Western Pipistrelle (Pipistrellus hesperus)
Order: Chiroptera, Family: Vespertilionidae
A small, drab-gray or smoke-gray bat with distinct, black, leathery facial mask and black membranes; tragus short, blunt, and slightly curved; underparts pale smoke-gray. Dental formula: I 2/3, C 1/1, Pm 2/2, M 3/3 X 2 = 34. External measurements average: (males), total length, 66 mm; tail, 27 mm; foot, 5 mm; forearm, 28 mm; (females), 73-30-5-28. Weight, 3-6 g.
Habits. This bat is associated chiefly with rocky situations along watercourses. Its daytime retreat is in the cracks and crevices of canyon walls or cliffs, under loose rocks, or in caves.
These are among the most diurnal of bats, beginning their foraging flights very early in the evening and often remaining active throughout the early morning hours. Pipistrelles are slow bats and may be distinguished on the wing by their slow, fluttery flight which is restricted to small foraging circuits. Occasionally, individual bats have been observed on the wing during mid-day, during which time they water to alleviate stress caused by the arid environment they inhabit.
Western pipistrelles forage from 2 to 15 m above ground on small, swarming insects and consume about 20% of their body weight in insects per feeding. Specific prey items include caddisflies, stoneflies, moths, small beetles, leaf and stilt bugs, leafhoppers, flies, mosquitoes, ants, and wasps. Stomach contents of individual bats often contain only a single species of insect, or if more than one species is present the remains are clumped together within the stomach, suggesting that they take advantage of swarming insects and feed intensively within such swarms.
The young, numbering one or two (usually two), are born in June and July after a gestation period of approximately 40 days. Maternity colonies may be established in buildings or rock crevices. The newborn bats weigh slightly less than 1 g at birth but grow rapidly. By August they can fly and are difficult to distinguish from adults.
The Mammals of Texas - Online Edition
Related Content
 The Shoebill, Balaeniceps rex also known as Whalehead is a very large bird related to the storks. It derives its name from its massive shoe-shaped bill.
The Shoebill is a very large bird, averaging 1.2 m (4 ft) tall, 5.6 kg (12.3 lbs) and 2.33 m (7.7 ft) across the wings. The adult is mainly grey, the juveniles are browner. It lives in tropical east Africa, in large swamps from Sudan to Zambia...
|
 Order: Falconiformes, Family: Accipitridae Snail Kites can be found in both South and Central America. Some are also found in Mexico and Cuba. The United States also has a small population concentrated in Florida.
Mass: 340 to 567 g.
Snail kites are medium-sized hawks, weighing from 12-20 oz. They are about 14-16 inches long and have a wingspan of 43-36 inches. The females are very slightly smaller than the male.
|
 Order: Passeriformes, Family: Corvidae American Crows are native to the Nearctic region all over North America. They can be found in the lower part of Canada and through the continental United States.
Adult American Crows are completely black birds weighing on average 450 g. The feathers have a glossy and slightly iridescent look. Crows have strong legs and toes. The bill is also black with a slight hook on the end. Stiff bristles c...
|
 Order: Passeriformes, Family: Corvidae Nearctic: Breeding range: The Gray Jay is found from tree line in northern Canada and Alaska south through boreal and subalpine forests to northern California on the west coast, Arizona and New Mexico in the Rocky Mountains, northern Wisconsin in the midwest, and New York in the east.
Winter range: The non-breeding range is essentially the same as the breeding range, as the Gray Jay does not mig...
|
 by David Rennie An army of 700,000 specially trained ducks and chickens has been mobilised to help fight China's biggest locust plague in 25 years. The birds, which are taught to pursue and eat locusts at the sound of a whistle, are part of a national campaign that includes 280,000 people backed by crop-dusting planes and special locust-killing micro-organisms imported from Britain. Swarms of locusts have d...
|
 Family: Alcidae The puffin's most striking feature is its large, brightly colored bill.
Early sailors dubbed the puffin the "sea parrot" because of its stout body, short wings, and orange or red webbed feet, which are placed far back on its body.
Males and females have the exact same markings. It's unknown whether this confuses the birds, but it certainly confuses bird-watchers.
During the summer...
|
|
(4.2)
Add Feedback