 fetuses, crown-rump length, 6), July (2 fetuses,
crown-rump length, 15), August (2 fetuses, crown-
rump length, 29; 4 fetuses, crown-rump length, 4; 3
fetuses, crown-rump length, 3), September (3 fetuses,
crown-rump length, 17), October (2 fetuses, crown-
rump length, 6), and November (3 fetuses, crown-
rump length, 10; 2 fetuses, crown-rump length, 14).
Like females, males exhibited reproductive activity
throughout most of the year; some measurements of
testes were as follows: March (15x8; 10x4), July
(11 x 6; 12x6), August (II x 6), September (14x7;
10x5), October (16x8), November (11 x 6; 15x5).
Young-of-the-year Merriam’s kangaroo rats were col¬
lected in August. It is of interest that one of the young
D. merriami obtained in August had cheeks and the
entire venter covered with yellow pollen. Seeds, as
well as insects and green vegetation, are the major food
items of this rat (Schmidly 1977).

Specimens examined (88).—Mountain Lodge,
Harte Ranch, 5; 1.5 mi. S, 2.75 mi. W Mountain Lodge,
Harte Ranch, 18; 0.25 mi. N, 2.25 mi. W Mountain
Lodge, Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain
Lodge, Harte Ranch, 2; 2.5 mi. N, 4 mi. W Mountain
Lodge, Harte Ranch, 3; 0.3 mi. N, 2 mi. W Mountain
Lodge, Harte Ranch, 1; 1.1 mi. S, 3.8 mi. W Mountain
Lodge, Harte Ranch, 5; 1 mi. N, 0.5 mi. E Mountain
Lodge, Harte Ranch, 2; Headquarters, Harte Ranch, 1;
2.5 mi. N, 1 mi. W Headquarters, Harte Ranch, 2; 0.25
mi. N, 1 mi. E Headquarters, Harte Ranch, 2; 1.25 mi E
Headquarters, Harte Ranch, 2; 0.5 mi. S, 1.5 mi. E Key
Place, Harte Ranch, 2; 1.4 mi. S, 3.4 mi. E Key Place,
Harte Ranch, 1; 4 mi. S Persimmon Gap Ranger Sta¬
tion, Harte Ranch, 7; 4 mi. S, 0.5 mi. E Persimmon Gap
Ranger Station, Harte Ranch, 9; 4 mi. S, 1 mi. E Per¬
simmon Gap Ranger Station, Harte Ranch, 4; 4.25 mi.
S, 1.25 mi. W Persimmon Gap Ranger Station, Harte
Ranch, l; 5 mi. S, 2.5 mi. W Persimmon Gap Ranger
Station, Harte Ranch, 4; 4 mi. S, 0.5 mi. W Persimmon
Gap Ranger Station, Harte Ranch, 1; 2.2 mi. N, 7.25
mi. W Persimmon Gap Ranger Station, Harte Ranch,
2; Coyote Tank, 0.25 mi. N, 6.6 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 3; 2.2 mi. N, 6.3 mi. W
Persimmon Gap Ranger Station, Harte Ranch, 3; 0.1
mi. N, 1.5 mi. E Twin Peaks, Harte Ranch, 2; Cedar
Creek, 0.75 mi. E Twin Peaks, Harte Ranch, 4.

Dipodomys ordii obscunis
(J. A. Allen 1903)

Ord’s kangaroo rat was not common during the
tenure of our work on Harte Ranch. This rat was en¬
countered only on sandy soils associated with arroyos
and roads. Females carrying fetuses were obtained only
in August (3 fetuses, crown-rump length, 5; 3 fetuses,
crown-rump length, 6; 2 fetuses, crown-rump length,
28). Ranges of measurements of testes of males taken
were recorded as follows: May, 10x6; August, 6x4
- 12x7; September, 9x3- 16 x 10. A juvenile D. ordii
was taken in July. Some animals examined in August
exhibited molting of pelage.

