Volant Adaptations

Volant Adaptations in Common Pigeon
Adaptations for flight are called as volant adaptations. Bats, birds and insects are well adapted for an active flight. Some important flight adaptations are
  • Boat or spindle shaped body that offers no resistance to air

  • Forelimbs are modified into wings

  • An exoskeleton of feathers which provide an insulation, thereby preventing the loss of heat and help maintain a constant body temperature.

  • The short tail with tail feathers which serves as a rudder in steering and counter balance during perching.

  • Presence of well developed flight muscles and a keeled sternum.

  • Presence of hollow or pneumatic bones to make their body light.

  • Presence of air sacs which serve as reservoirs of air and provide lightness and buoyancy to the body

  • A large cerebellum which allows the bird to maintain equilibrium and co-ordination.
Cursorial Adaptations

These are the adaptations for running and are found in flightless birds such as ostrich, kiwi and many other animals.

Cursorial Adaptations in Ostrich and Kiwi Respectively

  • More or less stream lined body so as to offer minimum resistances to air during running

  • Hind limbs are usually long and have claws.

  • In the forelimbs ulna and in the hind limbs the fibula bones are greatly reduced as an adaptation for fast running.
Fossorial Adaptations

Animals which dig into burrows for shelter and food are called fossorial animals. They have adaptations for burrowing.
  • Spindle shaped body to offer little resistance during going in and out of burrows.

  • Small tapering head with snout for burrowing

  • Eyesight is reduced as they are of no use in the dark

  • External ears tend to disappear as they might be an obstruction in burrowing.

  • Short and stout limbs are provided with strong claws for digging.

  • They hibernate during winter or unfavourable conditions.
Arboreal Adaptations

These adaptations help the animals in climbing and are found in various animals like squirrels, lemurs, sloths and rodents.

Arboreal Adaptations in Squirrel
  • The limb girdles are very stout giving support to the body in climbing.

  • Well developed claws help in grasping and climbing

  • Syndactyly or union of digits is seen in some animals.
Example: Chameleon

Chameleon Adaptation for Arboreal and Terrestrial Habitats andInsectivorous Mode of Feeding
  • In some animals like the tree frog Hyla, fingers and toes bear adhesive pads that help in climbing and clinging to the trees.

  • The presence of a prehensile tail is a common character in arboreal forms.

  • Accessory organs for climbing like spines and tubercles are found in the forearm of some lemurs.
Parasitic Adaptations

All parasitic have successfully adapted to live either on or inside their hosts. Some of their important adaptations are:

  • Presence of suckers or other structures for attachment to the host. (Tapeworm)

  • Loss of locomotory, sense and digestive organs, especially in endoparasites as they are fully dependent on the host and draw their nourishment from it.

  • Intermediate host and vector: To increase their chance of survival, many parasites have more than one host.
E.g., Malarial parasite plasmodium has 2 hosts - female anopheles mosquito and man.
  • Increased reproductive capacity - All successful parasites have very well developed reproductive organs and enormous productive capacity.

  • Complicated life cycle - The production of enormous number of eggs and several larval forms by some endoparasites like Fasciola is an adaptation to maintain the continuity of the species.