Birds

 

Birds belong to the Class Aves, which comes from the Latin word for "bird". Thus, this name (and Class) is unique to our feathered friends.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

To the right is an illustration of the anatomy of birds,

taken from the BirdSleuth Caribbean Curriculum by

The Cornell Lab of Ornithology and Birds Caribbean.

 

 

 

Flightless Birds

Birds are adapted for flight. Their hollow bones and lightweight feathers develop to enable them to take to the skies and stay airborne. However, there are still many species of birds (over 40) that are unable to fly. This may be for several reasons: their bodies became too heavy to be supported in flight, they lived in regions where flying wasn't necessary, or they developed other abilities which negated the need to fly, such as great speed on land or in water. Whatever the cause, many flightless birds exist today, including but not limited to the:

• Penguin

• Ostrich

• Emu

• Kiwi

• Cassowary

• Steamer Duck

• Giant Coot

• Kakapo

• The extinct but legendary Dodo bird

 

 

Types of Birds

There are many, many species - almost 10,500! Therefore, to make identifying and learning about the different types of birds easier, they are divided into groups based on their shapes or silhouettes. Of course, they are many more bird shapes and silhouettes, but these main 10 are a helpful guide for beginner bird-watchers. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Diet

Birds eat a variety of things, depending on their species and occasionally, on the season. 

Hummingbirds feed exclusively on nectar; perching birds, doves and woodpeckers eat seeds, grains, and insects and sap respectively, while parrots prefer nuts and fruits. Birds that live near water bodies, like waterfowl, wading birds and shorebirds, tend to feed on fish, eggs, crustaceans, frogs, algae, etc. Hunting birds such as owls and birds of prey seek out small rodents, reptiles or even other birds. Birds of prey, particularly vultures, are also known to eat carrion, or decaying flesh. 

A bird's diet can influence its physical and behavioural characteristics, such as methods of flight (birds of prey are often identified by their broad-winged gliding), sleep patterns (owls are nocturnal) and particularly the size and shape of their beaks/bills. In fact, Darwin's Finches and their different beak adaptations to different food sources were instrumental to the development of his theory of evolution. 

 

Reproduction

There are 6 main steps in the Bird Breeding Cycle. It follows the basic activities most birds go through each breeding season in order to produce the next generation.

1. Find and defend a territory - first birds (most often the males) must find a suitable territory to build their nest, and then defend it from other males.

2. Find a mate - in most species, the male must seek a mate. He does this by exhibiting his physical strength via fights (see above), giving "gifts" to potential mates, or showing off his colourful plumage and/or song. Since the female chooses, she is often the more plainly coloured of the two, while the males have extravagant hues. Probably the best known example of this is peacocks and peahens, the former of which is famous for his magnificent tail feathers. Some species, like penguins and swans, form pair bonds for life.

3. Build a nest and lay eggs - next, they work together to build a nest - anywhere from a tree to a cliff, with anything from twigs and leaves to pieces of fabric - and the female lays her clutch of eggs.

4. Incubate eggs - in most species, they take turns incubating the eggs to keep them at an ideal temperature for development.

5. Feed and raise nestlings - after the eggs hatch, the nestlings have to be fed and looked after until maturity. Often, this task is shared between parents. 

6. Fledge from the nest - the fledglings leave the nest once mature, but remain close to the parents for a while as they learn to survive on their own.

Once all of these steps have been completed, the breeding cycle is over. A nesting attempt is considered successful if at least one young survived to maturity. Unfortunately however, many nesting attempts fail because of a myriad of threats, both natural and anthropogenic.

 

Threats

• Natural

  • Unfavourable weather which may affect migration or availability of suitable nesting sites

  • Natural disasters like storms, volcanoes and tsunamis

  • Predators such as falcons and snakes

  • Natural death of mate

  • Mites

  • Hybridisation

  • Climate Change

• Human

  • Habitat destruction

  • Fires and deforestation

  • Poaching and hunting

  • Agriculture

  • Pesticides, particularly the now-banned DDT

  • Introduction of non-native species which disrupt ecosystem balance

  • Pollution

  • Human structures like tall buildings, electricity wires, wind turbines etc.

  • Coastal Development