May 212023
 

Bristle Feather Study

Bristle feathers are found on many species. Bristles are whisker-like feathers typically found around the mouth, eyelids and nares. Bristle feathers maybe unbranched or branched. The branched bristles can have minimum barbs at the base to more elaborate structures as found on nightjars. Some birds have both types of structures as shown in the various examples below. Bristles are sensitive to touch and vibrations. They assist in foraging and obstacle avoidance, protect from airborne particles, and sense airflow. Some sites state that bristles are used to funnel food. That was dispelled in an article about Willow Flycatcher  bristles.1

1Conover, Michael R.  and Miller, Don E. (1980) Rictal Bristle Function in Willow Flycatcher. The Condor, Vol. 82, No. 4, pp. 469-471

As part of a feather study, I documented the bristle feathers of each species with some interesting results.   

Two great articles on bristle feathers:

https://onlinelibrary.wiley.com/doi/full/10.1111/joa.13188

https://www.nature.com/articles/s41598-022-24781-7

 

Abert’s Towhee

ABTO, Melozone aberti

Abert's Towhee bristles

Abert’s Towhee bristles

Acorn Woodpecker

ACWO, Melanerpes formicivorus

Acorn Woodpecker bristle

Acorn Woodpecker bristle

American Crow

AMCR, Corvus brachyrhynchos

American Crow bristle

American Crow bristle

American Kestrel

AMKE, Falco sparverius

American Kestrel bristle

American Kestrel bristle

Barn Owl

BANO, Tyto alba

Barn Owl bristle feathers

Barn Owl bristle feathers

Clockwise from top left, nare, manible, below the eye, above the eye

Barn Owl bristle feathers

Barn Owl bristle feathers

Burrowing Owl

BUOW, Athene cunicularia

Burrowing Owl bristle feathers

Burrowing Owl bristle feathers

Burrowing Owl bristle feathers

Burrowing Owl bristle feathers

Cactus Wren

CACW, Campylorhynchus brunneicapillus

What look to be bristle feathers below the bill are actually modified contour feathers.

Cactus Wren bristle feather

Cactus Wren bristle feather

Cactus Wren bristle feathers

Cactus Wren bristle feathers

Chicken

CHIC, Gallus gallus

Despite many websites that specialize in chicken related information, chickens do not have bristle feathers.

chicken not a bristle

chicken not a bristle

Chukar

CHUK, Alectoris chukar

Chukars do not have bristle feathers

Chukar not a bristle

Chukar not a bristle

Cooper’s Hawk

COHA, Accipiter cooperii

Cooper's Hawk bristle

Cooper’s Hawk bristle

Curve-billed Thrasher

CBTH, Toxostoma curvirostre

Curve-billed Thrasher bristle

Curve-billed Thrasher bristle

Flammulated Owl

FLOW, Psiloscops flammeolus

Flammulated Owl bristle

Flammulated Owl bristle

Greater Roadrunner

GRRO, Geococcyx californianus

Greater Roadrunner bristles

Greater Roadrunner bristles

A second review produced these results.

GRRO bristles close-up

GRRO bristles close-up

From the bill area.

GRRO bill bristles

GRRO bill bristles

From around the eye.

GRRO eye bristles

GRRO eye bristles

Harris’s Hawk

HASH, Parabuteo unicinctus

Harris's Hawk bristle

Harris’s Hawk bristle

House Finch

HOFI, Haemorhous mexicanus

House Finch bristle

House Finch bristle

Ostrich Bristle Feather

OSTR, Struthio camelus

Ostrich

Ostrich

Close-up of Ostrich bristle feathers.  A close-up of the eye shows eyelash-like bristle feathers. Note the barbs.

ostrich bristle feathers

ostrich close-up

Ostrich bristle feather

Ostrich bristle feather

Ostrich bristle feather

Red-tailed Hawk

RTHA, Buteo jamaicensis

Red-tailed Hawk bristle

Red-tailed Hawk bristle

Ring-necked Pheasant

RNEP, Phasianus colchicus

Ring-necked Pheasant bristle

Ring-necked Pheasant bristle

A look at 300X magnification shows some type of growth reminiscent of a filoplume. The vane was not as delicate as a filoplume.

300X bristle feather tip

300X bristle feather tip

     

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