The Recent Mammals Of Tamaulipas, Mexico Part 16

_Distribution in Tamaulipas._--Northern and western parts of state.

The two specimens examined, an adult female and a young male, from the barrier beach 33 miles south of Was.h.i.+ngton Beach are intergrades between _L. c. merriami_, reported from the mainland from as near as Matamoros, and _L. c. curti_, which occurs farther to the south on the same series of barrier beaches. Of seven characters that seem to differentiate the two subspecies, the adult female from 33 miles south of Was.h.i.+ngton beach resembles _merriami_ in four as follows: tips of ears black (white in _curti_); nasals long; hind foot long; and supraoccipital process broad. The specimen resembles _curti_ in shortness of tail and in having small auditory bullae. Breadth of rostrum above premolars, the seventh character, is less than in typical specimens of either of the two subspecies. More material is needed from the barrier beach in order to establish with certainty the relations.h.i.+ps between jack rabbits occurring there.

_Records of occurrence._--Specimens examined, 4: 33 mi. S Was.h.i.+ngton Beach, 2; 12 mi. NW San Carlos, 1300 ft., 2.

Additional records: Nuevo Laredo (Nelson, 1909:150); Mier (_ibid._); Camargo (_ibid._); Matamoros (Hall, 1951:185); Tamaulipeca, San Carlos Mts. (_ibid._).

=Spermophilus mexica.n.u.s parvidens= Mearns

Mexican Ground Squirrel

1896. _Spermophilus mexica.n.u.s parvidens_ Mearns, Preliminary diagnoses of new mammals from the Mexican border of the United States, p. 1, March 25, type from Fort Clark, Kinney Co., Texas.

_Distribution in Tamaulipas._--Northern part of state, south at least to Xicotencatl.

Most of the specimens examined from Tamaulipas are in the brown phase (Howell, 1938:121) and differ from _S. m. parvidens_ from Texas, Coahuila, and Nuevo Leon in being darker dorsally. Nevertheless, some individuals are as pale as those examined from the mentioned states.

Measurements of Tamaulipan specimens average smaller than those given by Howell (1938:121) and Baker (1956:205) for _parvidens_.

Specimens from San Fernando differ slightly from those from Soto la Marina in having a relatively long tail (average 69.2 instead of 62.1 per cent of length of head and body) and in having the upper parts of the hind feet ochraceous instead of nearly white.

Two May-taken females from Soto la Marina carried 5 and 7 embryos that were 10 mm. in crown-rump length; another taken there was lactating.

Weight of six non-pregnant females from San Fernando averaged 160.6 (129-197) grams. Two males from the same locality weighed 164 and 145 grams.

_Measurements._--Average and extreme measurements of four males and three females from Soto la Marina are, as follows: 312.6 (296-330); 119.8 (110-130); 41.6 (38-43). Average cranial measurements of five specimens (two males, three females) from same locality are: greatest length of skull, 44.7 (43.7-47.4); zygomatic breadth, 26.9 (25.3-28.6); breadth of braincase, 19.4 (19.2-19.5); interorbital constriction, 13.3 (12.5-14.1); length of nasals, 15.9 (14.6-17.5); length of maxillary tooth-row, 8.3 (8.0-8.5).

_Records of occurrence._--Specimens examined, 20: San Fernando, 180 ft., 12; Soto la Marina, 500 ft., 8.

Additional records (Howell, 1938:121 unless otherwise noted): Nuevo Laredo; Mier; Camargo; Reynosa; Bagdad; Victoria; Xecotencatl [= Xicotencatl] (J. A. Allen, 1891:223).

=Spermophilus spilosoma oricolus= Alvarez

Spotted Ground Squirrel

1962. _Spermophilus spilosoma oricolus_ Alvarez, Univ.

Kansas Publ., Mus. Nat. Hist., 14:123, March 7, type from 1 mi. E La Pesca, Tamaulipas.

_Distribution in Tamaulipas._--Known only from the type locality and from parts of the barrier beach, but possibly occurs at other places in northeastern parts of state.

The 10 specimens from the type locality were trapped or shot on the beach, which was covered by thick, low, scattered bushes and gra.s.s. Of the many holes found there, some probably were used by ground squirrels and others by crabs. A female, taken on July 7 with two young at a place 33 miles south of Was.h.i.+ngton Beach, weighed 133 grams and had six placental scars. This specimen (reported as _Spermophilus spilosoma annectens_ by Selander _et al._, 1962:335) resembles others examined from the barrier beach (see Alvarez, 1962:124) and is therefore a.s.signed to _S. s. oricolus_.

_Records of occurrence._--Specimens examined, 24: 33 mi. S Was.h.i.+ngton Beach, 1; 88 mi. S, 10 mi. W Matamoros, 12; 89 mi. S, 10 mi. W Matamoros, 1; 1 mi. E La Pesca, 10.

=Spermophilus variegatus couchii= Baird

Rock Squirrel

1855. _Spermophilus couchii_ Baird, Proc. Acad. Nat. Sci.

