Original scientific paper

https://doi.org/10.21857/ydkx2co8n9

Adaptive final (last-laid) eggs in the Eurasian Blue Tit Cyanistes caeruleus

Zdravko Dolenec ; Mokrice 132, 49243 Oroslavje, Croatia

Abstract

The study was carried out in 2021 using nestboxes. I examined the egg-laying pattern of the socially monogamous free-living Eurasian Blue Tit Cyanistes caeruleus that breeds only once a year in the northwestern Croatia. Nestboxes were visited daily to record the laying date of the first and subsequent eggs. A total of 132 eggs from 12 clutches with 11 eggs in each nest (11-egg clutch is the dominant clutch size in the study area) was measured. The mean egg volume was 1.19 cm³ (± 0.12), and the mean egg volume of all final eggs was 1.22 cm³ (± 0.09). In
this study, the %D-value was 2.46. According to this value, the Eurasian Blue Tit population in north-western Croatia adopt a “brood survival strategy”, where females allocate greater resources in the final eggs.

Keywords

Eurasian Blue Tit Cyanistes caeruleus; breeding strategy; %D-value; NW Croatia

Hrčak ID:

293579

URI

https://hrcak.srce.hr/293579

Publication date:

10.2.2023.

Article data in other languages: croatian

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