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1.
The accomplishments of the Government of India/UNDP/FAO Project in the conservation of three species of crocodiles during the period 1975 to 1982 are reviewed. Sixteen crocodile rehabilitation centres and eleven crocodile sanctuaries have been established. A total of 879 gharials, 190 estuarine crocodiles and 493 mugger have been released. A viable breeding population of gharials now exists in the National Ghambal Sanctuary. A Crocodile Breeding and Management Training Institute was established by the Government of India in 1980 and has trained 48 managers of crocodile stations. Improvements are required in the management of crocodile sanctuaries and the evaluation of crocodile habitat. Releases of crocodiles in the wild require monitoring of survival and movements. There is a need for educating the public about crocodile conservation.  相似文献   

2.
Wildlife breeding farms have been promoted to aid biodiversity conservation by alleviating the pressure of harvest on wild populations. There is, however, growing concern that many breeding farms are being used to launder illegally caught wildlife. Surveys of wildlife traders in the Indonesian provinces of Maluku, West Papua and Papua were conducted between August 2009 and April 2011 to assess the trade of the green python (Morelia viridis), the species currently exported in the largest numbers from Indonesia declared as captive-bred. In total, 4227 illegally collected wild green pythons were recorded during surveys and high levels of harvest were found to have depleted and skewed the demographics of some island populations. Snakes were traced from their point of capture to breeding farms in Jakarta where they are to be exported for the pet trade, confirming the reports of wildlife laundering. Extrapolation of monthly collection estimates provided by traders revealed that at least 5337 green pythons are collected each year, suggesting that at least 80% of the green pythons exported from Indonesia annually are illegally wild-caught. The results of examination of 139 eggshells from five python species suggest that reptilian eggshells may be used as proof of provenance for each individual reptile exported. This method, in addition to the evidence that breeding farms play a significant role in the illegal exploitation of wildlife, allows conservation managers to begin to adequately monitor, regulate and determine the role of breeding farms in the conservation of wild populations.  相似文献   

3.
Commercial farming of wildlife, particularly in Southeast Asia, is currently the subject of much debate and to date, its conservation impact has been largely unexplored. This study used semi-structured interviews to build a detailed understanding of the dynamics of the commercial farming of Southeast Asian porcupine (Hystrix brachyura) in the northwest Vietnamese province of Son La. Although farm owners are obliged by law to propagate stock solely from farm-bred animals, 58% of farm owners admitted purchasing wild founder stock, with at least 19% continuing to buy wild individuals. Despite the number of farms, the primary demand on them is to supply other farms, and wild meat restaurants were still sourcing their meat from wild populations. Lower cost was a major factor driving the trade in wild animals, with wild adult porcupines being bought for half the price of farm-bred adults. With high demand from farms and restaurants, increased targeted hunting may be the cause of a dramatic decline in the wild population of porcupines across the region.  相似文献   

4.
The American crocodile is widely distributed in coastal and lowland wetlands in the northern Neotropics. As a result of commercial skin hunting in the 20th century, populations were greatly diminished, but in many areas have initiated a period of recovery since hunting and trade controls were enacted in the 1980s and 1990s. While a great deal of attention has been devoted to regulated commercial use as a management strategy for recovering crocodilian populations, these approaches are limited in their efficacy to deal with issues of habitat loss and fragmentation. Because habitat limitations are expected to be the most critical issue for crocodile conservation in the 21st century, there is an unfulfilled need for alternative strategies that prioritize habitat conservation. Here, we present results of an international effort to identify and prioritize the most critical habitats for this wide ranging species. We quantified information of a group of American crocodile experts and classified 69 areas in eight distinct crocodile bioregions as Crocodile Conservation Units (CCU), the most important areas for the conservation of this species. The relative importance of the CCUs in each bioregion was quantified using an algorithm that weighted factors that the experts considered to be most important for the long term conservation of viable populations of crocodiles. This effort is the initial step in the development of a regional conservation plan for the American crocodile. We identified two bioregions in particular where the creation of protected areas should be given a high priority, the Dry Pacific South America (northern Peru and southern Ecuador) and the Northwest and Central Pacific Mexico.  相似文献   

