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Habitat Selection Responses Of Parents To Offspring Predation Risk: An Experimental Test, Joseph J. Fontaine, Thomas E. Martin
Habitat Selection Responses Of Parents To Offspring Predation Risk: An Experimental Test, Joseph J. Fontaine, Thomas E. Martin
Wildlife Biology Faculty Publications
The ability of nest predation to influence habitat settlement decisions in birds is widely debated, despite its importance in limiting fitness. Here, we experimentally manipulated nest predation risk across a landscape and asked the question, do migratory birds assess and respond to variation in nest predation risk when choosing breeding habitats? We examined habitat preference by quantifying the density and settlement date of eight species of migratory passerines breeding in areas with and without intact nest predator communities. We found consistently more individuals nesting in areas with reduced nest predation than in areas with intact predator assemblages, although predation risk …
Gene Flow In Complex Landscapes: Testing Multiple Hypotheses With Causal Modeling., Samuel A. Cushman, Kevin Scot Mckelvey, Jim Hayden, Michael K. Schwartz
Gene Flow In Complex Landscapes: Testing Multiple Hypotheses With Causal Modeling., Samuel A. Cushman, Kevin Scot Mckelvey, Jim Hayden, Michael K. Schwartz
Wildlife Biology Faculty Publications
Predicting population-level effects of landscape change depends on identifying factors that influence population connectivity in complex landscapes. However, most putative movement corridors and barriers have not been based on empirical data. In this study, we identify factors that influence connectivity by comparing patterns of genetic similarity among 146 black bears (Ursus americanus), sampled across a 3,000-km2 study area in northern Idaho, with 110 landscape-resistance hypotheses. Genetic similarities were based on the pairwise percentage dissimilarity among all individuals based on nine microsatellite loci (average expected heterozygosityp0.79). Landscape-resistance hypotheses describe a range of potential relationships between movement cost and land cover, slope, …
How Transient Patches Affect Population Dynamics: The Case Of Hypoxia And Blue Crabs, Craig A. Aumann, Lisa A. Eby, William F. Fagan
How Transient Patches Affect Population Dynamics: The Case Of Hypoxia And Blue Crabs, Craig A. Aumann, Lisa A. Eby, William F. Fagan
Wildlife Biology Faculty Publications
Transient low-oxygen patches may have important consequences for the population dynamics of estuarine species. We investigated whether these transient hypoxic patches altered population dynamics of the commercially important blue crab (Callinectes sapidus) and assessed two alternative hypotheses for the causal mechanism. One hypothesis is that temporary reductions in habitat due to hypoxia increase cannibalism. The second hypothesis is that crab population dynamics result from food limitation caused by hypoxia-induced mortality of the benthos. We developed a spatially explicit individual-based model of blue crabs in a hierarchical framework to connect the autoecology of crabs with the spatial and temporal dynamics of …
Monitoring Low Density Avian Populations: An Example Using Mountain Plovers, Victoria J. Dreitz, Paul M. Lukacs, Fritz L. Knopf
Monitoring Low Density Avian Populations: An Example Using Mountain Plovers, Victoria J. Dreitz, Paul M. Lukacs, Fritz L. Knopf
Wildlife Biology Faculty Publications
Declines in avian populations highlight a need for rigorous, broad-scale monitoring pro-grams to document trends in avian populations that occur in low densities across expansive landscapes. Accounting for the spatial variation and variation in detection probability inherent to monitoring programs is thought to be effort-intensive and time-consuming. We determined the feasibility of the analytical method developed by Royle and Nichols (2003), which uses presence-absence (detection-non-detection) field data, to estimate abundance of Mountain Plovers (Charadrius montanus) per sampling unit in agricultural fields, grassland, and prairie dog habitat in eastern Colorado. Field methods were easy to implement and results suggest that the …
Tests Of Landscape Influence: Nest Predation And Brood Parasitism In Fragmented Ecosystems, J. J. Tewksbury, L. Garner, S. Garner, J. D. Lloyd, V. Saab, Thomas E. Martin
Tests Of Landscape Influence: Nest Predation And Brood Parasitism In Fragmented Ecosystems, J. J. Tewksbury, L. Garner, S. Garner, J. D. Lloyd, V. Saab, Thomas E. Martin
Wildlife Biology Faculty Publications
The effects of landscape fragmentation oil nest predation and brood parasitism, the two primary Causes of avian reproductive failure, have been difficult to generalize across landscapes, yet few Studies have clearly considered the context and spatial scale of: fragmentation. Working in two river systems fragmented by agricultural and rural-housing development, we tracked nesting Success and brood parasitism in > 2500 bird nests in 38 patches of deciduous riparian woodland. Patches oil both river Systems were embedded in one of two local contexts (buffered from agriculture by coniferous forest, or adjacent to agriculture), but the abundance of agriculture and human habitation within …