| Popis: |
The integument consists of skin and all its constituents, including hair, feathers, scales, horns, wattles, and all types of external structures. Because these structures are constantly exposed to abrasion, exposure to sunlight and weather, they must be replaced at regular intervals. In many species, skin is replaced more or less constantly, but in others, such as many reptiles, it may be shed every few months or yearly. Many sexually selected traits, such as bright nuptial skin or feathers, and antlers, are shed and regrown yearly. The periodic replacement of skin, hair, feathers, and scales is termed ‘molt.’ Although the hormonal control of integument replacement is progressing, the interrelationships of hormones and behavior associated with molt remain largely unexplored. |
