Lena Chow sent in an image of the Spotted Dove (Streptopelia chinensis) showing short rictal bristles arising from the base of the bill (below). We are familiar with the long bristles in nightjars but unfamiliar with short bristles as seen in this dove.
Bristles are specialised contour feathers where the rachis lacks barbs. Such bristles projecting from the base of the bills in birds are known as rictal bristles. These bristles are believed to channel insects into the mouth but there is yet to be proofs of this. Wind tunnel experiments have demonstrated that these bristles protect the eyes from flying insects and other debris. Conover & Miller (1980) released particles in front of the mouths of Willow Flycatchers and birds whose bristles were removed had their eyes struck by these particles. On the other hand, George (2004) believes that these bristles may help birds detect movements of prey held in the bill, functioning like whiskers in some mammals.
Eyelashes of birds are another example of rictal bristles.
References:
1. Conover, M. R. & D. E. Miller, 1980. Rictal bristle function in Willow Flycatcher. Condor 82: 469-471.
2. George, A. C., Jr., 2004. Form and function: The external bird.. Pp. 3.1-3.70 in: Podulka, S., R. W. Jr. Rohrbaugh & R. Bonney (eds.) Handbook of bird biology. Ithaca, NY: The Cornell Lab of Ornithology.
soonhuat
Dear YC Wee
I truly enjoy your nature blog on birds. I like birds watching at Mt Faber Park which is near my home. I saw a couple of white thrushs there recently on a few occasions 🙂
I am a librarian with the National Library Board where the libraries do organise talks on nature by organisations such as the Nature Society (Singapore). We also answer enquiries from the public at ASK@nlb.gov.sg where any topics can be asked on and the librarians will try their best to answer them. Your blog will serve as a useful resource on birds and nature in Singapore.
Keep up the good work in this informative blog.
Regards
Soon Huat
YC
Thanks for your support, Soon Huat. Happy that the blog is useful to you at the NLB.
Matt van Wallene
Please note that spotted doves do not have rictal bristles. Your picture shows the bird is molting. Example of adult spotted dove can be seen here: http://hollandwest.com/spotted-dove-spdo/
An example of bristles is the last photograph on this page: http://hollandwest.com/greater-roadrunner-grro/
BESG
Hi Matt,
Thank you for pointing out this post to us. The article was written at a time when research materials were not as wide-ranging and accessible on the internet.
We are glad you came across our blog site that features living things and particularly birds from this part of the world.