Our website is made possible by displaying online advertisements to our visitors.
Please consider supporting us by disabling your ad blocker.

Download links will be available after you disable the ad blocker and reload the page.

A Synopsis of the American Bats of the Genus Pipistrellus



Download options:

  • 81.34 KB
  • 195.55 KB
  • 97.11 KB

Description:

Excerpt


Four nominal species of the genus Pipistrellus are currently recognized in North America. They are (F. Cuvier) of eastern North America, (H. Allen) of western North America, (Ward) from Veracruz, Mexico, and Miller from Tabasco, Mexico.

In the past three years, specimens have been obtained in Veracruz (by Dalquest) of each of the southern species. One of these, P. cinnamomeus, previously was known from a single specimen; the other, P. veracrucis, was known only from six specimens which now are lost or misplaced. The results of our study of these recently acquired Mexican specimens constitute our principal contribution in this paper; we have done little more with the material from the United States and Canada than to codify the findings of other mammalogists with respect to the systematic status and geographic distribution.

Study of the available specimens reveals that there are only two species, and ; Pipistrellus veracrucis proves to be only a subspecies (geographic race) of P. subflavus, and Pipistrellus cinnamomeus proves to be a species of another genus, Myotis (see Hall and Dalquest, page 583 of this volume).

 

Genus Pipistrellus Kaup

1829. Pipistrellus Kaup, Skizzirte Entw.-Gesch. u. naturl. Syst. europ. Thierw., Vol. 1, p. 98, Type, Vespertilio pipistrellus Schreber (not seen by us, after Miller, N. Amer. Fauna, 13:87, 1897).

Range in the New World.—In North America from southern Canada to Honduras (47 degrees to 5 degrees North Latitude) and from the Atlantic to the Pacific; not recorded from the West Indies or South America.

Characters.—Size small; tail approximately as long as outstretched leg; ears well developed with prominent tragus; dental formula: i.; c.; p.; m.; two upper incisors subequal and outer one lacking a concavity on surface facing canine; dentition otherwise essentially as in Myotis Kaup except that third premolar is always, instead of rarely, absent.

Remarks.—There are two species in North America. Their geographic ranges, as now known, meet, but do not overlap. Certain differences between the two species are listed in the parallel columns below. Most of these differences in the skull and teeth are illustrated in figures 22 and 23 on page 92 of Miller's "Revision of the North American bats of the family Vespertilionidae (N. Amer. Fauna, 13, 1897)."

 

Structure Color Predominately gray Predominately brown Foot Less than half as long as tibia More than half as long as tibia Thumb, length of Less than 4.9 mm. More than 4.9 mm. Tragus Blunt, terminal part bent forward Narrow, straight Skull (dorsal profile) Nearly straight Dish-faced Braincase (viewed from above) Small Large Palate Extending far behind molars; spine short, narrow at base Extending short distance long, wide at base I2 Unicuspidate Bicuspidate I3 Accessory cusp present on anterointernal face Accessory cusp absent on anterointernal face P1 (occlusal view) Less than a seventh as large as canine More than a seventh as large as canine P1 (labial view) Concealed by C1 and P4 Not concealed P4 Touching canine Not touching canine i3 Touching i2 and c1 Separated by space from i2 and c1 p3 Lower than anterior cusp of canine As high as anterior cusp of canine Distance from c1 to m1 Less than length of m2; premolars crowded More than length of m2; premolars less crowded

 

Pipistrellus hesperus(Synonomy under subspecies)

Range.—Arid Sonoran life-zones of western North America from Washington southward to Jalisco....