Visibility correction factors for multiple species of sea ducks and diving ducks using an aerial remote sensing approach Active
Aerial ocular surveys used by the United States Fish and Wildlife Service provide the most cost and time-efficient method to evaluate the relative abundance and spatial distributions of breeding, staging, and wintering waterbirds. However, the survey method is subject to substantial visibility bias, and visibility correction factors must be calculated to correct for incomplete detection. Calculation of visibility correction factors in remote or areas with limited access, such as open-water environments, is difficult, but advances in remote sensing technologies provide a means to better estimate visibility correction factors in such places.
This study occurs over Lake Michigan, specifically the Wisconsin waters of Green Bay. This area has been identified as an important stopover site to migrating waterbirds and is a popular location for waterfowl hunting. The study involves two planes flying simultaneously over predetermined transects. The first plane, a U.S. Fish and Wildlife Service – Division of Migratory Bird Management 2008 Kodiak 100, is outfitted with advanced remote sensing technologies that allow images to be georeferenced without ground truth. The seven-by-one camera system captures high resolution (~ 1.5 cm ground sample distance) imagery and covers a swath roughly 400 m-wide at 1,000 feet above ground level. The second plane, a Wisconsin Department of Natural Resources Cessna Skymaster 337, conducted ocular surveys at 200 feet above ground level, with two observers counting out the right side of the plane. Ocular observations were made for every waterfowl species that were seen out 200 meters from the plane.
This study aims to use the counts derived from the remote sensing survey to develop visibility correction factors for the ocular survey. Visibility correction factors derived from this study will allow managers to better estimate the abundance of waterfowl using the Wisconsin waters of Green Bay. In addition, visibility correction factors derived from this study can be applied to previous ocular survey counts to provide a better understanding of waterbird use of Green Bay over time. The development of these methods will allow other federal, state, and tribal agencies to better understand their waterbird populations.
This project is ongoing and is in collaboration with Sea Duck Joint Venture, Wisconsin Department of Natural Resources, U.S. Fish and Wildlife – Division of Migratory Bird Management, and Louisiana Cooperative Fish and Wildlife Research Unit.
Click here for a yearly update.
Aerial ocular surveys used by the United States Fish and Wildlife Service provide the most cost and time-efficient method to evaluate the relative abundance and spatial distributions of breeding, staging, and wintering waterbirds. However, the survey method is subject to substantial visibility bias, and visibility correction factors must be calculated to correct for incomplete detection. Calculation of visibility correction factors in remote or areas with limited access, such as open-water environments, is difficult, but advances in remote sensing technologies provide a means to better estimate visibility correction factors in such places.
This study occurs over Lake Michigan, specifically the Wisconsin waters of Green Bay. This area has been identified as an important stopover site to migrating waterbirds and is a popular location for waterfowl hunting. The study involves two planes flying simultaneously over predetermined transects. The first plane, a U.S. Fish and Wildlife Service – Division of Migratory Bird Management 2008 Kodiak 100, is outfitted with advanced remote sensing technologies that allow images to be georeferenced without ground truth. The seven-by-one camera system captures high resolution (~ 1.5 cm ground sample distance) imagery and covers a swath roughly 400 m-wide at 1,000 feet above ground level. The second plane, a Wisconsin Department of Natural Resources Cessna Skymaster 337, conducted ocular surveys at 200 feet above ground level, with two observers counting out the right side of the plane. Ocular observations were made for every waterfowl species that were seen out 200 meters from the plane.
This study aims to use the counts derived from the remote sensing survey to develop visibility correction factors for the ocular survey. Visibility correction factors derived from this study will allow managers to better estimate the abundance of waterfowl using the Wisconsin waters of Green Bay. In addition, visibility correction factors derived from this study can be applied to previous ocular survey counts to provide a better understanding of waterbird use of Green Bay over time. The development of these methods will allow other federal, state, and tribal agencies to better understand their waterbird populations.
This project is ongoing and is in collaboration with Sea Duck Joint Venture, Wisconsin Department of Natural Resources, U.S. Fish and Wildlife – Division of Migratory Bird Management, and Louisiana Cooperative Fish and Wildlife Research Unit.
Click here for a yearly update.