Relationships of anti-predator escape and post-escape responses with body mass and morphology: a comparative avian study

Abstract

Background: Pointed and concave wingtips and shorter hind limbs make birds more vulnerable to predation. Question: Do behavioural anti-predator escape and post-escape responses compensate for these morphological characters that increase vulnerability to predation? Data studied: Body mass and size, indices of wingtip shape and hind limb length, flight initiation distance (the distance at which birds escape from a threat), and landing distance (the distance at which birds land after escaping from a threat) of 83 birds, mostly from North America, Europe, and Australia. Relationship data came mostly from molecular sources. Search method: Phylogenetically uncorrected: We regressed flight initiation distance and landing distance in different analyses on body mass and size, wing pointedness and convexity, femur and tarsus length. Phylogenetically corrected: We calculated independent contrasts with Compare 4.5 (Martins, 2004), ignoring branch lengths throughout. Conclusions: Birds with more pointed wings fled at longer distances and landed farther away than species with rounded wings, but hind limb length was not associated with flight initiation distance and landing distance.