Maine 2008 Coastwide Census for Gulls and Cormorants

Maine Coastal Islands NWR

Field work: 2008. Conducted coast-wide effort to survey the number of nesting gulls and cormorants along the entire coast of Maine. Table lists raw count data for each island. From Intro: “Prior to the 2008 effort outlined in this report, the last comprehensive effort to census gulls and cormorants in Maine was conducted in 1995-96. Since that time, managers had observed apparent shifts in the breeding distribution and species composition of seabirds but did not have data to evaluate the pattern on a state-wide scale. Maine has over 250 miles of coastline, 4,600 islands and ledges, and over 385 islands have recent records of nesting seabirds. The resource agencies in Maine simply did not have the workforce to logistical support to conduct traditional ground-based surveys on such a larger number of islands, during a 2-4 week survey window...In 2008, the US Fish and Wildlife Service and Maine Department of Inland Fisheries and Wildlife utilized a combination of aerial photography, aerial estimates, and ground-based surveys to complete a coastwide survey of great black-backed gulls (Larus marinus), herring gulls (L.argentatus) and double-crested cormorants (Phalacrocorax auritus) breeding in Maine...” Discussion: “While resource managers in Maine do not consider double-crested cormorants, great black-backed, or herring gulls high priority species fro management actions, population declines in the range of 30-45% over a 12 year period are significant. We have not researched the cause of these declines, but believe that a combination of factors such as declining food resources, increased predation rates, and disturbance have all combined to influence these seabird populations. For example, many managers associated the rapid increase in gull populations in the 1970’s and 1980’s to the year-round availability of food at over 400 open landfills in Maine. Between 1987-2000, 94% of the municipal landfills were closed. Commercial landings of important forage fish have also declined during this period. Data from Maine Department of Marine Resources indicates that in 1996 over 50,000 metric tons of herring were landed in Maine, while in 2008 that number had declined to 26,870 metric tons. The Decline of such a valuable forage fish in Maine could have influenced the decline of all three species of seabirds surveyed in tehis effort. The decline in cormorants and gulls nesting in Maine becomes more concerning when you consider recently released data from Massachusetts. Resource managers in Massachusetts also conducted surveys of colonial nesting seabirds in 1994-95 and then again in 2006-07. Results indicate large declines in numbers of pairs of double-crested cormorants (-19.5%), herring gulls (-42.2%), and great black-backed gulls (-40.0%).” /STUDY LOCATIONS:/ /ISLANDS/Baker Island/Bald Porcupine Island/Bar Island/Heron Island/Little Moose Island/Schoodic Island/Sheep Porcupine Island/Drum Island/Egg Rock/Green Island/Green Island Ledge/Ship Island/Trumpet Island/Babbige Island/Babson Island/Bald Island/Barred Islands/Bean Island/Birch Island/Black Island/Buckle Island/Butter Island/Burnt Island/Chato Island/Duck Island/Dumpling Island/Eastern Mark Island/East Torrey Island/Great Spoon Island/Greening Island/Gooseberry Island/Hardwood Island/Hat Island/Heart Island/Hog Island/Johns Island/Jordan Island/Lamp Island/Little Duck Island/Little Babson Island/Little Spoon Island/Little Gott Island/Moose Island/Opechee Island/Orono Island/Pell Island/Pond Island/Preble Island/Round Island/Rolling Island/Scrag Island/Shabby Island/Sheep Island/Spruce Island/Sutton Island/The Ledges/The Hub/West sister Island/West Torrey Island GIS CATEGORY 2; contains gull and cormorant count data for each island studied