Specimens examined (20)^1.25 mi. S, 2.75 mi.
W Mountain Lodge, Harte Ranch, 10; 1.5 mi. S, 2.75
mi. W Mountain Lodge, Harte Ranch, 3; 1.1 mi. S, 3.8
mi. W Mountain Lodge, Harte Ranch, 2; 0.3 mi. N, 2
mi. W Mountain Lodge, Harte Ranch, 1; 1.3 mi. N, 4
mi. W Mountain Lodge, Harte Ranch, 2; 0.4 mi. N, 1.2
mi. E Key Place, Harte Ranch, 1; Southeast Windmill,
5.1 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
Harte Ranch, I.

Reithrodontomys megalotis megalotis
(Baird 1858)

The western harvest mouse was encountered rather
sporadically in the area during this study. This rodent
preferred habitats in lowlands, with rank vegetation that
provides a rather thick thatch of ground cover. Harvest
mice were most common in areas adjacent to earthen
tanks and catch basins where water periodically ac¬
cumulated. Gravid females were recorded in March (3
fetuses, crown-rump length, 20), September (4 fetuses,
crown-rump length, 4; 7 fetuses, crown-rump length, 3),
and October (4 fetuses, crown-rump length, 4). Some
measurements of testes of males were recorded as fol¬
lows: March, 6 x 3, 8 x 3, 7 x 3, 4 x 2; June, 7 x 3, 7
x 4, 5 x 3; September, 10 x 5, 9 x 5, 5 x 2; October, 3
x 2, 4 x 2.

Specimens examined (30).—Buttrill Spring,
Harte Ranch, 1; Crazy Windmill, 0.7 mi. S, 3.2 mi. W
Mountain Lodge, Harte Ranch, 2; 0.25 mi. N, 1 mi. E

Yancey et al.-Mammals of the Harte Ranch Area of Big Bend National Park

9

Headquarters, Harte Ranch, 3; 1.25 mi. E Headquarters,
Harte Ranch, 2; 0.75 mi. S Headquarters, Harte Ranch,
l; North Windmill, 1 mi. N, 7 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 4; 4.25 mi. S, 1.75 mi.
W Persimmon Gap Ranger Station, Harte Ranch, 5;
2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 7; Coyote Tank, 0.25 mi. N, 6.6 mi. W
Persimmon Gap Ranger Station, Harte Ranch, 5.

Peromyscus boylii rowleyi
(J. A. Allen 1893)

The brush mouse was the least common member
of the genus Peromyscus that was encountered during
our study. This species was found only in dense, brushy
vegetation in the bottom of the ravine adjacent to the
outflow from Buttrill Spring. An adult female had 3
fetuses (crown-rump length, 21). An adult male had
testes that measured 13x7. One subadult exhibited
molting of the pelage.

Specimens examined(5). —Buttrill Spring, Harte
Ranch, 5.

Peromyscus eremicus eremicus
(Baird 1858)

The cactus mouse was the most common of all
members of the genus Peromyscus present in the study
area. The preferred habitats of this species were slopes
with large rocks, cacti, shrubs, and grasses. It is of
interest to note that a large number of these mice were
taken from within the man-made structure at Mountain
Lodge. Information on reproduction of cactus mice
includes the following: females collected in March
contained from 2 to 4 fetuses (crown-rump length, 3
- 12); May, 3 fetuses (crown-rump length, 5); July, 2
fetuses (crown-rump length, 5 - 18); August, 2 to 4
fetuses (crown-rump length, 3 - 18); September, 2 to
3 fetuses (crown-rump length, 3 - 13); and Novem¬
ber, 3 to 4 fetuses (crown-rump length, 6 - 9). Males
were reproductively active in all months of the year;
measurements of testes ranged from 8 x 3 to 10x6.
Neonates were found in nests in March and August.
Molting of pelage was observed in specimens obtained
from August through October.

