Mammals of the Harte Ranch area of Big Bend National Park, Brewster County, Texas

2006·9.4 MB·English

by  Franklin D Yancey

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 surveys of invertebrates, amphibians, reptiles, birds,
biodiversity of mammals on the Harte Ranch area of and plant communities.
Big Bend National Park. The Harte Ranch area is about
75,000 acres in size, and is located in the northwestern Our major objectives were to determine the kinds
portion of Big Bend National Park. It is situated west of extant mammals on Harte Ranch, and to sample
of Persimmon Gap Ranger Station, north of the Pitcock- and observe mammals in as many of the microhabitats
Rosillos Ranch, and east of Terlingua Ranch. throughout the geographic area as possible. We em¬
ployed standard methods of capturing and monitoring
This survey of mammals of the Harte Ranch area mammals as described by Jones et al. (1996). We con¬
was carried out in accordance with the work of a unique centrated our efforts on the use of Sherman live traps
Research Consortium organized by Dr. Milford Fletcher (over 10,000 trap-nights) which allowed for the release
(National Park Service) and Dr. David Schmidly (then of animals captured that were not needed as voucher
of Texas A&M University). We made every effort to specimens. All field research activities were conducted
coordinate our field activities with those of the other in the most discrete manner possible in consideration
members of the Research Consortium, which included of the sensitivities of the local human population in
the region.
2 Occasional Papers, Museum of Texas Tech University
Results
During our field research, 66 specific localities embryos (crown-rump length, 11); lactating females
within the Harte Ranch section of Big Bend National were collected on 19-21 July. Measurements of testes
Park were sampled (Table 1). These sampling data, of males obtained in July and August ranged from 2 x
supplemented with a variety of observational data, re¬ 2 to 4 x 4; in October and November, testes of males
sulted in the documentation of 42 species of mammals measured from 1 x 1 to 3x2. Volant young-of-the-year
at Harte Ranch (Table 2). pipistrelles were captured on 19-21 July.
In the accounts that follow, 42 species of mam¬ Specimens examined (49). Mountain Lodge,
mals that are known to occur on the Harte Ranch sec¬ Harte Ranch, 48; Cedar Creek, 0.75 mi. E Twin Peaks,
tion of Big Bend National Park are treated. Although Harte Ranch, 1.
ordinal and familial headings are not utilized here, they
are presented in Table 2. Accounts are presented in Eptesicus fuscus pallidus
the currently accepted phylogenetic sequence through Young 1908
genera; species are arranged alphabetically within
each genus. Scientific and vernacular names of taxa A lactating female was captured on 20 July in a
follow Manning and Jones (1998) and Baker et at mist net placed over water. In the Big Bend of Texas,
(2003). Linear measurements in these accounts are female big brown bats inhabit lowland areas during the
in millimeters. Specimens listed are deposited in the summer months (Schmidly 1991).
Collection of Recent Mammals at the Museum of Texas
Tech University. Specimens examined (1).—Mountain Lodge,
Harte Ranch, 1.
My otis yumanensis yumanensis
(H. Allen 1864) Lasiurus cinereus cinereus
(Palisot de Beauvois 1796)
Only two specimens of Yuma myotis were ob¬
tained during this study. Both bats were captured in On two occasions during the night of 10 Novem¬
mist nets placed over water. According to Schmidly ber, a hoary bat was observed in a mist net set over
(1991), this bat usually forages near open water in low¬ water; the bat escaped before it could be retrieved.
land habitats. Testes of these bats, captured on 8 and 10 According to Schmidly (1991) this species is restricted
November, measured 1 x 1 and 3x1, respectively. mostly to wooded, montane areas of the Big Bend.
Specimens examined (2).—Mountain Lodge, Specimens examined (0).
Harte Ranch, 1,0.6 mi. S, 1.5 mi. E Key Place, Harte
Ranch, 1. Corynorhinus townsendiipallescens
(Miller 1897)
Pipistrellus hesperus maximus
Hatfield 1936 Two specimens of Townsend’s big-eared bat were
obtained during this study. A male, taken from inside
The western pipistrelle was the most common a building on 8 November, had testes that measured 4
bat encountered during this study. Although specimens x 2. A non-gravid female was netted over water on 8
were obtained by use of mist nets set over water at November.
only two localities, these mammals were observed fly¬
ing about at dusk and dawn at numerous places in the Specimens examined(2).—Key Place, Harte Ranch,
study area, especially along roads and adjacent to Chalk 1; 0.6 mi. S, 1.5 mi. E Key Place, Harte Ranch, 1.
