Interactive effects of prey and p,p′-DDE on Burrowing Owl population dynamics
Gervais, Jennifer A.
Hunter, Christine M.
Anthony, Robert G.
MetadataShow full item record
KeywordAthene cunicularia; Burrowing Owl; DDE; Elasticity; Interactive effects; Matrix population model; Multiple stressors; Population level risk assessment; Prospective analysis
We used population models to explore the effects of the organochlorine contaminant p,p'DDE and fluctuations in vole availability on the population dynamics of Burrowing Owls (Athene cunicularia). Previous work indicated an interaction between low biomass of voles in the diet and moderate levels of p,p'DDE in Burrowing Owl eggs that led to reproductive impairment. We constructed periodic and stochastic matrix models that incorporated three vole population states observed in the field: average, peak and crash years. We modeled varying frequencies of vole crash years and a range of impairment of owl demographic rates in vole crash years. Vole availability had a greater impact on owl population growth rate than reproductive impairment if vole populations peaked and crashed frequently. However, this difference disappeared as the frequency of vole crash years declined to once per decade. Fecundity, the demographic rate most affected by p,p'DDE, had less impact on population growth rate than adult or juvenile survival. A life table response experiment of time-invariant matrices for average, peak and crash vole conditions showed that low population growth under vole crash conditions was due to low adult and juvenile survival rates, whereas the extremely high population growth under vole peak conditions was due to increased fecundity. Our results suggest that even simple models can provide useful insights into complex ecological interactions. This is particularly valuable when temporal or spatial scales preclude manipulative experimental work in the field or laboratory.
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 16 (2006): 666–677.
Showing items related by title, author, creator and subject.
Effects of branching spatial structure and life history on the asymptotic growth rate of a population Goldberg, Emma E.; Lynch, Heather J.; Neubert, Michael G.; Fagan, William F. (2010-09-08)The dendritic structure of a river network creates directional dispersal and a hierarchical arrangement of habitats. These two features have important consequences for the ecological dynamics of species living within the ...
Effects of warm water intrusions on populations of macrozooplankton on Georges Bank, Northwest Atlantic Brown, Harmon; Bollens, Stephen M.; Madin, Laurence P.; Horgan, Erich F. (2004-06-21)As part of the Georges Bank/North West Atlantic GLOBEC (Global Ocean Ecosystems Dynamics) Program, macrozooplankton and micronekton were collected on 30 Broad Scale Survey Cruises between January – June, 1995 –1999, using ...
Hunter, Christine M.; Caswell, Hal (2004-09-17)Selectivity of harvest influences harvest sustainability because individuals with different characteristics contribute differently to population growth. We investigate the effects of selection based on chick weight on a ...