The term is now used to describe the loss of any interacting species, including competition with their counterpart, and specialist herbivores with their food source.
The most frequently cited example is that of the extinct passenger pigeon and its parasitic bird lice Columbicola extinctus and Campanulotes defectus.
Recently, C. extinctus was rediscovered on the band-tailed pigeon,[4] and C. defectus was found to be a likely case of misidentification of the existing Campanulotes flavus.
This curvilinear relationship between host and affiliate extinction levels may also explain, in part, why so few coextinction events have been documented to date.
There are also several instances of predators and scavengers dying out or becoming rarer following the disappearance of species which represented their source of food: for example, the coextinction of the Haast's eagle with the moa, or the near-extinction of the California condor after the extinctions of its primary food, the dead carcasses of North American Pleistocene megafauna; in the latter, the condor survived by possibly relying on beached marine mammals.
Coextinction may also occur on a local level: for example, the decline in the red ant Myrmica sabuleti in southern England, caused by habitat loss, resulted in the extirpation of the large blue butterfly (which is dependent on the ant as a host for its larvae) from Great Britain.
[citation needed] Coextinction can extend beyond biodiversity and has direct and indirect consequences on the communities of lost species.
One main consequence of coextinction that goes beyond biodiversity is mutualism, by loss of food production with a decline in threatened pollinators.
There is a continued disappearance in the habitat, human intervention, and a great loss in vital ecosystem services.
Along with forest loss other risk factors include: coastal development, overexploitation of wildlife, and habitat conversion, that also affect human well-being.