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Full-Text Articles in Life Sciences
Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore
Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore
Tyler Harms
A decrease in wetland habitats throughout North America has caused a decline in populations of marsh birds. The objective of this study was to estimate population densities and abundances of secretive marsh birds in Iowa. Call-broadcast surveys were conducted in conjunction with distance sampling for eight species of marsh birds at wetlands in three regions of Iowa during 2009 and 2010. Regions were defined by observed microhabitat characteristics which also corresponded to physiographic regions. Region-specific density estimates were obtained using Program Distance for four species of marsh birds for which sufficient detections existed (Pied-billed Grebe [Podilymbus podiceps], Least …
The Complexity Of Amphibian Population Declines: Understanding The Role Of Cofactors In Driving Amphibian Losses, Andrew Blaustein, Barbara Han, Rick Relyea, Pieter Johnson, Julia Buck, Stephanie Gervasi, Lee Kats
The Complexity Of Amphibian Population Declines: Understanding The Role Of Cofactors In Driving Amphibian Losses, Andrew Blaustein, Barbara Han, Rick Relyea, Pieter Johnson, Julia Buck, Stephanie Gervasi, Lee Kats
Lee Kats
Population losses and extinctions of species are occurring at unprecedented rates, as exemplified by declines and extinctions of amphibians worldwide. However, studies of amphibian population declines generally do not address the complexity of the phenomenon or its implications for ecological communities, focusing instead on single factors affecting particular amphibian species. We argue that the causes for amphibian population declines are complex; may differ among species, populations, and life stages within a population; and are context dependent with multiple stressors interacting to drive declines. Because amphibians are key components of communities, we emphasize the importance of investigating amphibian declines at the …
Effects Of Urbanization On The Distribution And Abundance Of Amphibians And Invasive Species In Southern California Streams, Seth Riley, Gary Busteed, Lee Kats, Thomas Vandergon, Lena Lee, Rosi Dagit, Jacob Kerby, Robert Fisher, Raymond Sauvajot
Effects Of Urbanization On The Distribution And Abundance Of Amphibians And Invasive Species In Southern California Streams, Seth Riley, Gary Busteed, Lee Kats, Thomas Vandergon, Lena Lee, Rosi Dagit, Jacob Kerby, Robert Fisher, Raymond Sauvajot
Lee Kats
Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and ex- otic predators and characterized stream habitat and invertebrate communities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish ( Procambarus clarkii) and fish, and had fewer …