Ridge. A female examined on 19 May contained two
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 41. 0.25 mi. N, l mi. W Headquarters, Harte Ranch
2. 1 mi. N Mountain Lodge, Harte Ranch 42. 0.25 mi. N, 1 mi. E Headquarters, Harte Ranch
3. 0.75 mi. N Mountain Lodge, Harte Ranch 43. 1.25 mi. W Headquarters, Harte Ranch
4. 0.25 mi. N, 2.25 mi. W Mountain Lodge, Harte Ranch 44. 1.25 mi. E Headquarters, Harte Ranch
5. 0.5 mi. N, 2 mi. W Mountain Lodge, Harte Ranch 45. 0.75 mi. S Headquarters, Harte Ranch
6. 0.3 mi. N, 2 mi, W Mountain Lodge, Harte Ranch 46. 0.5 mi. N, 1.4 mi. W Headquarters, Harte Ranch
7. 0.5 mi. N, 1.5 mi. W Mountain Lodge, Harte Ranch 47. 0.1 mi. W Airstrip Lodge, Harte Ranch
8. 0.5 mi. N, 0.1 mi. W Mountain Lodge, Harte Ranch 48. 2.2 mi. N, 7,25 mi. W Persimmon Gap Ranger Station,
9. 1.75 mi. N, 2.75 mi. E Mountain Lodge, Harte Ranch Harte Ranch
10. 2.1 mi. N, 3.2 mi. E Mountain Lodge, Harte Ranch 49. 4 mi. S Persimmon Gap Ranger Station. Harte Ranch
11. 1.75 mi. N, 1.5 mi. E Mountain Lodge, Harte Ranch 50. 4 mi. S, 0.5 mi. E Persimmon Gap Ranger Station, Harte
12. 1.5 mi. N, 2 mi. E Mountain Lodge, Harte Ranch Ranch
13. 1.5 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch 51. 4 mi. S, 1 mi. E Persimmon Gap Ranger Station, Harte
14. 1.5 mi. N, 0.75 mi. E Mountain Lodge, Harte Ranch Ranch
15. 1.25 mi. N, 1 mi. E Mountain Lodge, Harte Ranch 52. 4 mi. S, 2 mi. W Persimmon Gap Ranger Station, Harte
16. 1 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch Ranch
17. 2.5 mi. W Mountain Lodge, Harte Ranch 53. 4 mi. S, 0.5 mi. W Persimmon Gap Ranger Station, Harte
18. 0.5 mi, S Mountain Lodge, Harte Ranch Ranch
19. 0.5 mi, S, 2.5 mi. W Mountain Lodge, Harte Ranch 54. 4.25 mi. S, 1.75 mi W Persimmon Gap Ranger Station,
20. 1 mi. S, 2.5 mi. W Mountain Lodge, Harte Ranch Harte Ranch
21. 1.25 mi. S, 2.5 mi. W Mountain Lodge, Harte Ranch 55. 4.25 mi. S, 1.25 mi. W Persimmon Gap Ranger Station,
22. 1.25 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch Harte Ranch
23. 1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch 56. 5 mi. S, 2.5 mi. W Persimmon Gap Ranger Station, Harte
24. 2 mi. S, 0.5 mi. E Mountain Lodge, Harte Ranch Ranch
25. 1.3 mi. N Mountain Lodge, Harte Ranch 57. 2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger Station,
26. 1.5 mi. N, 0.4 mi. E Mountain Lodge, Harte Ranch Harte Ranch
27. 0.4 mi. N, 1 mi. W Mountain Lodge, Harte Ranch 58. Coyote Tank, 0.25 mi. N, 6.6 mi. W Persimmon Gap
28. 2.5 mi. N, 4 mi. W Mountain Lodge, Harte Ranch Ranger Station, Harte Ranch
29. 1.3 mi. N, 4 mi. W Mountain Lodge, Harte Ranch 59. Northwest Windmill, 1 mi. N, 7 mi. W Persimmon Gap
30. LI mi. S, 3.8 mi. W Mountain Lodge, Harte Ranch Ranger Station, Harte Ranch
31. Key Place, Harte Ranch 60. Crazy Windmill, 0.7 mi. S, 3.2 mi. W Mountain Lodge,
32. 1.5 mi. N, 2.6 mi. E Key Place, Harte Ranch Harte Ranch
33. 0.4 mi. N, 0.8 mi. E Key Place, Harte Ranch 61. Southeast Windmill, 5.1 mi S, 0.5 mi. E Persimmon Gap
34. 0.4 mi. N, 1.2 mi. E Key Place, Harte Ranch Ranger Station, Harte Ranch
35. 0.25 mi. N Key Place, Harte Ranch 62. Buttrill Spring, Harte Ranch
36. 0.25 mi. N, 0.25 mi. E Key Place, Harte Ranch 63. 0.1 mi. N, 1.5 mi. E Twin Peaks, Harte Ranch
37. 0.5 mi. S, 1.5 mi. E Key Place, Harte Ranch 64. Cedar Creek, 0.75 mi. E Twin Peaks, Harte Ranch
38. 0.6 nu. S, 1.5 mi. E Key Place, Harte Ranch 65. Cedar Creek, 0.8 mi. S, 0.4 mi. E Twin Peaks, Harte Ranch
39. Headquarters, Harte Ranch 66. Rosillos Peak, Harte Ranch
40. 2.5 mi. N, 1 mi. W Headquarters, Harte Ranch
Table 2 — Checklist of mammals known to occur on the Harte Ranch section of Big Bend National Park.
Order Chiroptera f4 Bats
Family Vespertilionidae (vespertilionid bats) Order Lagomorpha — Lagomorphs
Myotis yumanensis (Yuma myotis) Family Leporidae (hares and rabbits)
Pipistrellus hesperus (western pipistrelle) Sylvilagus audubonii (desert cottontail)
Eptesicus fnscus (big brown bat) Lepus californicus (black-tailed jackrabbit)
Lasiurus cine reus (hoary bat) Order Rodentia — Rodents
Corynorhintis townsendii (Townsend’s big- Family Sciuridae (squirrels and allies)
eared bat) Ammospermophilus interpres (Texas antelope
Antrozous pallidus (pallid bat) squirrel)
Family Molossidae (free-tailed bats) Spermophilus spilosoma (spotted ground
Tadarida brasiliensis (Brazilian free-tailed bat)
4 Occasional Papers, Museum of Texas Tech University
Table 2. (coni.)
