Several smaller species have become extinct or are gravely endangered, probably because of predation by introduced foxes.
Despite the apparent inroads made by introduced religions, much of the population also maintains traditional religious beliefs, and rituals of magic, spells, and sorcery are still widely practiced.
The lake is also prized for trout fishing, although the native cutthroat trout are now endangered by introduced predators, notably lake trout.
Its fragmented population of about 3,000 animals is declining owing to habitat destruction and predation by introduced mongooses and by feral dogs and cats.
Urban habitats tend to be dominated by introduced plant and animal species that have a long history of association with humans and that show adaptations to urban conditions.
Forty years ago, when the Swiss ecologist Vinzenz Ziswiler added up the number of birds wiped out by introduced predators, he found that cats were implicated in 17 of 43 extinctions.
An earlier effort to reintroduce 'alala into the wild failed in part because the native hawk, the 'io, was able to capture birds that may have been weakened by introduced disease or lost adaptive responses to the predator, or both.
The bird's decline has been attributed to habitat degradation caused by feral livestock coupled with predation by introduced species such as the great horned owl (Bubo virginianus), common mynah (Acridotheres tristis), and house rat (Rattus rattus).
Consequently, this species, which has a small pink flower, was declared extinct, presumed outcompeted by introduced species, until it was found accidentally in 2005 by a researcher working on the edge of its recorded range.
BIG BEND GAMBUSIA (Gambusia gaigei) A small fish reintroduced to three ponds in Big Bend National Park in Texas, its main threats are habitat loss and predation by introduced sunfish and other species.
In addition, they have suffered most from competition with and habitat destruction by introduced animals such as rabbits, sheep, goats, and cattle and from predation by the foxes and feral cats.
