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Natal dispersal allows individuals to reach suitable breeding sites. The effect of present plant phenology as a cue for dispersal into areas with favourable stages of development has been well established across avian and mammalian taxa. However, the effect of past experience is less understood. We studied the effect of past and present phenology of the environment on the direction and distance of natal dispersal in a passerine bird, the pied flycatcher ( Ficedula hypoleuca). We monitored spring settlement of local recruits in six nest box plots along a 10-km stretch of a south-north gradient of plant and caterpillar food development. We found that males used both past experience of caterpillar phenology from early life and actual plant phenology during the recruitment season as independent cues for breeding settlement. Males that had experienced a mismatch with the caterpillar food peak as a nestling, and/or those that arrived late in the spring in the recruitment year, moved north of their natal site, whereas males that had experienced a better match with the caterpillars as a nestling, and/or those that migrated earlier in the spring, settled at a similar site or more to the south. In females, no such effects were found, suggesting that the usage of phenological cues is sex specific. In summary, tracking environmental phenology by natal dispersal may represent an effective mechanism for settling in new favourable areas, and may thus potentially cause rapid change of a species' geographical breeding range in response to climate change. [ABSTRACT FROM AUTHOR]

Female pied flycatchers Ficedula hypoleuca prefer to mate with males having complex songs, but the benefits of this preference are not known. One potential benefit might be that males with complex songs are of higher quality and thus contribute more to the feeding of the brood than males with simple songs. We tested this by recording the feeding rate of males in two different populations in Norway. Neither the feeding rate nor the male′s contribution to the feeding relative to his mate correlated significantly with song complexity (27 and 21 males studied, respectively). However, male feeding rate may be influenced by female feeding effort. Therefore, we also recorded body mass change of 13-day-old nestlings of 30 males during a period of eight hours of enforced female absence. The males were matched in pairs according to brood size and, if necessary, nestlings were exchanged between broods to reduce initial differences in body mass. Both males in each pair were treated on the same day. The change in brood mass did not differ significantly between males with complex and simple songs, and the latter males did not lose more body mass than the former males during female absence. Thus, we conclude that female pied flycatchers mated with males having large song repertoires do not seem to benefit in terms of increased feeding effort from their mates. [ABSTRACT FROM AUTHOR]

We report an attempt to induce extrapair copulations and fertilizations in a species with a low intensity of sperm competition, the pied flycatcher Ficedula hypoleuca. Shortly after pair formation males were made less attractive to females by removing certain wing andtail feathers. Earlier research has shown that this manipulation reduces a male's pairing success. The idea was to test whether females mated to such males (N = 9) were more likely to obtain extrapair fertilizations than females mated to unmanipulated controls (N = 9). Paternity testing was carried out on all 98 young in the 18 broods, using a set of six microsatellite markers isolated from the species. Extrapair fertilizations were revealed in only three (17%) broods; two broods of handicapped males and one of a control male. A total of seven (7%) offspring were not genetically related to their putative father, a level which agrees well with results of other studies of this and other populations. We conclude that there was no evidence to suggest that the fertilization pattern was altered by the experimental manipulation. One reason for the lack of response could be that female mate choice in this species is based on male phenotypic, and not genotypic, quality. [ABSTRACT FROM AUTHOR]

Reports on a field experiment in which food availability was reduced to pied flycatcher broods to demonstrate that asynchronous hatching is not necessary for the process of brood reduction in the pied flycatcher, even under conditions of food shortage. Methods; Results; Discussion.

Examines the effects of parental ability on clutch size in tits (Parus spp.), for the two sexes separately. Field experiments; Blue Tits (p. caeruleus); Coal Tits (P. ater); Great Tits (P. major); When the Tits were handicapped; Breeding success.