Columbdae is a family of birds that includes the pigeons and doves and the order is Columbiformes. The family columbdae is further divided into five subfamilies which are then further classified into 42 genera and 308 species. They have distinct features that make them easily identifiable. They also have a global presence although they cannot be found in Antarctica. The pigeons and the doves are to be found in almost all terrestrial ecosystems which range from the deserts to thick forests and also they are prevalent in the large cities. Pigeons and doves are burly birds and measure between 15 to 75 centimeters in length. They are either seed-eating or fruit eating. Many of the seed-eating ones are beige, gray and in brown colors. The fruit eaters are characteristically more brightly colored in comparison. These birds could be solitary or very social. The passenger pigeons, which are long extinct, are said to have occurred in so large a flock (2 million birds) that they blocked the sun.

Geographic Range
Pigeons and doves are widely considered to inhabit different habitats and are found almost everywhere in the land ecosystem. As said earlier, this does not include the Antarctica. However, their highest diversity will be found in Australasia, South America and the Pacific Islands. Some species like Rock Doves have proved that they can be colonize most of the geographical ranges following their successful introduction to these ranges.

Habitat
Columbidae are birds that inhabit almost all the terrestrial habitats which range from temperate to tropical areas. These habitats include highland forests, tropical forests, lowland forests, riparian forests, deserts, and boreal forests. Other terrestrial habitats include cliffs, mangroves, corrals atolls etc. their highest density will be found in tropical rainforests and they are also known to colonize all altitudes of land ranging from the sea level to over 500 meters above the sea level. They can also colonize the oceanic islands owing to their excellent flying prowess.

Physical Description
With a length that range from 15 to 75 centimeters, the pigeons and doves are of stocky built and weigh from 30 to 2000 grams. Doves are the smaller species within the columbdae while the larger species are called the pigeons. However, the names do not imply the real difference between the two bird groups and are often used interchangeably. They have small heads with legs that are small and beaks that are short.

Conservation
There have been concerted efforts to conserve the members of this family. This has seen the RSPB team up with an NGO in Britain B.T.O (British Trust Ornithology) which works with other organizations in Ghana, Burkina Faso, Denmark and Netherlands. This operation has seen the launch of the largest research project of its kind which is aimed at understanding the migratory birds.

This study was necessitated by the sharp drop in the number of migrants. And factors that contribute to the decline of migrants have been identified as climate change which has led to erratic rainfall and land degradation.