preen glands造句

• Adult ratites have no preen gland ( uropygial gland ) that contains preening oil.
• The preen gland is small and tufted.
• All cormorants have preen gland secretions that are used ostensibly to keep the feathers waterproof.
• Like cormorants, they have a vestigial preen gland and their plumage gets wet during diving.
• Apart from ingesting the material, they also chew it, mix it with preen gland oil and apply it to their feathers.
• Fat quills are modified feathers that produce a lipoid substance that is used in a similar way to the secretions of the preen gland.
• They produce very little oil from their preen gland; it is the air trapped in their dense plumage that prevents them from becoming waterlogged.
• The male spreads the preen gland secretion, which is yellow, onto the primary feathers and bill to give them the bright yellow colour.
• The tinamous'possession of powder-down feathers and preen glands, which the ratites lack, is another distinguishing characteristic between the two orders.
• In some birds, feather colors may be created, or altered, by secretions from the " uropygial gland ", also called the preen gland.
• As it grows it is golden yellow, but the bird rubs its casque on its preen gland, whose oily secretion tints the surface of the casque bright red.
• They carved the casques, or made them into sheets, coloured them with the secretion of the preen gland, and made them into belt buckles for high officials.
• Individuals perched near incubating partners also carrying out head rubbing, whereby the stork oils the bare head skin on its preen gland and then rubs its head on its plumage.
• It and the bill are yellow; the red secretion of the preen gland covers the sides and top of the casque and the base of the bill, but often leaves the front end of the casque and the distal half of the bill yellow.
• The feathers of the sides of head, sides of the neck, breast, and scapular area are basically white but are stained gold to buff, perhaps by the powder down typical of herons or by secretions of the preen gland; the color varies from bird to bird.
• "In vitro " studies suggest that the preen oils of rock doves ( " Columba livia " ) are effective against lice, however " in vivo " studies which removed the preen gland from captive birds had no significant effect on louse loads over the course of four months ( but did reduce plumage quality ), suggesting that preen oil may not be an important defense against lice in this species.