Specimens examined (106).—Mountain Lodge,
Harte Ranch, 39; 0.5 mi. N, 2 mi. W Mountain Lodge,
Harte Ranch, 1; 0.3 mi. N, 2 mi. W Mountain Lodge,

Harte Ranch, 6; 2.5 mi. N, 4 mi. W Mountain Lodge,
Harte Ranch, 5; l.l mi. S, 3.8 mi. W Mountain Lodge,
Harte Ranch, 3; 2 mi. S, 0.5 mi. W Mountain Lodge,
Harte Ranch, 3; Buttrill Spring, Harte Ranch, 2; 0.1
mi. W Airport Lodge, Harte Ranch, 7; Headquarters,
Harte Ranch, 1; 2.5 mi. N, 1 mi. W Headquarters,
Harte Ranch, 2; 0.5 mi. N, 1.4 mi. W Headquarters,
Harte Ranch, 2; 0.25 mi. N, 1 mi. E Headquarters,
Harte Ranch, 1; 0.5 mi. S, 1.5 mi. E Key Place, Harte
Ranch, 5; 4 mi. S Persimmon Gap Ranger Station,
Harte Ranch, 3; 4 mi. S, 0.5 mi. E Persimmon Gap
Ranger Station, Harte Ranch, 2; 4.25 mi. S, 1.25 mi.
W Persimmon Gap Ranger Station, Harte Ranch, 4;
2.2 mi. N, 7.25 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 3; 2.2 mi. N, 6.3 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 7; 0.1 mi. N, 1.5 mi. E
Twin Peaks, Harte Ranch, 7; Cedar Creek, 0.75 mi. E
Twin Peaks, Harte Ranch, 2; Cedar Creek, 0.8 mi. S,
0.4 mi. E Twin Peaks, Harte Ranch, 1.

Peromyscus leucopus texanus
(Woodhouse 1853)

The white-footed mouse was most abundant in
lowland areas of creosote scrub, especially in places
where vegetation (grasses, forbs) occurred among the
creosote bushes. Pregnant females were examined in
March (4-6 fetuses, crown-rump length, 3 - 19), May
(3-6 fetuses, crown-rump length, 10 - 12), September
(3-5 fetuses, crown-rump length, 11-16), and October
(4 fetuses, crown-rump length, 4). Lactating females
were taken in each of these months also. Males ex¬
hibited evidence of reproductive activity in all months
of the year; measurements of testes ranged from 6 x
3 to 18x7.

Specimens examined (97).—0.3 mi. N, 2 mi. W
Mountain Lodge, Harte Ranch, 1; 1.25 mi. S, 2.75 mi.
W Mountain Lodge, Harte Ranch, 7; Crazy Windmill,
0.7 mi. S, 3.2 mi. W Mountain Lodge, Harte Ranch, 8;
1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch,
7; 1.1 mi. S, 3.8 mi. W Mountain Lodge, Harte Ranch,
1; 1 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch,
1; Buttrill Spring, Harte Ranch, 6; 0.25 mi. N, 0.25
mi. E Key Place, Harte Ranch, 1; 0.4 mi. N, 0.8 mi. E
Key Place, Harte Ranch, 2; 0.5 mi. S, 1.5 mi. E Key
Place, Harte Ranch, 3; 0.25 mi. N, 1 mi. E Headquar¬
ters, Harte Ranch, 15; 1.25 mi. W Headquarters, Harte
Ranch, 1; 0.75 mi. S Headquarters, Harte Ranch, 1;
1.25 mi. E Headquarters, Harte Ranch, 7; 2.5 mi. N, 1

10

Occasional Papers, Museum of Texas Tech University

mi. W Headquarters, Harte Ranch, 2; 4.25 mi. S, 1.75
mi. W Persimmon Gap Ranger Station, Harte Ranch,
3; Southeast Windmill, 5.1 mi. S, 0.5 mi. E Persimmon
Gap Ranger Station, Harte Ranch, 2; 2.2 mi. N, 7.25
mi. W Persimmon Gap Ranger Station, Harte Ranch,
5; North Windmill, 1 mi. N, 7 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 11; 2.2 mi. N, 6.3 mi. W
Persimmon Gap Ranger Station, Harte Ranch, 4; Coyote
Tank, 0.25 mi. N, 6.6 mi. W Persimmon Gap Ranger
Station, Harte Ranch, 9.

