Ebo Gwinner was involved in the planning stage, the experimental realization and the writing of a draft manuscript of this project. Unfortunately, he died before the manuscript was completed.
Reduced nestling growth of East African Stonechats Saxicola torquata axillaris in the presence of a predator
Article first published online: 7 JUL 2006
Volume 148, Issue 3, pages 468–476, July 2006
How to Cite
SCHEUERLEIN, A. and GWINNER, E. (2006), Reduced nestling growth of East African Stonechats Saxicola torquata axillaris in the presence of a predator. Ibis, 148: 468–476. doi: 10.1111/j.1474-919X.2006.00549.x
- Issue published online: 7 JUL 2006
- Article first published online: 7 JUL 2006
- Received 21 February 2005; revision accepted 31 January 2006.
We investigated nestling growth of tropical East African Stonechats Saxicola torquata axillaris to evaluate the effects of nest predation, predator presence and food availability. We provided some Stonechat pairs with supplemental food, while others in a similar habitat served as a control. Concomitantly, we assessed the presence of Fiscal Shrikes Lanius collaris in supplemental fed and unsupplemented territories. Fiscal Shrikes prey on adult Stonechats and nestlings. We found that nestling growth was considerably reduced in Stonechat pairs that shared their territory with a Shrike. This effect was greater in nestlings of pairs that did not receive supplemental food. The reduction in nestling growth rates was significantly correlated with a reduced rate of visiting by the parents. Behavioural observations further suggested that parents reduced their feeding visits to the nest presumably to minimize their own predation risk, rather than predation risk of their brood. Our experiments show that the lower reproductive investment in tropical Stonechats can be attributed to risk-sensitive behaviour of the parents, especially when food is in limited supply.