As I mentioned yesterday, our Hawaiian tour checklist has 108 birds on it of which 46 are introduced. Yes, 42% of the birds we expect to see would not be in Hawaii if people hadn’t brought them there.
The red-crested cardinal (Paroaria coronata), above, is one of them. A member of the tanager family native to northern Argentina, Bolivia, southern Brazil, Paraguay and Uruguay in South America, he was introduced to Hawaii in 1928. Being a land-based bird, he was stuck on the islands as soon as he got off the boat but he’s made himself at home in disturbed habitats and urban parks. Fortunately he’s not considered invasive so I’ll be happy to see him in Hawaii.
On the other hand, two bulbul species introduced to Hawaii in the 1960’s are not a happy sighting. Both have become invasive.
The red-vented bulbul (Pycnonotus cafer) is a prolific resident breeder of the Indian subcontinent who’s been introduced in tropical areas around the world. On the Pacific islands he’s become invasive and is now one of the world’s 100 worst invasive species — a dubious distinction.
Red-vented bulbuls are easily found in urban Honolulu.
The red-whiskered bulbul (Pycnonotus jocosus) is a fruit-eating bird of tropical Asia who’s not in the top 100 pests worldwide, but he’s invasive in Hawaii.
The two bulbul species made a difference in a very short time. According to Wikipedia, they changed the color of monarch butterflies in Hawaii over a period of just 20 years. The bulbuls prefer to eat orange-colored monarchs so orange ones are scarce now and white morphs are common.
(photos from Wikimedia Commons; click on the captions to see the originals)
Tour Day 1: Honolulu