5.
OBJECTIVE: To examine global food demand patterns and how changing diets may stimulate demand for and trade of Mediterranean diet products. DESIGN: Literature review. Trends in global and US food consumption patterns are examined and trade data are reviewed to evaluate the impact of changing diets on trade of Mediterranean diet products. Market access issues are also addressed briefly to highlight the role of policy in the trade of Mediterranean diet products. RESULTS: Diets are shifting towards higher-value products such as meats, fruits and vegetables, and a wider array of packaged food products. Trade in these products has also grown in the past two decades, with several non-traditional importers and exporters becoming increasingly active in the global market. CONCLUSIONS: Income-driven demands for quality and variety are likely to increase the demand for Mediterranean diet products globally. While the middle-income countries appear to be the best growth prospects, the USA remains a potential growth market if these products can meet the growing consumer demand for variety, quality and convenience. Although consumer trends globally indicate growth in demand for Mediterranean diet products, the additional demand may not be reflected by a corresponding growth in trade. Trade in Mediterranean diet products continues to be hampered by higher than average trade barriers and high transportation costs for perishables.  相似文献   

6.
Many snake species are declining globally, yet data unavailability in temperate grasslands hinders snake conservation in one of the world’s most endangered biomes. To encourage and inform the conservation of snakes in these regions, I examined snake species diversity and abundance during 2 years of a mark-recapture study at 22 sites located in six American tallgrass prairie preserves in northern Illinois, USA. I emphasized landscape-scale relationships after accounting for covariance with environmental factors at both finer (microhabitat) and broader (regional) scales. A total of 120 snakes representing seven species was captured using drift fence arrays associated with funnel traps and sheet metal cover. The low numbers and diversity of snakes captured, when compared to historic evidence, indicate that since the 1930s Midwestern snake populations have declined. Non-metric multidimensional scaling and Mantel tests demonstrate that differences in snake species composition in remnant and degraded prairies are discernable along gradients of urban and agricultural land cover. However, different patterns of abundance for individual snake species indicate that the relative importance of specific landscape factors differ among species, which has significant conservation implications. Here, I recommend that conservationists use a species-specific approach to manage snake populations. I also stress the need for thorough inventory of snake populations and studies of snake-habitat relationships to advance our understanding of snake ecology and conservation within the little studied temperate grassland habitats of South America and eastern Eurasia.  相似文献   

7.
Illegal wildlife trade is a widespread activity with direct impacts on biodiversity and street markets are frequently pointed out as hotspots in the wildlife trade route. However, due to its illegal character, it is difficult to accurately estimate how many individuals and how much money are handled by traders. Precise data on the number of individuals and species involved, and the drivers behind the illegal wildlife trade are essential for fighting it. We use the example of the metropolitan area of Recife, in northeastern Brazil, a well-known route of illegal wildlife in the country, to access the extent and impact street markets may have on biodiversity. We present quantitative and qualitative information on the illegal trade of wild birds in eight street markets in the area, indicating which species are preferred and why, estimating the number of animals and the volume of money involved, and quantifying the impact that the removal of those animals may have. We observed a high and diversified species offer, biased towards adult male songbirds, with birds of 15 families and 55 species on sale. Birds are kept in poor conditions and some individuals are sold for as little as US$ 1.00. However, we projected that up to 50,000 wild birds may be sold annually in the markets surveyed, including possibly 16,800 individuals of Sporophila nigricollis (the yellow-bellied seedeater), the most frequently observed species. The activity is profitable and may deal with significant amounts of money (up to nearly US$ 630,000.00/year). The numbers involved indicate that street markets are significant wildlife sinks, with a large and frequently ignored impact that must be taken into account in the control and conservation of the biodiversity, not just in Brazil but elsewhere.  相似文献   

8.
We used models integrating road maps, traffic volume, and snake movements to examine the potential for roads to contribute to mortality in two species of water snakes that differ in their vagility, use of terrestrial habitats, and conservation status. Road networks and traffic volumes typical of three regions in Indiana, USA, may account for mortality of 14-21% of the population per year in the more vagile, terrestrial, and imperiled copperbelly water snake (Nerodia erythrogaster neglecta) but only 3-5% mortality in the more sedentary, aquatic, and common northern water snake (Nerodia sipedon). The majority (>91%) of road crossings and associated mortality are predicted to occur during overland migrations to other wetlands, suggesting roads bisecting travel routes between wetlands may function as mortality sinks. Our models highlight the proportionately greater risk of mortality for the more vagile and imperiled species, N. e. neglecta, and suggest current wetland conservation strategies that focus on the wetland alone are unlikely to adequately protect wetland biodiversity from certain types of anthropogenic habitat modification. What is needed is a landscape approach to wetland conservation that considers not only the quality of wetlands and nearby terrestrial habitats, but also ensures that terrestrial corridors between wetlands remain permeable and offer safe passage for wildlife.  相似文献   

9.
More species of snakes are becoming endangered yet information on their effective management is lacking. The present study assessed the general biology of the prairie garter snake, an endangered species in Ohio, USA, and the potential impact of mortality due to game management practices in a state wildlife area (automobile traffic and grass mowing operations). Alterations to the present management practices include alternatives such as rescheduling of mowing operations to coincide with the snake's periods of inactivity and using signs to caution motorists to avoid hitting snakes on the road. Future management of wildlife areas should not focus upon a single species or trophic level but rather consider both non-game and game species.  相似文献   

10.
The protein deficiency problems of Africa south of the Sahara are growing in seriousness with the increasing human population. Domestic livestock, on which very high hopes have hitherto been set, have continued to fail to meet existing demands, let alone to keep in step with increasing human population growth. There has been increasing exploitation of the meat of wild animals, whose management is ignored. This source of meat supplements domestic sources. The exploitation of wild animals, coupled with increasing pressure on the habitat of the animals, is exterminating most of the wild animal species involved. Advice that existing scientific knowledge on the management of wild animals must be applied to ensure their rational exploitation on a sustained-yield basis, has continued to be ignored— with the excuse that facts and figures are not available to justify investment in wildlife conservation that will ensure a sustained yield of the badly-needed animal protein. Every attempt must be made by those entrusted with the responsibility of wildlife conservation to bring together scattered information on the subject and, at the same time, begin to collect, systematically, statistical information on the utilization of wild animal meat as food—also to ensure that wildlife conservation receives the priority it deserves in the management of natural resources in Africa south of the Sahara. This is inevitable if wildlife conservation is to be able to meet the economic justification without which one nation after another will continue to give very low priority to wildlife conservation—to the detriment of the region—where malnutrition and poaching are serious realities as are also overgrazing, expansion of desert land, and human population explosion. Despite the fact that general experience indicates the need for concerted action, it appears that, in the absence of readily-available statistical data, which are supposed to be required by policy-makers and financiers, these people are not prepared to face their duty effectively to finance proper wildlife conservation and rational utilization of wildlife resources of Africa south of the Sahara.  相似文献   

11.
Excessive hunting pressure, due in large part to commercialization, has reduced the populations of many tropical large mammal species. Wildlife over-exploitation is severe in Indonesia, especially on Sulawesi, where human resources and funding are inadequate to monitor the wildlife trade and enforce existing protection laws. In response, the Wildlife Crimes Unit program was established in December 2001 to: (i) monitor wildlife transportation into North Sulawesi and market sales; (ii) provide legal and technical support to law enforcement agencies; and (iii) promote public awareness of wildlife and protection laws. Over a two-year period, 6963 wild mammals en route to markets were encountered (∼8 individuals h−1) and 96,586 wild mammals were documented during market surveys. The trade of some protected mammals declined significantly over this period, but overall trade in wild mammals increased by 30%. High volume of trade in non-protected animals such as the Sulawesi pig Sus celebensis and large flying foxes (Pteropodidae), raise concerns about the sustainability of current harvesting. To combat this problem, we recommend that: (1) efforts are continued to reduce trade in protected species; (2) protected status is extended to heavily traded but non-protected taxa, such as flying foxes; (3) the effects of hunting on rat and bat populations, as well as its impact on forest dynamics, are quantified; and (4) work is carried out with local communities to strengthen awareness, set sustainable limits on wild mammal harvesting, and establish practical mechanisms for enforcing these limits.  相似文献   

12.
Knowledge and attitudes of children towards wildlife and the environment were assessed through questionnaires given to 366 children in 9 schools in southwest Guyana. Children’s responses revealed that they had a general knowledge of wildlife but knew few details about specific species. Respondents thought that wildlife was important but were nonetheless tolerant of several forms of environmental exploitation. Visits by conservation organizations, Conservation International and Foster Parrots, were shown to increase appreciation of wildlife and the need to set up more protected areas, but unless programmes were concentrated and sustained they had little effect on attitudes towards environmental utilization and exploitation. Experience of the natural world in terms of owning a domestic animal or pet, having visited a zoo, or being a member of a wildlife club had little impact on children’s knowledge of wildlife and did not change attitudes to utilization and exploitation. Surprisingly, Guyanese children did not have particularly positive views about classic flagship species, such as jaguars, giant anteaters and tapirs, when compared to other species. Our findings suggest that zoos, wildlife clubs and conservation organizations could enhance the dissemination of their message through making more frequent and sustained visits, imparting more detailed knowledge, and exposing children to the potential dangers of utilization and exploitation; also that conservation organizations should reassess their use of standard flagship species in South America.  相似文献   

13.
Commercial crocodile rearing stations in Rhodesia are described, including regulations which govern their operation. When crocodile eggs are collected from the wild a quota of juveniles equivalent to 5% of the number collected must be released at the age of 3 years. Figures for hatching success and juvenile growth on rearing stations compared with wild populations indicate that both these parameters are better on the rearing stations. The growth rate on a rearing station is twice as fast as in the wild. Data on juvenile survival on the rearing stations suggest that it is of the order of 50% to the age of 3 years. No comparative information is available for wild populations. Survival of station-reared crocodiles after release into the wild is good, although growth slows substantially. Juveniles for release are a valuable tool in management, for restocking suitable areas or supplementation of natural recruitment. Crocodile farms may provide an answer to future management of this species, and a ready source of breeding stock is available in ‘problem’ animals which are relocated rather than shot. Crocodile rearing and farming in developing countries could provide the incentive to maintain a renewable resource rather than to exploit and destroy existing populations.  相似文献   

14.
Between October 1978 and July 1980, day and night crocodile surveys were conducted at low, normal and high water levels over 2703 km of river and lakeshore in the Western and Southern Highlands provinces of Papua New Guinea. The 1353 crocodiles seen ranged between 0·18 and 2·23 animals per km.Night counts recorded 12·9 times as many crocodiles as day counts over the same area. This may indicate more nocturnal activity than occurs in other crocodilians. Unhunted areas had a greater proportion of large crocodiles than did hunted regions. As the water level rose, the ‘visible juveniles’ category decreased as a result of migration into newly flooded adjacent swamplands. The upstream range of New Guinea crocodiles on the Strickland River extended only to the Burnett River junction.There was an increase in flight distance with increasing body size and this rate of increase was over twice as large for hunted populations as for unhunted ones.  相似文献   

15.
Organochlorine (OC) residues were recently detected in nonviable Morelet's crocodile (Crocodylus moreletii) eggs from northern Belize. To further the assessment of contaminant exposure in Belizean crocodiles, nonviable Morelet's crocodile eggs (n = 11) from southern Belize and American crocodile (Crocodylus acutus) eggs (n = 12) from the coastal zones of Belize were screened for 20 OCs. Results indicated p,p-DDE to be the most prevalent OC (96% occurrence) in eggs examined, with concentrations ranging from 5 to 372 ng/g. These concentrations are similar to those observed in crocodile eggs (10-180 ng/g) from northern Belize. A general trend toward higher DDE concentrations in Morelet's crocodile eggs (mean = 103 ppb) compared with American crocodile eggs (mean = 31 ppb) was observed. However, this trend may be due to site-specific contamination rather than differences in interspecific susceptibility to chemical exposure. Other OCs detected in crocodile eggs included the parent compound, p,p-DDT, and its metabolite, p, p-DDD.  相似文献   

16.
The effects of mineral exploitation on wildlife through physical and chemical modification of the environment are normally considered to be deleterious to nature conservation. However, the extraction of minerals frequently alters landform to provide new habitats for plants and animals. Groups of abandoned lead-zinc mines in north-east and central-west Wales have been examined and evaluated for their significance to wildlife conservation.The extraction of mineralsl has created cliffs, ledges and crevices together with adits and shafts, which provide relatively undisturbed breeding sites for several imporatant bird species. Similarly, toxic metalliferous spoils provide sites for colonisation by several plants which have evolved metal-tolerant populations, and many calcareous metalliferous spoils not grossly polluted by lead and zinc provide refugia for regionally rare plants of conservation interest, including several species of orchid. The significance of derelict land clearance and reclamation works on old metal mines and their integration with wildlife conservation are discussed and recommendations are made for avoidance of conflict between the objectives of redevelopment and conservation interests.  相似文献   

17.
Papua New Guinea has astonishing biological and cultural diversity which, coupled with a strong community reliance on the land and its biota for subsistence, add complexity to monitoring and conservation and in particular, the demonstration of declines in wildlife populations. Many species of concern are long-lived which provides additional challenges for conservation. We provide, for the first time, concrete evidence of a substantive decline in populations of the pig-nosed turtle (Carettochelys insculpta); an important source of protein for local communities. Our study combined matched village and market surveys separated by 30 years, trends in nesting female size, and assessment of levels and efficacy of harvest, each of which was an essential ingredient to making a definitive assessment of population trends. Opportunities for an effective response by local communities to these declines needs to consider both conservation and fisheries perspectives because local communities consider the turtle a food resource, whereas the broader global community views it as a high priority for conservation. Our study in the Kikori region is representative of harvest regimes in most rivers within the range of the species in Papua New Guinea, and provides lessons for conservation of many other wildlife species subject to harvest.  相似文献   

18.
Introduced species are an increasingly pervasive problem. While studies on the ecology and behavior of these pests are numerous, there is relatively little known of their physiology, specifically their reproductive and stress physiology. One of the best documented introduced pest species is the brown tree snake, Boiga irregularis, which was introduced onto the Pacific island of Guam sometime around World War II. The snake is responsible for severely reducing Guam's native vertebrates. We captured free-living individuals throughout the year and measured plasma levels of stress and sex hormones in an effort to determine when they were breeding. These data were compared to reproductive cycles from a captive population originally collected from Guam. Free-living individuals had chronically elevated plasma levels of the stress hormone corticosterone and basal levels of sex steroids and a remarkably low proportion were reproductively active. These data coincide with evidence that the wild population may be in decline. Captive snakes, had low plasma levels of corticosterone with males displaying a peak in plasma testosterone levels during breeding. Furthermore, we compared body condition between the free-living and captive snakes from Guam and free-living individuals captured from their native range in Australia. Male and female free-living snakes from Guam exhibited significantly reduced body condition compared to free-living individuals from Australia. We suggest that during the study period, free-living brown tree snakes on Guam were living under stressful conditions, possibly due to overcrowding and overexploitation of food resources, resulting in decreased body condition and suppressed reproduction.  相似文献   

19.
Market-based incentives are one means of encouraging farmers to grow landraces that are also of social value, thereby contributing to the conservation of crop genetic diversity on farms – and in principle, the cheapest. This study uses a participatory, market systems approach supplemented by baseline data from an ongoing project to analyze markets for rice landraces and modern varieties in Nepal. Nepal is located in the area of origin and diversity for Asian rice. With the exception of traditional Basmati rice (which is of high aromatic quality), most rice landraces are traded through small-scale informal channels. Traders earn higher profits handling modern varieties than landraces, with the exception of Basmati, which competes with modern varieties. The superior consumption qualities of Basmati are valued in markets, but conserving these landraces may not have great social value. Furthermore, farmers who grow Basmati are clearly better off than those who do not. Findings raise questions about the role of market-based incentives for conserving landraces on farms, the costs entailed in establishing a structure to generate them, and about efficiency vs. equity considerations in the design of conservation programs.  相似文献   

20.
The purpose of this study was to examine certain aspects of the life history and ecology of the timber rattlesnake (Crotalus h. horridus) in Pennsylvania, and to evaluate the reported decline in numbers of this species. The influence of commercial hunting has been considered and suggestions are made for conservation of this unpopular but intriguing snake.The previous and present abundance of rattlesnakes was first considered by a programme of interviews with commercial hunters. Visits were also made to many supposed den sites in central Pennsylvania, and to four rattlesnake hunts held in the summer of 1976. There were consistent reports of a large recent decline in the number of rattlesnakes seen and captured. These opinions of the scarcity of rattlesnakes were personally confirmed by visits to known dens. One rattlesnake den was chosen for a study on dates of first capture in the spring, on transplantation of snakes from other localities, on movements of newly released and long-term den residents, and on rodent populations. During three consecutive springs the dates of first capture of rattlesnakes varied only between April 23 and 30, despite marked differences in the pattern of air and ground temperature variation. Many snakes transplanted to a new den site apparently left the area almost immediately. Six out of 33 adults released were recaptured at the new den; three of these hibernated there. Only one of the 48 newborn rattlesnakes released soon after birth in the autumn was recaptured in the subsequent spring. On emergence from hibernation two rattlesnakes were tracked by radiotelemetry. They remained at the den until June, and left soon after shedding. One snake was followed to a distance 1055 m from the den over a period of 69 days. Considerable rodent food was available on the talus slopes of this den. Mice (Peromyscuc leucopus) were abundant; in a 0·7 ha grid trapped for one week the population was estimated at 61/ha. Nine gravid rattlesnakes were held in the laboratory to obtain information on litter size. The average litter was seven (range 5–9) and females lost an average of 41% of their body weight during parturition. The metabolic demands of pregnancy are high and females only reproduce every two, or possibly every three, years. The smallest female to produce a litter had a snout-vent length of 770 mm, and it is estimated that this animal was five years old. Positive correlations between head length and snout-vent length, and body weight and snoutvent length were found. No significant differences in these relationships between the sexes or between snakes freshly caught in different areas were noted. There was a decline in relative body weight and head length after prolonged starvation in captivity. Male rattlesnakes have significantly longer tails than females. The timber rattlesnake in Pennsylvania is rapidly approaching extinction. Prohibition of bounties, snake hunts, and commercial sale of snakes, and protection of rattlesnakes in remote areas of state and national forests would significantly enhance the prospects for survival of viable populations of Crotalus horridus.  相似文献   

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