Animal Life in the Yosemite
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THE MAMMALS

PACIFIC PALLID BAT. Antrozous pacificus Merriam

Field characters.—Size large among the local bats; slightly smaller than Hoary Bat, several times size of Little California and Merriam bats. (See text fig. 7 and pl. 21.) Total length 4—4-1/2 inches (103-118 mm.), tail 1-1/2—1-3/4 inches (36-46 mm.), hind foot 1/2 inch or over (12-14 mm.), ear 1—1-1/3 inches (26-32 mm.), spread about 13-14 inches. Coloration pale brown above, light buff beneath; flight membranes dark brown, ears and muzzle light brown.

Occurrence.—Common in Lower Sonoran Zone, at Snelling. Lives in buildings during daytime, foraging abroad at late dusk. Hunts near the ground. Colonial.

The Pacific Pallid Bat is a rather large-bodied bat with extremely large ears. Its coloration as compared with that of the other local species is very pale. It was found at only one station, Snelling, but may possibly occur in portions of the adjacent foothill country, for it has been found in the Upper Sonoran Zone in other parts of central California. This bat appeared abroad in late May at about 7:45 P.M. Some were seen to forage on the leeward side of a row of cottonwoods near the Merced River.

On the evening of May 27, 1915, some boys were found making an effort to rid the village church in Snelling of a colony of pallid bats which had taken possession of the wall of a gable. One of our party lent his assistance in order to obtain some specimens. A trap of wire screen was set up in front of the opening. At 6:30 P.M. the bats had become active within the walls and could be heard squeaking. The first individual emerged at 7:30, escaped the net and flew away. Another coming out soon afterward likewise went free of the net, but then circled and alighted on the side of the building. No more came out until 7:40; then they began to emerge and drop into the net at the rate of about four per minute. As darkness came on the animals came out faster and faster. The net was taken down at 8:00 o'clock after which still more were seen to emerge from the wall, circle about a bit, and then fly away. The gable of the church which harbored the bats also housed a swarm of bees and a Red-shafted Flicker.


Fig. 7. Pacific Pallid Bat; from freshly collected specimen, natural size. Snelling, May 26, 1915.

Of the bats captured, 1 male and 19 females were saved as specimens. The male was not in breeding condition. Fifteen of the females contained 2 embryos each, 3 had 1 embryo and 1 none. Many of the embryos were of such large size as to indicate that they would have been born very soon.



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Animal Life in the Yosemite
©1924, University of California Press
Museum of Vertebrate Zoology

grinnell/mammals11.htm — 19-Jan-2006