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Caspian Tern Life History


Habitat Shorelines

  • Breeds in wide variety of habitats along water, such as salt marshes, barrier islands, dredge spoil islands, freshwater lake islands, and river islands.
  • During migration and winter found along coastlines, large rivers and lakes. Roosts on islands and isolated spits.
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Food FishAlmost entirely fish; occasionally crayfish and insects.Back to top


Nest Placement

Nest Ground

Nest Description

A scrape in ground. Lined often with dried vegetation, small pebbles, broken shells or other debris. May have elaborate rim of sticks. Nesting colonies occur on island beaches, often near colonies of other bird species.

Nesting Facts

Clutch Size:1-3 eggs
Number of Broods:1 brood
Egg Length:2.3-2.9 in (5.8-7.3 cm)
Egg Width:1.6-1.9 in (4.2-4.8 cm)
Incubation Period:25-28 days
Nestling Period:1-2 days
Egg Description:Buff, sparingly marked with dark spots and sometimes large irregular blotches.
Condition at Hatching:Eyes open. Covered with down and able to leave nest (usually after several days).
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Behavior Aerial Dive (water)Flies over water with bill pointing down; plunges into water to catch fish.Back to top


Conservation Low ConcernThere is little information on Caspian Tern populations trends, but the species appears to be stable overall, according to the North American Breeding Bird Survey. In some areas, numbers may be increasing, where birds use man-made dredge spoil islands and dikes for breeding. In other areas, the species is listed as rare or vulnerable because of the scattered nature of breeding colonies. Caspian Tern are declining in Europe. The North American Waterbird Conservation Plan estimates a continental population of between 66,000-70,000 breeders, and lists it a Species of Low Concern. It rates a 10 out of 20 on the Continental Concern Score. Caspian Tern is not on the 2016 State of North America's Birds Watch List. Beach nesting areas vulnerable to disturbance and predation.Back to top


Cuthbert, Francesca J. and Linda R. Wires. (1999). Caspian Tern (Hydroprogne caspia), 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. (2019). Longevity records of North American birds. Version 1019 Patuxent Wildlife Research Center, Bird Banding Laboratory 2019.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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