University of Kansas Publications
Museum of Natural History

Volume 14, No. 16, pp. 475-481, 1 fig.
March 2, 1964

A New Subspecies of the Fruit-eating Bat, Sturnira ludovici, from Western Mexico

By

J. KNOX JONES, JR., AND GARY L. PHILLIPS

University of Kansas
Lawrence
1964

University of Kansas Publications, Museum of Natural History

Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr.

Volume 14, No. 16, pp. 475-481, 1 fig.
Published March 2, 1964

University of Kansas Lawrence, Kansas

PRINTED BY HARRY (BUD) TIMBERLAKE, STATE PRINTER
TOPEKA, KANSAS
1964

A New Subspecies of the Fruit-eating Bat,
Sturnira ludovici, from Western Mexico

BY

J. KNOX JONES, JR., AND GARY L. PHILLIPS

The fruit-eating bats of the genus Sturnira are represented on the North American mainland by two species, S. lilium and S. ludovici. The former, in most areas the smaller of the two, is widely distributed in México and Central America and is common in many places. On the other hand, S. ludovici, described by Anthony (1924:8) from near Gualea, Ecuador, generally has been regarded as rare; insofar as we can determine only 20 specimens of the species have been recorded previously from North America (Costa Rica, Honduras, and México).

In 1961 (M. Raymond Lee) and 1962 (Percy L. Clifton), field representatives of the Museum of Natural History collected mammals in western México. Among the bats obtained by them were 23 specimens of S. ludovici, which represent an heretofore undetected subspecies that is named and described below.

Sturnira ludovici occidentalis, new subspecies

Holotype.—Adult female, skin and skull, no. 92798 Museum of Natural History, The University of Kansas, from Plumosas, 2500 feet elevation, Sinaloa; obtained on August 31, 1962, by Percy L. Clifton (original no. 2939).

Distribution.—Western México; known certainly from south-western Durango south to southern Jalisco (see Fig. 1).

Diagnosis.—Size small both externally and cranially (forearm in adults 40.4-44.1 mm., greatest length of skull 21.7-22.9); rostrum short and abruptly elevated; skull relatively broad; dorsal pelage drab brownish over-all, usually lacking epaulets (pale yellowish brown when present); ventral pelage brownish gray.

Comparisons.—From Sturnira ludovici ludovici, the only other subspecies of the species, S. l. occidentalis differs in averaging smaller in most external and cranial dimensions (in some measurements the upper size limits of occidentalis barely overlap the lower limits in specimens of ludovici examined), in having a relatively broader skull with a shorter, more abruptly elevated rostrum, and in being paler both dorsally and ventrally.

From Sturnira lilium parvidens, with which it is sympatric, S. l. occidentalis usually (but not always) differs in being brownish (rather than yellowish to yellowish orange) dorsally and in lacking epaulets, and differs in the following cranial features: first upper incisors simple (rather than weakly bifid in unworn condition), larger, and more nearly straight when viewed from the front; second upper incisors reduced; lower incisors bilobate rather than trilobate; lingual cusps on m1 and m2 greatly reduced; M2 usually turned inward from M1 at distinct angle. The two species have approximately the same external and cranial dimensions in western México.

Measurements (in millimeters).—External measurements of the holotype are as follows: total length, 58; length of hind foot, 15; length of ear, 18; forearm (average of both), 42.5. Corresponding average and extreme measurements of 11 adults from 4 km. N Durazno, Jalisco, followed by those of eight adults from 17 km. SE Talpa, Jalisco, are: 61.9 (59-65), 60.9 (57-68); 14.1 (12-15), 13.0 (13); 16.1 (15-18), 16.0 (15-17); 42.2 (40.4-43.8), 42.9 (41.6-44.1); weight in grams, 16.8 (15-19, six specimens only), 19.2 (16.3-22.5).

Cranial measurements of the holotype additional to those given in Table 1 are: condyloincisive length, 19.7; breadth across upper canines, 5.5; length of mandibular tooth-row (c-m3), 6.7.