Peromyscus maniculatus blandus
Osgood 1904

This deer mouse was taken in lowland habitats,
usually in areas that were relatively open with regard to
vegetation. Pregnant females were collected in March
(4 fetuses, crown-rump length, 4), August (4 fetuses,
crown-rump length, 5; 3 fetuses, crown-rump length,
8), and September (5 fetuses, frown-rump length, 6;
6 fetuses, crown-rump length, 4). Measurements of
testes of males obtained in several months were as fol¬
lows: March, 10 x 6, 9 x 4; June, 8x5; August, 11 x
4; October, 10x5.

Specimens examined (26).—2.5 mi. N, 4 mi. W
Mountain Lodge, Harte Ranch, 1; 0.7 mi. S, 3.2 mi. W
Mountain Lodge, Harte Ranch, 2; 1.25 mi. S, 2.75 mi.
W Mountain Lodge, Harte Ranch, 3; 1.1 mi. S, 3.8 mi.
W Mountain Lodge, Harte Ranch, 1; 1.4 mi. N, 3.4 mi.
E Key Place, Harte Ranch, 1; 0.25 mi. N, 1 mi. E Head¬
quarters, Harte Ranch, 1; 1.25 mi. E Headquarters, Harte
Ranch, 1; North Windmill, 1 mi. N, 7 mi. W Persimmon
Gap Ranger Station, Harte Ranch, 2; Coyote Tank, 0.25
mi. N, 6.6 mi. W Persimmon Gap Ranger Station, Harte
Ranch, 8; 2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger
Station, Harte Ranch, 6.

Peromyscus pectoralis laceianus
Bailey 1906

The white-ankled mouse was collected on a rocky
slope with fairly open vegetation above the outflow
from Buttrill Spring, as well as on a rock-strewn area on
Rosillos Peak. A female obtained in October contained
4 fetuses (crown-rump length, 4). Measurements of
testes of males taken in May ranged from 6 x 3 to 11 x
5; animals examined in August had testes that ranged
in measurements from 10 x 5 to 14x8.

Specimens examined (17).—Buttrill Spring, Harte
Ranch. 11; Rosillos Peak, Harte Ranch, 6.

Onychomys arenicoia arenicola
Mearns 1896

Schmidly (1977) reported that Mearn’s grasshop¬
per mouse was extremely rare in the Big Bend region,
based, in part, on only a single specimen known at that
time from Big Bend National Park. This mouse was
reported to occur in lowland habitats in association
with D. merriami (Schmidly 1977). However, we also
found this grasshopper mouse on sandy substrates, with
open vegetation, in association with D. ordii. Pregnant
females were captured in March (4 fetuses, crown-rump
length, 6; 4 fetuses, crown-rump length, 12), July (4
fetuses, crown-rump length, 12), and August (4 fetuses,
crown-rump length, 10). A lactating female was taken
in September. Measurements of testes of males were
recorded as follows: May, 9 x 5, 20 x 9; July, 11x6;
September, 10 x 3, 7 x 3; November, 8x3. Young
animals were observed in May, June, September, and
November.

Specimens examined (13).—-Mountain Lodge,
Harte Ranch, 1; 1.3 mi. N, 4 mi. W Mountain Lodge,

Harte Ranch, 1; 0.3 mi. N, 2 mi. W Mountain Lodge,

Harte Ranch, 2; 2.5 mi. N, 4 mi. W Mountain Lodge,

Harte Ranch, 1; 1.25 mi. S, 2.75 mi. W Mountain

Lodge, Harte Ranch, 1; 1.5 mi. S, 2.75 mi. W Mountain
Lodge, Harte Ranch, 3; Crazy Windmill, 0.7 mi. S, 3.2
mi. W Mountain Lodge, Harte Ranch, 2; Coyote Tank,
2.5 mi. N, 4 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 1; 0.1 mi. N, 1.5 mi. E Twin Peaks, Harte
Ranch, 1.

Sigmodon hispidus berlandieri
Baird 1855

The hispid cotton rat was found commonly in
thick vegetation in lowland areas, especially in the
vicinity of earthen tanks and catch basins where water
periodically accumulated. However, this mammal also
occasionally was taken in open creosote shrub areas,
as well as in rocky habitats, such as at the base of
Chalk Ridge. Gravid females were observed in March
(7 fetuses, crown-rump length, 3), August (8 fetuses,
crown-rump length, 10), and September (6 fetuses,
crown-rump length, 15). Males were reproductively

Yancey et al.-Mammals of the Harte Ranch Area of Big Bend National Park

11

active throughout most of the year; measurements of
testes ranged from 8 x 4 in March to 30 x 12 in Sep¬
tember.

