These alien fish have caused massive population declines in native fish and amphibian species, and competition for food or predation may lead to the eventual displacement of these species.
Moreover, the researchers identified massive population declines, ranging from 60% to 98% for all six North American bats studied, and extensive local extinctions, the most severe being for the northern long-eared bat (pictured above), which has disappeared from 69% of its former hibernation sites.
Farmland birds have suffered massive population declines over the past decades [15], especially in the industrialized countries, and this trend continues [16], now even affecting remote mountainous areas [17].
Wild animals, especially gorillas and chimpanzees, can also be infected by Ebola virus, but the infection is highly lethal and causes huge outbreaks and massive population declines (5, 14 ).
An extreme illustration is provided by toxic invasive cane toads (Bufo marinus), which cause almost certain, rapid death in susceptible individuals, leading to massive population declines and local extinctions (Doody et al. 2009).
They may not believe that humans will ALL be gone by the middle of the century, but some of them are OK with talking about massive, catastrophic "population decline" due to rapid, human-induced climate change.
The massive human population declines due to plague epidemics (estimated at about 40% during the Black Death of 1347 1352 and 20% during the Great Plague of 1665 1666), from which Europe recovered only four centuries later, may be one cause of leprosy's decline.
Public health can also be affected by massive population movements along narrow coastal regions, and by regional conflicts arising from declining agricultural and water resources.
Thus overall population decline is serious.
