Supplementary feeding of wild birds indirectly affects the local abundance of arthropod prey
Abstract
Providing supplementary food for wild birds is a globally popular pastime; almost half of the households in many developed countries participate and billions of US dollars are spent annually. Although the direct influence of this additional resource on bird survivorship and fecundity has been studied, there is little understanding of the wider ecological consequences of this massive perturbation to (what are usually) urban ecosystems. We investigated the possible effects of wild bird feeding on the size and survivorship of colonies of a widespread arthropod prey species of many small passerine birds, the pea aphid [Acyrthosiphon pisum (Harris); Hemiptera: Aphididae], in suburban gardens in a large town in southern England. We found significantly fewer aphids and shorter colony survival times in colonies exposed to avian predation compared to protected controls in gardens with a bird feeder but no such differences between exposed and protected colonies in gardens that did not feed birds. Our work therefore suggests that supplementary feeding of wild birds in gardens may indirectly influence population sizes and survivorship of their arthropod prey and highlights the need for further research into the potential effects on other species.
In Gärten mit Vogelfütterung fanden wir signifikant weniger Blattläuse und kürzere Überlebenszeiten für Kolonien, die dem Räuberdruck durch Vögel ausgesetzt waren, als für die geschützten Kontrollen. In Gärten ohne Vogelfütterung gab es diese Unterschiede nicht. Unsere Untersuchung legt somit nahe, dass das Füttern von Vögeln in Gärten indirekt die Populationsgrößen und Überlebensraten ihrer Beutetiere beeinflussen könnte, und sie unterstreicht die Notwendigkeit für weitere Forschungen zu möglichen Einflüssen auf andere Arten.- Publication:
-
Basic and Applied Ecology
- Pub Date:
- May 2012
- DOI:
- 10.1016/j.baae.2012.03.001
- Bibcode:
- 2012BApEc..13..286O
- Keywords:
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- Avian supplementary feeding;
- Bird feeding;
- Domestic gardens;
- Pea aphids;
- Predator exclusion;
- Prey depletion;
- Urban ecology;
- Urban ornithology