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1.
Freshwater habitat alteration and marine fisheries can affect anadromous fish species, and populations fluctuating in size elicit conservation concern and coordinated management. We describe the development and characterization of two sets of 96 single nucleotide polymorphism (SNP) assays for two species of anadromous alosine fishes, alewife and blueback herring (collectively known as river herring), that are native to the Atlantic coast of North America. We used data from high‐throughput DNA sequencing to discover SNPs and then developed molecular genetic assays for genotyping sets of 96 individual loci in each species. The two sets of assays were validated with multiple populations that encompass both the geographic range and the known regional genetic stocks of both species. The SNP panels developed herein accurately resolved the genetic stock structure for alewife and blueback herring that was previously identified using microsatellites and assigned individuals to regional stock of origin with high accuracy. These genetic markers, which generate data that are easily shared and combined, will greatly facilitate ongoing conservation and management of river herring including genetic assignment of marine caught individuals to stock of origin.  相似文献   

2.
IAN CARTER  & PETER NEWBERY 《Ibis》2004,146(S2):221-229
Conservation efforts in the United Kingdom have increasingly sought to restore the populations and ranges of birds affected by changes to their habitat or by direct human persecution. One approach is reintroduction, although this is likely to be appropriate in only a limited set of circumstances, involving a small number of species. This paper reviews the use of reintroduction as a tool for conserving birds associated with lowland farmland, highlighting the benefits of this approach to conservation, as well as the potential dangers. Two case studies are presented to illustrate how different reintroduction techniques are required, depending on the species involved and the donor stock available. The internationally agreed, though not legally binding, IUCN guidelines for reintroduction projects are summarized, together with the requirements of The Wildlife & Countryside Act (1981) in relation to the release of birds into the wild in Britain. Potential changes to current legislation are suggested, to prevent inappropriate and potentially damaging reintroduction projects from being carried out in the future.  相似文献   

3.
Bighorn sheep populations experienced a drastic reduction in both distribution and abundance until the advent of modern wildlife management, where improving viability of extant populations and translocating animals into historical habitat range have been the most important management policies. The fact that subspecies relationships among bighorn are ambiguous,together with the importance of selecting appropriate source stock and the expense of translocation projects, makes an understanding of subspecies relationships and genetic variation, within and between populations, important for the management and conservation of this species. In this study, genetic variation in 279 bighorn sheep from 13 study sites in Arizona, California, New Mexico and Alberta, Canada were examined by analyzing ten microsatellite loci to determine interpopulation differentiation and relationships between closely related taxa. All populations contained a substantial amount of genetic variation. Genetic differences between populations were large and roughly proportional to geographic distance. The significance of this to desert subspecies relationships and management is discussed.  相似文献   

4.
The Australian lungfish, Neoceratodus forsteri, exists as remnant natural populations in two rivers of south-east Queensland, Australia, and several translocated populations. Lungfish habitats have been impacted by agriculture and forestry, alien plants and fish and by river impoundment and regulation of flows. The species has been listed as vulnerable under Australian Commonwealth legislation. A proposal to construct Traveston Crossing Dam on the free-flowing main channel of the upper Mary River could seriously threaten the lungfish. The dam can be stopped by Commonwealth legislation if important populations of lungfish in the Mary River are likely to be significantly impacted by the new dam. This paper assembles evidence that impoundment of the Mary River and regulation of river flows are likely to decrease and fragment important lungfish populations, disrupt the breeding cycle, reduce juvenile recruitment, and isolate and decrease habitat availability/quality to such an extent that the species is likely to decline. Proposed mitigation strategies include fish transfer facilities, provision of flow releases from the dam (environmental flows) to sustain lungfish habitat and breeding downstream, and translocation of hatchery-reared juvenile lungfish into suitable natural habitats. These mitigation efforts may not be sufficient to secure the genetic diversity and long-term viability of lungfish populations in the Mary River.  相似文献   

