亚洲虎种群恢复的机遇与挑战

虎(Panthera tigris)作为顶级捕食者, 对维持森林生态系统服务和结构完整性有着重要作用, 是研究和保护工作的旗舰物种。历史上, 虎曾广泛分布于亚洲大部分地区, 如今仅分布于南亚、东南亚和东北亚的破碎化栖息地, 各区域种群处于濒危或极度濒危状态。准确了解野生虎的种群状态和生态需求信息对于科学开展保护和恢复工作至关重要。本文通过综述近几十年的研究文献, 总结了野生虎种群现状和主要威胁因素, 评价了已有研究的重点与不足, 为未来亚洲虎种群的研究和保护提出了建议。目前与虎相关的研究主要集中在分布范围最广的孟加拉虎(P. t. tigris)和东北虎(P. t. altaica) 2个亚种, 而最急需关注的其他亚种仍研究不足。经过近十几年的努力和保护投入, 目前野生虎种群数量已从2010年的大约3,200只恢复到现在约4,500只, 但在越南、柬埔寨和老挝3个国家已经灭绝。虎面临的主要威胁包括持续的栖息地破坏和隔离、猎物缺乏、近交衰退、人虎冲突、贸易与盗猎和疾病威胁等。未来的研究和保护工作需要加强种群和栖息地连通性恢复、个体重引入、疾病管控以及加强跨境合作和反盗猎等。     

西藏墨脱格当乡野生虎捕食家畜现状与保护建议

曾经在西藏东南的阔叶林中广泛分布的孟加拉虎,目前仅有一个小种群残留在墨脱县境内。2000年5－6月间,在大型家畜遭受野生虎捕食最严重的墨脱县格当乡展开调查,试图寻找减轻虎害的方法。结果表明：1994－1995年虎的捕食率达到最高,对牛和骡马的捕食率分别是17．9％和9．4％;但1996年后,捕食率分别降低到7．8％和1．8％,这可能与1996年当地曾捕杀过一头虎有关。1993－1999年间,全乡牛的数量下降了11％,但骡马数量上升了23％,这是因为当地为增加运输能力而从别处购得骡马。据反映,目前格当乡境内大约有4－5头虎。1997年和1999年,均见母虎和小虎同行,说明该种群尚有繁殖。在抽样的21户居民家中,1999年4月到2000年5月间,66．6％的人家有大型牲畜遭虎捕杀,共损失牛27头,马12匹,而自1993年以来,21户中共有18户（85．8％）,有牲畜被杀记录,共计损失117头。其中对牛的捕食率达19．7％,对马达11．9％,平均每户损失牛1．2头,骡马0．5匹。非法狩猎减少了虎的猎物如野猪、羚牛等的数量,是老虎转向家畜的主要原因之一。虎害已对格当乡群众的经济造成较大负面影响。但格当乡以及周边地区保护着中国最后的野生孟加拉虎种群,为确保虎的长期生存同时减少人－虎冲突,建议改变目前放牧方式,尽可能联合放牧、增加看护;改善放牧地条件,清除牧场周围蕨草丛;减少对羚牛等有蹄类的猎杀,以减少对老虎猎物种群的破坏;对部分家畜移入棚内试行圈养,既保护家畜,又提高乳制品产量和增加农家肥料;实行多种经营方法,建议养一些山羊和家禽;政府应该帮助安置好部分愿意外迁的居民,这样既满足这些居民的需要,同时也减轻对当地野生动物种群的压力。     

西藏南迦巴瓦峰地区孟加拉虎的初步研究

１９９４年５～６月、９～１０月及１９９５年６～１２月,作者对西藏东南部南迦巴瓦峰和邻近地区的孟加拉虎的分布及生态进行了野外调查,初步弄清了该地区虎的现状。通过在墨脱县格当乡的抽样调查及跟踪观察虎的移动和觅食,查明了金珠藏布江流域内近两年有关虎捕食大型牲畜的报告属实。１９９３年１０月至１９９５年７月,该河谷内因虎捕食共损失牛、马和骡３０２头,估计活体总重量约５９８８１ｋｇ,平均月损失２７２２ｋｇ,相当于自然状态下１１头虎的月进食量。全乡１２个村的牲畜均受到不同程度的影响,受损的户数占该乡总户数的６２％,户牲畜损失率为７．７％～１００％不等。对其它动物的调查表明,虎大量捕食牲畜与低海拔河谷的开发和环境中虎的自然食物缺乏有关     

红外相机技术在陕西观音山自然保护区兽类监测研究中的应用

国外使用红外相机技术开展野生动物调查研究已有较长的历史,最早的报道见于Champion(1927),在20世纪90年代逐渐发展成熟,广泛用于动物种群数量和密度的研究.如应用红外相机和种群捕获模型(Capture-recapture)对印度Nagarahole国家公园的孟加拉虎(Panthera tigris)的种群数量和密度的研究(Karanth,1995;Karanth和Nichols;1998),验证了红外相机技术与种群捕获模型的结合在孟加拉虎种群预测方面的优势,有效解决了监测中孟加拉虎数量稀少、活动隐秘等问题.     

