An endangered species is one that is somewhere on the road towards extinction. In New Zealand, due to pressure from introduced species and habitat loss, more than 4,000 of our unique species are somewhere along this path. The Endangered Species Foundation is committed to giving them a fighting chance.
Extinction and evolution
Extinction is a part of life on earth; one of the two outcomes in the path of evolution that sees creatures either adapt to change in their environment and evolve, or fail to adapt and go extinct.
Extinction is not new. Since life began on earth some 4 billion years ago, some creatures have simply proved more capable than others in capitalising on new opportunities and resources. Those that cannot compete or fall behind the pace of change are eventually lost. Most (over 95%) of the species that have ever existed on the earth are now extinct.
Like change, extinction is a constant. Scientists estimate the ‘normal’, or baseline, rate of extinction to be about one species every 1000 years, however sometimes – when change is particularly rapid – this rate may rise dramatically.
Over the course of history, there have been five “spasms” of extinction – where a large proportion of species disappeared within very short spaces of time (geologically speaking). These are likely a result of massive and rapid environmental changes caused by major natural catastrophes. The meteor that wiped out many of the dinosaurs and other organisms (and consequently allowed mammals to flourish) was the fifth spasm of extinction.
A sixth wave of extinction?
Currently the global rate of extinction is thought to average about one species per year. This is over 1000 times more than the baseline rate scientists have described as ‘normal’, leading some biologists to decidethat we are currently in the middle of a sixth wave of extinction.
While we have known about extinction for a long time, it is only recently that people have realised that our actions, or changes we have caused, can result in the disappearance of species. This became evident only when species that people had actually seen alive now obviously had no live individuals left. The cases of species like the passenger pigeon, the Carolina parakeet, and of course the dodo, were emphatic examples of extinction happening right before our eyes.
Into the 1970’s some scientists still thought a natural balance would establish between the exotic predators and plants that humans have introduced and the native wildlife and plants. However, as many of our species continue to be pushed towards extinction, it has become clear than many will simply disappear without our intervention.
We may have contributed to the threat these species face, but we also have the opportunity to slow the process, and to give them a fighting chance.