RED-VENTED BULBUL (Pycnonotus cafer) – (See images below)
DESCRIPTION: The Red-vented Bulbul has a black head, short crest and throat, with grey upper parts in a scaly pattern. It has a white rump and a red vent (hence the name). The black tail is edged in white. The bill, legs and feet are black. Sexes are similar. The bird is approximately 8 inches (20 cm) long.
NAME: The English name ‘Bulbul’ is from Persian and means ‘nightingale’. The Latin genus name ‘Pycnonotus’ is from Greek and means ‘strong back’. The Latin species name ‘cafer’ refers to South Africa.
HABITAT: On Oahu, is found in urban areas as well as mountain forests. It likes perching on poles and wires.
DIET: Omnivorous. Feed on flowers, insects, fruit, even geckos.
NESTING: The red-vented bulbul builds its nest in a tree from sticks. It breeds year-round, and around three eggs are laid.
DISTRIBUTION: The Red-vented bulbul is native to India and south east Asia. Introduced to Hawaii. It was first observed on Oahu in the 1950s and it is believed that it was from a cage release. Since then they have spread all over this island.
CONSERVATION: This bird has the dubious distinction of being on the list of the 100 most invasive species of the world. The species is  unwelcome in New Zealand, for example, where some individuals have been illegally released. On Hawaii, it is listed as ‘Injurious Wildlife’.
NOTES: This bird is considered a pest, as it loves fruit such as guava and papaya, and orchid buds. Its spread outside Oahu in Hawaii is being controlled. Red-vented bulbuls prey on Monarch butterflies and caterpillars on Oahu, because these contain less toxins than their counterparts in North America. As a result, these butterflies have evolved a white morph as a means of survival.
SIMILAR SPECIES: Red-whiskered Bulbul

Red-vented Bulbul in St. Thomas Orchid tree – Fort DeRussy Park, Oahu – © Denise Motard
Red-vented bulbul, Fort DeRussy Park
Red-vented Bulbul upside down in St. Thomas Orchid tree – Fort DeRussy Park, Oahu – © Denise Motard
Red-vented bulbul upside down, Oahu
Red-vented Bulbuls on rock – Fort DeRussy Park, Oahu – © Denise Motard
Red-vented bulbuls, Fort DeRussy Park
The features of this red-vented bulbul are much easier to see, however it is no longer alive. Near Ala Moana canal, Waikiki.
Dead Red-vented bulbul, Ala Moana Pk.
Here are videos of the same acrobatic Red-vented bulbul on the St. Thomas Orchid tree:

Red-vented bulbuls are kept as cage birds in their native countries because of their singing:

This bulbul below was trying to clean a berry before swallowing it whole: