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A New Long-eared Myotis (Myotis Evotis) From North

A New Long-eared Myotis (Myotis evotis) from Northeastern Mexico



=University of Kansas= =Lawrence= 1955

=University of Kansas Publications= =Museum of Natural History=

Vol. 9, No. 3, pp. 81-84

December 10, 1955

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Robert W. Wilson




A New Long-eared Myotis (Myotis Evotis) From Northeastern Mexico



Long-eared bats obtained by field parties from the University of Kansas in the Mexican states of Coahuila, Nuevo Leon, and Tamaulipas, are found to belong to the species, _Myotis evotis_, but are not referable to any named subspecies. They are named and described as follows:

#Myotis evotis auriculus# new subspecies

_Type._--Female, adult, skin and skull; No. 55110, Univ. Kansas Mus. Nat. Hist.; 10 mi. W and 2 mi. S Piedra, 1200 ft., Sierra de Tamaulipas, Tamaulipas; 9 June 1953; obtained by Gerd H. Heinrich, original number 7061.

_Distribution._--Coastal foothills and adjacent mountains of northeastern Mexico from central Coahuila south and east to central Veracruz.

_Diagnosis._--Size medium (see measurements), ears small for the species; color dark, upper parts (_j_14) Ochraceous-Tawny (color terms are after Ridgway, Color Standards and Color Nomenclature, Washington, D. C., 1912), underparts Warm Buff, ears pale; skull large, teeth large, mandible long.

_Comparison._--From _Myotis evotis evotis_ (H. Allen), from Colorado, Wyoming, and Montana, _M. e. auriculus_ differs in: Ears averaging shorter; color darker and richer; ears paler and contrasting less, in color, with pelage; skull larger in all measurements taken except that of least interorbital constriction; forehead, when viewed laterally, rising more abruptly, because frontal region is more inflated; teeth larger.

_Remarks._--_Myotis evotis auriculus_, although no larger externally than _M. e. evotis_, has a larger skull, which in lateral view has a more abruptly rising forehead. The teeth, especially the first upper premolars, of _auriculus_ are noticeably larger than those of _evotis_. The first two lower premolars are sub-equal in _auriculus_ whereas in _evotis_ the first lower premolar usually is larger. The mandible, in relation to the greatest length of the skull, is longer in _auriculus_ (ratio, 71-74) than in _evotis_ (ratio, 67-71).

Coahuilan specimens, although assigned to _auriculus_, are slightly paler (upper parts (16) Ochraceous-Tawny; underparts (_e_) Light Buff) and have less abruptly rising foreheads than do the bats from Tamaulipas. In these features, the Coahuilan animals are somewhat intermediate between typical _auriculus_ and _evotis_. The bat from Nuevo Leon, in both color and degree of slope of forehead, is intermediate between those from Coahuila and those from Tamaulipas.

A bat from Perote, Veracruz, identified as _Myotis evotis chrysonotus_ (J. A. Allen) [=_M. e. evotis_] by Miller and Allen (U. S. Nat. Mus., Bull. 144:118 and 120-121, May 25, 1928) is here assigned to _M. e. auriculus_. Measurements given by these authors indicate that this bat has a large skull, which is characteristic of this subspecies. Another specimen, similarly assigned by these authors and from the San Luis Mountains in northwestern Chihuahua, seems to be _M. e. evotis_, although the published measurements (_loc. cit._) show that this bat tends toward _auriculus_ in size of skull and mandible.

All specimens were taken in mist nets stretched over water. Those from Coahuila were snared over a concrete water tank situated near the base of low hills in mixed mesquite and chaparral. In Nuevo Leon, one bat was netted over a small pond around which grew some low trees in an intermontane valley in the Sierra Madre Oriental. In Tamaulipas two bats were caught in a mist net stretched across a narrow, brush-bordered arroyo in the Sierra de Tamaulipas. One adult male weighed 7.0 grams; average and extreme weights of 7 adult, non-pregnant females were 6.8 (5.2-8.0). Females taken on March 25 and 26 were not pregnant; one obtained on June 20 was lactating. Funds for financing field work were made available by the Kansas University Endowment Association and the National Science Foundation.

_Measurements._--Measurements, in millimeters, of the holotype and another female (No. 55111 KU) from the type locality and 3 females (Nos. 44726, 44729-30 KU) from Coahuila, respectively, are: total length, 94, 93, 97, 86, 96; length of tail vertebrae, 43, 42, 41, 39, 45; length of hind foot, 9.5, 9, 10, 10, 8; height of ear from notch, 20, 20, 20, 18, 20; length of forearm, 37.9, 38.4, 40.2, 37.3, 38.5; greatest length of skull, 16.1, 16.4, 16.2, 15.8, 16.1; condylobasal length, 15.4, 15.4, 15.6, 15.0, 15.4; zygomatic breadth, 9.7, 9.9, 10.1, 9.4, 9.9; least interorbital constriction, 3.9, 3.8, 3.9, 3.7, 3.7; breadth of braincase, 7.5, 7.6, 7.5, 7.5, 7.6; occipital depth, 5.9, 5.9, 5.5, 5.7, 5.6; palatal length, 8.5, 8.7, 8.7, 8.7, 8.9; mastoid breadth, 8.2, 8.4, 8.3, 8.2, 8.3; breadth across third upper molars, 6.1, 6.2, 6.3, 6.1, 6.1; length of maxillary tooth-row, 6.5, 6.5, 6.7, 6.6, 6.6; length of mandible, 11.5, 11.8, 11.9, 11.2, 11.7; length of mandibular tooth-row, 8.0, 8.0, 8.1, 8.1, 8.1.

_Specimens examined._--Total, 8, all in the University of Kansas Museum of Natural History. Coahuila: 4 mi. W Hacienda La Mariposa, 2300 ft., 5 (2 alcoholics). Nuevo Leon: Iturbide, 5000 ft., Sierra Madre Oriental, 1. Tamaulipas: 10 mi. W and 2 mi. S Piedra, 1200 ft., Sierra de Tamaulipas, 2.

_Transmitted April 16, 1955._

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