Affiliation:
1. Ecological Restoration, Faculty of the Environment Simon Fraser University 8888 University Drive Burnaby BC V5A 1S6 Canada
2. Centre for Wildlife Ecology, Department of Biological Sciences Simon Fraser University 8888 University Drive Burnaby BC V5A 1S6 Canada
3. 901 Highway 3A Nelson BC V1L 6J5 Canada
4. Goldeneye Ecological Services PO Box 663 Golden BC V0A 1H0 Canada
5. Wildlife Research Division, Science and Technology Branch Environment and Climate Change Canada 5421 Robertson Road Delta BC V4K 3N2 Canada
Abstract
AbstractDam construction projects have created opportunities for water security, targeted flood protection, and energy production but at the cost of increasing anthropogenic pressure on affected aquatic ecosystems. Wetland ecosystems are often among the most vulnerable, as underlying hydrological regimes influence overall wetland structure and function. Marsh bird species are wetland and riparian habitat specialists, many of which are experiencing population declines across North America. We examined how the alteration of hydrological regimes for generating hydroelectric power affected the occurrence of secretive marsh bird species in the western montane region of British Columbia, Canada. We established survey stations in wetlands across 2 regions, the West Kootenay and the Columbia Wetlands, sampling across a spectrum of hydrological regimes and other potentially relevant factors. At each station, we assessed wetland occupancy during the breeding season using broadcast‐callback surveys focused on 5 secretive marsh bird species: American bittern (Botaurus lentiginosus), American coot (Fulica americana), pied‐billed grebe (Podilymbus podiceps), sora (Porzana carolina), and Virginia rail (Rallus limicola). Additionally, we measured vegetation structure and the proximity and size of nearby water bodies for each survey station. We then used occupancy models to assess important correlates behind wetland occupancy for these marsh bird species, considering water management operations, regional differences, and local‐ and landscape‐level wetland characteristics. Secretive marsh bird species were more likely to occupy wetlands in areas with less frequently altered hydrological regimes. Occupancy models highlighted local‐ and landscape‐level characteristics as important correlates for wetland occupancy by marsh birds. Wetlands with frequently altered hydrological regimes had more open water cover and less tall vegetation present, conditions that were negatively associated with occupancy. Altered wetlands in this study were farther from the next nearest wetland, which was also negatively associated with occupancy. We suggest reservoir management is altering vegetation communities within these wetlands, indirectly promoting lower occupancy of secretive marsh bird species.
Subject
Nature and Landscape Conservation,Ecology,Ecology, Evolution, Behavior and Systematics,Nature and Landscape Conservation,Ecology,Ecology, Evolution, Behavior and Systematics