Specimens examined (40).—Mountain Lodge,
Harte Ranch, 1; 1.25 mi. S, 2.75 mi. W Mountain
Lodge, Harte Ranch, 1; Crazy Windmill, 0.7 mi. S,
3.2 mi. W Mountain Lodge, 5; Buttrill Spring, Harte
Ranch, 4; 0.4 mi. N, 0.8 mi. E Key Place, Harte Ranch,

1; 0.25 mi. N, 0.25 mi. E Key Place, Harte Ranch, 2; 0.5
mi. S, 1.5 mi. E Key Place, Harte Ranch, 1; 0.1 mi. W
Airport Lodge, Harte Ranch, 1; 0.75 mi. S Headquar¬
ters, Harte Ranch, 1; 0.25 mi. S, 1 mi. E Headquarters,
Harte Ranch, 1; Coyote Tank, 0.25 mi. N, 6.6 mi. W
Persimmon Gap Ranger Station, Harte Ranch, 4; 1.4
mi. N, 4.6 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 5; 2.2 mi. N, 7.25 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 5; 4.25 mi. S, 1.75 mi.
W Persimmon Gap Ranger Station, Harte Ranch, 4;
5.1 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
Harte Ranch, 2; 2.2 mi. N, 6.3 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 2.

Neotoma mexicana mexicana
Baird 1855

Only one specimen of the Mexican woodrat was
obtained during this study. The animal was collected
from among large rocks on Rosillos Peak.

Specimens examined (1).—Rosillos Peak, Harte
Ranch, 1.

Neotoma micropus canescens
J. A. Allen 1891

The southern plains woodrat is well known for its
habits of constructing “houses,” or middens, consisting
of piles of sticks, cacti, and debris (Schmidly 1977).
However, we did not observe any such “houses” during
our work in the area studied, although we searched con¬
stantly for these structures. These woodrats were as¬
sociated mostly with creosote scrub-grassland habitats.
Pregnant females were obtained in March (3 fetuses,
crown-rump length, 30), May (3 fetuses, crown-rump
length, 50), July (2 fetuses, crown-rump length, 25), and

August (3 fetuses, crown-rump length, 40). A lactating
female was taken in September. Some measurements
of testes of adult males were recorded as follows: June,
18 x 8; July, 15 x 8, 15 x 10; August, 19 x 14, 17 x 8;
September, 12x6; October, 15x6.

Specimens examined (25).—Mountain Lodge,
Harte Ranch, 1; 1.3 mi. N, 4 mi. W Mountain Lodge,
Harte Ranch, 7; 0.4 mi. N, 1 mi. W Mountain Lodge,
Harte Ranch, 1; 1.5 mi. S, 2.75 mi. W Mountain Lodge,
Harte Ranch, 3; 1.1 mi. S, 3.8 mi. W Mountain Lodge,
Harte Ranch, 2; 0.25 mi. N, 1 mi. E Headquarters, Harte
Ranch, 1; 0.25 mi. N, 0.25 mi. E Key Place, Harte
Ranch, 2; North Windmill, 1 mi. N, 7 mi. W Persim¬
mon Gap Ranger Station, Harte Ranch, 1; Coyote Tank,
0.25 mi. N, 6.6 mi. W Persimmon Gap Ranger Station,
Harte Ranch, 1; 2.2 mi. N, 6.3 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 3; 4 mi. S Persimmon
Gap Ranger Station, Harte Ranch, 1; 4 mi. S, 0.5 mi.
E Persimmon Gap Ranger Station, Harte Ranch, 2;
Southeast Windmill, 5.1 mi. S, 0.5 mi, E Persimmon
Gap Ranger Station, Harte Ranch, 1.

