Noteworthy Mammals From Sinaloa, Mexico

Volume 14, No. 12, Pp. 145-159, 1 Fig. in Text

Published May 18, 1962

UNIVERSITY OF KANSAS

Lawrence, Kansas

PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS

1962

29-3000

Noteworthy Mammals from Sinaloa, Mexico

J. KNOX JONES, JR., TICUL ALVAREZ, and M. RAYMOND LEE

In several of the past twelve years field parties from the Museum of Natural History have collected mammals in the Mexican state of Sinaloa. Most of the collections contained only a modest number of specimens because they were made by groups that stopped for short periods on their way to or from other areas, but several collections are extensive. Field work by representatives of this institution now is underway in Sinaloa with the aim of acquiring materials suitable for treating the entire mammalian fauna of that state.

Among the mammals thus far obtained are specimens of twenty species that represent significant extensions of known range, are of especial taxonomic or zoogeographic interest, or that complement published information, and it is these records that are reported herein.

The following persons obtained specimens mentioned beyond: J. R. Alcorn (1950); J. R. and A. A. Alcorn (1954 and 1955); R. H. Baker and a party of students (1955); W. L. Cutter (1957); S. Anderson and a party of students (1959); M. R. Lee (1960 and 1961); and J. K. Jones, Jr., accompanied by R. R. Patterson and R. G. Webb (1961). The Kansas University Endowment Association and the American Heart Association provided funds that helped to defray the cost of field operations.

In the accounts that follow, all measurements are in millimeters and all catalogue numbers refer to the mammal collection of the Museum of Natural History, The University of Kansas. Placenames associated with specimens examined are indicated on the accompanying map (Fig. 1).

Notiosorex crawfordi (Coues).--A non-pregnant female (75184) was obtained on November 29, 1957, at El Fuerte by W. L. Cutter. Comparison of this specimen with topotypes of N. evotis (see below) and with undoubted examples of N. crawfordi proves our specimen to be referable to the latter. We presume that the shrew reported as evotis on geographic grounds from El Carrizo by Hooper (1961:120) also is referable to crawfordi. External measurements of our female are: total length, 77; length of tail, 20 (tip missing); length of hind foot, 11; length of ear from notch, 8; weight in grams, 4. Cranial measurements of this individual are given in Table 1.

Notiosorex evotis (Coues).--Four topotypes (85533-36), all males, were collected by Lee at Mazatl['a]n. One was caught on December 17, 1960, in a museum special trap set "in low weeds near thorn bush" in a sandy field at the north edge of Mazatl['a]n, less than a mile from the ocean. A few trees and some grasses grew in this area; Mus musculus and Perognathus pernix were taken in the same line of traps. Additional trapping at this locality failed to produce more shrews. The other three specimens were captured alive on February 1 (one) and February 2 (two), 1961, in the wake of a bulldozer that was clearing land adjacent to the place where the first specimen was trapped. The ground cover being cleared away consisted mostly of dry, dense weeds and short, thorny scrub; the latter was sparse in some places and formed dense thickets in others. One individual that was kept alive for a short time in a can ate crickets and roaches readily and ate one spider, but refused isopods. On one occasion it ate six crickets in about three hours. Wet oatmeal and oatmeal mixed with peanut butter both were refused.

TABLE 1. CRANIAL MEASUREMENTS OF TWO SPECIES OF NOTIOSOREX.

Table Legend for the table headers:

Column CA: Catalogue number, or number of specimens averaged, and sex Column CO: Condylobasal length Column IN: Interorbital constriction Column MA: Maxillary breadth Column CR: Cranial breadth Column PA: Palatal length Column LE: Length of maxillary tooth-row

========================================================================== CA | CO | IN | MA | CR | PA | LE -----------------------+-------+-------+-------+-------+---------+--------

Notiosorex crawfordi, Huachuca Mts., Arizona

| | | | | | Average 6 (2, 4) | 16.01 | 3.72 | 5.08 | 8.32 | 6.59 | 5.93 Minimum | 15.7 | 3.6 | 4.9 | 7.8 | 6.3 | 5.8 Maximum | 16.5 | 3.85 | 5.2 | 8.8 | 7.15 | 6.2

El Fuerte, Sinaloa

75184 KU, | 16.5 | 3.7 | 5.0 | 8.4 | 6.9 | 6.1

SW Guadalajara, Jalisco

33318 KU, | .. | 3.6 | 4.9 | .. | 7.1 | 5.7 42583 KU, ? | 15.0+ | 3.5 | 4.6 | .. | 6.6 | 5.4+/- 42584 KU, ? | .. | 3.6 | 4.9 | .. | 7.1+/- | 6.1+/-