squirrel) Erethizon dorsatum (porcupine)
Spermophilus vanegalus (rock squirrel)
Family Geomyidae (pocket gophers) Order Carnivora — Carnivores
Cratogeomys castanops (yellow-faced pocket Family Canidae (canids)
gopher) Can is latrans (coyote)
Family Heteromyidae (pocket mice and kangaroo Urocyon cinereoargenteus (common gray fox)
rats) Family Procyonidae (procyonids)
Perognathus flavus (silky pocket mouse) Bassariscits astntus (ringtail)
Chaetodipus eremicus (Chihuahuan Desert Procyon lotor (common raccoon)
pocket mouse) Family Mustelidae (mustelids)
Chaetodipus nelsoni (Nelson’s pocket mouse) Mustela frenata (long-tailed weasel)
Dipodomys merriami (Merriam’s kangaroo rat) Family Mephitidae (skunks)
Dipodomys ordii (Ord’s kangaroo rat) Mephitis mephitis (striped skunk)
Family Muridae (mice and rats) Family Felidae (cats)
Reithrodontomys megalot is (western harvest pel is concolor (mountain lion)
mouse) Lynx rufus (bobcat)
Peromyscus boy Hi (brush mouse)
Peromyscus eremicus (cactus mouse) Order Artiodactyla — Even-toed Ungulates
Peromyscus leu Copus (white-footed mouse) Family Dicotylidae (peccaries)
Peromyscus maniculatus (deer mouse) Tayassu tajacu (collared peccary)
Peromyscus pectoralls (white-ankled mouse) Family Cervidae (cervids)
Onychomys arenicola (Mearns’ grasshopper Cervus elaphus (elk)
mouse) Odocoileus hemionus (mule deer)
Sigmodon hispidus (hispid cotton rat) Family Antilocapridae (pronghorn)
Neotom a mexicana (Mexican woodrat) Antilocapra americana (pronghorn)
Neotom a micropus (southern plains woodrat) Family Bovidae (bovids)
Family Erethizontidae (New World porcupines) Ammotragus lervia (Barbary sheep)
Antrozous pallidus pallidus Specimens examined (22).—Mountain Lodge,
(Le Conte 1856) Harte Ranch, 17; Key Place, Harte Ranch, 2; Head¬
quarters, Harte Ranch, 3.
The pallid bat was found commonly from March
through September during this study, especially in as¬ Tadarida brasiliensis mexicana
sociation with man-made structures and open water. (Saussure 1860)
Before the collapse of the structure, the old adobe
house at the former headquarters of the Harte Ranch Brazilian free-tailed bats were captured in mist
was an important night roost for these bats. Pregnant nets set over water from March through November.
females (embryo crown-rump length, 23-26) were As a result of the well-known segregation of sexes in
obtained on 19 and 22 May, respectively. Lactating these bats, females were obtained only in March (3),
females were present on 19-21 July. Testes of a male October (2), and November (1). Measurements of tes¬
captured in March measured 5x3; bats obtained in tes of males ranged from 2 x 1 to 6 x 3; animals with
May had testes that ranged in size from 2 x 1 to 6 x 2. the larger testes were obtained in September, October,
A male examined in August had testes that measured 9 and November.
x 5. Volant young-of-the-year pallid bats were present
in July and August. 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
Specimens examined (18).—Mountain Lodge,
(Mearns 1896)
Harte Ranch, 1; 1 mi. N Mountain Lodge, Harte Ranch,
2; 0.25 mi. N, 2.25 mi. W Mountain Lodge, Harte
On the Harte Ranch, the desert cottontail is found
Ranch, 1; 1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte
primarily in xeric lowlands, especially in Nine Point
Ranch, 1; 1.5 mi. N, 2 mi. E Mountain Lodge, Harte
Draw and its tributaries. It seems that these mammals
Ranch, 1; 1.75 mi. N, 2.75 mi. E Mountain Lodge, Harte
are especially wary in the area; they are not found far
Ranch, 1; 0.5 mi. S, 1.5 mi. E Key Place, Harte Ranch,
from cover. Desert cottontails were rare during the
1; 0.25 mi. N Key Place, Harte Ranch, l; 1.5 mi. N, 2.6
first two years of this study. However, in May and
mi. E Key Place, Harte Ranch, 1; Headquarters, Harte
June of 1992, they were abundant, and many young
Ranch, 3; 0.7 mi. N Headquarters, Harte Ranch, 1; 4.25
animals were observed. Lactating females were taken
mi. S, 1.25 mi. W Persimmon Gap Ranger Station, Harte
in March, May, and August. A female with six fe¬
tuses (crown-rump length, 35), one with three fetuses Ranch, 1; 4 mi. S, 2 mi. W Persimmon Gap Ranger Sta¬
(crown-rump length, 12), and a female with two fetuses tion, Harte Ranch, 1; 4 mi. S Persimmon Gap Ranger
(crown-rump length, 55) were collected in March, May, Station, Harte Ranch, 1; 4 mi. S, 0.5 mi. E Persimmon
and August, respectively. Testes of males collected in Gap Ranger Station, Harte Ranch, 1.
March through November measured from 27 x 17 to
50 x 20. A male taken on 8 November exhibited fresh Ammospermophilus interpres
winter pelage, (Merriam 1890)
Specimens examined (12).—Mountain Lodge, The Texas antelope squirrel is not common on
Harte Ranch, 2; 1 mi. N Mountain Lodge, Harte Ranch, the Harte Ranch. Animals were observed on several
2; 1.3 mi. N Mountain Lodge, Harte Ranch, 1; 0.5 mi. occasions along the road in the vicinity of Key Place,
N, 1.5 mi. W Mountain Lodge, Harte Ranch, 1; 1.25 and near the western boundary of the area, but none
mi. N, 1 mi. E Mountain Lodge, Harte Ranch, 1; 1.5 were collected. As with several other kinds of mam¬
mi. N, 0.4 mi. E Mountain Lodge, Harte Ranch, 1; 1.5 mals in the area, we were impressed with the wariness
mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch, 1; 1.75 exhibited by this species.
mi. N, 1.5 mi. E Mountain Lodge, Harte Ranch, 1; 0.25
mi. N Key Place, Harte Ranch, 1; 4 mi. S Persimmon Specimens examined (0).
