Khng Eu Meng’s image of the Asian Paradise-flycatcher (Terpsiphone paradisi) clearly shows the presence of a number of bristles around the mouth of the bird.
According to field ornithologist Wang Luan Keng: “Those are rictal bristles. All flycatchers and most insectivorous birds have them. Used for helping to catch insects…”
Many studies have been done on the functions of these rictal bristles. Below are but a sample.
According to Erritzoe (2007), rictal bristles are stiff feather shafts found around the gape of certain birds such as nightjars, swallows and flycatchers. They are believed to assist the bird in catching insects when in flight.
Lederer (1972) suggests that these bristles “perform tactile functions, serve as an insect scoop, or protect other facial feathers. In the Tyrannidae, at least, motion pictures indicate that they do not play a part in prey capture.”
Experiments by Conover & Miller (1980) showed that these bristles failed to reduce the ability of Willow Flycatchers to catch houseflies when they were either removed or taped against the side. However, wind tunnel experiments showed that these bristles did protect the eyes from insects the bird was trying to capture.
Cunningham et al. (2011) suggest that rictal bristles have a tactile function in prey handling, information gathering during flight and possibly prey detection in their study of New Zealand birds.
Khng Eu Meng (image), Wang Luan Keng (references) & Jeremiah Loei (reference)
17th October 2016
1. Conover, M.R. & Miller, D.E., 1980. Rictal bristle function in Willow Flycatcher. The Condor 82(4): 469-471. LINK.
2. Cunningham, S.J., Alley, M.R. & I. Castro, 2011. Facial bristle feather histology and morphology in New Zealand birds: Implications for function. Journal of Morphology 272(1): 118-128. LINK.
3. 3. Erritzoe, J., K. Kampp, K. Winker & C. B. Frith, 2007. The ornithologist’s dictionary. Lynx Edicions, Barcelona. 290 pp.
4. Lederer, R.J. 1972. The role of avian rectal bristles. The Wilson Bulletin 84(2): 193-197. LINK.
This post is a cooperative effort between Birds, Insects N Creatures Of Asia and BESG to bring the study of birds and their behavior through photography and videography to a wider audience.