5.
Extirpated organisms are reintroduced into their former ranges worldwide to combat species declines and biodiversity losses. The growing field of reintroduction biology provides guiding principles for reestablishing populations, though criticisms remain regarding limited integration of initial planning, modeling frameworks, interdisciplinary collaborations, and multispecies approaches. We used an interdisciplinary, multispecies, quantitative framework to plan reintroductions of three fish species into Abrams Creek, Great Smoky Mountains National Park, USA. We first assessed the appropriateness of habitat at reintroduction sites for banded sculpin (Cottus carolinae), greenside darter (Etheostoma blennioides), and mottled sculpin (Cottus bairdii) using species distribution modeling. Next, we evaluated the relative suitability of nine potential source stock sites using population genomics, abundance estimates, and multiple‐criteria decision analysis (MCDA) based on known correlates of reintroduction success. Species distribution modeling identified mottled sculpin as a poor candidate, but banded sculpin and greenside darter as suitable candidates for reintroduction based on species‐habitat relationships and habitats available in Abrams Creek. Genotyping by sequencing revealed acceptable levels of genetic diversity at all candidate source stock sites, identified population clusters, and allowed for estimating the number of fish that should be included in translocations. Finally, MCDA highlighted priorities among candidate source stock sites that were most likely to yield successful reintroductions based on differential weightings of habitat assessment, population genomics, and the number of fish available for translocation. Our integrative approach represents a unification of multiple recent advancements in the field of reintroduction biology and highlights the benefit of shifting away from simply choosing nearby populations for translocation to an information‐based science with strong a priori planning coupled with several suggested posteriori monitoring objectives. Our framework can be applied to optimize reintroduction successes for a multitude of organisms and advances in the science of reintroduction biology by simultaneously addressing a variety of past criticisms of the field.  相似文献   

6.
Understanding the vulnerability of tree species to anthropogenic threats is important for the efficient planning of restoration and conservation efforts. We quantified and compared the effects of future climate change and four current threats (fire, habitat conversion, overgrazing and overexploitation) on the 50 most common tree species of the tropical dry forests of northwestern Peru and southern Ecuador. We used an ensemble modelling approach to predict species distribution ranges, employed freely accessible spatial datasets to map threat exposures, and developed a trait‐based scoring approach to estimate species‐specific sensitivities, using differentiated trait weights in accordance with their expected importance in determining species sensitivities to specific threats. Species‐specific vulnerability maps were constructed from the product of the exposure maps and the sensitivity estimates. We found that all 50 species face considerable threats, with an average of 46% of species’ distribution ranges displaying high or very high vulnerability to at least one of the five threats. Our results suggest that current levels of habitat conversion, overexploitation and overgrazing pose larger threats to most of the studied species than climate change. We present a spatially explicit planning strategy for species‐specific restoration and conservation actions, proposing management interventions to focus on (a) in situ conservation of tree populations and seed collection for tree planting activities in areas with low vulnerability to climate change and current threats; (b) ex situ conservation or translocation of populations in areas with high climate change vulnerability; and (c) active planting or assisted regeneration in areas under high current threat vulnerability but low climate change vulnerability, provided that interventions are in place to lower threat pressure. We provide an online, user‐friendly tool to visualize both the vulnerability maps and the maps indicating priority restoration and conservation actions.  相似文献   

7.
Animal behaviour can affect the outcome of conservation translocations. It is important to understand the behaviour of the species being considered for translocation and how its behaviour varies over life stages. There may be uncertainty about what life stages are best as founders for release back into wild populations. A technique called head‐starting whereby juvenile life stages are raised in captivity and then released is one potential pre‐release strategy. However, juveniles of many species have a dispersive role in the life cycle, potentially raising difficulties for establishing new populations due to dispersal from the intended habitat following release. For this study, we compared aspects of the behaviour of captive adult and neonate pygmy bluetongue lizards (Tiliqua adelaidensis) – an endangered species for which translocation is likely to be an important management strategy – to determine if neonate behavioural characteristics are appropriate for their translocation. We filmed adult and neonate pygmy bluetongue lizards and compared their behaviour. We also filmed adults over an activity season to compare seasonal behaviour. Behavioural parameters measured included basking time, burrow exits, burrows occupied and walking the perimeter wall. Neonates basked significantly more than adults in summer and autumn. Neonates are likely to be basking more than adults because they are in a stage of rapid growth and need to gain body mass before the winter inactivity period. Neonates exited burrows more often than adults and used a greater number of burrows. These results indicate neonate lizards are actively exploring their habitat. Neonates are unlikely to be as suitable for translocation as they are actively moving about and more likely to be predated upon or disperse from the translocation site. Our finding can be applied to other species that have active juvenile life stages and are at particular risk of predation due to their small size.  相似文献   

