20 



Intestines 



Generally, Chiroptera have quite short intestmes, presumably a concession to their flight 

 ability. Tlius, indigestable bits are expelled after a surprisingly short tinie. Among bats, 

 the frugivorous species have the longest intestmes, whereas the latter are very short in 

 insect-eaters and flower bats - probably due to their diet containing more energy. This 

 may also explain their astuteness in flight. 



Adaptations in host plants to Chiropterophily 

 Size and Constitution 



Despite of their low weight - even in terms of chiroptera - nectar feeding bats represent 

 heavyweights compared to other pollinators. This influenced both the structure of the 

 blossoms and the entire constitution of chiropterophilous plants. Though the plants belong 

 to completely different taxa they do share some common features: according to Baker 

 (1961), plants which are supposed to be pollinated by bats must be strong and thus are 

 usually tree-shaped. So, we find the following form types in order of frequency (Dobat & 

 Peikert 1985): 



1. Trees (e.g. Ceiba, Crescentia, Parkia) 



2. Slinibs (e.g. Sym bo lernt hiis) 



3. Pillar cacti (e.g. Carnegia) 



4. Lianas (e.g. Mucuna) 



5. Epiphytes (e.g. Capcmea, Markea, Trienaea, Vriesea) 



6. Herbaceous plants (e.g. Agave, Musa) 



7. Herbs (e.g. Lisianthus) 



Undoubtedly, most of them are woody, tree-shaped plants. Though the existence of quite 

 low, ground growing chiropterophilous herbaceous plants and herbs seems to be incom- 

 patible with these physical demands, Baker's view as cited is nevertheless supported in 

 two respects: first, these plants are quite rare, and second, they tend to gigantism. All in 

 conmion their blossoms are shifted as high as possible, thus facilitating orientation for the 

 bats approacliing them and at the same time reducmg access for imspecific and thus less 

 efficient nectar consumers. 



Blossom sliape 



Tliere is an enormous variety in adaptations which caimot be discussed in detail here 

 (review in Dobat & Peikert 1985). It is, however, interestmg how some chiropterophil 

 plants adapted their blossom shape to the head morphology of selected pollinating bat 

 species. Despite their various shapes (bellflowers, fuimel-shaped blossoms, dish-hke 

 flowers, tubular blossoms, labiate flowers, papilionaceous flowers, capitulum flowers, 

 spadiciform flowers, spadiciform brush-like flowers, brush-like flowers, brush-like 

 bellflowers) there is a conmion feature: the anthers always extend beyond the corolla, so 

 the blossom shape forces the pollinator into a position allowing the pollen to be fixed 

 witliin the fur (face, neck and shoulders) guaranteemg that any contaminated fur area will 

 most probably touch the stigma of the next blossom to be visited. 



Blossom exposition 



Blossom exposition represents an important further characteristic of chiropterophilous 

 flowers, facilitating access to the blossoms or inflorescences by shifting them out of the 



