Snowy Plover Survey – Great Salt Lake, UT
Summary Report 2008.  

The Avian Ecology Lab is coordinating a lake-wide survey of Snowy Plover.  The goal of the survey is to assess the distribution and abundance of breeding SNPL throughout the entire Great Salt Lake (GSL) Ecosystem.  The GSL survey is part of the US Fish and Wildlife Service International Survey of Breeding Snowy Plovers.  

Although it would be desirable to count every plover inhabiting the Great Salt Lake (Lake) during the breeding season, it became obvious during the development of this survey that a true census of the Lake’s Snowy Plover population was infeasible and unrealistic, and that a sampling approach was needed.  To develop the sampling frame, experts designated the Lake’s shoreline habitats as having known locations of breeding plovers, having the potential to support breeding plovers, or having low potential to support breeding Snowy Plovers.  Following these probabilities of encountering Snowy Plovers, sampling intensity will be allocated on the “potentialness” of the Lake’s habitat; the known location stratum will receive the most intense effort and the low potential the least.  Within a GIS, these strata were overlaid with a grid of 225-ha clusters of twenty-five 9-ha (300 x 300 m) cells, which yielded 2,130 sample clusters.  A random sample of clusters was drawn from each stratum across the entire Lake.  Because some clusters will fall in areas that are inaccessible, more units have been selected than can actually be surveyed.  The sampling method is a two-stage process.  First a rapid survey of the cluster is conducted to 1) determine occupancy of each 9-ha cell within the 225-ha cluster and 2) make an initial count of the number of plovers in each cell.  Second, a follow-up more intensive search of all 9-ha cells where plovers were detected is conducted to determine total abundance.  Cell densities will be used to generate an estimate, with confidence intervals, of the Snowy Plover population inhabiting the Lake during the breeding season.  The Lake estimate will be combined with other estimates from throughout the North American breeding range to yield an overall estimate of total population size.

Cooperative Agencies and Organizations

• US Fish and Wildlife Service

• Weber State University

• UT Division of Wildlife Resources

• Antelope Island State Park

• Kennecott Utah Copper

• US Magnesium

• Ft Hays State University

• University of Nayarit, Mexico

• Wasatch Audubon Society

• Tracy Aviary

Kris Purdy slogging through Great Salt Lake mud in search of SNPL