Philadelphia, 1:332, April, type from Santa Catarina, a few miles west of Monterrey, Nuevo Leon.

1955. _Spermophilus variegatus couchii_, Baker, Univ. Kansas Publ., Mus. Nat. Hist, 9:207, June 15.

_Distribution in Tamaulipas._--Possibly in southwestern part; reported only from Ciudad Victoria (Howell, 1938:141).

Since Baird (1855:332) described _S. v. couchii_ and mentioned a specimen from Ciudad Victoria that was obtained by Berlandier, no other record from Tamaulipas has come to light. Probably the species obtained by Berlandier was introduced at Ciudad Victoria by man.

=Sciurus aureogaster aureogaster= Cuvier

Red-bellied Squirrel

1829. [_Sciurus_] _aureogaster_ Cuvier, _in_ Geoffroy St.-Hilaire, and F. Cuvier, Hist. Nat. Mamm., 6, livr. 59 pl. with text, September (binomen published only at end of work, table generale et methodique, 7:4, 1842), type locality "California"; restricted to Altamira, Tamaulipas, by Nelson (Proc. Was.h.i.+ngton Acad. Sci., 1:38, May 9, 1899).

_Distribution in Tamaulipas._--Tropical forest of southern part; north at least to Rancho Santa Rosa.

According to one collector (Schaldach), natives referred to _Sciurus aureogaster_ as "ardilla pinta" or "ardilla colorada." He recorded in his field notes that _S. aureogaster_ was most active between 7:00 and 9:00 a. m. and again from 3:00 to 5:00 p. m., that the nest was constructed of green oak leaves, and that the nest resembles somewhat in size and form that of _S. carolinensis_.

Of 53 specimens examined, 17 are black and one from 70 kilometers south of Ciudad Victoria is clearly more whitish than the others. Specimens from the northeastern part of the range of the species (= southeastern Tamaulipas) average darker than those from the south and west. In individuals that are not black, the ventral reddish color covers the shoulders and in some it extends between the shoulders to the median dorsal area.

Among females collected from December through May, only one, taken 43 kilometers south of Ciudad Victoria on March 17, was pregnant (one embryo).

The weight of seven adult males from Soto la Marina and the Sierra de Tamaulipas averaged 492.5 (400-575) grams.

Specimens herein reported from San Fernando provide the northernmost record of the species.

_Records of occurrence._--Specimens examined, 53: San Fernando, 180 ft., 5; 9-1/2 mi. SW Padilla, 800 ft., 3; Rancho Santa Rosa, 25 km. N, 13 km. W Cd. Victoria, 260 m., 8; 3 mi. NE Guemes, 5; Soto la Marina (3 mi. N), 500 ft., 6; Sierra de Tamaulipas, 10 mi. W, 8 mi. S Piedra, 1200 ft., 6; 43 km. S Cd. Victoria, 1; Ejido Santa Isabel, 2 km. W Pan-American Highway, 2000 ft., 5; 70 km. (by highway) S Cd.

Victoria, 6 mi. W of Pan-American Highway, 3; 2 mi. W El Carrizo, 7; Rancho Pano Ayuctle, 6 mi. N Gomez Farias, 300 ft., 2; Rancho Pano Ayuctle, 25 mi. N, 3 km. W El Mante, 300 ft., 1; 8 km. W, 10 km. N El Encino, 400 ft., 1.

Additional records: Rio Corono (= Corona) (J. A. Allen, 1891:222); Victoria (Kelson, 1952:249); Santa Maria (Goodwin, 1954:8); 3 mi. NW Acuna, 3500 ft. (Hooper, 1953:4); Forlon (Nelson, 1899:42); NE Zamorina (Hooper, 1953:4); Gomez Farias (Goodwin, 1954:8); Altamira (Nelson, 1899:42); Tampico (J. A. Allen, 1891:222).

=Sciurus deppei negligens= Nelson

Deppe's Squirrel

1898. _Sciurus negligens_ Nelson, Proc. Biol. Soc.

Was.h.i.+ngton, 12:147, June 3, type from Altamira, Tamaulipas.

1953. _Sciurus deppei negligens_, Hooper, Occas. Papers Mus.

Zool., Univ. Michigan, 544:4, March 25.

_Distribution in Tamaulipas._--Tropical forest in southern part of state, north to Rancho Santa Rosa and Padilla.

In Tamaulipas this squirrel is called "ardilla chica" or "ardilla barcina," and is abundant in areas where tall trees and dense brush prevail. This species evidently does not have restricted periods of activity, as does _S. aureogaster_, but is active throughout the day.

At El Carrizo a nest, nine to 10 inches in diameter and constructed of leaves and small sticks, was in a thick tangle of branches 25 feet above the ground. A male having testes 11 mm. long was in the nest.

Among 16 females collected in the months of February, May and June, only two, taken in February, were lactating. A female from 70 kilometers south of Ciudad Victoria, had four placental scars, three on the right side and one on the left, along with a resorbed embryo on the right side; according to the collector "the scars appeared quite recent, as evidenced by the fact that not all of the blood had been resorbed yet."