Red-whiskered Bulbul - Behaviour and Ecology

Behaviour and Ecology

The Red-whiskered Bulbul feeds on fruits (including those of Thevetia peruviana that are toxic to mammals), nectar and insects.

The breeding season is spread out and peaks from December to May in southern India and March to October in northern India. Breeding may occur once or twice a year. The courtship display of the male involves head bowing, spreading the tail and drooping wings. The nest is cup-shaped, and is built on bushes, thatched walls or small trees. It is woven of fine twigs, roots, and grasses, and embellished with large objects such as bark strips, paper, or plastic bags. Clutches typically contain two to three eggs. Adults (possibly the female) may feign injury to distract potential predators away from the nest. The eggs have a pale mauve ground colour with speckles becoming blotches towards the broad end. Eggs measure 21 mm and are 16 mm wide. Eggs take 12 days to hatch. Both parents take part in raising the young. Young birds are fed on caterpillars and insects which are replaced by fruits and berries as they mature. The chicks are psilopaedic (having down only in the pterylae). Eggs and chicks may be preyed on by the Greater Coucal, Calotes versicolor, and crows.

They defend territories of about 3,000 square metres (32,000 sq ft) during the breeding season. They roost communally in loose groups of hundred or more birds.

On the island of Réunion, this species established itself and also aided the spread of alien plant species such as Rubus alceifolius. In Florida they feed on fruits and berries of as many as 24 exotic plants including loquat (Eriobotrya japonica), Lantana spp., Brazilian pepper (Schinus terebinthifolius) and figs (Ficus). Populations on the island of Reunion have also diversified within thirty years according to their food resources with visible variations in bill morphology.