Zoos - Why are so many species becoming extinct?

There are three main reasons for the alarming decline and extinction of so many species namely:
 

Destruction of habitat (which includes the loss of food source etc.)
Poaching - when an animal is killed illegally. It usually occurs when an animal possesses something that is considered valuable.
Pollution - also plays an important part in the loss of animal and plant species.
Climate change - the global phenomenon of climate transformation caused by human activities

You can also add to this list “introduced species” which upset the balance of an eco-system and “disease” which is, in the case of amphibians, responsible for their rapid decline in numbers.

The destruction of habitat seems almost invariably to be caused by overpopulation and the resulting human demand for resources.   The main threat to these natural habitats is, of course, the steadily and dangerously increasing human population which currently stands at over 7.8 billion people (November 2020).  Approximately 132 million more people come into the world each year.  Although the birth rate has now leveled off, births are still outnumbering deaths so the world population is on target to rise to 8 billion by 2025 and 9 billion by around 2050.  There’ll be an extra 2.3 billion people on the planet, the world population was only 2.5 billion in 1950!

People need homes to live in, shops, schools, hospitals and other amenities.  They also need food to eat.  Animals’ territories are shrinking as villages and towns are built and crops planted in those areas.  The fragmentation of habitats restricts the availability of food and water to the animals as they can’t move as easily from one place to another.  Sometimes wild animals try and follow their original routes, only to find themselves confronted by people trying to protect their crops and livestock.  Elephants have been known to trample crops in India and lions have taken cattle in Africa.  This increased level of human and animal confrontation is becoming a major problem and can result in casualties on both sides.

Hunting and poaching was and to a lesser extent still is a significant cause of the decline in endangered species. If we can educate people and prevent purchases of the end product of the poachers’ work - whether a fur coat, carved ivory, crocodile handbags or shoes, etc., then the poacher will become redundant and one pressure will be relieved as far as wild animal species are concerned. 

We must preserve areas of this world in which natural ecosystems are able to flourish. Zoos and wildlife parks - however good they may be - are no substitute for natural habitat, but where it has become so degraded that animals struggle to survive there, perhaps this is a sensible time to take some into captivity to breed in safety.  This has been the case for the golden lion tamarins from Brazil where their habitat has all but gone and the Amur leopard where only 30 remain in the wild.