8.
9.
Restoration of habitat for endangered species often involves translocation of seeds or individuals from source populations to an area targeted for revegetation. Long-term persistence of a species is dependent on the maintenance of sufficient genetic variation within and among populations. Thus, knowledge and maintenance of genetic variability within rare or endangered species is essential for developing effective conservation and restoration strategies. Genetic monitoring of both natural and restored populations can provide an assessment of restoration protocol success in establishing populations that maintain levels of genetic diversity similar to those in natural populations. California’s vernal pools are home to many endangered plants, thus conservation and restoration are large components of their management. Lasthenia conjugens (Asteraceae) is a federally endangered self-incompatible vernal pool annual with gravity- dispersed seeds. Using the molecular technique of intersimple sequence repeats (ISSRs), this study assessed levels and patterns of genetic variability present within natural and restored populations of L. conjugens. At Travis Air Force Base near Fairfield, California, a vernal pool restoration project is underway. Genetic success of the ecologically based seeding protocol was examined through genetic monitoring of natural and restored populations over a three-year period. Genetic diversity remained constant across the three sampled generations. Diversity was also widely distributed across all populations. We conclude that the protocol used to establish restored populations was successful in capturing similar levels and patterns of genetic diversity to those seen within natural pools. This study also demonstrates how genetic markers can be used to inform conservation and restoration decisions.  相似文献   

10.
The severely threatened Chinese flora urgently needs a new, well adapted to China and properly formulated conservation strategy. The present review provides a detailed conservation methodology that complements previously described guidelines for preservation of plant species with extremely small populations (PSESP) in China. This review adds to the above concept in several aspects, making it relevant to all threatened Chinese plant species. The proposed integral conservation strategy has the following crucial components: -ecoregional basis for conservation planning and implementation; -a unified scoring system that is used in regional systematic planning for reserve design, monitoring and assessment of efficiency of a reserve network, and creation of seed banks and living collections; -a focus on population demography and the presence of naturally occurring regeneration as the key criteria for defining the conservation status of a species and the appropriate major focus of the species recovery plan; -creation of multi-species living collections that preserve species genetic variation and provide material for in situ actions; -experimental translocation of threatened species into multiple locations within and outside their known range. Adopting and implementing these strategies successfully and more fully in China requires that the country changes PA legislation and improves PA management, the National Science Foundation of China (NSFC) re-prioritizes the type of research that receives research funds, and local scientists improve their approach toward information sharing.  相似文献   

11.
Reintroduction or translocation of threatened plant species, as part of in situ conservation efforts, often failed because of the lack or the poor quality of remaining natural habitats due to human disturbances and invasion by alien species, especially in island ecosystems. We conducted a study on Ochrosia tahitensis (Apocynaceae), a critically endangered endemic small tree in the tropical high volcanic island of Tahiti (French Polynesia, South Pacific) to find the most suitable sites for future translocation. Distribution models were produced based on climate, topography, and plant community inventories (i.e. species composition and abundance, canopy height and openness, basal area of woody species) of the few remnant populations. Results show that this species, comprising 32 reproductive trees within 16 populations known in the wild, remains restricted to a few ecological refuges representing a very small part of its potential ecological range located on the northwest side of the island, and shares its current habitats with a set of more common native woody species found in mesic-wet forests. The use of native plant communities as a proxy for habitat suitability along with species distribution modelling can enhance translocation success in island ecosystems, but only if the major threats causing population decrease, mainly forest destruction and fragmentation and invasive alien species, are effectively managed.  相似文献   

