Activity budgets of male Maccoa ducks

Abstract

The behaviour of breeding and non-breeding male maccoa ducks (Oxywa maccoa) was studied in South Africa. Individual ducks were observed continuously from sunrise to sunset in the wild, and all ritualized and non-ritualized behaviour was recorded. Diurnal time budgets of territorial and non-territorial males were translated into energy budgets, showing relative time and energy expenditures for resting, foraging, preening and bathing, territorial defence and courtship activities. A territorial male spent one-third of the daytime on active behaviour associated with reproduction. Territorial males averaged 297 displays per fifteen-hour day, or about one display every three minutes. Active defence of territory occupied 15 per cent of a male's time budget, adding an estimated 20 per cent to the energy a non-breeding male spent on self-maintenance. Active courtship of females occupied IS per cent of a male's time budget, adding 18 per cent to the energy a non-breeding male spent on self-maintenance. The increase in time spent on reproductive behaviour over that of a non-breeding male is achieved mainly through decrease of time allocated to resting in the budget of the non-breeder. Territorial males increased energy expenditure by a factor of 1,3, but devoted the same portion of time as non-breeders to actual feeding (21 per cent). Energy and time-saving strategies were associated with territorial defence and courtship, contributing towards optimization of time and energy budgeting.