Habitat-specific demography and source-sink dynamics in a population of Siberian jays

Nystrand, Magdalena; Griesser, Michael; Eggers, Sönke; Ekman, Jan (2010). Habitat-specific demography and source-sink dynamics in a population of Siberian jays. Journal of animal ecology, 79(1), pp. 266-274. Oxford: Blackwell 10.1111/j.1365-2656.2009.01627.x

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P>1. There are a number of models describing population structure, many of which have the capacity to incorporate spatial habitat effects. One such model is the source-sink model, that describes a system where some habitats have a natality that is higher than mortality (source) and others have a mortality that exceeds natality (sink). A source can be maintained in the absence of migration, whereas a sink will go extinct. 2. However, the interaction between population dynamics and habitat quality is complex, and concerns have been raised about the validity of published empirical studies addressing source-sink dynamics. In particular, some of these studies fail to provide data on survival, a significant component in disentangling a sink from a low quality source. Moreover, failing to account for a density-dependent increase in mortality, or decrease in fecundity, can result in a territory being falsely assigned as a sink, when in fact, this density-dependent suppression only decreases the population size to a lower level, hence indicating a 'pseudo-sink'. 3. In this study, we investigate a long-term data set for key components of territory-specific demography (mortality and reproduction) and their relationship to habitat characteristics in the territorial, group-living Siberian jay (Perisoreus infaustus). We also assess territory-specific population growth rates (r), to test whether spatial population dynamics are consistent with the ideas of source-sink dynamics. 4. Although average mortality did not differ between sexes, habitat-specific mortality did. Female mortality was higher in older forests, a pattern not observed in males. Male mortality only increased with an increasing amount of open areas. Moreover, reproductive success was higher further away from human settlement, indicating a strong effect of human-associated nest predators. 5. Averaged over all years, 76% of the territories were sources. These territories generally consisted of less open areas, and were located further away from human settlement. 6. The source-sink model provides a tool for modelling demography in distinct habitat patches of different quality, which can aid in identifying key habitats within the landscape, and thus, reduce the risk of implementing unsound management decisions.

Item Type:	Journal Article (Original Article)
Division/Institute:	08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Evolutionary Ecology
UniBE Contributor:	Griesser, Michael
ISSN:	0021-8790
ISBN:	0021-8790
Publisher:	Blackwell
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:17
Last Modified:	05 Dec 2022 14:04
Publisher DOI:	10.1111/j.1365-2656.2009.01627.x
Web of Science ID:	000272656600029
URI:	https://boris.unibe.ch/id/eprint/5239 (FactScience: 209969)