Gap Ranger Station, Harte Ranch, 1.
Spermophilus spilosoma marginatus
Lepus californicus texianus Bailey 1890
Waterhouse 1848
Spotted ground squirrels occur predominantly
The black-tailed jackrabbit is a widespread and in habitats on coarse, sandy-gravelly soils in the area.
often common inhabitant of the study area, especially in These animals also are wary; they seldom ventured far
open creosote bush and mesquite grasslands. Although from cover of shrubs and grasses. Information obtained
no precise census data are available, it seems that this on reproduction in this species includes females col¬
hare was increasing in numbers in the area during the lected in September with four and seven placental scars,
last year of our study. Reproductive data gathered on L. respectively. A male obtained in May had testes that
californicus included a female with one fetus (crown- measured 22 x 13; measurements of testes of an animal
rump length, 28) collected in July, one with three fetuses
collected in September were 13x7. A male examined
(crown-rump length, 40) obtained in August, and a
on 21 May exhibited distinct molting of the pelage.
female containing two fetuses (crown-rump length,
Some of these ground squirrels taken in September and
38) examined in September. Lactating females were
October had extensive deposits of fat.
collected in March, July, and August. Testes of adult
males measured in June were 42 x 19, whereas males
Specimens examined (8).—0.5 mi. S, 2.5 mi. W
collected in August had testes that were 25 x 10, 28 x
Mountain Lodge, Harte Ranch, 1; 2.1 mi. N, 3.2 mi.
8, and 50 x 18, respectively.
E Mountain Lodge, Harte Ranch, l; 0.25 mi. N, 0.25
6 Occasional Papers, Museum of Texas Tech University
mi. E Key Place, Harte Ranch, 3; 0.4 mi. N, 0.2 mi. E habitat preferences of this rodent coincide with those
Key Place, Harte Ranch, 1; 0.4 mi. N, 0.8 mi. E Key determined by Porter (1962). Pregnant females were
Place, Harte Ranch, 1; 0.4 mi. N, 1.2 mi. E Key Place, taken in March (4 fetuses, crown-rump length, 7),
Harte Ranch, 1. July (3 fetuses, crown-rump length, 4), and August (6
fetuses, crown-rump length, 3; 3 fetuses, crown-rump
Spermophilus variegatus grammurus length, 5; 4 fetuses, crown-rump length, 10; 3 fetuses,
(Say 1823) crown-rump length, 11; 4 fetuses, crown-rump length,
12; 2 fetuses, crown-rump length, 18). Lactating fe¬
Rock squirrels were observed in the vicinity of males also were collected in August. Measurements of
Buttrill Spring and on rocky outcrops on the western testes of males taken in various months were recorded
slopes of the Rosillos Mountains, however no speci¬ as follows: March, 4x2; May, 6x3; July, 2 x 2, 3
mens of this taxon were collected. In addition to being x 2, 5 x 4, 7 x 4; August, 2 x 1, 2 x 2, 4 x 2, 4 x 3;
uncommon in the area, these squirrels were extremely November, 2x1. Animals undergoing seasonal molt
wary. were examined in July and August.
Specimens examined (0). Specimens examined (64).—Mountain Lodge,
Harte Ranch, 7; 2.5 mi. N, 4 mi. W Mountain Lodge,
Cratogeomys castanops clarkii Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain Lodge,
(Baird 1855) 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
Yellow-faced pocket gophers were found in deep, Lodge, Harte Ranch, 1; 1.1 mi. S, 3.8 mi. W Mountain
sandy soils of the lowlands in the western portion of the Lodge, Harte Ranch, 6; 1 mi. N, 0.5 mi. E Mountain
study area. In addition these animals were located in Lodge, Harte Ranch, 4; 0.5 mi. S, 1.5 mi. E Key Place,
shallow, rocky soils in the vicinity of Mountain Lodge.
Harte Ranch, 2; Headquarters, Harte Ranch, 1; 0.25
Schmidly (1977) reported that these gophers require
mi. N, 1 mi. E Headquarters, Harte Ranch, 1; 0.5 mi.
topsoils of a depth of seven to eight inches, suggesting N, 1.4 mi, W Headquarters, Harte Ranch, 1; 4 mi. S
that C. castanops should be distributed more widely in Persimmon Gap Ranger Station, Harte Ranch, 1; 4
the area than our records indicate. A female obtained in
mi. S, 1 mi. E Persimmon Gap Ranger Station, Harte
September contained three fetuses (crown-rump length,
Ranch, 2; 4 mi. S, 0.5 mi. E Persimmon Gap Ranger
49). Measurements of testes of a male collected in No¬
Station, Harte Raneh, I; 4.25 mi. S, 1.25 mi. E Persim¬
vember were 7x5. Animals taken in May, September,
mon Gap Ranger Station, Harte Ranch, 9; Southeast
and November exhibited evidence of molting.
Windmill, 5 mi. S, 0.5 mi. E Persimmon Gap Ranger
Station, Harte Ranch, 1; 0.1 mi. N, 1.5 mi. E Twin
Specimens examined (5).—Mountain Lodge,
Peaks, Harte Ranch, 4; Cedar Creek, 0.75 mi. E Twin
Harte Ranch, 2; 0.75 mi. N Mountain Lodge, Harte
Peaks, Harte Ranch, 10; Cedar Creek, 0.8 mi. S, 0.4
Ranch, 1; 1 mi. S, 2.5 mi. W Mountain Lodge, Harte
mi. E Twin Peaks, Harte Ranch, 1.
