Endangered Species 2 Essay, Research Paper
WWF’s policy on captive breeding is that: “The productive management of captive pandas would be helpful in ensuring the long-term survival of the species. All potential breeding animals in captivity should be included in an integrated programme, whose main aim should be to provide animals for re-introduction into the wild. WWF urges all institutions in the world which currently hold pandas to contribute fully to this breeding programme.”
There are currently 23 pandas at the China Conservation and Research Centre for the Giant Panda in Wolong and an estimated total of 103 animals in captivity worldwide. Along with fieldwork, Chinese scientists have worked continuously to improve the success rate of captive breeding of the Giant Pandas. This has proved to be quite a challenge, all the more so since pandas are only receptive to breeding for a very brief period in late spring or early summer. Research efforts have, however, paid off. Since 1991 natural mating has resulted in eight births at the Wolong centre.
In addition to experience gained over the years at Wolong, the recent success of births can be attributed to improved cooperation between China’s Ministry of Forestry and the country’s zoos involved in panda breeding, as well as to an exchange of information and technology between Chinese and western scientists.
Some problems are, however, still experienced with animal husbandry, particularly the care and welfare of infants. Disease and rejection by the mother have been the main cause of death among cubs. Investigation of these, and other aspects of panda reproduction, now form an active part of the ongoing research programme.
The main threats to the Giant Panda are habitat destruction and poaching. Young animals are caught for zoos, and adults are killed for their pelts which are used to make coats and sleeping mats. These mats are claimed to allow the sleeper to predict the future, and to keep away ghosts.6 Although capital punishment has been introduced for poachers, illegal hunting continues. A single Giant Panda pelt can sell for US $100,000 on the black market.3 Panda meat is unpalatable and hence little subsistence hunting occurs. Many hunters set snares for deer and other animals, especially Musk Deer, and at least one incidental Giant Panda death has been documented.6 Although illegal, such snaring occurs inside as well as outside the reserve system.
Available Giant Panda habitat has been severely reduced by logging and forest clearance for agricultural settlement. In the Sichuan Province, where the majority of Giant Pandas live, satellite mapping and surveys completed in 1974/5 and 1985/8 revealed that the area of habitat occupied by pandas had been reduced from over 20,000 km2 to only 10,000 km2; a similar rate of decline exists in Gansu and Shaanxi.5
During the late eighties, pandas suffered high mortality due to the flowering, seeding and die-back of bamboo over wide areas. This is a natural phenomenon, which may happen every 30 to 80 years, but its effects are exacerbated by the restrictions that increased human settlement have placed on Panda movements. Giant Pandas are now unable to disperse to other areas of suitable habitat in times of food shortage, and many have died of starvation. In the Wanglang Reserve, a population estimated at 196 individuals in 1969 had been reduced to only 10-20 by 1980 because of lack of food.5 Bamboo die-off may however have been an important feature of the species’ population dynamics, with enforced emigration promoting out-breeding and maintenance of a healthy population. The small, isolated populations of Giant Panda which remain may be threatened by in-breeding, which is liable to reduce reproduction rate, fertility and survival of young.7
1. Servheen, C. 1990. The Status and Conservation of the Bears of the World. Int. Conf. Bear Res. and Manage. Monogr. Series No. 2. 32.
2. Anon. 1990. Panda Research. International Bear News, Vol. 90 (3), No. 1.
3. Mills, J. 1992. Milking the bear trade. International Wildlife, 22 (3): 38-45.
4. Jien, G. 1991. Ailuropoda melanoleuca. IUCN/SSC Bear Specialist Group Newsletter, No. 2., February 1991.
5. Menghu, W. and Tieqin, H. (eds.). 1989. National Conservation Management Plan for the Giant Panda and its Habitat: Sichuan, Shaanxi and Gansu Provinces, The People’s Republic of China. Joint Report of the WWF & Ministry of Forestry of the People’s Republic of China.
6. Schaller, G. B., Hu Jinchu, Pan Wenshi & Zhu Jing. 1985. The Giant Pandas of Wolong. The University of Chicago Press: London.
7. Taylor, A. H. and Zisheng, Q. 1993. Bamboo regeneration after flowering in the Wolong Giant Panda Reserve, China. Biological Conservation, 63, 231-234.
8. Anon. 1992. Giant Panda Loans. International Bear News, Spring 1992.
Until the 1930s, hunting for sport was probably the main cause for the decline in tiger populations. Between 1940 and the late 1980s, the greatest threat was loss of habitat because of activities such as logging or mineral exploitation.7,14,17. Loss of their natural habitat often leads tigers to move into settled areas in search of food, where they are sometimes destroyed.20 For example, until the mid 1960s tigers were considered “an impediment to agricultural and pastoral progress” and their elimination was actively encouraged in China.22 Habitat destruction may also have an indirect influence on tiger populations through a reduction in the availability of prey.20
In recent years, the illegal hunting of tigers for body parts utilized in traditional Oriental medicines has become a major problem.17 The prosperity of the Southeast Asian and East Asian economies since the 1970s has led to an ever-increasing demand for these medicines. In India, the Wildlife Protection Society of India (WPSI) reported poaching figures indicating about 93 tigers killed in 1994, 115 in 1995, and 40 in 1996. But the Society warns that these figures represent only a fraction of actual poaching activities.15
In Russia the economic crisis combined with a relaxation of border controls and a ready access to the wildlife markets of China, Korea and Japan, led to a dramatic increase in the level of poaching.15,17 In the early 1990s, between 60 and 70 tigers were poached every year. However, the establishment of anti-poaching brigades by the government in 1993 and 1994 with support from several conservation groups, including WWF, has finally paid off. There were fewer than 20 known cases of poaching in 1995 and 1996 respectively.24
The loss of female reproductive potential and the disruption of the complex territorial system of tigers, which leads to low cub survival, means that the impact goes beyond the actual number of tigers killed.16 A further threat is posed by the loss of genetic diversity caused by the reduction of population sizes, and the separation of these populations through habitat fragmentation, which restricts dispersal.13 Studies have shown that loss of genetic diversity within tiger populations leads to decreases in litter size, infant survival and male fertility.12,15,18
Project Tiger:1 Project Tiger, started in 1973, involved the creation of a network of tiger reserves throughout India which were composed of a ‘core’ zone free from all human activity and a ‘buffer’ zone in which land use compatible with conservation needs was permitted. Since the start of the programme, the population of tigers in India increased from approximately 1,900 to around 4,300 in 1989.2 This apparent success has been undermined in recent years by an increase in illegal killing of tigers. Effectively masked by the high profile and visibility of tigers in the reserves, the scale of these activities has only recently become clear.8,13 Although 20 tiger reserves had been created by autumn 19944, the actual population of tigers had fallen to approximately 3,750 according to the 1993 census.5,8 In Ranthambhore National Park, for example, the number of tigers had decreased from over 40 in 1989 to 15 in 199311, a population size similar to that recorded when Project Tiger began. Latest estimates suggest there may be 18-20 tigers, including 9 cubs. 25 Since 1994, three more reserves were added, bringing the total to 23. But the Director of Project tiger, P.K. Sen, said in 1997 that despite these conservation efforts that there may be fewer than 3,000 tigers remaining in India. There is little protection for tigers living outside the reserves, representing over 50% of the country’s tiger population.28
A recent initiative by the US National Zoo, IUCN Captive Breeding Specialist group and a number of other North American scientific organizations has resulted in the development of an Action Plan for the creation of a Tiger Genome Resource Bank. This is intended to assist in the maintenance of the genetic diversity of both captive and wild tiger populations, so reducing the deleterious effects of inbreeding.6 A comprehensive captive breeding scheme is in operation incorporating zoological institutions worldwide. Details of this scheme are recorded each year in a Tiger Studbook (table 3).19
Smith, J.L.D. and McDougal, C. 1991. The contribution of variance in lifetime reproduction to effective population size in tigers. In Conservation Biology 5(4): 484-490.
Thornback, J. 1978. The Red Data Book Vol. 1. IUCN: Morges.
Anon. 1994. Hopes of rediscovering the Javan Tiger Fade. In Cat News 21: 12-13.
Toyne, P. and Hoyle, D., 1998, Tiger Status Report: 1998 –The Year for the Tiger
Anon. 1997. Tiger Link News, Vol.3, No.1 pp.24 (June).
HABITAT : Rocky scrubland.
GEOGRAPHICAL SPREAD: California, USA.
CURRENT POPULATION: Reduced to eight birds in the wild in the mid 1980s. In mid 1994 there was a total of 89 birds, with 85 of these in three captive breeding facilities. Most of 13 birds released into the wild (Los Padres National Park) have not survived.
SIZE: Wingspan up to 275cm.
WEIGHT: Approximately 9kg.
AVERAGE LIFE EXPECTANCY: Long lived, do not breed until their sixth year
NORMAL DIET: Carrion, and small mammals
NORMAL LIFESTYLE: Lays one egg every other year.
PREVIOUS GEOGRAPHICAL SPREAD: Widely distributed across North America until about 11,000 years ago; subsequently confined to the Pacific coast, south to Baja California, and further restricted to part of California since around 1940
REASONS FOR DECLINE: Initial prehistoric decline was probably due to loss of many large mammal species in North America, with further decline as later human populations colonised the West. The species declined rapidly throughout the 20th century, because of direct persecution, trapping, egg collection and ingestion of lead from shot animals. There may have been some competition with eagles and coyotes for prey and carrion. The excessive use of pesticides possibly contributed to a reduction in overall breeding success.
CURRENT THREATS: Released birds have suffered mortality following collision with power lines and by accidental poisoning. The problem of lead contamination within the range of the species remains unaddressed.
CONSERVATION PROJECTS: In the mid 1980s the remaining eight wild birds were captured to join other zoo-held stock in a captive breeding recovery programme that aims to release birds into more secure parts of the former range. The programme aims to improve the status of the species by establishing two wild communities of c.150 birds, each in the most recent historical range in California, and at another site (with insurance stock in Los Angeles and San Diego Zoos).
SPECIAL FEATURES: Since the 13 birds release, 4 have been recaptured due to behavioural difficulties, one died from ethylene glycol ingestion, 3 died in collisions with power lines, and 1 was killed by a car. The remaining four birds have been moved to a more remote part of the National Forest Lion Canyon in December 1994, and another five captive-bred birds have joined them there.
Collar, N.J., Gonzaga, L.P., Krabbe, N., Madro o Nieto, A., Naranjo, L.G., Parker (III), T.A., and Wege, D.C. 1992. Threatened Birds of the Americas. The ICBP/IUCN Red Data Book. ICBP (now BirdLife International), Cambridge.
Collar, N.J., Crosby, M.J., and Stattersfield, A.J. 1994. Birds to Watch 2. The World List of Threatened Birds. BirdLife International, Cambridge.
HABITAT : Primary dipterocarp forest.
GEOGRAPHICAL SPREAD: Luzon, Samar, Leyte and Mindanao, in the Philippines.
CURRENT POPULATION: An estimated 200 birds survived in the mid 1980s. The status on Leyte and Samar is not known; there may be around 50 pairs on Luzon; very few are known to survive on Mindanao. However, some areas have not yet been surveyed and despite its large size, this species remains quite poorly known
SIZE: 91cm. Wingspan of 200cm
AVERAGE LIFE EXPECTANCY: 30 to 60 years.
NORMAL DIET: A wide variety of forest species (including monkeys); no documentation exists of taking of domestic livestock.
NORMAL LIFESTYLE: A giant forest raptor and the primary predator of the Philippines. Dominant forest trees on steep mountain slopes are the preferred nesting sites, the nest itself usually on an epiphytic fern. Lays one egg, rearing one offspring every two years. A pair of Eagles have a territory of 60 to 100sq. km.
PREVIOUS GEOGRAPHICAL SPREAD: Before clearance of its forest habitat began the species was found throughout Luzon, Leyte, Mindanao and Samar.
REASONS FOR DECLINE: Primary forest clearance, hunting and trapping. The Eagle has always been a rare species, even before clearance of the forests began it has estimated that the maximum population could not have exceeded 6000 individuals. Clearance of the forest also leads to a loss of food source for the Eagles.
CURRENT THREATS: Primarily habitat clearance, driven by the expanding human population; hunting may also be a factor. The forests which support the Eagle may be gone by the year 2000 is recent trends continue.
CONSERVATION PROJECTS: Fully protected by law, and its capture for zoos is strictly controlled. Considerable sums of money from the United States and Europe have been spent on this project. The Philippine Eagle Conservation Program (PECP), based in Mindanao has been attempting to breed the Eagles presently held in captivity. There have been difficulties with this programme and so far no young have been hatched. An egg and chick removal strategy to create a viable captive population has been initiated, whereby eggs and chicks are taken from forest fragments which can not be protected. Hopefully Eagles raised in this manner will lead to the creation of a gene pool from which reintroduction into the wild can take place. An Adopt-a-Nest scheme has also been initiated by the PECP, whereby local people are paid a set amount of money if they report occupied nests, and also additional amounts of money at each confirmed stage of the egg in the nest, egg hatched and eaglet fledged. A small number (13 in 1992) are held by the Philippines Parks and Wildlife Service for breeding and return to the wild
SPECIAL FEATURES: The Philippine Eagle is remarkable for its large wing area and the length and depth of beak. The species may act as an indicator of the health of the Philippine forest ecosystem, and has cultural importance for the indigenous peoples within its range.
Collar, N.J., Crosby, M.J., and Stattersfield, A.J. 1994. Birds to Watch 2. The World List of Threatened Birds. BirdLife International, Cambridge.
The jackass penguin, a flightless seabird, is found nowhere in the world except off the coast of southern Africa, i.e. it is endemic to this area. It breeds on 24 offshore islands between Namibia and Port Elizabeth. Additional colonies were established in the 1980s on the mainland at Betty’s Bay and Simonstown. There is also a colony on the mainland of Namibia, although it is not known when this colony was established. Nesting on the mainland is unusual for jackass penguins because they are ground-nesting birds and are vulnerable to the many predators on the mainland.
Jackass penguins used to nest by burrowing into guano (bird droppings which have accumulated into a hardish substance, sometimes several metres deep). Most of the nutrient-rich guano was removed for fertiliser in the 19th century. Penguins now nest in burrows in sand, under overhanging rocks, under bushes, or even in the open. Jackass penguins can breed at any time of the year, usually laying two eggs. Most adult birds feed during the day and the chicks are fed regurgitated food in the late afternoon. The parent birds take turns in guarding the nest site and catching food. Fish eaten include sardine, maasbanker and anchovy. Squid are also eaten.
The total present population of jackass penguins is about 120 000 birds. In 1930, the total population numbered at least 1,2 million birds. Penguin numbers have therefore decreased by at least 90% in 60 years, and this fall is continuing. Dassen Island, off Yzerfontein, may have once sheltered over 1 million penguins – it now has about 30 000. Dyer Island, near Gaansbaai, now has about 20 000 penguins. The largest colony at present is St. Croix Island near Port Elizabeth, with about 50 000 penguins.
THREATS TO PENGUINS
The collapse of the jackass penguin population this century has been a result of the following:
· Harvesting of eggs for human consumption.
· Reduction of the penguin’s food supply by commercial fishing.
· Oil pollution from oil tankers. This could devastate the major colonies. Oil tankers may illegally clean out their tanks as they pass round the Cape to fill up with oil in the middle east.
· Large-scale removal of guano in the 19th century has decreased the ability of penguins to construct nests through burrowing. This has led to increased competition for breeding space with larger animals such as seals. Penguins breeding on the mainland are vulnerable to mainland predators not found on islands, such as leopards, genets and domestic dogs and cats, and also to human disturbance unless the colonies are adequately fenced and patrolled.
All the islands where jackass penguins breed, except Robben Island, are protected as provincial nature reserves or fall within the West Coast National Park. However, there is competition with seals for the limited breeding space available on some islands, and some individual seals are known to kill and eat penguins. At Mercury Island seals have been successfully displaced from penguin breeding sites. At Dassen and Robben Islands steps have been taken to eliminate the feral cat populations.
Efforts have been made to protect the new mainland breeding colonies at Betty’s Bay and Simonstown. A 100-metre fence has been erected at Stony Point peninsula at Betty’s Bay, and this is successfully preventing human disturbance and attacks by predators. The colony has grown to more than 100 nesting pairs.
The South African National Foundation for the Conservation of Coastal Birds (SANCCOB) carries out valuable work in rescuing oil-soaked penguins (and other seabirds) and rehabilitating them back to the wild. SANCCOB has one of the world’s highest rates of success in saving oiled seabirds, primarily because penguins respond better to captivity and cleaning than do flying birds.
· ROBERTS’ BIRDS OF SOUTHERN AFRICA.
G.L. Maclean. John Voelcker Bird Fund, Cape Town, 1985.
· OCEANS OF LIFE OFF SOUTHERN AFRICA.
A. Payne and R. Crawford (eds). Vlaeberg Publishers, Cape Town, 1989.
· SECRETS OF THE SEAS.
Illustrated guide to marine life off southern Africa. A. Payne and R. Crawford (eds). Vlaeberg Publishers, Cape Town, 1992.
HABITAT : Primarily shallow-water zones with seaweed (algae) or seagrass, and require sandy beaches for nesting.
GEOGRAPHICAL SPREAD: Circum-tropical marine waters. Although very many nesting locations are known worldwide, most populations are depleted and many are declining, some have already been extirpated (e.g. in the Caribbean). Only about a dozen large populations with around 2,000 or more nesting females per year are known at present; these occur on Ascension, around western and northern Australia, Costa Rica, Europa and nearby islands in the Mozambique Channel, Pacific Mexico, Oman, Pakistan, and possibly the Philippines, Sabah and Sarawak.
CURRENT POPULATION: Assessment of Marine Turtle populations is very difficult. Attention is focused on nests and nesting females. Because females rarely nest every year, but more usually at two, three or four year intervals, and because it is not possible to determine what proportion of the total mature female population is at the nest beach in any given year, population estimates are typically not precise. It is further complicated by the fact that nesting numbers on individual beaches can show extreme variation from one year to another. In a good year over 10,000 females may nest on Europa, and up to 80,000 at Raine Island (Australia); these appear to be the only stable populations not heavily exploited.
SIZE: Average nesting female carapace length 80 to 110cm.
WEIGHT: Average nesting female 110 to 185kg..
AVERAGE LIFE EXPECTANCY: Potentially long-lived.
NORMAL DIET: Herbivorous; exclusively seagrass and seaweed (algae).
NORMAL LIFESTYLE: Hatchlings emerge mostly at night from eggs buried in beach sand and make their way to the sea. The Green Turtle forages in shallow, inshore waters. Aggregations of Green Turtles often occur over shallow-water seagrass pastures or other suitable feeding grounds. Migrating Green Turtles may travel 20 to 40km per day. It is suggested that migratory behaviour is particularly linked with herbivory, since the richest feeding grounds (notably sea grasses) are most often found in shallow areas of coastal deposition, and do not typically coincide with the best nesting grounds (often isolated predator-free island beaches). Females do not attain maturity in the wild for 15 to 50 years. After a period of two to five decades, females typically migrate to a nesting beach often used by aggregations of turtles. Females remigrate at intervals of three years, and may lay three clutches of 100 to 120 eggs.
PREVIOUS GEOGRAPHICAL SPREAD: As present but with more nesting sites.
REASONS FOR DECLINE: Although traditionally used as a food source by many littoral peoples, the primary cause of decline in Green Turtle populations is systematic commercial exploitation of eggs and adults, coupled with beach disturbance.
CURRENT THREATS: Heavily utilised in most of the range; adults and eggs for food, juveniles for curios, and adults also for hide and oil. Incidental catch causes much mortality. Local subsistence and local commercial exploitation appear to be having an increasing impact on sea turtle populations, as tribal cultures decline, modern technology (e.g. outboard motors) spreads, and human populations in the tropics increase.
CONSERVATION PROJECTS: Chelonia mydas is listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Appendix I listing requires that trade in the taxon and its products is subject to strict regulation by ratifying states and international trade for primarily commercial purposes is forbidden. Nominally protected by legislation in much of the range, however, in many areas the legislation is inadequately enforced. Some nesting beaches fall within National Parks or Nature Reserves and are accorded varying degrees of protection. Legislation should be enforced, more protected areas are required (for nesting beaches, internesting habitat, and other life cycle phases). The slow maturation period for Marine Turtles can mask the effects of exploitation and conservation action. It is possible to monitor the populations at some localities from the air or by boat. Since the Green Turtle is a migratory species, passing through the jurisdictions of many countries, international cooperation and regional agreements on conservation are highly desirable. Has bred in captivity, but large-scale closed-cycle captive breeding has not yet been demonstrated to be possible.
SPECIAL FEATURES: The Green Turtle is the largest of the hard-shelled sea turtles (the Leatherback Dermochelys can grow much larger) although size, weight, and carapace shape can vary markedly between different populations.
Groombridge, B. and Luxmoore, R. 1989. The Green Turtle and Hawksbill World Status, Exploitation and Trade. CITES Secretariat, Switzerland.
Groombridge, B. 1982. The IUCN Amphibia Reptilia Red Data Book: Testudines, Crocodylia, Rhynchocephalia. IUCN, Switzerland.