< Terug naar vorige pagina

Publicatie

Great and blue tit laying dates vary with fine-scale variation in local tree composition but not tree budburst

Tijdschriftbijdrage - Tijdschriftartikel

Many studies have investigated how spring temperature affects laying dates and how this in turn affects the synchrony between nestling food demands and the insect food peak that follows tree budburst. While there is strong evidence that temperature itself acts as a cue for this plasticity in annual timing, the exact nature of the cue and response remains to be elucidated. Here we use long-term data on Great and Blue Tits and an unprecedented dataset on the location and phenology of 1396 trees to investigate whether small-scale variation in laying date can be explained by local tree phenology, and/or by tree species composition around nestboxes. Individual trees maintained their relative timing of budburst between years, while differences among tree species were more variable between springs. Contrary to expectation, we found no relation between first-egg dates and average budburst date at different distances around the nestbox. This can at least partly be explained by the very low degree of spatial autocorrelation in tree budburst. We did find an effect of local tree composition whereby Blue Tits, but not Great Tits, laid earlier in nestboxes surrounded by more oaks and fewer beeches. Although Blue Tit nest failure rate was higher in territories with more beech trees, independently of laying date, we found no evidence for preferential occupation of oak-dominated territories. Thus although we found some evidence for fine-scale effects of tree species on timing of breeding, the underlying mechanism remains unclear.
Tijdschrift: Journal of ornithology
ISSN: 2193-7192
Volume: 162
Pagina's: 709 - 722
Jaar van publicatie:2021