Pallid Bat

Antrozous pallidus

photo by

Merlin Tuttle

Click for social vocalizations made by this bat.

Click for feeding vocalizations made by this bat.

  Pallid bats have great ears! They can also see pretty well. But, like all bats, they use their voices to make ultrasonic sounds that bounce back to their ears and these reflected sounds let the bats "see" flying insects and the environment they are flying through. Pallid bats occur from British Columbia to west TX and south to Baja and Central Mexico. Pallid bats are generally found in grasslands and desert habitats. Populations can be non-migratory and are known to winter in places from CA to KS. Mating occurs in Oct, and like other bats, sperm and egg don't meet until spring. Gestation takes about 9 weeks, with young born in spring. Colonies or parts of colonies with only females ("maternity roosts") gather in rock crevices and old buildings, starting in Apl. Females often have two young each year and nurse them for 6-8 weeks. Females breed in the summer after they are born.Adults probably hibernate over much of range.

  Pallid bats are medium-sized (total body length 92-135 mm) and often feed on the ground early in the night.They can run on folded wings and hind feet; they can hop around to catch insects. They then retire to night roosts where they hang out to digest their catch (Jerusalem crickets, scorpions, grasshoppers, beetles, etc.). They may feed again near dawn. By daylight, they retire to "day roosts" in rock crevices where they hide. Pallid bats are known from Pinnacles, Hastings and Santa Lucia Preserve.

Big Brown Bat

Eptesicus fuscus

photos by

Roger Barbour (L)

and

Merlin Tuttle (R)

Click for traveling vocalizations made by this bat.

  Probably about the largest bat we have with uniform brown fur (total length 105-118 mm).Brown bats are very common in North America, and occur in most habitats, including old buildings.Often seen flying around city lights, where they feed on flying insects. Breeding occurs in the fall, with maternity colonies forming the following spring. Often, two are born, and each may be as much as 10% of mothers weight at birth! Young can fly at 3-4 weeks. Adults can live up to 18 years. Feeding bats eat up to 3 gram/hour and a typical barn colony of 500 bats can remove hundreds of pounds of insects (mostly beetles) each year. Non-migratory, hibernating in cool, dry caves. Hibernation may use up 1/3 of body weight. Drink by flying over water and scooping sips while airborne. Hawks and Great Honed Owls are know predators. Big brown bats are known from Pinnacles, Hastings and Santa Lucia Preserve.

Western Mastiff Bat

Eumops parotis

Photso by Roger Barbour

Click for traveling vocalizations made by this bat.