Habitat Fragmentation

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Habitat disruption and fragmentation are two main anthropogenic impacts which affect the biodiversity of the world. Habitat fragmentation may be defined as a loss of habitat area combined with loss of connectivity between habitat patches and an increase in the proportion of the landscape compromised by habitat edges (Henrik, 1994). Fragmentation varies among different spatial scales but human activity has caused widespread fragmentation of many habitats which naturally would have had a more continuous distribution. Anthropogenic impacts negatively affect our birds. Sekercioglu, Daily, and Ehrlich in 2004 recorded that an overall 21% of bird species are currently extinction-prone and 6.5% are functionally extinct, contributing negligibly to…show more content…
One major contributor is deforestation which is the conversion of areas with continuous forests to areas with remnants of patches in a matrix of non forest vegetation. Consequently, fragments size, degree of diversity and time directly influences the density of birds in fragments and across the landscape as a whole. Some species will always be exterminated because by chance their habitats within the landscape will all be destroyed. Species distribution patterns are usually patchy in the tropical rain-forest landscape and this increases the likelihood of certain species being exterminated by deforestation. Therefore, fragment edges may be inhospitable to some, and maybe a majority of forest species leading to an effective reduction in fragment size, and making fragment shape an important determinant of fragment quality for species (Turner, 1996). Several studies have shown a decline in the diversity of resident species of forest birds over time within a fragment or across a landscape. Willis 1974, 1979; Leck 1979; Diamond, Bishop & van Balen 1987; Kattan, Alvarez- Lopez & Giraldo 1994), and Leck (1979) reported a loss of 25 species of birds from a highly isolated 87 hectare forest fragment Rio Palenque in Ecuador over a period of 5 years. In the Colombian Andes, a third of the species have been lost in 80 years. While in Barro Colorado Island, a Protected Area in Panama; 45 breeding birds species have been lost in the first 50 years after being claimed as a Protected Area due to successional development to the forest. In countries like Singapore, where there is massive deforestation accounting to about 99.8%, the resident avifauna population declined by as much as 28% (Turner,

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