DOMINANCE AND PATCH DISTRIBUTION OF GREAT TITS PARUS MAJOR: A PRELIMINARY TEST OF THEORETICAL PREDICTIONS

1. Predictions from existing models on 'ideal free distribution of unequal competitors' were tested by comparing the intake rates of the birds in relation to their bowl preferences. 2. Three types of distributions across two patches (1 and 2, where 1 provides higher food production rate than 2) were tested: truncated (H 1 > L 1 H 2 > L 2 ), semi-truncated (H 1 > H 2 > L 1 L 2 ), and mixed (H 1 H 2 > L 1 L 2 ). H i indicates highest individual intake rate in patch i, L i indicates lowest individual intake rate in patch i. 3. The birds were studied in groups of six. They were fed by presenting two bowls containing mealworms, one bowl had twice the food-input rate of the other. 4. Four birds visited the high-density bowl more often than the low-density bowl, whereas the other two birds showed no or opposite preferences. 5. The semi-truncated distribution was the only distribution that could not be rejected by any criteria. 6. When members of the experimental group were exchanged, the changes in individual intake rates suggest that the intake rate is related to each individual's quantitative competitive ability rather than to the individual's rank.

Poultry Production in and around Dar es Salaam, Tanzania: Competition and Complementarity

This paper describes poultry production in and around the city of Dar es Salaam. The emphasis throughout is on the relationship between small-scale producers and the large, integrated firms which supply them with essential inputs such as chicks and feed, and also produce poultry products on their own account. It is argued that while at one level the integrated firms and the small-scale producers are unequal competitors, complementarity is probably the more important aspect of their relationship. Based on the limited profitability of small-scale egg and broiler production it is concluded that this is not an appropriate arena for poverty-oriented development intervention.