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  The Mammals of Texas - Online Edition

Hairy-legged Vampire
Order Chiroptera : Family Phyllostomidae : Diphylla ecaudata Spix

Hairy-legged Vampire (Diphylla ecaudata).  Photo by Merlin D. Tuttle, Bat Conservation International.Description. A relatively large, sooty-brown bat with no tail; a narrow, hairy interfemoral membrane; short, rounded ears; and a short, pug-nosed snout. The dentition is highly modified with the middle upper incisors larger than the canines; the outer incisors very small and set so close to the canines that they are easily overlooked; the crowns of the outer lower incisors seven-lobed, fan-shaped, and more than twice as wide as the inner lower incisors; premolars and molars very small and probably non-functional. Dental formula: I 2/2, C 1/1, Pm 1/2, M 2/2 X 2 = 26. External measurements average: total length, 85 mm; foot, 13 mm; forearm, 53 mm. Weight, 30-40 g.

Species distribution mapDistribution in Texas. From southern Texas southward to eastern Peru and Brazil. Known from Texas on the basis of one female taken May 24, 1967 from an abandoned railroad tunnel 19 km west of Comstock, Val Verde County.

Habits. This bat is primarily an inhabitant of tropical and subtropical forestlands. Its daytime retreat is normally a cave which it may share with other species of bats, but it has also been found roosting in mine tunnels and hollow trees. In the Mexican state of San Luis Potosi, Walter Dalquest found that these vampires were more solitary than the common vampire (Desmodus), and they did not gather in groups, even when several individuals inhabited a cave. Consequently, pools of digested blood do not form and there is only a slight odor of ammonia in the caves they inhabit. He found about 35 individuals, mostly females with young, in one cave but usually only one, two, or three were present in a given cave. These bats are shy, quick of movement, and readily take flight when molested.

The food of Diphylla is the blood of warm-blooded vertebrates, mainly birds, including domestic chickens. Ernest Walker reported that Diphylla attacks the legs and cloacal region of chickens. One bat was "observed alighting on the tail of a chicken, hanging by its hind legs and biting the exposed skin in the cloacal region, and then lapping up the blood while in an upright position."

This species seems to be reproductively active throughout the year. Pregnant females have been reported from Mexico and Central America in March, July, August, October, and November. The number of embryos per female is normally one, but one female captured July 8 in Chiapas, Mexico, contained two nearly full-term (crown-rump length 34 mm) embryos. The reproductive condition of the female captured in Texas was not recorded.

Although only one specimen of the hairy-legged vampire is known from Texas, it is possible that a thorough search of the caves in the Hill Country and along the Rio Grande will reveal additional records of this species or the common vampire (Desmodus rotundus) which have been taken in northern Mexico no more than 200 km from the Texas border. Since Diphylla is a possible reservoir of bovine paralytic rabies, it is of economic importance to the cattlemen and sportsmen of Texas.

Photo credit: Merlin D. Tuttle, Bat Conservation International.