Heermann's Gull Life History

Habitat

Habitat Shorelines

  • Nests on arid offshore islands.
  • Winters along coast and out to sea.
  • Rarely inland.
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Food

Food FishSmall fish, marine invertebrates, lizards, insects, refuse, and carrion.Back to top

Nesting

Nest Placement

Nest Ground

Nest Description

Nest a shallow depression in the ground, or an open platform of sticks, dry grass, and weeds. Nests in colonies among boulders or nestled in grass.

Nesting Facts
Clutch Size:1-3 eggs
Egg Description:Pale bluish gray to olive, with brown blotches.
Condition at Hatching:Semiprecocial with eyes open. Covered in down, grayish white mottled with dusky on back, pinkish buff on head and underparts.
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Behavior

Behavior Ground ForagerPicks food from surface of water, plunges into water to pursue fish. Hovers and dips over waves. Steals food from marine mammals and other birds.Back to top

Conservation

Conservation Restricted RangeThere is little information on Heermann's Gull population trends. The North American Waterbird Conservation Plan estimates 350,000 breeding birds on the continent and lists it as a Species of Moderate Concern. These gulls rate a 16 out of 20 on the Continental Concern Score. Heermann's Gull is on the 2016 State of North America's Birds' Watch List, which includes bird species that are most at risk of extinction without significant conservation actions to reverse declines and reduce threats. The species is vulnerable to human disturbance because 90-95% of the total world population breeds on one island, Isla Raza. The island was made a wildlife sanctuary in 1964, and populations have increased since then. Heermann's Gull is listed as Near Threatened on the IUCN Red List.Back to top

Credits

Islam, Kamal. 2002. Heermann's Gull (Larus heermanni), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. A. Cruz, M. Coulter, I. Davidson, L. Dickson, N. Edelson, R. Elliott, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, W. Sydeman, J. Trapp, J. Wheeler and K. Wohl (2002). Waterbird conservation for the Americas: The North American waterbird conservation plan, version 1. Washington, DC, USA. 

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

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