CHIROPTERA 27 



the Horseshoes' method of alighting, and they only do so occa- 

 sionally and with but partial success. It is noticeable that all 

 three have weak thumbs. 



Practically all bats are gregarious : even the Whiskered and 

 Barbastelle, so long supposed to be solitary, have been found in 

 colonies. In the case of the Noctule, Leisler's Bat, and the 

 Serotine, these colonies are not known to include individuals of 

 other species. The two Horseshoes are moderately exclusive, 

 but are often encountered in each other's company in regions 

 where both occur, and in France the smaller kind is on good 

 terms with the Notch-eared Bat. Most other small bats do not 

 object to the presence of an alien, but as a rule each species, and 

 indeed each individual,^ is segregated, and in hibernation the 

 most sociable, as the Long-eared and Leisler's, are often solitary. 

 In spite, however, of the sociability of the majority, individuals 

 may often be found living by themselves and frequently changing 

 their lodgings with the whim of the evening. It is certain that, 

 apart from sex, the causes leading to the congregation or the 

 segregation of bats are still obscure and in need of investigation. 

 Besides thus changing their domicile, many bats alter their 

 feeding grounds with the season, since they must perforce 

 attend the migrations of their prey. Rivers and pools, lanes 

 and hedges, ivy-covered walls and ruins are all sought at the 

 times when they most attract insects, a knowledge of the habits 

 and flights of which is essential to a bat-hunter.' During the 

 cockchafer flights the Kentish Serotines catch these beetles as 

 they buzz at low elevations around trees and bushes, but later 

 in the summer not one will be seen where before they have been 

 numerous. So the Noctule and Leisler's Bat vary their hunt- 

 ing-grounds, and may travel considerable distances from home ; ^ 

 although, where food is always abundant, their appearance and 

 movements are almost as regular as clockwork. Agam, 

 Daubenton's Bat probably takes a flight in mid-air before 



1 In the Mexico bat-cavern each species was disposed "in a band of some feet or 

 yards in width ; then a slight vacant space, followed by a band of another species." 

 —Ward op cit., 635. ^ F. Norton, Midland Naturalist, 149, 1883. 



3 C 'Ni'coUe and C. Comte state that of forty-seven examples of Pipistrellus 

 /6«>5/«, marked and liberated at a distance of two kilometres from their retreat, six 

 were eventually recaptured where originally taken.- Cow//, rend. Soc. Btol., Pans, Ix., 

 738-739. 1906. 



