Individual Differences of Female Chronotypes and their Fitness Consequences in Wild Great Tits Parus major

Description

Diel timing is thought to be an adaptive trait, where consistent diel rhythms facilitate the anticipation of predictable situations such as the start and the end of the day. Individuals can have consistent earlier or later chronotypes compared to their conspecifics. In Great Tit males, early chronotypes seem to gain extrapair paternity improving their fitness. However, between individual variation in chronotypes remains considerable high and little is known about fitness consequences for females. Here, we assess fitness consequences for female chronotypes in Great Tits during the breeding season in a nest box population on the island of Vlieland, the Netherlands. We recorded nest temperature using temperature loggers during incubation and early chick provisioning, when females maximise their time spent on the nest. From these data we extracted the activity onsets relative to the conspecifics to obtain mean chronotypes for 151 known females during three breeding seasons. Chronotype was then correlated to fitness parameters from brood monitoring data. Our data indicates that later chronotypes start breeding later, are more successful in hatching at least one egg, and are more likely to initiate a second brood after a successful first one. However, they did not have more hatchlings or fledglings than the other chronotypes. Chronotype was also unrelated to female weight as well as chick condition, probably due to the many other factors influencing chick provisioning. These results suggest that females with different chronotypes might not differ in their quality but could have different breeding strategies. Further research might investigate fitness consequences beyond the breeding season, as well as life-time reproductive success, to explore fluctuations in selection pressure and potential differences in pace-of-life between females with different chronotypes.

Periode	24-feb.-2023
Evenementstitel	Annual Meeting of the Ethological Society and BfR
Evenementstype	Conference
Locatie	Berlin, GermanyToon op kaart
Mate van erkenning	National