Erethizon dorsatum epixanthum
Brandt 1835

Schmidly (1977) reported that the porcupine was
increasing in both geographic range and numbers of
animals in the Trans-Pecos. In December, we observed
a porcupine along the road at a place near an earthen
tank about 0.4 mi. N, 0.8 mi. E Key Place on the Harte
Ranch. No specimens of this taxon were collected.

Specimens examined (0).

Cams latrans texensis
Bailey 1905

Coyotes were common in a variety of habitats
throughout the study area. Sightings indicate these car¬
nivores are abundant especially in the northern portion
of Harte Ranch, such as in the vicinity of North Wind¬
mill. However, these mammals can be heard almost
nightly from Mountain Lodge and along Chalk Ridge.
No coyotes were collected during this study.

Specimens examined (0).

12

Occasional Papers, Museum of Texas Tech University

Vrocyon cinereoargenteus scottii
Mearns 1891

Based on our observations of animals, common
gray foxes are most abundant on the lower slopes north
of the Rosillos Mountains. For example, animals were
seen several times in the vicinity of Key Place and near
Mountain Lodge. No specimens of this taxon were
collected.

Specimens examined (0).

Bassariscus astutus flavus
Rhoads 1894

Ringtail sign (feces) was noted in numerous areas,
especially in the vicinity of Buttrill Spring and along
Chalk Ridge. It is assumed that the ringtail is present
throughout the study area in rocky habitats.

Specimens examined (1).—Mountain Lodge,
Harte Ranch, 1.

Procyon lotor mexicanus
Baird 1858

The unmistakable tracks of the common raccoon
were seen in mud and sand along Cedar Creek at a
place 0.75 mi. E Twin Peaks at the western boundary
of the study area. This omnivorous mammal may be
more common along watersheds in the region than
our observations indicate. No specimens of this taxon
were collected.

Specimens examined (0).

Mustela frenata neomexicana
(Barber and Cockerell 1898)

The long-tailed weasel is rare in the Trans-Pecos
region of Texas (Schmidly 1977); it occurs mostly in
areas close to permanent water.

Specimens examined (1).—0.75 mi. N Mountain
Lodge, Harte Ranch, 1.

Mephitis mephitis varians

Gray 1837

Although common in Texas, the striped skunk is
less numerous in parts of the Trans-Pecos region than
elsewhere in the state (Schmidly 1977; Jones and Jones

1992) . It occurs usually in association with agricultural
areas and in the vicinity of human habitations. We
observed striped skunks only on two occasions during
this study.

Specimens examined (1).—Key Place, Harte
Ranch, 1

Puma concolor stanleyana
Goldman 1938

The mountain lion is common in many parts of
Big Bend National Park and the Trans-Pecos area (Waid
1990), as well as in some other parts of Texas (Bigony

1993) . No mountain lions were collected or observed
directly during this study. However we observed fresh
tracks of a large and small animal (perhaps a female and
cub) in the mud of a temporary pond at a place 4.25 mi.
S and 1.75 mi. W Persimmon Gap Ranger Station.

Specimens examined (0).

Lynx rufus texensis
J. A. Allen 1895

Bobcats are fairly common in the Trans-Pecos
region (Schmidly 1977), especially in the vicinity of
rocky areas. We observed only two of these mammals
during this study; both were seen along the road, one
about 3 mi. E Mountain Lodge, and the other near the
western boundary of Harte Ranch. No specimens of
this taxon were collected.

Specimens examined (0).

Yancey et al.-Mammals of the Harte Ranch Area of Big Bend National Park

13

Tayassu tajacu angulatus

(Cope 1889)

Herds of the collared peccary often were seen,
indicating they are common in the study area. Signs
(tracks, feces, rooted areas) and animals have been
seen throughout the lowland portions of Harte Ranch.
These animals were concentrated especially in arroyos
and near sources of water in the area.

Specimens examined (1).^1.5 mi. N, 0.75 mi.
E Mountain Lodge, Harte Ranch, 1.

Cervus elaphus nelsoni
Bailey 1935

An antlered male was observed in the areajust to
the northwest of Mountain Lodge. In addition, a cow
and calf were seen in Nine Point Draw just outside
of the western boundary of the study area. The elk
observed at Harte Ranch may have wandered from
the groups of these animals that have been introduced
into either the Guadalupe or Davis mountains in recent
times. No specimens of this taxon were collected.

