Roosting Ecological Characteristics And Related Functional Morphological Comparison Of Three Typical Species Of Bats In The Wuling Mountains

Roosting ecology and functional morphology mainly involves animals’ behavioral,morphological,functional,environmental and ecological features as well as the relationship among these features.Bats are the common animal name of Chiroptera Order,which are of real flight in Mammalia Class.With nocturnal habits,most bat species select some humid-dark caves as their roostsites,which brings about much difficulty to research and rare literature of their habitat characteristics and functional morphology.In this study,three representative cave-dwelling bats,Rhinolophus sinicus(8♀、15♂),Hipposideros armiger(9♀、13♂)and Myotis altarium(7♀、16♂)were used as the objects of investigation.A comparative research was conducted including roostpoint distribution,roosting behavior,body & roostsite temperature,roosting safety,as well as patagium,muscle and skeleton morphological characteristics of the bats in the karst caves of Xiangxi Tujia and Miao Nationality Autonomous Prefecture and Zhangjiajie City.The main results were as follows:(1)There were no significant differences between the female and male individuals within the populations of R.sinicus,H.armiger and M.altarium as to external morphological characteristics and skeletons.(2)In terms of roosting ecology,R.sinicus belonged to residence-type bats.During hibernation in cold season,they roosted in colony while dispersed when diurnating in warm season.R.sinicus took a vertical upside-down roosting posture hanging in the air with only their hindfoot claws hooked in cave walls or ceiling.H.armiger were migratory and they came to breed in Xiangxi and Zhangjiajie from April to November.Their roostsites were generally in the ceiling of near cave entrances.They took usually the similar roosting posture as R.sinicus but sometimes having a different upside-downness with forelimbs and thumbs as assisted hooking parts in case of accidently falling of heavy body weight.M.altarium only stayed in Xiangxi and Zhangjiajie to hibernate mainly in side walls of near cave entrances.They always roosted solitarily except when mating.M.altarium had sorts of roosting posture,including upside-downness with their abdomens clinging to cave wall,taking a crouch down in a pit or small platform,squeezing in a slot,et al.The three species of bats selected different karst cave microenvironments,forming spatial and temporal niche differentiation and reducing interspecies competition.In addition,there was a positive linear correlation between body and roostpoint temperature of the three species of bats,and their body temperature was always slightly higher than roostpoint one.(3)As for functional morphology,we found that there were main differences in sternum,hind limbs and clwas among them to account for their roosting ecologicaldifference.R.sinicus was a medium size,upside-down roosting posture only with hind legs and claws hooking in the rock wall.For R.sinicus,the ratio of length to width of wing & body mass to forearm length were low,which meant weak flying ability but much flexibility.For.H.armiger,of a large size,upside-down roosting posture sometimes with forelimbs and thumbs as assisted hooking parts and the ratio of length to width of wing & body mass to forearm length were high,which meant strong flying ability but poor agility.However,M.altarium was of smaller size with a smaller length to width ratio of wing as well as higher flexibility but poorer flying ability when.compared with R.sinicus or H.armiger.(4)The patagium was of double-layer structure with much elastin fibers for flexiblity.There existed differences in patagium and hair among the three species of bats.There were embossments on the patagium of R.sinicus and H.armiger,but no bumpus on that of M.altarium.Their arrangements were imbricated for wing-hair and coronary for back-hair.The wing-hair tip was spherical in H.armiger,which had two kinds of back-hair arranging coronarily and hastately,respectively.The wing-hair tip was conic and coronarily arranging in M.altarium with two kinds of back-hair arranging imbricatedly and hastately,respectively.