150 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



man, field notes; Goldman, 1951, p. 290). In shallow cave in region of oak and 

 pine near Mojarachic (Knobloch, 1942, p. 297). 



Behavior: Information on behavior is scant. E. W. Nelson (field 

 notes) remarked of a Pdtzcuaro specimen that: 



When first taken in hand its long ears were bent spirally back and downward 

 close against the sides of the head exactly like a pair of little recurved horns. 

 While examining the animal with surprised curiosity these horns suddenly ex- 

 tended and became a pair of huge upright ears. While examining these ears at 

 first I noted a fine regular waviness to the inner margin of the coiled ear which 

 disappeared when the ear was extended. 



The field notes of E. A. Goldman tell of a group of big-eared bats 

 found in the Sierra de Valparaiso in December, 1897: 



I found eight specimens of this species hibernating in a cave at 8,200 feet 

 altitude. Six of them in formalin were unfortunately lost along with my tank 

 by my hunter while descending to the town of Valparaiso. They were hanging 

 as usual by their feet, from the roof of the cave and at considerable distances 

 from each other — 6 to 10 or 12 feet. Their eyes were closed and their bodies cold 

 and stiff. Their wings were hanging very close to the sides of their bodies. Their 

 long ears had the margins rolled inwards and they were curled over backward and 

 downward somevfhat like the horns of a sheep and were pressed close to the sides 

 of the head. When first taken from the cave the only signs of life that I noticed 

 in them was a very slight moving of the feet, and they would hook them to my 

 finger. I tied them all up together in a [handkerchief?] and carried them to 

 camp. Their blood soon began to circulate, their bodies became warm and they 

 revived sufficiently to be able to chatter and bite at each other and my fingers. 

 Six hours after the}' were taken from the cave they could crawl about but although 

 uninjured none of them were able to fly or at least made no effort to do so. The 

 cave was cold and damp and a strong current of air passed in at one entrance and 

 out at another. 



Food: Not known. 



Migration: Like other species of Plecotus, P. mexicanus is not 

 known to make extensive migrations (see table 5 and p. 146). 



Hibernation: According to Goldman's 1897 field notes (above), 

 this species may become very lethargic under certain conditions. 



Reproduction : Dalquest noted on specimen labels that no embryos 

 were found among a large group of females collected at Las Vigas in 

 January. Adult males (10) and adult females (53) were together in 

 this colony. Adults of both sexes (3 males, 10 females) likewise were 

 found together at Santa Rosa in November. A group of nine females, 

 accompanied by five immatures, almost fully grown, but with finger 

 joints not completely ossified, were collected near Pacheco on 25 

 August. Solitary immature individuals of slightly younger age were 

 found on 14 July at Jico and at Pdtzcuaro. 



Molt: Two of nine adult females collected near Pacheco on 25 

 August were beginning to molt on chest and shoulders (new hairs still 

 short and prostrate). Two of five immatures collected with this 

 group were beginning to molt on the belly. 