Remarks.—The pattern of geographic variation in size in Sturnira ludovici resembles that in many other species of tropical bats in North America in that individuals from the northern parts of the range are smaller than those from the south. Mexican specimens herein assigned to S. l. ludovici average somewhat smaller than specimens from Central America and the northern part of South America (but are within the currently understood size limits of that subspecies) and average paler as well. Additional material is needed from central and eastern México before the limits of distribution of the two subspecies of ludovici can be determined accurately.

All specimens examined of the new subspecies were trapped in mist nets. The holotype was captured in a net stretched across an old road among large fruit trees situated along a small river (a tributary of the Río del Baluarte). Tropical deciduous vegetation grew in the narrow valley of the river but the adjacent hills supported oak. A specimen of Artibeus jamaicensis jamaicensis was netted along with the holotype and on the previous night, August 30, one individual each of Glossophaga soricina leachii and Sturnira lilium parvidens were taken in the same net. Baker and Greer (1962:69) also reported the two species of Sturnira as netted together 6 mi. S Pueblo Nuevo in adjacent Durango.

Table 1.—Some Measurements of Adults of Two Subspecies of
Sturnira ludovici.

¹ Holotype of Sturnira hondurensis (measurements after Goodwin, 1940:2).

² Holotype of Sturnira ludovici ludovici (measurements after Anthony, 1924:9).

Other specimens of S. l. occidentalis were taken under the following circumstances: 17 km. SE Talpa, Jalisco (night of November 3-4, 1962)—nine individuals netted over the Río Mascota in "pine-oak zone" along with representatives of S. l. parvidens, Artibeus toltecus, Chiroderma salvini, Eptesicus fuscus miradorensis, Lasiurus borealis teliotis, and Rhogeëssa gracilis; 20 km. WNW Purificación, Jalisco (night of November 20-21, 1962)—two specimens captured in a mist net stretched beneath branches of a fig tree at the edge of the Río Jicote in which Glossophaga commissarisi, S. l. parvidens, Artibeus turpis nanus, and Artibeus lituratus palmarum also were taken; 4 km. N Durazno, Jalisco (nights of November 21-22 and 22-23, 1961)—11 specimens, of which 10 were females, netted in company with G. s. leachii, S. l. parvidens, A. j. jamaicensis, A. toltecus, Centurio senex, and L. b. teliotis over a stream in a small canyon that supported "fairly dense stands of very tall deciduous trees." Five of the 10 females from 4 km. N Durazno were pregnant; each contained a single embryo. Crown-rump length of the embryos averaged 26.8 (24-30) mm. No gross reproductive activity was evident in other females of S. l. occidentalis collected.

Fig. 1. Distribution of Sturnira ludovici in North America. 1. S. l. ludovici.
2. S. l. occidentalis.

Specimens examined.—A total of 26, arranged from north to south, as follows: Durango: ½ mi. W Revolcaderos, 6600 ft., 2 (MSU); 6 mi. S Pueblo Nuevo, 3000 ft., 1 (MSU). Sinaloa: Plumosas, 2500 ft., 1 (the holotype). Jalisco: 17 km. SE Talpa, 5200 ft., 9; 20 km. WNW Purificación, 1400 ft., 2; 4 km. N. Durazno, 11.

Specimens of S. l. ludovici used in comparisons included a paratype (AMNH) from near Gualea, Ecuador, a specimen from Mindo, Ecuador, two specimens from La Cruz Grande, La Paz, Honduras (AMNH—paratypes of "Sturnira hondurensis"), and the following from México: 10 mi. SW Villa Juárez, 4850 ft., Puebla, 2; 11 km. W Quiroga, about 7000 ft., Michoacán, 2 (UMMZ); and Vista Hermosa, 1500 meters, Oaxaca, 5.

Acknowledgements.—For the loan of comparative materials we are grateful to R. H. Baker of The Museum, Michigan State University (MSU), W. H. Burt of the Museum of Zoology, University of Michigan (UMMZ), and R. G. Van Gelder of the American Museum of Natural History (AMNH). Specimens listed above that bear no designation as to collection are in the Museum of Natural History of The University of Kansas.

Literature Cited

Anthony, H. E.

Baker, R. H., and J. K. Greer

Goodwin, G. G.

Hershkovitz, P.

Transmitted June 24, 1963.