Factors of the Extinction Crisis
Habitat loss: human impact on size/quality/existence of habitat is the most important factor of species extinction
- Destruction: removal or change of the whole habitat, e.g. deforestation (farm land, clear-cut timber harvest), development
- Pollution: species die or cannot reproduce (e.g. accumulation of pesticides in tissues; direct death through chemicals; plastics)
- Disruption: human activities affect livelihood or behavior(e.g. frequent visits in bat caves; anchoring boats over reefs)
- Fragmentation: increasing development leaves smaller and smaller patches of original habitat; fragments become too small to sustain species’ survival by
- habitat too small relative to species’ territorial range
- habitat can no longer provide sufficient food/prey of species
- small habitat ? small population ? lack of genetic variability; inbreeding; sex ratio; catastrophic events