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US Fish & Wildlife Service FieldNotes

IZEMBEK: Slight decline detected in Tundra Swan nesting

Region 7, June 25, 2014
Swans nesting on the tundra.
Swans nesting on the tundra. - Photo Credit: n/a

In mid-May refuge Pilot, Ken Richardson, and Wildlife Biologist, Stacey Lowe, conducted the annual Tundra Swan survey on Izembek and Pavlof Refuge Units. The annual survey is conducted to monitor population trends and distribution of nesting pairs on the refuge.

Over the last two decades, nesting populations on the Izembek Unit have continued to decline. Swans utilizing the Pavlof Unit have remained more stable, but also appear to have declined since the early 1990’s. This year 445 swans and 92 nests were observed. The density of swans and the number of breeding pairs in both survey units were slightly lower than the long term average. Eggs were observed in several nests, however no cygnets were observed. The reason for the long term decline is unknown at this time.


Tundra swan pairs typically mate for life but do not always reproduce every year. Nesting is usually initiated in May and young hatch in June. Pairs will vigorously defend their nests from predators such as red fox, jaegers, and gulls; however they usually succumb to larger nest predators like wolves and brown bears.

Additional incidental observations recorded during the flight included 11 moose, 9 bears, many scattered small groups of caribou, and over 40 sandhill cranes.

Contact Info: Kristen Gilbert, 907-786-3391, Kristen_Gilbert@fws.gov