Article Abstract:
Stone ramparts are built by female blackstarts nesting close to the ground to serve as an 'early-warning' mechanism to prevent them from being trapped inside nest cavities and predated. This was found in an investigation of several hypotheses on the function of stone ramparts, whereby individually marked blackstarts at the En-Gedi Nature Reserve in Israel were monitored. Results indicated that the ramparts function as barricades so that predators are forced to clear the stones first to gain access to the nest and thus allow the nesting female time to get away.
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Article Abstract:
The removal of males in pairs of orange-tufted sunbirds increased the provisioning effort of lone females. However, this compensatory response is incomplete as evidenced by the reduction in total visit rate in the male-removed group. The females' inability to fully compensate for the lack of partner may be caused by time constraints on the rate of food collection or due to efforts done at a physiological maximum.
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Article Abstract:
An analysis of parental care in the orange-tufted sunbird revealed that males showed more mobbing efforts than their female partners and the nest guarding activity increased both in males and females with increased brood size. For provisioning at higher rates, males failed to guard nests. Visit rates decreased in experimental nests and larger broods as evidenced by the lower chick growth rates.
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