Optimal foraging in great tits (Parus major)

Optimal Foraging, Predation Risk and Territory Defence

“…Travelling between patches has costs other than time, for example the energetic costs or increased risk of predation while flying between bushes, and Cowie (1977) showed that when energetic costs of flying are taken into account, the model gave a more accurate prediction of the birds' behaviour. Fig.…”

“…Using Great Tits searching for mealworms hidden in sawdust-filled plastic pots (patches) in a large aviary, Cowie (1977) showed that the model was successful in predicting the relationship between average travel time and average time spent in a patch. When the travel time was experimentally increased, the time spent in each patch increased by the predicted amount.…”

“…Although there was a considerable spread of visit lengths, the modal length of visit to a patch was as predicted by the marginal value model in three birds during control conditions, and there was a shift by those individuals towards shorter visits in the experimental treatments. It is possible to work out how much an individual would lose in terms of rate of Cowie (1977). A.…”

“…The model predicts, on the basis of maximising intake as the optimality criterion, how long a predator should spend in a patch of food which is gradually depleted. If the depletion 87 curve of prey within a patch and the average time taken by the predator to travel between patches are both measured, the model can be tested using a graphical solution (Cowie 1977, Parker & Stuart 1976.…”

Adaptive Behavior and Learning

“…Cowie (1977) did this with great tits (Parus major) in a large artificial aviary. The birds were looking for mealworms hidden in sawdust-filled plastic cups (the patches) on the branches of artificial trees.…”