Ranch, 1; 1.25 mi. S, 2.5 mi. W Mountain Lodge,
Harte Ranch, l.
Chaetodipus eremicus
(Mearns 1898)
Perognathus flavus gilvus
Osgood 1900
In accordance with the preferences of habitats of
these pocket mice reported by Porter (1962), we found
The silky pocket mouse was one of the more com¬
the Chihuahuan Desert pocket mouse in all kinds of
mon small rodents encountered throughout the study
vegetation in habitats on rock-free, sandy soils (and
area. Although not especially abundant in any given
occasionally on gravel) where we sampled mammals
place at any given time, this heteromyid was obtained in
during this study. This mouse was the most abundant
numerous habitats on both sandy and rocky substrates
heteromyid collected during our fieldwork at Harte
during the course of this study. Our perceptions of the
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, 5.1 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
crown-rump length, 6), May (6 fetuses, crown-rump Harte Ranch, 3; Cedar Creek, 0.8 mi. S, 0.4 mi. ETwin
length, 4), June (8 fetuses, crown-rump length, 2; 6 Peaks, Harte Ranch, 2.
fetuses, crown-rump length, 7), July (2 fetuses, crown-
rump length, 3), August (4 fetuses, crown-rump length,
Chaetodipus nelsoni canescens
5; 4 fetuses, crown-rump length, 12; 3 fetuses, crown-
(Merriam 1904)
rump length, 21), September (4 fetuses, crown-rump
length, 10), and November (3 fetuses, crown-rump
Nelson’s pocket mouse occurs in habitats on
length, 13). Ranges of measurements of testes of
gravelly and rocky substrates within the study area.
males were recorded as follows: March, 7 x 4 - 11 x
Precise habitats of this heteromyid in the Big Bend area
6; June, 3 x 2 - 8 x 4; July, 3x1 -7x3; August, 6x4
were described in detail by Porter (1962). We found
- 10x4; September, 4 x 2 - 6 x 3; November, 3x1,4
pregnant females of this species only in June (3 fetuses,
x 1. Molting was noted in specimens obtained during
crown-rump length, 5; 4 fetuses, crown-rump length, 8)
July and August.
and August (5 fetuses, crown-rump length, 8). Testes of
males taken through the year were measured as follows:
Specimens examined (179).—Mountain Lodge,
Harte Ranch, 5; 1.5 mi. S, 2.75 mi. W Mountain March, 8x4; May, 12x6; June, 8x4; July, 11 x 4, 9 x
Lodge, Harte Ranch, 51; 0.5 mi. N, 2 mi. W Mountain 4, 8 x 3; August, 3 x l, 4 x 2, 5 x 2; September, 5x2;
Lodge, Harte Ranch, 1; 2.5 mi. N, 4 mi. W Mountain November, 4 x 2, 6 x 3, 6 x 4. Young-of-the-year were
Lodge, Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain collected in July and August. Based on examination of
Lodge, Harte Ranch, 4; 2.5 mi. W Mountain Lodge, specimens obtained, molting of pelage seemingly takes
Harte Ranch, 3; Crazy Windmill, 0.7 mi. S, 3.2 mi. W place in late summer (July, August).
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 Specimens examined (121).—Mountain Lodge,
Mountain Lodge, Harte Ranch, 1; 1 mi. N, 0.5 mi. E Harte Ranch, 25; 0.5 mi. N, 0.1 mi. W Mountain Lodge,
Mountain Lodge, Harte Ranch, 3; Headquarters, Harte Harte Ranch, 10; 0.3 mi. N, 2 mi. W Mountain Lodge,
Ranch, 4; 0.25 mi. N Headquarters, Harte Ranch, 2; Harte Ranch, 7; 1 mi. N Mountain Lodge, Harte Ranch,
0.75 mi. N Headquarters, Harte Ranch, 6; 1.25 mi. E 1; 2.5 mi. N, 4 mi. W Mountain Lodge, Harte Ranch,
Headquarters, Harte Ranch, 14; 2.5 mi. N, 1 mi. W
1; 2 mi. S, 0.5 mi. E Mountain Lodge, Harte Ranch, 7;
Headquarters, Harte Ranch, 6; Buttrill Spring, Harte
Buttrill Spring, Harte Ranch, 33; 0.5 mi. S, 1.5 mi. E
Ranch, 3; 0.1 mi. W Airstrip Lodge, Harte Ranch, 1;
Key Place, Harte Ranch, 11; 1.4 mi. S, 3.4 mi. E Key
Key Place, Harte Ranch, 1; 0.5 mi. S, 1.5 mi. E Key
Place, Harte Ranch, 5; 0.5 mi. N, 1.5 mi. W Headquar¬
Place, Harte Ranch, 7; 1.4 mi. S, 3.4 mi. E Key Place,
ters, Harte Ranch, 7; 4.25 mi. S, 1.25 mi. W Persimmon
Harte Ranch, 5; Bone Spring, Harte Ranch, l; 4 mi.
Gap Ranger Station, Harte Ranch, 1; 4 mi. S, 0.5 mi. E
S Persimmon Gap Ranger Station, Harte Ranch, 6;
Persimmon Gap Ranger Station, Harte Ranch, 1; 4 mi.
4 mi. S, 0.5 mi. W Persimmon Gap Ranger Station,
5, 1 mi. E Persimmon Gap Ranger Station, 1; 0.1 mi.
Harte Ranch, 1; 4.25 mi. S, 1.25 mi. W Persimmon
N, L5 mi. ETwin Peaks, Harte Ranch, 4; Cedar Creek,
Gap Ranger Station, Harte Ranch, l; 4.25 mi. S, 1.75
mi. W Persimmon Gap Ranger Station, Harte Ranch, O. 75 mi. E Twin Peaks, Harte Ranch, 3; Cedar Creek,
8; 5 mi. S, 2.5 mi. W Persimmon Gap Ranger Station, 0.8 mi. E, 0.4 mi. S Twin Peaks, Harte Ranch, 4.
