A sum of its individual parts? Relative contributions of different eggshell regions to intraclutch variation in birds

0364252 - ÚBO 2012 RIV DK eng J - Journal Article
Polačiková, L. - Hauber, M. E. - Procházka, Petr - Cassey, P. - Honza, Marcel - Grim, T.
A sum of its individual parts? Relative contributions of different eggshell regions to intraclutch variation in birds.
Journal of Avian Biology. Roč. 42, č. 4 (2011), s. 370-373. ISSN 0908-8857. E-ISSN 1600-048X
R&D Projects: GA ČR(CZ) GD524/05/H536; GA AV ČR IAA600930605; GA MŠMT LC06073
Institutional research plan: CEZ:AV0Z60930519
Keywords : blunt egg pole * Great reed warblers * parasitic eggs * discrimination
Subject RIV: EG - Zoology
Impact factor: 2.280, year: 2011

Egg rejection in several species of hosts is based on cues only at the blunt pole and not at the sharp pole of the foreign and own eggshell. We investigated whether intraclutch variation is confined to a specific egg pole in species where the extent of intraclutch variation in the overall egg appearance is known to positively covary with either egg rejection rate or the probability of being parasitized. Pooling measurements of brightness across the whole egg surface led to statistically non-significant results and masked positive correlations of blunt pole brightness with egg rejection or parasitism risk, respectively. In contrast, patterns of blue chroma were important across the whole egg. We advocate the use of a combination of region-specific and whole-eggshell based colour metrics and manipulations in cognitive, perceptual, and ecological studies of foreign egg rejection.
Permanent Link: http://hdl.handle.net/11104/0199779