Prioritizing habitats based on abundance and distribution of molting waterfowl in the Teshekpuk Lake Special Area of the National Petroleum Reserve, Alaska

Abstract

The National Petroleum Reserve in Alaska (NPR-A) encompasses more than 9.5 million hectares of federally managed land on the Arctic Coastal Plain of northern Alaska, where it supports a diversity of wildlife, including millions of migratory birds. Within the NPR-A, Teshekpuk Lake and the surrounding area provide important habitat for migratory birds and this area has been designated by the Bureau of Land Management as the Teshekpuk Lake Special Area (TLSA) because numerous waterfowl species use the area for breeding and molting. Our goal was to provide a mechanism for land managers to assess relative value of areas for molting waterfowl. This approach was based on the population densities of Pacific black brant ( Branta bernicla nigricans ) and cackling geese ( Branta hutchinsii ) and pre-defined thresholds for the minimum fraction of the population contained within selected areas. Prioritizations were based on long-term records of population density combined with global-positioning system data to reveal small-scale patterns of habitat use. The highest population density of the Pacific black brant was found along the Beaufort Sea coast on the eastern edge of the study area, whereas cackling geese were somewhat more widely distributed. Depending on the criteria used for prioritization and width of protective buffers placed around selected units, 52–85% of the Goose Molting Area was identified as high-priority area. The effectiveness of this approach to protection of molting birds assumes that buffers around high value units are wide enough to provide adequate protection from disturbance related to oil and gas development.