Harte Ranch, 8; 2.2 mi. N, 7.25 mi. W Persimmon Gap
Ranger Station, Harte Ranch, 6; North Windmill, 1 Dipodomys merriami ambiguus
mi. N, 7 mi. W Persimmon Gap Ranger Station, Harte Merriam 1890
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 Merriam’s kangaroo rat was associated most
mi. W Persimmon Gap Ranger Station, Harte Ranch, commonly with gravelly and rocky soils, but with a
7; 4 mi. S, 0.5 mi. E Persimmon Gap Ranger Station, wide array of types of vegetation. Reproductive data
Harte Ranch, 2; 4 mi. S, 1 mi. E Persimmon Gap gathered on this species included pregnant females
Ranger Station, Harte Ranch, 5; Southeast Windmill, 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, Dipodomys ordii obscunis
crown-rump length, 15), August (2 fetuses, crown- (J. A. Allen 1903)
rump length, 29; 4 fetuses, crown-rump length, 4; 3
fetuses, crown-rump length, 3), September (3 fetuses, Ord’s kangaroo rat was not common during the
crown-rump length, 17), October (2 fetuses, crown- tenure of our work on Harte Ranch. This rat was en¬
rump length, 6), and November (3 fetuses, crown- countered only on sandy soils associated with arroyos
rump length, 10; 2 fetuses, crown-rump length, 14). and roads. Females carrying fetuses were obtained only
Like females, males exhibited reproductive activity in August (3 fetuses, crown-rump length, 5; 3 fetuses,
throughout most of the year; some measurements of crown-rump length, 6; 2 fetuses, crown-rump length,
testes were as follows: March (15x8; 10x4), July 28). Ranges of measurements of testes of males taken
(11 x 6; 12x6), August (II x 6), September (14x7; were recorded as follows: May, 10x6; August, 6x4
10x5), October (16x8), November (11 x 6; 15x5). - 12x7; September, 9x3- 16 x 10. A juvenile D. ordii
Young-of-the-year Merriam’s kangaroo rats were col¬ was taken in July. Some animals examined in August
lected in August. It is of interest that one of the young exhibited molting of pelage.
D. merriami obtained in August had cheeks and the
entire venter covered with yellow pollen. Seeds, as Specimens examined (20)^1.25 mi. S, 2.75 mi.
W Mountain Lodge, Harte Ranch, 10; 1.5 mi. S, 2.75
well as insects and green vegetation, are the major food
mi. W Mountain Lodge, Harte Ranch, 3; 1.1 mi. S, 3.8
items of this rat (Schmidly 1977).
mi. W Mountain Lodge, Harte Ranch, 2; 0.3 mi. N, 2
Specimens examined (88).—Mountain Lodge, mi. W Mountain Lodge, Harte Ranch, 1; 1.3 mi. N, 4
Harte Ranch, 5; 1.5 mi. S, 2.75 mi. W Mountain Lodge, mi. W Mountain Lodge, Harte Ranch, 2; 0.4 mi. N, 1.2
Harte Ranch, 18; 0.25 mi. N, 2.25 mi. W Mountain mi. E Key Place, Harte Ranch, 1; Southeast Windmill,
Lodge, Harte Ranch, 2; 1.3 mi. N, 4 mi. W Mountain 5.1 mi. S, 0.5 mi. E Persimmon Gap Ranger Station,
Lodge, Harte Ranch, 2; 2.5 mi. N, 4 mi. W Mountain Harte Ranch, I.
Lodge, Harte Ranch, 3; 0.3 mi. N, 2 mi. W Mountain
Reithrodontomys megalotis megalotis
Lodge, Harte Ranch, 1; 1.1 mi. S, 3.8 mi. W Mountain
(Baird 1858)
Lodge, Harte Ranch, 5; 1 mi. N, 0.5 mi. E Mountain
Lodge, Harte Ranch, 2; Headquarters, Harte Ranch, 1;
The western harvest mouse was encountered rather
2.5 mi. N, 1 mi. W Headquarters, Harte Ranch, 2; 0.25
sporadically in the area during this study. This rodent
mi. N, 1 mi. E Headquarters, Harte Ranch, 2; 1.25 mi E
preferred habitats in lowlands, with rank vegetation that
Headquarters, Harte Ranch, 2; 0.5 mi. S, 1.5 mi. E Key
provides a rather thick thatch of ground cover. Harvest
Place, Harte Ranch, 2; 1.4 mi. S, 3.4 mi. E Key Place,
mice were most common in areas adjacent to earthen
Harte Ranch, 1; 4 mi. S Persimmon Gap Ranger Sta¬
tanks and catch basins where water periodically ac¬
tion, Harte Ranch, 7; 4 mi. S, 0.5 mi. E Persimmon Gap
cumulated. Gravid females were recorded in March (3
Ranger Station, Harte Ranch, 9; 4 mi. S, 1 mi. E Per¬
fetuses, crown-rump length, 20), September (4 fetuses,
simmon Gap Ranger Station, Harte Ranch, 4; 4.25 mi.
crown-rump length, 4; 7 fetuses, crown-rump length, 3),
S, 1.25 mi. W Persimmon Gap Ranger Station, Harte
and October (4 fetuses, crown-rump length, 4). Some
Ranch, l; 5 mi. S, 2.5 mi. W Persimmon Gap Ranger
measurements of testes of males were recorded as fol¬
Station, Harte Ranch, 4; 4 mi. S, 0.5 mi. W Persimmon
lows: March, 6 x 3, 8 x 3, 7 x 3, 4 x 2; June, 7 x 3, 7
Gap Ranger Station, Harte Ranch, 1; 2.2 mi. N, 7.25
x 4, 5 x 3; September, 10 x 5, 9 x 5, 5 x 2; October, 3
mi. W Persimmon Gap Ranger Station, Harte Ranch,
x 2, 4 x 2.