Specimens examined (0).

Odocoileus hemionus crooki
(Mearns 1897)

Based on sightings, mule deer are common on
the Harte Ranch. Animals (bucks, does, fawns) have
been observed on numerous occasions in all habitats of

the area, especially on the lower slopes and lowlands
adjacent to the Rosillos Mountains. Signs (tracks,
feces) and these animals seem common especially
adjacent to sources of water. No specimens of mule
deer were collected.

Specimens examined (0).

Antilocapra americana mexicana
Merriam 1901

The creosotebush-grassland flats in the eastern
portion of the study area seemingly are the preferred
habitats of pronghorn on the Harte Ranch. Pairs and
small groups of up to six animals have been seen in this
region. No specimens of this taxon were collected.

Specimens examined (0).

Ammotragus lervia

(Pallas 1777)

A male Barbary sheep was observed in the high
country south of Mountain Lodge and in the vicinity of
Rosillos Peak. Signs (tracks, feces) of this introduced
species (native of North Africa) have been observed
above Buttrill Spring. According to Traweek (1985),
the total population of Barbary sheep in the wild in
Texas exceeds 5000 animals. No specimens of Barbary
sheep were collected during this study.

Specimens examined (0).

Discussion

Schmidly (1977) listed a total of 96 species of
mammals that may have inhabited the Trans-Pecos area
within the past 100 years; of those 96 species, 42 were
found to occur on the Harte Ranch section of Big Bend
National Park. These 42 species represent 60% of the
70 species of mammals known to occur within Big Bend
National Park in its entirety (Borell and Bryant 1942;
Easterla 1973; Anonymous 1989; Jones et al. 1993).
Given the relatively small area of the Harte Ranch, these
42 species indicate a considerable amount of diversity.
Furthermore, it is probable that further field research in

the area will result in the discovery of additional species
of mammals that inhabit the Harte Ranch section of Big
Bend National Park.

Other reports on the bats of Big Bend National
Park (Easterla 1973) and adjacent areas (Schmidly
1977, 1991; Yancey 1996) suggest a considerably more
abundant and diverse bat fauna in the Big Bend region
than was noted during this study. The species composi¬
tion of a bat community is influenced by the availability
of roosting sites (day, night), as well as the abundance

14

Occasional Papers, Museum of Texas Tech University

of food items and permanent sources of water (Findley
1993), and each of these factors may have played a role
in the scarcity of bats at Harte Ranch. We have observed
that some roosting places for bats, especially man-made
structures, in the area have been impacted greatly by hu¬
man disturbances. Vandalism and collapse of some of
these structures have reduced the numbers of roosting
sites available for this important group of mammals.

Although elk and Barbary sheep were observed
in the area, the paucity of introduced mammals is
rather interesting. For example, it is noteworthy that
no specimens of either Mus or Rattus were obtained
during the time of our intensive sampling of mammals
in the area.

Some interesting trends in the composition of the
mammalian fauna of the Harte Ranch area were noted
during the course of our study. For example, during
the first year of fieldwork, specimens of Sigmodon and

Pewmyscus were difficult to obtain anywhere. However,
these particular kinds of small mammals seemed rela¬
tively abundant in appropriate habitats during subsequent
years of sampling. Incidentally, it is our perception that
many species of mammals have become more abundant
and widespread during the tenure of our studies at Harte
Ranch. This could be related to the removal of livestock
and corresponding recovery of habitats.

Based on some of the aforementioned comments
in the accounts of species, we were impressed with the
levels of wariness exhibited by some mammals, such as
desert cottontails and members of the family Sciuridae.
These habits of wariness by these mammals could be
the result of pressures from predators, such as coyotes,
bobcats, hawks, owls, and snakes. Also, we noted
throughout our study that casings of expended firearm
cartridges were common along the main road through
the Harte Ranch.

