Our skin is covered with sparse hair. To keep warm and protected, our ancestors created various kinds of clothing to fit their needs. Today, in our modern world, clothing fulfils more than functional needs but can also be fashionable. People put on different styles of clothing for different purposes. In nature, animals also have their "clothing" fashions - the exoskeleton, scales, hairs and feathers may change according to specific needs. Let’s take a look at "fashion" in the animal kingdom!
As we grow, the clothing we wear no longer fits. This happens in the animal kingdom too. For example, arthropods such as insects, shrimps and crabs, as well as reptiles like snakes and lizards, are covered with hard shells or scales to protect their bodies from injury. The shells and scales do not grow. Hence, from time to time, these animals moult to replace the external coverings that no longer fit. The newly grown covering is very soft, and will harden after a while. So moulting animals hide away to prevent attack. For some animals, moulting allows broken body parts to re-grow. How amazing this is!
Children have kids' clothing, which is considerably different to adult clothing. Similarly, birds and mammals may have different kinds of feathers and hair for their juveniles and adults. Baby birds do not have to forage themselves, so their feather are mostly for keeping warm. Most baby birds have fine down, which only turns into feathers when they mature. Another example is baby penguins and seals, which do not have to dive into the water to feed, so are covered with fine down which is more water absorbent. When they mature, this down falls off, and waterproof smooth feathers and hairs grow instead, as adaptations for swimming.
When dating, we dress up. Animals also put on attractive wear for courting. Some birds have brightly coloured or unique feathers during the breeding season. For example, Little Egrets (Egretta garzetta) that are readily seen in Hong Kong have special whitish ornamental feathers, in both sexes. Chinese Pond Heron (Ardeola bacchus), another wetland bird, changes from brown to red and blue above during the breeding season. The difference in appearance is so striking that many people could mistake the same bird in breeding and non-breeding season for two species!
We put on different clothing for different seasons. Birds and mammals in polar or mountainous areas must change twice each year to adapt to the temperature changes as well as the change in colour in the environment. In winter, polar or mountainous areas are covered with snow. Hence, both predators and prey, such as Arctic Fox (Alopex lagopus) and Ptarmigan, have snowy white fur or feathers which provide camouflage and warmth. When the snow melts in spring, their fur and plumage becomes thinner and changes to brown, which can match the environment while reducing the burden of the thick fur or feathers.