Geographic variation in avian clutch size and nest predation risk along a productivity gradient in South Africa

0369550 - ÚBO 2012 RIV ZA eng J - Journal Article
Hořák, D. - Sedláček, O. - Tószögyová, A. - Albrecht, Tomáš - Ferenc, M. - Jelínek, V. - Storch, D.
Geographic variation in avian clutch size and nest predation risk along a productivity gradient in South Africa.
Ostrich. Roč. 82, č. 3 (2011), s. 175-183. ISSN 0030-6525. E-ISSN 1727-947X
R&D Projects: GA ČR(CZ) GAP505/11/1617; GA MŠMT LC06073
Institutional research plan: CEZ:AV0Z60930519
Keywords : home-range size * Passerine birds * hypothesis * edge * community * forest * sites
Subject RIV: EG - Zoology
Impact factor: 0.427, year: 2011

Geographic variation in avian clutch size is thought to be related to the variation in nest predation rate and food availability. We studied predation on artificial ground nests along a large-scale geographic gradient in South Africa, and calculated mean clutch sizes of birds occurring in atlas quadrates surrounding our study sites. Clutch sizes generally increased with increasing productivity and seasonality. The least productive desert site was characterised also by the highest predation rate, whereas all the other sites located in savannas revealed much lower and more or less constant predation rate. We found no evidence for relationship between nest predation rates and clutch sizes of ground-nesting birds. This indicates that food availability is the major factor responsible for geographical variation in bird clutch sizes across South Africa, though high predation rate might also contribute to low clutch size in least productive arid environments.
Permanent Link: http://hdl.handle.net/11104/0203585