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
Specimens examined (30).—Buttrill Spring,
Persimmon Gap Ranger Station, Harte Ranch, 3; 0.1
Harte Ranch, 1; Crazy Windmill, 0.7 mi. S, 3.2 mi. W
mi. N, 1.5 mi. E Twin Peaks, Harte Ranch, 2; Cedar
Mountain Lodge, Harte Ranch, 2; 0.25 mi. N, 1 mi. E
Creek, 0.75 mi. E Twin Peaks, Harte Ranch, 4.
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, 6; 2.5 mi. N, 4 mi. W Mountain Lodge,
Harte Ranch, 2; 0.75 mi. S Headquarters, Harte Ranch, Harte Ranch, 5; l.l mi. S, 3.8 mi. W Mountain Lodge,
l; North Windmill, 1 mi. N, 7 mi. W Persimmon Gap Harte Ranch, 3; 2 mi. S, 0.5 mi. W Mountain Lodge,
Ranger Station, Harte Ranch, 4; 4.25 mi. S, 1.75 mi. Harte Ranch, 3; Buttrill Spring, Harte Ranch, 2; 0.1
W Persimmon Gap Ranger Station, Harte Ranch, 5; mi. W Airport Lodge, Harte Ranch, 7; Headquarters,
2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger Station, Harte Ranch, 1; 2.5 mi. N, 1 mi. W Headquarters,
Harte Ranch, 7; Coyote Tank, 0.25 mi. N, 6.6 mi. W Harte Ranch, 2; 0.5 mi. N, 1.4 mi. W Headquarters,
Persimmon Gap Ranger Station, Harte Ranch, 5. 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
Peromyscus boylii rowleyi Ranch, 5; 4 mi. S Persimmon Gap Ranger Station,
(J. A. Allen 1893) Harte Ranch, 3; 4 mi. S, 0.5 mi. E Persimmon Gap
Ranger Station, Harte Ranch, 2; 4.25 mi. S, 1.25 mi.
The brush mouse was the least common member W Persimmon Gap Ranger Station, Harte Ranch, 4;
of the genus Peromyscus that was encountered during 2.2 mi. N, 7.25 mi. W Persimmon Gap Ranger Station,
our study. This species was found only in dense, brushy Harte Ranch, 3; 2.2 mi. N, 6.3 mi. W Persimmon Gap
vegetation in the bottom of the ravine adjacent to the Ranger Station, Harte Ranch, 7; 0.1 mi. N, 1.5 mi. E
outflow from Buttrill Spring. An adult female had 3 Twin Peaks, Harte Ranch, 7; Cedar Creek, 0.75 mi. E
fetuses (crown-rump length, 21). An adult male had Twin Peaks, Harte Ranch, 2; Cedar Creek, 0.8 mi. S,
testes that measured 13x7. One subadult exhibited 0.4 mi. E Twin Peaks, Harte Ranch, 1.
molting of the pelage.
Peromyscus leucopus texanus
Specimens examined(5).—Buttrill Spring, Harte (Woodhouse 1853)
Ranch, 5.
The white-footed mouse was most abundant in
Peromyscus eremicus eremicus lowland areas of creosote scrub, especially in places
(Baird 1858) where vegetation (grasses, forbs) occurred among the
creosote bushes. Pregnant females were examined in
The cactus mouse was the most common of all March (4-6 fetuses, crown-rump length, 3 - 19), May
members of the genus Peromyscus present in the study (3-6 fetuses, crown-rump length, 10 - 12), September
area. The preferred habitats of this species were slopes (3-5 fetuses, crown-rump length, 11-16), and October
with large rocks, cacti, shrubs, and grasses. It is of (4 fetuses, crown-rump length, 4). Lactating females
interest to note that a large number of these mice were were taken in each of these months also. Males ex¬
taken from within the man-made structure at Mountain hibited evidence of reproductive activity in all months
Lodge. Information on reproduction of cactus mice of the year; measurements of testes ranged from 6 x
includes the following: females collected in March 3 to 18x7.
contained from 2 to 4 fetuses (crown-rump length, 3
- 12); May, 3 fetuses (crown-rump length, 5); July, 2 Specimens examined (97).—0.3 mi. N, 2 mi. W
fetuses (crown-rump length, 5 - 18); August, 2 to 4 Mountain Lodge, Harte Ranch, 1; 1.25 mi. S, 2.75 mi.
fetuses (crown-rump length, 3 - 18); September, 2 to W Mountain Lodge, Harte Ranch, 7; Crazy Windmill,
3 fetuses (crown-rump length, 3 - 13); and Novem¬ 0.7 mi. S, 3.2 mi. W Mountain Lodge, Harte Ranch, 8;
ber, 3 to 4 fetuses (crown-rump length, 6 - 9). Males 1.5 mi. S, 2.75 mi. W Mountain Lodge, Harte Ranch,
were reproductively active in all months of the year; 7; 1.1 mi. S, 3.8 mi. W Mountain Lodge, Harte Ranch,
measurements of testes ranged from 8 x 3 to 10x6. 1; 1 mi. N, 0.5 mi. E Mountain Lodge, Harte Ranch,
Neonates were found in nests in March and August. 1; Buttrill Spring, Harte Ranch, 6; 0.25 mi. N, 0.25
Molting of pelage was observed in specimens obtained mi. E Key Place, Harte Ranch, 1; 0.4 mi. N, 0.8 mi. E
from August through October. 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¬
Specimens examined (106).—Mountain Lodge, ters, Harte Ranch, 15; 1.25 mi. W Headquarters, Harte
Harte Ranch, 39; 0.5 mi. N, 2 mi. W Mountain Lodge, Ranch, 1; 0.75 mi. S Headquarters, Harte Ranch, 1;
Harte Ranch, 1; 0.3 mi. N, 2 mi. W Mountain Lodge, 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 Specimens examined(17).—Buttrill Spring, Harte
mi. W Persimmon Gap Ranger Station, Harte Ranch, Ranch. 11; Rosillos Peak, Harte Ranch, 6.
