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Capsule Regrowth rate of tail feathers is more strongly affected compared to feather length and symmetry. Aims To assess the value of avian feathers as bioindicators. Methods The origin and persistence of fluctuating asymmetry (FA) in homologous pairs of regrowing feathers was studied in captive birds under different levels of environmental stress, respresented by exposure to lead (Pb). Homologous feathers of individually housed birds were plucked synchronously or with a delay of seven days. We measured growth rate, regeneration time, final size and FA of regrown feathers and related them to Pb stress. Results Asymmetry decreased as feathers reached their final length. This was not due to compensatory growth but rather a consequence of the programmed growth trajectory of single feathers. Tail feathers grown under higher Pb pollution showed increased regeneration times, decreased growth rates and shorter lengths, but no changes in development times nor in FA. For differences between both (i) original and i...

Postnuptial moult was studied in three consecutive years in a small population of Nuthatches. Fourteen to 25 individuals were captured in active moult each year with an average of 2.1 captures per bird per season. The total duration of moult was estimated as 88 days. Secondary moult was completed a few days after the end of primary moult. Primary moult rate was maximal at the beginning of moult, because many feathers were then growing simultaneously. Individual differences in the timing of moult were small, with a maximal spread of 21 days, and there was little variation between years. No differences in moult were found between sexes or age classes. Birds with failed broods moulted before successful breeders and early breeding females before late breeders. Duration and timing of moult are compared with other resident passerine species. A hypothesis based on summer territorial behaviour is put forward to explain the high degree of synchronization within the population and the relation between breeding and ...

Sixteen Nuthatches recovered over 20 km from their site of ringing (maximum = 102 km) showed a distinct preference for the soutwest direction. Most of them were recovered in their first year of life. No relation was found between fledging date and dispersal distance. The number of non‐local recoveries (more than 0 km) increased from August onwards. The fact that the southwest preference is detectable over small distances and the lack of correspondence between our recovery data and invasion records in the literature suggest that the preference is not necessarily associated with eruptive behaviour. A possible explanation is that dispersing Nuthatches would temporarily join migratory flocks of other species and adopt their direction of migration.

The timing of fledging in a population of nuthatches, breeding mainly in natural holes, was studied in 5 successive breeding seasons, with a total of 70 successful broods. Fledging date varied significantly among years, and was correlated with female age and body size, but not male age or body size. Fledging dates varied significantly among territories, but the responsible factors are not clear and may not be related to other aspects of territory quality. First-year females immigrating in winter or spring bred later than residents, which may be due to an indirect effect of territory quality. There is no evidence for an effect of duration of the pair-bond nor of changes in nest site between years. An important advantage of breeding early in nuthatches is that juvenile birds start to establish territories within weeks of fledging, and early young have a better chance of obtaining a high quality territory.