Adapting to Climate Change: Trends and Severe Storm Responses by Migratory Landbirds and Their Habitats

Science Center Objects

USGS scientists will be analyzing weather surveillance radar observations of birds departing stopover habitats to measure responses to climate change.

American Redstart

Male American Redstart (Setophaga ruticilla) captured upon the Louisiana coast during migration. Migratory landbirds like this American Redstart stopover in unfamiliar habitats across Texas and Louisiana as they migrate between tropical non-breeding areas and temperate breeding areas every spring and autumn. Photo by T.J. Zenzal.

 

 

The Science Issue and Relevance: Over two-thirds of all landbirds in North America migrate long distances to areas in Mexico, Central and South America, and the Caribbean islands. Habitats within Texas and Louisiana support high numbers of birds as they stop to rest and refuel during their migratory journeys through the Gulf of Mexico region. These “stopover” habitats are often at odds with human population growth and are impacted by natural disturbance and climate change. Predicted habitat loss from sea-level rise and extreme weather events, coupled with mismatches in the timing of peak bird migration with peak food abundance, may limit the availability and quality of stopover habitats. There is urgency for the conservation of areas to support migrating landbirds, many of which are already in decline across North America. Information on how birds respond at multiple scales is crucial to management partners such as U.S. Fish and Wildlife Service; U.S. Forest Service; Gulf Coast Bird Observatory; The Nature Conservancy; Louisiana Department of Wildlife and Fisheries; Texas Parks and Wildlife Department; National Audubon Society, ; Lower Mississippi Valley Joint Venture (JV), Oaks and Prairies JV, Gulf Coast JV; and others.

weather surveillance radars

Locations and 80 km radius coverage area of NOAA weather surveillance radars throughout Texas and Louisiana. Each radar is denoted by its three-letter name. Map produced by J.J. Buler.

 

 

 

 

 

 

 

 

Methodology for Addressing the Issue: Our objective is to determine how stopover habitat use by migrating landbirds changes in response to (1) climate change, (2) land cover change, and (3) short-term weather events (i.e., tropical storms, droughts, hurricanes). We will analyze data from 25 years of weather surveillance radar observations of birds departing stopover habitats to measure the responses of migrants to climate change. We will predict bird responses under various climate scenarios and produce maps to visualize where birds stopover and how their stopover distributions change across Texas and Louisiana in response to past and future habitat changes. This decision support tool will assist resource managers in addressing (1) declines of migratory bird populations linked to changes in availability of stopover habitat and (2) how climate change may impact landbird populations.

Mean bird stopover density

Mean bird stopover density during spring 2019 around the LCH radar in Lake Charles, LA. Map by J.J. Buler.

 

 

 

 

Future Steps: Over the life of the project, we will produce maps of seasonal mean bird stopover use both observed around each weather surveillance radar (finest native resolution) and predicted across each state (240-m resolution) from statistical models. We will also produce stopover use maps at specific areas of interest across Texas and Louisiana as needed by management partners, who will use the results of this project to develop a better understanding of migrant habitat selection and how habitat selection and use may change under predictive scenarios of future climate and landcover change. This information will provide a spatially-explicit decision support tool that land managers and conservation planners can use for targeted current and future habitat acquisition, restoration, and conservation efforts.