Asian Openbill + Birds of the Week Invitation LXV

You might think that Asian openbills (Anastomus oscitans) are incapable of vocalization, until you see them in their nesting colonies. These are noisy with the honking sounds of the adults and the constant crying of the young for food. Since the birds are seen in large numbers across their range (Gujarat in the west to Vietnam in the east, and Lahore in the north to Singapore in the south) it should not be hard for you to find a few trees where colonies of Openbills raise their young during the monsoon. Some populations which breed in the eastern Gangetic plains disperse as far as Thailand in drier seasons. The featured photo was taken in Danapur, near Patna, and I wonder whether this flock is one of the travellers. In recent years Openbills have begun to colonize south eastern China.

The gap between their jaws is the feature that gives them their name. However, as you can see from the featured photo of youngers adults and chicks, it is not always there. it seems to develop with age. The notion that the gap is used to break shells of the molluscs which are its primary food, is mistaken, since young birds without the gap can forage and feed as well as older gapped birds. The actual mechanism which let the bird extract flesh from the shell seems to be the small misalignment of the tips of the bill. You can see this feature clearly in the photo above, where the tip of the upper beak is twisted slightly to the right.

---

There aren’t many places on WordPress where bird watchers can share posts. If you post any photos of birds this week (starting today and up to next Monday), it would be great if you could leave a link in the comments, or a pingback, for others to follow. You don’t have to post a recent photo, nor do you have to post a photo of the same bird as mine, but do use the tag “Bird of the Week” to help others find your post. For more information see the main landing page for this invitation.

Bird of the Week LXIV