The ways we impact species is varied. The acronym HIPPO describes the categories conservation biologists list them under - habitat destruction, invasive species, pollution, population growth and overhunting.
Habitat destruction is the most common and greatest threat to species - the health of their populations are inextricably linked to the state of the ecosystems that sustain them. Without places to live, there is no wildlife, it's that simple.
Destruction and loss of habitat happens when land is cleared for human use, such as agriculture, logging, mining, dams, urbanisation and development. Few species are unaffected by this - it is the main threat to 85% of threatened and endangered species. Fragmentation of habitat is equally as bad. Habitat is broken up by fields, roads, towns etc pushing species into smaller and more isolated areas. They lose access to food and mates, and are more vulnerable to extreme weather events and the effects of inbreeding.