3; Southeast Windmill, 5.1 mi. S, 0.5 mi. E Persimmon
Gap Ranger Station, Harte Ranch, 2; 2.2 mi. N, 7.25 Onychomys arenicoia arenicola
mi. W Persimmon Gap Ranger Station, Harte Ranch, Mearns 1896
5; North Windmill, 1 mi. N, 7 mi. W Persimmon Gap
Schmidly (1977) reported that Mearn’s grasshop¬
Ranger Station, Harte Ranch, 11; 2.2 mi. N, 6.3 mi. W
per mouse was extremely rare in the Big Bend region,
Persimmon Gap Ranger Station, Harte Ranch, 4; Coyote
based, in part, on only a single specimen known at that
Tank, 0.25 mi. N, 6.6 mi. W Persimmon Gap Ranger
time from Big Bend National Park. This mouse was
Station, Harte Ranch, 9.
reported to occur in lowland habitats in association
Peromyscus maniculatus blandus with D. merriami (Schmidly 1977). However, we also
Osgood 1904 found this grasshopper mouse on sandy substrates, with
open vegetation, in association with D. ordii. Pregnant
This deer mouse was taken in lowland habitats, females were captured in March (4 fetuses, crown-rump
usually in areas that were relatively open with regard to length, 6; 4 fetuses, crown-rump length, 12), July (4
vegetation. Pregnant females were collected in March fetuses, crown-rump length, 12), and August (4 fetuses,
(4 fetuses, crown-rump length, 4), August (4 fetuses, crown-rump length, 10). A lactating female was taken
crown-rump length, 5; 3 fetuses, crown-rump length, in September. Measurements of testes of males were
8), and September (5 fetuses, frown-rump length, 6; recorded as follows: May, 9 x 5, 20 x 9; July, 11x6;
6 fetuses, crown-rump length, 4). Measurements of September, 10 x 3, 7 x 3; November, 8x3. Young
testes of males obtained in several months were as fol¬ animals were observed in May, June, September, and
lows: March, 10 x 6, 9 x 4; June, 8x5; August, 11 x November.
4; October, 10x5.
Specimens examined (13).—-Mountain Lodge,
Specimens examined (26).—2.5 mi. N, 4 mi. W Harte Ranch, 1; 1.3 mi. N, 4 mi. W Mountain Lodge,
Mountain Lodge, Harte Ranch, 1; 0.7 mi. S, 3.2 mi. W Harte Ranch, 1; 0.3 mi. N, 2 mi. W Mountain Lodge,
Mountain Lodge, Harte Ranch, 2; 1.25 mi. S, 2.75 mi. Harte Ranch, 2; 2.5 mi. N, 4 mi. W Mountain Lodge,
W Mountain Lodge, Harte Ranch, 3; 1.1 mi. S, 3.8 mi. Harte Ranch, 1; 1.25 mi. S, 2.75 mi. W Mountain
W Mountain Lodge, Harte Ranch, 1; 1.4 mi. N, 3.4 mi. Lodge, Harte Ranch, 1; 1.5 mi. S, 2.75 mi. W Mountain
E Key Place, Harte Ranch, 1; 0.25 mi. N, 1 mi. E Head¬ Lodge, Harte Ranch, 3; Crazy Windmill, 0.7 mi. S, 3.2
quarters, Harte Ranch, 1; 1.25 mi. E Headquarters, Harte mi. W Mountain Lodge, Harte Ranch, 2; Coyote Tank,
Ranch, 1; North Windmill, 1 mi. N, 7 mi. W Persimmon 2.5 mi. N, 4 mi. W Persimmon Gap Ranger Station,
Gap Ranger Station, Harte Ranch, 2; Coyote Tank, 0.25 Harte Ranch, 1; 0.1 mi. N, 1.5 mi. E Twin Peaks, Harte
mi. N, 6.6 mi. W Persimmon Gap Ranger Station, Harte Ranch, 1.
Ranch, 8; 2.2 mi. N, 6.3 mi. W Persimmon Gap Ranger
Station, Harte Ranch, 6. Sigmodon hispidus berlandieri
Baird 1855
Peromyscus pectoralis laceianus
Bailey 1906 The hispid cotton rat was found commonly in
thick vegetation in lowland areas, especially in the
The white-ankled mouse was collected on a rocky vicinity of earthen tanks and catch basins where water
slope with fairly open vegetation above the outflow periodically accumulated. However, this mammal also
from Buttrill Spring, as well as on a rock-strewn area on occasionally was taken in open creosote shrub areas,
Rosillos Peak. A female obtained in October contained as well as in rocky habitats, such as at the base of
4 fetuses (crown-rump length, 4). Measurements of Chalk Ridge. Gravid females were observed in March
testes of males taken in May ranged from 6 x 3 to 11 x (7 fetuses, crown-rump length, 3), August (8 fetuses,
5; animals examined in August had testes that ranged crown-rump length, 10), and September (6 fetuses,
in measurements from 10 x 5 to 14x8. crown-rump length, 15). Males were reproductively