Acknowledgments

A great number of people interested in the area,
as well as students of mammals, have provided us with
numerous kinds of assistance during this study. We are
grateful especially to Mary Ann Jones, Burhan Ghara-
ibeh, Jim Goetze, Robert Hollander, and A. Michelle
Wallace for working with us and tolerating us in the
field. Ken Grigsby, Philip Koeppe, Keith Yarborough,
and Mike Fleming have assisted us also in numerous
ways. Suzy Stewart helped us greatly by making ar¬
rangements for the use of some of the facilities at Big

Bend National Park. Numerous people who live in
the areas adjacent to the Park were very courteous and
helpful to us. Special thanks are extended to George
Ellington, Alan Baker, and Mike McDougal, as well
as Dewayne Phillips and Jim Low. Special acknowl¬
edgment is given to the late J. Knox Jones, Jr., for his
direction and participation in the early stages of this
project. Permissions to collect mammals were provided
by the Texas Parks and Wildlife Department and the
National Park Service.

Literature Cited

Anonymous. 1989. Mammal checklist of Big Bend National
Park Rio Grande Wild and Scenic River 1989. Big
Bend Natural History Association.

Baker, R. J., L. C. Bradley, R. D. Bradley, J. W. Dragoo, M.
D. Engstrom, R. S. Hoffmann, C. A. Jones, F. Reid,
D. W. Rice, and C. Jones. 2003 Revised checklist
of North American mammals north of Mexico,
2003. Occasional Papers, Museum of Texas Tech
University 229:1-23.

Borell, A. E., and M. D. Bryant. 1942. Mammals of the
Big Bend area of Texas. University of California
Publications in Zoology 48:1-62.

Easterla, D. A. 1973. Ecology of 18 species of Chiroptera
at Big Bend National Park, Texas. The Northwest
Missouri State University Studies 34:1-165.

Findley, J. S. 1993. Bats: a community perspective. Cam¬
bridge University Press, New York, xi + 167 pp.

Jones, C., W. J. McShea, M. J. Conroy. andT. H. Kunz. 1996.

Capturing mammals. Pp. 115-155 in Measuring
and monitoring biological diversity: standard
methods for mammals (D.E. Wilson, F.R. Cole,
J.D. Nichols, R. Rudran, and M.S. Foster, eds.).
Smithsonian Institution Press, Washington, D.C.
xxvii f 409 pp.

Yancey et al-Mammals of the Harte Ranch Area of Big Bend National Park

15

Jones, J. K.., Jr., R. W. Manning, and F. D. Yancey, II. 1993.

Records of five species of small mammals from
western Texas. The Texas Journal of Science
45:104-105.

Manning, R. W., and C. Jones. 1998. Revised checklist
of Recent land mammals of Texas, 1998. Occa¬
sional Papers, Museum of Texas Tech University
182:1-19.

Porter, R. D, 1962. Movements, populations, and habitat
preferences of three species of pocket mice ( Perog -
nathus ) in the Big Bend region of Texas. Unpub¬
lished Ph.D. dissertation, Texas A&M University,
College Station. 255 pp.

Author s addresses:

Franklin D. Yancey, III

Department of Biological Sciences and
the Museum of Texas Tech University
Lubbock, TX 79409

Current address:

50377 Rawhide Lane
Coarsegold, CA 93614

Schmidly, D. J. 1977. The mammals of Trans-Pecos Texas.
Texas A&M University Press, College Station, xiii
T 225 pp.

Schmidly, D. J. 1991. The bats of Texas. Texas A&M Uni¬
versity Press, College Station, xvi + 188 pp.

Waid, D. D. 1990. Movements, food habits, and helminth
parasites of mountain lions in southwestern Texas.
Unpublished Ph.D. dissertation, Texas Tech Uni¬
versity, Lubbock, xii + 129 pp.

Yancey, F. D., II. 1996. The mammals of Big Bend Ranch
State Park, Texas. Special Publications, Museum
of Texas Tech University 39:1-210.

Clyde Jones

Department of Biological Sciences
and the Museum of Texas Tech University
Lubbock, TX 79409
e-mail: cjmajones@aol. com

Richard W. Manning

Department of Biological Sciences and
the Museum of Texas Tech University
Lubbock, TX 79409

Current address:

107 LBJ Cove

San Marcos, TX 78666

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