Nature and Environmental Book Reviews

Short List of Best Nature and Environmental Books

 

 

Conservation of Endangered Animals

by David Yarian, Ph.D.

Humans first entered North America via the Bering land bridge about 13,000 years ago. Extinctions of all the major fauna of the continent – North American horses, a camel, the Shasta ground sloth, the saber-toothed tiger, a tapir, a giant sloth, a giant beaver and the flat-headed peccary – followed shortly.

The mammoth, the mastodon and the short-faced bear lasted a little longer, becoming extinct around 12,000 years ago. Skeletal remains of many of these animals have been found, with the distinctive spear points of the Clovis culture lying within their bones.

Further evidence for the role of humans in the extinction of large animals is to be found in the Caribbean islands, whose major fauna (ground sloths, large rodents, many bird and bat species) went extinct about 6250 years ago, also coincident with the arrival of humans.

Humans first arrived in Australia some 53,000 years ago. Recent study has shown that a bird called Genyornis, about twice as heavy as the largest living emu, died out abruptly around 50,000 years ago. There is at present no unequivocal evidence for the survival of any Australian megafauna more recently than 40,000 years ago.

Of all the continents, only Africa possesses anything like an intact fauna, including the large carnivores, elephants, rhinos, giraffes, etc. Scientists believe that since modern humans first evolved in Africa over 100,000 years ago, African species had time to learn strategies to deal with the dangers of human hunters.

In Eurasia, North and South America, and Australia, native species had no fear of humans when they arrived, so were easily slaughtered -- and rapidly driven to extinction. (Tim Flannery, in his excellent book The Eternal Frontier summarizes this evidence.)

Many more species have become extinct since humans first became mighty hunters. Habitat disturbance, the encroachment of human populations, climate disruption, pollution, spreading of toxic wastes, the use of insecticides and herbicides, overfishing and overhunting have all contributed to species loss.

Many animals and plants are endangered today. The World Conservation Union (IUCN) has calculated the percentage of endangered species as 40 percent of all organisms! While some species have been afforded legal protections, most have not.

The IUCN Red List categorizes species along a continuum of degree of imperilment. Their categories include:

 

  • Extinct: the last remaining member of the species has died. Examples: Dodo, Passenger Pigeon

  • Extinct in the wild: captive individuals survive, but there is no free-living, natural population. Example: Alagoas Curassow (a type of pheasant)

  • Critically endangered: faces an extremely high risk of extinction in the immediate future. Examples: Ivory-billed Woodpecker, Javan Rhino

  • Endangered: faces a very high risk of extinction in the near future. Examples: Cheetah, Blue Whale, Snow Leopard

  • Vulnerable: faces a high risk of extinction in the medium-term. Examples: Gaur (a southeast Asian ox), Lion

 

Some animals are developing an uneasy truce with humans, finding ways to survive in and around urban areas. In my neighborhood of suburban Nashville, TN I have sighted deer, red foxes, rabbits, squirrels, possums, raccoons, skunks, chipmunks, red-tailed hawks, turkey vultures, Canada geese, barn owls, red-headed woodpeckers, as well as native songbirds and migratory birds that are passing through. Unfortunately, some of these animals have also been sighted at the side of highways, testament to the high mortality inflicted by automobiles on animal populations.

Each contact with an animal living in the wild (whether in the suburbs, or in a wilderness area) offers the opportunity for moments of wonder, as we witness them going about their ancient ways. Perhaps they acknowledge our presence, perhaps not. Yet this encounter reminds us of the compelling persistence of life on this planet, and the rich diversity of speciation that has spread across the globe.

The books and DVDs in the sections on Wild Animals serve to call our attention to the animals of the world, from microscopic creatures at the bottom of the food chain, to the primates, some of whom have developed rudimentary language skills. These beautiful and compelling books and videos give us fascinating glimpses of animals in their natural habitat – the wild.

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