Across diverse taxa, morphological traits mediate social interactions and mate selection. Physiological constraints on signal elaboration have been widely documented, but the potential for trait display to influence physiological state remains poorly understood. We tested for the presence of causal links between ventral plumage colour-a trait known to covary with reproductive performance-and ph...

We examined the first arrival dates in the UK over a 56 yr period of 2 hirundines, sand martin Riparia riparia and barn swallow Hirundo rustica, in relation to temperatures along migration routes and at destination. Changes in arrival dates have been much greater for sand martin than for barn swallow, and the arrival order of the 2 species now appears to have reversed. There appear to be 2 reas...

Dolenec, Z.: Breeding characteristics of the barn swallow (Hirundo rustica) in NW Croatia. Nat. Croat., Vol. 11, No. 4., 439–445, 2002, Zagreb. The research was carried out in the village of Mokrice (46°00'N, 15°55'E) in NW Croatia during 1998–1999. Egg length averaged 19.16 mm, egg breadth 13.72 mm, egg volume 1840.8 mm3, egg shape index 1.40 and egg weight 1.81 g (during both years). The nest...

Telomere length and dynamics are increasingly scrutinized as ultimate determinants of performance, including age-dependent mortality and fecundity. Few studies have investigated longevity in relation to telomere length (TL) in the wild and none has analysed longevity in relation to TL soon after hatching, despite the fact that telomere shortening may mostly occur early in life. We show that TL ...

Parents of a variety of animal species distribute critical resources among their offspring according to the intensity of begging displays. Kin selection theory predicts that offspring behave more selfishly in monopolizing parental care as relatedness with competitors declines. We cross-fostered two eggs between barn swallow (Hirundo rustica) clutches and compared the loudness of begging between...