Published By US Fish and Wildlife Service, Department of the Interior
Issued over 9 years ago
US
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Summary
Description
An extensive aerial survey of trumpeter swans in Alaska in 1975 disclosed a total of 4,170 birds. An adjusted comparison with a somewhat less complete survey in 1968 indicates a 24 increase or a compounded annual increase of 3.1 Changes in land status and economic activity may limit continuing increase. An extensive aerial survey of trumpeter swans in Alaska in 1975 disclosed a total of 4,170 birds. An adjusted comparison with a somewhat less complete survey in 1968 indicates a 24 increase or a compounded annual increase of 3.1. Changes in land status and economic activity may limit continuing increase.