Izvorni znanstveni članak

https://doi.org/10.20302/NC.2025.34.26

Clutch and egg size in marine and freshwater common terns Sterna hirundo

Toni Kočevar orcid.org/0009-0000-2883-4953 ; Ulica Marina Držića 9, 47000 Karlovac, Croatia
Jelena Kralj orcid.org/0000-0002-1500-5897 ; Institute of Ornithology, Croatian Academy of Sciences and Arts, Trg Nikole Šubića Zrinskog 11, 10000 Zagreb, Croatia *

* Dopisni autor.

Sažetak

Clutch and egg sizes in birds are affected by intrinsic and environmental factors. Clutch size is affected by food availability and predation risk, while egg size is influenced by parental age and environmental conditions during both the breeding and pre-breeding period. In the Common Tern Sterna hirundo, egg size decreases with the laying sequence, and the survival rate of the last-hatching chicks is lower compared to their siblings. We studied the differences in clutch size, egg volume, and egg volume reduction in Common Terns inhabiting marine and freshwater habitats. Clutch size varied between studied regions. Egg size differed annually, but the greater volume reduction of second and third egg was found in marine habitats and among late clutches, regardless of the year. Egg volume and reductions were correlated with females’ body characteristics.

Ključne riječi

egg volume reduction; habitat; female morphometry; Adriatic Sea; Croatia

Hrčak ID:

336297

URI

https://hrcak.srce.hr/336297

Datum izdavanja:

31.12.2025.

Posjeta: 282 *