Time-activity budgets of drake Gadwall and Northern Shoveler ducks were studied in the winter of 1985. Total duck numbers peaked in mid-March. Gadwall numbers increased from late January to mid-March and then declined, while Northern Shoveler numbers declined from late January to mid-February and then increased to mid-March before declining. Behavior categories considered in the time-activity budgets were flying, preening, swimming, courtship, feeding, and resting. Time allocated to these different activities varied for both duck species, with feeding being the only behavior pattern wherein differences were significant. Gadwalls spent 58% of their time feeding. Northern Shovelers only 26%. Possible reasons for these differences are suggested.
Webb, G. Merrill and Brotherson, J. D.
"Time-activity budgets of drake Gadwall and Northern Shovelers on industrial cooling ponds during late winter and early spring in central Utah,"
Great Basin Naturalist: Vol. 48
, Article 18.
Available at: http://scholarsarchive.byu.edu/gbn/vol48/iss2/18