Differences between Choices Spatiotemporal Scales Involved Tradeoffs

Habitat selection shows fundamental differences depending on the activity considered, in particular in spatiotemporal scales involved. Estimating a foraging patch quality may take only up the time to try to find a food item (Figure 5). The equivalent rule for assessing a breeding patch quality implies attempting to breed to obtain information on expected breeding success in this patch, thus spending time and energy for one breeding attempt there, which may represent a significant portion of life span. In other words, foraging decisions are more dynamic than breeding habitat decisions. Breeding habitat choice may occur only once in life, when individuals decide whether to stay on or leave the natal site (natal site fidelity vs. dispersal). In mobile iteroparous species, individuals can change breeding sites between breeding events (breeding dispersal), but in many species, once the breeding place has been selected, individuals remain on that place for the whole breeding season.

□ Before experiment □ After experiment

350 300 250 200 150 100 50 0

Corvids playback (n=24)

Songbirds playback (n = 10)

Corvids playback (n=24)

Songbirds playback (n = 10)

Experimental treatment

Figure 6 An example of breeding habitat selection. Influence of the perceived nest predation risk on (a) dispersal distance and (b) nest site preferences in Siberian jays (Perisoreus infaustus). When exposed to nest predator playbacks (corvids) compared to control playbacks (songbirds) or no playback during breeding, individuals changed their breeding site choice in the following year. Data from Eggers S, Griesser M, Nystrand M, and Ekman J (2006) Predation risk induces changes in nest-site selection and clutch size in the Siberian jay. Proceedings of the Royal Society London Series B 273: 701-706.

Selecting a habitat or patch often implies different habitat requirements for different activities, and may thus follow different decision rules. However, different types of habitat selection may strongly interact and therefore be traded off against one another, for instance, in species searching for food and reproductive sites simultaneously. Even when selecting a breeding and foraging location are distinct activities during the life cycle, selecting a breeding habitat constrains foraging during the whole breeding period, especially in species spatially constrained during reproduction, for example, sessile and territorially breeding species. Furthermore, breeding habitat choice is often strongly linked with mate choice, which implies that constraints linked to sexual selection also influence breeding habitat choice, while they are unlikely to influence foraging habitat choice.

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment