As the populations of more and more large animal species dwindle as the result of poaching and loss of habitat, biologists and conservationists have been forced to propose and investigate alternatives to previous methodology in hopes of preserving a wild population of iconic endangered species or at least maintaining a viable population in zoos.
Scientists of the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin announced the successful cryopreservation of endangered feline ovary cortex in the journal Veterinary Research on Feb. 27, 2013.
The researchers successfully froze and thawed oocytes in the ovary cortex of different cat species at minus 196 degrees Celsius in liquid nitrogen. Each of the feline species listed on the Red List for endangered species of the International Union for Conservation of Nature (IUCN) required a slightly different set of parameters to achieve successful cryopreservation. The method is an adaptation of human medicine that extracts some of the ovary cortex and preserves that cortex while a woman undergoes radiation treatment for cancer.
The IZW owns the genome resource bank “Arche“ that contains a variety of sperm samples of various wildlife species.
The aim of the research is to have a viable source of gametes that can be used to preserve cat species worldwide in the face of inevitable extinction.
Dr. Duan Biggs of the Australian Research Council Centre of Excellence for Environmental Decisions and the University of Queensland and colleagues proposed the legalization of rhino horn trade in a last ditch effort to prevent rhino extinction in the Feb. 28, 2013, issue of the journal Science.
Poaching of rhino to feed an unabated trade for rhino horn in China has prompted the scientists to propose the collection of rhino horn from animals that die of natural causes and the humane shaving of living rhino’s horns to meet world demand. The researchers estimate that present populations of black rhinos and white rhinos would meet world demand for rhino horn and reduce or eliminate poaching by providing a lower priced product that could be tracked by DNA fingerprinting techniques.
Cryopreservation has been used to preserve and store plant, human, and animal tissues like eggs, sperm cells, blood, embryos, and seeds.
The potential of this method was originally seen in some animals that can survive freezing and thawing.
Modern cryopreservation techniques seek to maintain tissues at a low enough temperature to prevent any enzymatic activity or oxidation from producing cell deterioration.
Liquid nitrogen at minus 196 degrees Centigrade is the most preferred coolant.
The tiger has been acclaimed as one of the world’s favorite animals. Present estimates indicate that 4,000 wild tigers live in parts of Russia, China, Indonesian, India, and Southeast Asia.
The Bali tiger, Javan tiger, and Caspian tiger are known to be extinct.
Loss of habitat due to human expansion and encroachment is the major threat to tiger populations. Despite a variety of conservation efforts most experts expect the captive tiger population in zoos to exceed the wild population in as little as 50 years.
Rhino horns are composed of keratin, the same protein that makes up human hair and nails.
Rhino horn is not used as an aphrodisiac and has never been recommended as an aphrodisiac in traditional Chinese medicine. Rhino horn is recommended as a cure for fever and convulsions in traditional Chinese medicine.
The major markets for illegal rhino horn are China and other Asian countries for medicine and Yemen and Oman as dagger handles.
In 2011, 448 rhinos were killed in South Africa alone for their horns. Rhino horn sold for $65,000 per kilogram in 2012.
There are 20,000 white rhinos still alive. The majority live in parks and preserves in South Africa.
The species is divided into the southern white rhino and the northern white rhino. There are only seven known northern white rhino left alive including those in captivity.
The white rhino is the largest land dwelling animal after the elephant
Three of the seven subspecies of black rhino are known to be extinct.
The remaining four species are represented by approximately 5,000 living animals.
The majority of black rhinos are considered extinct in their former native habitats and have been relocated to regions of South Africa and southwestern Africa. The animals exist only in manmade preserves, parks, and zoos.