13 



incapable of surviving by means of prolonged lethargy phases. Onset of the rainy season 

 with the chmate gettmg cooler sets off migration m Leptonycteris (East er la 1973). During 

 summer, L. nivalis is foimd in the higher levels of Big Bend National Park, Texas, and 

 several areas of Northern Mexico; and in winter they go furtlier south, passing down at 

 least to Jalisco and Morelos (Barbour & Davis 1969; Kunz 1982). 

 Where tlie supply of night-flowering plants does not support a minimimi of mdividuals 

 required to sustain genetic diversity, these habitats will be compliant to less specialized 

 genera who also include quite a lot of small insects m their diet {Glossophaga, Anoura 

 and Lonchophylla). Correspondingly, most of them have more extensive distribution areas. 



Habitat data on single taxa: 



Lionycteris: Most specimens of L spuirelli Handley (1976) recorded in Venezuela were 

 captured in humid forest, roosting in caves and rocky crevices during the day. In Peru, 

 Tuttle (1970) captured two bats at the edge of indigenous viUages, one of them amongst 

 flowering Cashew trees. 



Lonchophylla: Spends the day in hollow trees, sometimes in caves. In Venezuela, Handley 

 (1976) collected most of his L. rohusta and L. thomasi in humid forested areas. Detailed 

 information on L. thomasi from the Peaivian rain forest was given by Koepcke (1987). 

 From six specimens, three were captured in open riverine woodland, two in a tall cassava 

 field and one at a river bank. Several months she observed these bats in their day shelters 

 beneath embankments and among the roots of hollow trees. Though they sometimes 

 moved to another roost, the species altogether proved sedentary durmg the mating season. 



Platalina: There are no ecological data on Platalina genovensiiim yet. 

 Brachyphylla: These bats prefer caves, though there are some records from buildings and 

 one from a well (Novak & Paradiso 1983). Tliey live in small groups (Beatty 1944) or in 

 large colonies (5000 - 10,000 individuals). Tlieir day shelters are not always in the dark 

 (entrance areas of caves, well shafts, dense fohage). As observations in captive specimens 

 revealed that tliey do prefer tlie darkest area of their cages, staying within lighter areas 

 may be accepted as a temporary behaviour (Swanepoel & Genoways 1983). 

 Erophylla: Buden (1976) recorded E. sezekorni not only from the deeper, darker cave 

 areas but also from the lighter surroundings of the entrance. Koopman et al. (1957), 

 however, cohected their specmiens on several islands of the Bahamas exclusively in the 

 deeper cave areas. 



Phy lionycteris: Roosts in caves during the day (Novak & Paiadiso 1983). 

 Glossophaga: G. soricina exploits a variety of different roosts - natural hideouts like 

 caves, hollow trees and crevices, but also artificial Inding-places: drainage pipes, deserted 

 mines, cellars, roof framework or undersides of bridges (Tuttle 1976; Webster 1982). 

 According to this wide range of roost selection they show a considerable compliance to 

 other bat species: there are more than 30 other species which are known sometimes to 

 share the same roost (Webster et al. 1984). Tlie strongest coincidence is found with 

 Carollia perspicillata: In Peru, more than 60% of all known day shelters have been 

 recorded for both genera (Graham 1988). Apparently, the members of both taxa even 

 share the same locations within a shelter forming mixed clusters - probably an evidence 

 of muUial benefit by means of sociaHzation, such as less effort in thermoregulation and 

 water budget. According to Koepcke (1987), G. soricina prefers lighter vegetation or 

 densely covered cultivated land. One of the bats she observed flew between the dwelling 



