Clutch size determination in the marsh tit (Parus palustris)
By providing supplemental food to Marsh Tits (Parus palustris) from the day the first egg was laid, effects on clutch size could be directly attributed to food without the confounding effects on laying date. Females provisioned with additional food responded by laying, on average, on egg more than control females. Differences in territory quality did not influence this result because, on territori