2 mi. E La Palma, Michoac['a]n

42586 KU, ? | .. | 3.8 | 4.9 | .. | 6.9 | .. 42587 KU, ? | .. | 3.8 | 4.8 | .. | 6.9 | 6.0 42588 KU, ? | .. | .. | 4.9 | .. | 6.9 | 6.2

Notiosorex evotis, Mazatl['a]n, Sinaloa

Average 4 () | 17.68 | 4.05 | 5.37 | 8.68 | 7.60 | 6.58 Minimum | 17.4 | 4.0 | 5.3 | 8.5 | 7.5 | 6.5 Maximum | 17.9 | 4.1 | 5.4 | 8.8 | 7.7 | 6.7 -----------------------+-------+-------+-------+-------+---------+--------

Average and extreme external measurements of the four males are as follows: total length, 93.2 (90-98); length of tail, 25.5 (23-27); length of hind foot, 11.9 (11-13); length of ear from notch, 7.7 (7-8); weight in grams, 5.4 (4.4-6.3). Cranial measurements are given in Table 1.

Notiosorex evotis was described by Coues (1877:652) on the basis of a single specimen, obtained at Mazatl['a]n by Ferdinand Bischoff in 1868, that originally had at least the partial skull inside. Subsequently the skull was removed and evidently lost (Poole and Schantz, 1942:181). Coues named evotis as a species distinct from crawfordi (described by him in the same paper) on the basis of larger size, shorter tail, and alleged slight differences in color. He did not describe the skull, but did note that the dentition was "substantially the same as that of N. crawfordi." Evidently, the only other correctly identified specimen of evotis on record is an individual from Mazatl['a]n in the British Museum, the skull of which was figured by Dobson (1890:pl. 23, fig. 20).

Merriam (1895:34) characterized evotis, known to him by only the holotype, as: "Similar to N. crawfordi, but slightly larger and darker." He did not examine the skull, which by that time had been "lost or mislaid." Merriam reduced evotis to subspecific status under crawfordi with the following remarks: "In the absence of sufficient material of N. evotis, it is impossible to determine its exact relations to crawfordi. Dobson did not recognize it as distinct, but figured its teeth under the name crawfordi [loc. cit., possibly a lapsus]. For the present it seems best to retain it as a subspecies."

Merriam's arrangement of evotis as a subspecies of crawfordi has been followed by subsequent workers, mostly, we suppose, because additional material of undoubted evotis has not until now been available. Comparisons of our four specimens with specimens (from Jalisco, Sinaloa and Tamaulipas) and published descriptions and measurements (see especially Hoffmeister and Goodpaster, 1954:46-47, 51) of crawfordi reveal that evotis has a longer body and hind foot than crawfordi but a relatively (sometimes actually) shorter tail and ear, and a distinctly larger, heavier skull (see Table 1). The upper parts of our specimens average pale brownish gray and are paler, not darker, than the upper parts of crawfordi. But, all of the latter were obtained in the warm months of the year except one November-taken individual from El Fuerte, Sinaloa, the dorsal pelage of which approaches in color that of the darkest of the evotis. The pelage of both kinds probably is paler in winter than in summer and may be indistinguishable in the same season. Ventrally, all four evotis are grayish white, faintly to moderately tinged with brownish buff.

Notiosorex evotis differs cranially from Notiosorex crawfordi as follows: larger (see measurements); mesopterygoid fossa squared rather than broadly U-shaped anteriorly; rounded process on maxillary at posterior border of infraorbital canal well developed (faint or lacking in crawfordi); occipital condyles smaller and, in lateral view, elevated above basal plane of skull; upper molars slightly more crowded in occlusal view. These differences, although admittedly slight, appear to be constant in the specimens we have seen, but ought to be used cautiously owing to the small samples studied.

Shrews of the genus Notiosorex have been reported twice previously from localities in west-central M['e]xico, other than from Mazatl['a]n, as follows: 21 mi. SW Guadalajara (remains from owl pellets) and 13 mi. S, 15 mi. W Guadalajara, Jalisco, by Twente and Baker (1951:120-121); and Cerrito Loco, 2 mi. E La Palma, Michoac['a]n (remains from owl pellets), by Baker and Alcorn (1953:116). The remains were referred to evotis on geographic grounds in one instance and were so referred inferentially in the other. Examination of the specimens upon which these reports were based reveals that all are crawfordi on the basis of characters previously cited. As a result, N. evotis is known only from the type locality at Mazatl['a]n, whereas N. crawfordi is widely distributed on the Mexican Plateau as far south as Jalisco and northern Michoac['a]n, and occurs on the west side of the Sierra Occidental as far south as northern Sinaloa.

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