Science Informing the Status and Trends of Migratory Birds

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Through the Changing Arctic Ecosystems (CAE) Initiative, the U.S. Geological Survey (USGS) is informing key resource management decisions by better understanding how wildlife populations of special interest to the Department of the Interior (DOI) are responding to rapid physical changes in the Arctic. Below are some examples of how CAE research is informing decision-making on the status and trends of migratory birds.

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Snow Goose near the Colville River, northern Alaska

Snow Goose near the Colville River, northern Alaska

(Credit: Ryan Askren, USGS. Public domain.)

Implications for increasing snow goose populations in northern Alaska

New Areas Added by USFWS to the Arctic Coastal Plain Aerial Survey for Black Brant Geese

Starting in 1976, the U.S. Fish and Wildlife Service (USFWS) Migratory Bird Management Office (Anchorage, Alaska) has conducted annual aerial surveys of the Teshekpuk Lake area (broken outline in the map below) to monitor abundance and distribution of molting geese in this area and in particular, molting Black Brant.  Over this time span the size of the molting Black Brant population has been stable at about 20,000 birds in the traditional survey area (Flint et al. 2008).

In the early 2000’s, five new Black Brant molting areas (solid frames in the map below) outside of the traditional Teshekpuk survey area were identified by USGS Alaska Science Center.  USGS subsequently identified a process of salt water inundation, sedimentation, and colonization of these coastal areas by a high quality plant forage that Black Brant prefer (Tape et al. 2014) and also documented that geese are moving into these newly vegetated areas (Flint et al. 2014).

From 2011 to 2013, the USFWS added two of the five new areas (Cape Simpson and the Piasuk River Delta) to their annual survey and found an additional 7,000 – 15,000 molting Black Brant in each area, increasing the total count of molting Black Brant by approximately 50% (from 20,000 to 30,000; Wilson et al. 2014).  Cape Simpson and the Piasuk River Delta are now incorporated into the annual Teshekpuk Lake area survey flown by the USFWS.  The remaining three areas (North Kogru, Atiguru Point, and the Colville River Delta) are surveyed every 5 years, starting in 2010.

The net result of adding the additional survey areas is a 50% increase in the estimated size of the molting population of Black Brant.  These data contributed to the Bureau of Land Management 2013 Record of Decision to revise leasing and petroleum related infrastructure allowances in the Cape Simpson and Piasuk River Delta areas.  More information about the USGS Changing Arctic Ecosystems research on Black Brant can be found here:

Funding Support from the Arctic Goose Joint Venture for USGS Snow Goose and Black Brant Research

The Arctic Goose Joint Venture is a multi-agency partnership established under the North American Waterfowl Management Plan to further the scientific understanding and the management of North America’s geese.  In 2014, the Arctic Goose Joint Venture offered matching funding to on-going projects addressing questions related to overabundant Snow Geese in North America and particularly those that examined impacts of Snow Geese to other species.  USGS Changing Arctic Ecosystems research demographic processes of Snow Geese and Black Brant on the Arctic Coastal Plain of Alaska was selected for support by the Arctic Goose Joint Venture in 2015.

Snow Geese are the most rapidly increasing species of waterbird on the Arctic Coastal Plain of Alaska and management agencies are concerned that they may outcompete Black Brant for nesting and brood rearing habitat.  Experience with Snow Geese elsewhere in North America has demonstrated the importance of managing their populations before they become overabundant. Rapidly increasing Snow Goose populations may cause considerable damage of vegetation in nesting areas.  Furthermore, within the Pacific Flyway there is special concern regarding the population status of Black Brant, which for the past three decades have remained near or below management goals.  Given that populations of Black Brant are also expanding on the Arctic Coastal Plain, but in decline in western Alaska, the continued productivity of northern colonies is important to the overall population. 

USGS Changing Arctic Ecosystems research will provide management agencies in the Arctic Goose Joint Venture with needed information to contrast demographic processes of Snow Geese and Brant on the Arctic Coastal Plain.

Provided spatial and temporal maps of population change of waterbirds on Alaska’s North Slope