12.
Human enterprise has led to large‐scale changes in landscapes and altered wildlife population distribution and abundance, necessitating efficient and effective conservation strategies for impacted species. Greater sage‐grouse (Centrocercus urophasianus; hereafter sage‐grouse) are a widespread sagebrush (Artemisia spp.) obligate species that has experienced population declines since the mid‐1900s resulting from habitat loss and expansion of anthropogenic features into sagebrush ecosystems. Habitat loss is especially evident in North Dakota, USA, on the northeastern fringe of sage‐grouse’ distribution, where a remnant population remains despite recent development of energy‐related infrastructure. Resource managers in this region have determined a need to augment sage‐grouse populations using translocation techniques that can be important management tools for countering species decline from range contraction. Although translocations are a common tool for wildlife management, very little research has evaluated habitat following translocation, to track individual behaviors such as habitat selection and fidelity to the release site, which can help inform habitat requirements to guide selection of future release sites. We provide an example where locations from previously released radio‐marked sage‐grouse are used in a resource selection function framework to evaluate habitat selection following translocation and identify areas of seasonal habitat to inform habitat management and potential restoration needs. We also evaluated possible changes in seasonal habitat since the late 1980s using spatial data provided by the Rangeland Analysis Platform coupled with resource selection modeling results. Our results serve as critical baseline information for habitat used by translocated individuals across life stages in this study area, and will inform future evaluations of population performance and potential for long‐term recovery.  相似文献   

13.
为了将有限资源合理投放到关键区域, 实现物种保护成效的最大化, 找出质量最好的栖息地及它们之间的迁徙通道是制定保护规划的第一步。本研究以三江源的雪豹(Panthera uncia)栖息地为对象, 基于野外调查数据和高分辨率卫星遥感数据, 利用物种分布模型、保护规划模型和连通度分析工具, 找出了三江源地区雪豹的核心栖息地分布和潜在迁徙通道位置, 分析了目前保护中的潜在威胁, 并提出了针对三江源西、中、东三块区域的不同保护对策。结果表明: (1)三江源西部核心栖息地比较小而破碎, 但迁徙通道较多且没有明显窄点, 未来应关注青藏线的潜在阻碍作用, 同时应防范道路沿线的野生动物盗猎; (2)中部区域横跨玉树-杂多-囊谦的雪豹栖息地是三江源最大的核心雪豹栖息地, 在连通其他种群中也处于中心地位, 应通过种群监测确定其健康稳定, 对开发、偷猎等威胁防微杜渐, 保持其源种群的作用; (3)东部区域人口密度高, 受人类活动的影响最大, 需保证阿尼玛卿、年保玉则两块核心栖息地的质量, 并重点监测甘德县境内的省道处雪豹的迁徙通道是否畅通。三江源地区雪豹栖息地总体质量较好, 建议将维持核心源种群的稳定性, 保持种群间迁徙通道的畅通作为三江源的雪豹景观保护工作的整体目标。未来应充分利用天地一体化监测手段, 开展重要保护物种栖息地状况的评估和预警, 尤其是非保护地区域物种核心栖息地的开发建设活动。  相似文献   

14.
Overexploitation, pollution, habitat loss or emerging diseases have led to a large number of species to extinction. This has made zoos and wildlife enclosures expand their goals beyond entertainment and fun; their participation in conservation and research programs is important for the recovery of multiple species. To ensure success, staff need to know the specific requirements of each species. In case of the Iberian ibex (Capra pyreanica), a wild ungulate endemic to the Iberian Peninsula, different sarcoptic mange outbreaks caused dramatic declines of some ibex populations, which led managers and researchers to explore strategies aimed at preventing and controlling this disease and to reduce its impact on ibex populations. Such management plans included the creation of stock reservoirs as an in-situ conservation measure. The objective of the stock reservoir El Toril, as a key part of a general management plan, is to keep in captivity (in range) a sex and age structured representation of the free-ranging population, with most of its genetic variability, destined for conservation programs. However, under captivity conditions with potential for high concentration of animals, direct contact and stress occur and the appearance, transmission, and severity of diseases could be favored. Therefore, it is necessary to establish health protocols in order to guarantee animal welfare. Spanish Animal Health laws establish specific requirements and preventive measures for controlling diseases in captive populations: sarcoptic mange, tuberculosis, brucellosis and bluetongue are notifiable diseases, and the staff of the reservoir must apply specific diagnostic methods to detect them. The management recommendations presented here may be very useful for other managers involved in the conservation of wild ruminants.  相似文献   

15.
Re-introductions are increasingly used conservation tools. Often, criteria for re-introducing species are based on policies or politics and little attention paid, albeit theoretical, to understanding what ecological possibilities habitats may have in sustaining introduced animals. Assessing potential carrying capacities is complex but easier for grazers, since biomass of these herbivores is empirically correlated with habitat primary productivity.The case is made here that the Barbary macaque, Macaca sylvanus, a vulnerable North African primate with a large surplus captive stock, can be viewed as a grazer. Because of this attribute, and unlike congenerics, it is possible to estimate potential densities in extant habitats in a fashion similar to predicting stocking levels for domestic herbivores. Thus, from values of consumable primary productivity for domestic stock in Mediterranean countries and the monkey's energy requirements, attainable macaque populations in studied habitats could be much higher than actual. Though these numbers may be unreachable in nature, this study shows that present macaque populations could increase after restorative management of habitats in which re-stocking with captive-born animals may play a part. However, since only 10% of potential monkey habitat in Morocco and Algeria is occupied by the species, finding areas for releasing captive-born macaques is more advisable.  相似文献   

16.
The endemic great Indian bustard (GIB) is evolutionarily trapped between open nesting and k-selection that endangers its persistence under prevailing levels of habitat loss and hunting. A global population of about 300 birds is further fragmented into eight populations in the states of Rajasthan (shared with Pakistan), Maharashtra, Andhra Pradesh, Gujarat, Karnataka, and Madhya Pradesh in India. The largest population of 100–125 birds exists in Jaisalmer, Barmer, and Bikaner districts of Rajasthan. Remaining populations number less than 35 birds each. Prevalent GIB conservation strategies use legislation to (a) secure traditional breeding areas by declaring small Protected Areas (PA) or (b) protect vast areas with varied human land uses. The vagrant nature of GIB reduces the benevolent effect of small PAs, while large reserves alienate people by curbing legitimate subsistence rights through strict legislation. These factors along with ill-informed habitat management challenge the current PA approach, even causing local extinctions. Population viability analysis shows that GIB populations of ≤35 birds can persist only under unrealistic conditions of first year mortality ≤40%, and no human caused mortality of adult birds. Even the largest population (≥100 birds) is sensitive to additional loss of adult birds to human causes. With current levels of hunting in Pakistan, extinction is a real threat. A landscape conservation strategy using conservation/community reserve concept that includes controlled traditional land uses with GIB-friendly infrastructural development is needed. The declining rate of GIB populations calls for immediate commencement of ex situ conservation breeding programs.  相似文献   

17.
In South Africa, the oribi, Ourebia ourebi is an endangered small antelope that requires conservation management and intervention to prevent their extinction. Use of translocation for the conservation of subpopulations facing local extinction in the wild has been proposed. In this study, fifteen oribi from threatened populations were captured and released (November 2004) on a private game reserve in KwaZulu-Natal, South Africa. Radio telemetry was used to monitor the dispersal and survival of translocated oribi. Only one death occurred during that period. All other released oribi survived, and most remained in close proximity of the release site for more than a year postrelease. Reproduction also occurred. This suggests that, translocation could be a viable option for conserving wild populations of oribi, assuming that other factors, such as availability of suitable grassland habitat and that poaching has been curtailed, are met.  相似文献   

18.

