Comparing interspecific and intraspecific allometry in the Anatidae

• Published in: Journal für Ornithologie
• Main Authors: Green, Andy J., Figuerola, Jordi, King, Roy
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing 2001
• Subjects: Morphology; scaling; tarsus length; wildfowl; wing length; Avian Studies
• Online Access: http://hdl.handle.net/10261/43200; https://doi.org/10.1046/j.1439-0361.2001.00075.x

Interspecific scaling relationships (e. g. of limb size with body mass) in vertebrates are usu- ally assumed to be functional (e. g. biomechanical) attributes. In this paper on the Anati- dae, we study the scaling of wing length and tarsus length with body mass, relationships that can be expected to have biomechanical significance. At an interspecific level, both wing length and tarsus are positively allometric, a finding consistent with results from pre- vious comparative avian studies. These trends remained significant in regressions control- ling for the effects of phylogeny, but interspecific slopes were less steep within tribes than in the whole family (a taxon-level effect). We are not aware of any biomechanical resaons that explain these patterns satisfactorily. Intraspecific (static) allometries in Green-winged Teal (Anas crecca) and Marbled Teal (Marmaronetta angustirostris) are different: wing length is negatively allometric and tarsus is isometric. These anomalies suggest that inter- specific and intraspecific scaling relationships do not share common causes. Our results bring into question the significance of interspecific allometries in vertebrate morphology, which may to some extent be non-functional by-products of morphological optimisation processes within species and ecological differences between them Peer reviewed