Hatching success in first clutches of Asian tits ( Parus cinereus ) is associated with parental time investment during incubation

This is the authors' abstract. We don't add key points for this paper.

In avian reproduction, the egg incubation period is typically an energetically and temporally demanding stage for parents. Parents must balance their investment in embryo development with their own survival, primarily because they cannot forage while incubating the eggs. In this regard, reproductive performance generally depends on the level of biparental care. The present study examines parental behaviour of Asian tit (Parus cinereus) pairs during the incubation period of their first clutch of the breeding season. Using generalized linear mixed models (GLMMs) and linear mixed models (LMMs), we evaluated various factors that influence parental investment and its effect on hatching success. Our results showed that female nest attendance has a significant positive relationship with first-egg laying date and a significant negative relationship with ambient temperature. For the male provisioning effort, only ambient temperature exerted a significant negative influence, with higher temperatures associated with reduced provisioning frequency. On the other hand, female incubation investment directly impacted only on hatching success. Our results highlight sex-specific contributions to parental investment, providing insight into adaptive strategies of cavity-nesting birds during incubation.