We applied spatial distribution and reserve selection modeling to identify critical habitat network for 50 critically endangered plant species of Uzbekistan. We created maps of relative habitat suitability, converted them into maps of species critical habitat, and the latter served as input to the spatial conservation prioritization program Zonation. Although all studied species were extremely rare, the extent of their predicted critical habitat ranged from 2.6 to 15,508 km2 and did not correlate with the number of occurrence records. It appears that the extent of the threatened species predicted suitable area is an indicator of whether the species rarity is inherent due to vary narrow ecological niche or caused solely by anthropogenic activity. This has important conservation implications. Imperiled species from the first category are less amenable (if at all) to such conservation actions as trans- or relocation (i.e. there is no alternative to protecting the last remaining populations). Species from the second group can potentially grow in many more locations than they currently occupy, and therefore, for these species, translocation can be the most appropriate strategy when their last remaining locations are degraded or can not be protected for whatever reason. Based on results of nature reserve design that utilized SDM-predicted maps for 50 imperiled species, we recommend adding new areas to the existing network of protected areas to cover critical habitats of highly threatened plant species. The highest priority for adding have the territories harboring critical habitat of disproportionally high number of imperiled species, and we found that they all are concentrated in the eastern part of Uzbekistan.

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19.
Land use change alters species' abundance and distributions by affecting habitat availability and quality. The decline of bird populations worldwide is of major concern, and habitat protection and restoration are primary conservation actions. However, conservation decisions largely consider only short-term habitat changes and species’ population dynamics in a given area. Disregarding long term modifications in species’ available habitat, and the role of a given population for a species’ global population may lead to misdirected conservation action. Our goal here was to combine the assessment of conservation responsibility, with that of century-long available habitat dynamics, in order to inform better conservation practice. We compiled available habitat data for 170 bird species in the Carpathian Region from 1860 to 2010 from historic maps and satellite data. We analyzed these species’ range distributions, IUCN extinction risk and population trends, and we identified 29 species of high conservation responsibility, and all of them were forest or and grassland specialists. Furthermore, we found major land use trends including cropland abandonment and increase in forests and grasslands that resulted in increases in potential habitat for the species for which the Carpathians have high conservation responsibility. The loss of row-crop agriculture, on the other hand, reduced habitat for species for which the Carpathians do not have high responsibility, and thus subsidizing agriculture may not be warranted from a conservation perspective. More broadly, many regions worldwide are undergoing rapid land use changes, and we suggest that these should be analyzed relative to a given regions’ conservation responsibility to see if there are opportunities for conservation, i.e., cases similar to the Carpathians, where conservation efforts ‘only’ have to foster current land use trends, and make them permanent, rather than to try to revert the loss of habitat.  相似文献   

20.
Few results of research aimed at solving questions arising from butterfly conservation are rigorously tested by manipulating populations and habitats in the field. Some factors common to successful conservation projects are analysed. In most non-migratory species, population density may vary by up to two orders of magnitude between sites or over time, and is primarily determined by the extent to which a subset of each species’ foodplant (or ant host) exists in the optimum growth-form or micro-habitat preferred by its larvae. Successful conservation projects have identified the optimum subset of each species’ larval resource before managing sites to increase its representation. In contrast, short-term fluctuations around a site’s carrying capacity or equilibrium level are mainly attributable to variation in weather, and are generally two orders of magnitude smaller than that attributable to larval habitat quality. There is little evidence that changing the abundance of adult resources, apart from shelter, influences population size or trends. The main constraint of the adult stage is the inability of many species to track the generation of new habitat patches that arise across modern landscapes. Within-patch larval habitat quality is again critical at the meta-population scale, explaining slightly more examples of patch occupancy than site isolation. This is because the higher density populations supported by optimum habitat are less likely to go extinct, and immigrants to new high-quality patches have a higher probability of founding new populations. Such patches may also generate up to a hundred times more emigrants per hectare than low-quality source patches.  相似文献   

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