Bihoreaux gris, plumes trichoptiles

...en ce jour de septembre ils étaient 16 à se bagarrer pour les mêmes branches!

 Nycticorax nycticorax
Pelecaniformes - Ardeidae

Parc ornithologique du Teich

Nikon 500 mm + convert.

Mire sur les adultes, leurs attitudes, avec cet œil rouge extraordinaire, ces 3 plumes trichoptiles blanches derrière la tête, et des tons bien tranchés entre le gris-bleu sombre de la tête, le gris soutenu du manteau et ce blanc-crème du dessous.

The Black-crowned Night Herons were 16 all together to fight for the same branches back in September!
I shall focus here on the adults, their attitudes and their looks with this striking red eye, the 2 to 3 long trichoptile feathers on the head, the grey coat feathers, and the creamy white underparts.

Feathers are skin appendages (or adnexa) as nails and claws; they are productions stemming from the skin and characterized by a high rate of a particular protein, a keratin, and often by particular electric properties. They have a protection role against temperature variations, a support function for movement or flight, an aesthetic role and ethological functions (colors, motives, glittering characteristics which can play a role in inter-individual and inter-species recognition, sexual parade), etc... Feather morphology is very variable according to the location on the bird; some have barbules, some are fine and long. In the breeding season adult night-herons grow 2 to 3 long white feathers behind the head called trichoptiles feathers: they look like hairs and are useful for males of several bird species for courtship display.

Les plumes trichoptiles :

The trichoptile feathers: