Ecological Morphology and Flight in Bats (Mammalia; Chiroptera): Wing Adaptations, Flight Performance, Foraging Strategy and Echolocation

摘要: Bat wing morphology is considered in relation to flight performance and behaviour clarify the functional basis for eco-morphological correlations flying animals. Bivariate are presented between dimensions body mass a range of bat families feeding classes, principal-components analysis used measure overall size, size shape. The principal components representing shape (as opposed size) interpreted as being equivalent loading aspect ratio. Relative length area hand-wing or wingtip determined independently derive index, which measures degree roundedness pointedness wingtip. optimal form bats adapted different modes predicted by means mechanical aerodynamic models. We identify model aspects likely influence adaptation significantly; these include selective pressures economic forward (low energy per unit time distance (equal cost transport)), at high low speeds, hovering, turning. Turning measured two quantities: manoeuvrability, referring minimum space required turn given speed; agility, relating rate can be initiated. High speed correlates with loading, good manoeuvrability favoured turning agility should associated fast loading. Other factors influencing adaptations, such migration, foetus young carrying loads (all favour large area), cluttered environments (short wings) landing, identified. predictions cast into size-independent form, related observed species bats. In this way we provide broadly based interpretation forces that Measured speeds permit testing predictions. Comparison open-field free-flight confirms mass, proportions expected; there no direct Some adaptive trends clear from analysis. Insectivores hunt ways, reflected their morphology. Bats hawking high-flying insects have small, pointed wings give transport. hunting among vegetation, perhaps gleaning, very short rounded wingtips, often relatively short, broad wings, giving speeds. Many insectivorous forage `flycatching' (perching while seeking prey) somewhat similar gleaners. Insectivorous foraging more open habitats usually slightly longer hence lower Piscivores over stretches water, long power transport, unusually long, tips control stability flight. Carnivores must carry heavy loads, thus areas; strategies consist perching, structure behaviour. Perching hovering nectarivores both small area: surprising result may environmental pressure wingspan advantage during commuting flights; wingtips valuable lift generation slow an indicator behaviour) echolocation considered. It demonstrated adaptations predictably closely paralleled call structure, owing joint constraints locating food ways. Pressures on depend also most favouring smaller Power rises rapidly increases; available margin greater than larger species, they generalized repertoire Trophic strategy important, restrict ranges classes: insectivores primary carnivores frugivores larger. results community ecology considered, our tested through comparisons comparable, sympatric species. Our apply all kinds communities, but other (for example echolocation) contribute specialization behaviour, separation not solely None less, believe approach, identifying morphological clarifies relationships