Document Detail
Predator-induced reductions in nest visitation rates are modified by forest cover and food availability
Abstract/OtherAbstract :
Bird parents can alert predators to the location of their nest. One mitigating option is that parents reduce their nest visitation rate in exchange for a lower predation risk. Here, using field data and experiments, we show that Siberian jay <it>Perisoreus infaustus</it> parents adjust feeding visit rates depending on an interaction of 3 factors: predator activity, nest concealment, and food availability. The rate of nest visits increased with the degree of nest concealment; yet, this relationship was modified by the presence of corvid predators. As the vegetation became more dense, parents at sites with high corvid activity disproportionately increased their feeding visit rates when compared with birds at sites with low corvid activity. We experimentally assessed how nesting cover affects this response of parents to the presence of corvids by using an Eurasian jay <it>Garrulus glandarius</it> model. Parents nesting at open sites ceased nest visits, whereas those nesting in dense forest continued feeding, albeit at a lower rate. Cover may thus not fully compensate for the effect of predator activity on feeding visit rates. However, offspring exposed to high predator activity might still receive the same amount of food because parents may adjust load sizes to compensate. This idea was confirmed by an experiment showing that in areas of high predator activity, food-supplemented birds significantly decreased nest visits when compared with nonsupplemented birds. These results indicate that some bird species can employ multiple nest-defense strategies to reduce predator-attracting nest visits; yet, these strategies may carry fitness consequences through reduced offspring quality.
Authors :
Eggers, Sönke, Griesser, Michael, Ekman, Jan
Related Documents :
469019 - Seasonal food web models for the oregon inner-shelf ecosystem : investigating the role ...
9062609 - Plasticity of consumer-prey interactions in the sea: chemical signaling, consumer learn...
8499569 - Characterization of multispecies living ecosystems
8810489 - The role of piscivores in a species-rich tropical river
33824269 - Population dynamics of brown shrimp (crangon crangon) in the belgian coastal waters: 2....
36606749 - Aquatic and terrestrial foraging by a subarctic herbivore: the beaver
33240919 - A preliminary investigation of winter daily food intake by four small teleost fish spec...
469019 - Seasonal food web models for the oregon inner-shelf ecosystem : investigating the role ...
9062609 - Plasticity of consumer-prey interactions in the sea: chemical signaling, consumer learn...
Contributors :
-
Publication Detail :
Publisher :  Oxford University Press     Type :  TEXT     Format :  text/html    
Date Detail :
2008-09-01 00:00:00.0
Subject :
Articles
Coverage :
-
Relation :
-
Source :
-
Copyright Information :
Copyright (C) 2008, International Society for Behavioral Ecology
Other Details :
Languages :  en    
Export Citation :
APA/MLA Format     Download EndNote     Download BibTex

Previous Document:  Heterospecific eavesdropping in a nonsocial species
Next Document:  Why be diurnal? Shifts in activity time enable young cane toads to evade cannibalistic conspecifics