西藏东南部金珠藏布流域虎的数量和分布现状

采用Ｆ检验和ｔ检验的方法,对西藏东南部金珠藏布流域野外收集的孟加拉虎足迹数据进行数理统计,统计结果得到虎的６个个体样本,结合在当地的大量访查工作,确证了该流域至少有５只虎的分布。另外嘎隆藏布流域发现１只虎的踪迹。金珠藏布流域虎的活动小区有一定重叠,说明它们可能存在一定的亲缘关系。对金珠藏布流域及邻近地区虎的活动情况也进行了调查,调查结果表明虎的分布和数量自７０年代以来呈减少趋势。     

卡西裸趾虎一新亚种记述

裸趾虎属分布于亚洲热带地区.卡西裸趾虎分布于印度、缅甸和中国西藏的墨脱县.通过对采自西藏察隅县的标本分析和比较,认为其是卡西裸趾虎Crytodactylus khasiensis的1个新亚种,命名为卡西裸趾虎察隅亚种Crytodactylus khasiensis cayuensis.新亚种具卡西裸趾虎的基本特征,但新亚种与卡西裸趾虎指名亚种Crytodactylus k.khasiensis、缅甸亚种Crytodactylus k.tamaiensis区别明显,不同在于:1)上唇鳞9～12枚,下唇鳞8～11枚;2)体中部腹面横列鳞28～34枚;3)雄性具肛前孔6～9个.仅分布于西藏察隅县下察隅镇.     

基于东北虎潜在栖息地保护的自然保护地整合

东北虎(Panthera tigris altaica)是我国国家一级重点保护野生动物,现主要分布在张广才岭、老爷岭和完达山等地的几个自然保护区内。在这些自然保护区周边还分布有大量的森林公园、风景名胜区、湿地公园等不同类型的自然保护地,这些自然保护地在一定程度上也可为东北虎提供栖息场所,但管理目标、管理体制等原因造成了人为的范围隔离、空间重叠等各种乱象。为响应我国建立以国家公园为主体的自然保护地体系,为东北虎豹国家公园建设提供支撑,本文基于44个东北虎分布点信息和11个相关环境因子,利用MaxEnt模型对东北虎的潜在栖息地进行了预测。基于东北虎栖息地范围内的国家级自然保护区、国家森林公园,国家湿地公园等自然保护地与东北虎栖息地的适宜性等级分布格局,利用成本距离法对东北虎栖息地范围内的自然保护地进行了整合研究。结果发现:(1)东北虎在我国的潜在适宜分布区主要集中在穆棱市、珲春市、敦化市、宁安市、延吉市、海林市、东宁县、汪清县、饶河县、宝清县,共约10000 km2,占黑龙江、吉林二省总面积的1.5%;(2)东北虎潜在扩散区共约51000 km2,占黑龙江、吉林二省总面积的8%;(3)以成本距离图中等值线值为0.5作为边界,将30个自然保护区及周边47个其他类型的自然保护地划分为9个自然保护地群,总面积为77818.7 km2,以供未来东北虎的保护和自然保护地整合中参考。     

基于东北虎潜在栖息地保护的自然保护地整合

东北虎(Panthera tigris altaica)是我国国家一级重点保护野生动物,现主要分布在张广才岭、老爷岭和完达山等地的几个自然保护区内。在这些自然保护区周边还分布有大量的森林公园、风景名胜区、湿地公园等不同类型的自然保护地,这些自然保护地在一定程度上也可为东北虎提供栖息场所,但管理目标、管理体制等原因造成了人为的范围隔离、空间重叠等各种乱象。为响应我国建立以国家公园为主体的自然保护地体系,为东北虎豹国家公园建设提供支撑,本文基于44个东北虎分布点信息和11个相关环境因子,利用MaxEnt模型对东北虎的潜在栖息地进行了预测。基于东北虎栖息地范围内的国家级自然保护区、国家森林公园,国家湿地公园等自然保护地与东北虎栖息地的适宜性等级分布格局,利用成本距离法对东北虎栖息地范围内的自然保护地进行了整合研究。结果发现:(1)东北虎在我国的潜在适宜分布区主要集中在穆棱市、珲春市、敦化市、宁安市、延吉市、海林市、东宁县、汪清县、饶河县、宝清县,共约10000 km2,占黑龙江、吉林二省总面积的1.5%;(2)东北虎潜在扩散区共约51000 km2,占黑龙江、吉林二省总面积的8%;(3)以成本距离图中等值线值为0.5作为边界,将30个自然保护区及周边47个其他类型的自然保护地划分为9个自然保护地群,总面积为77818. 7 km2,以供未来东北虎的保护和自然保护地整合中参考。     

墨脱弯脚虎繁殖一例报道

正墨脱弯脚虎(Cyrtopodion medogensis)隶属壁虎科(Gekkonidae)弯脚虎属,为中国特有种(赵尔宓等1999)。目前已知该种分布于西藏林芝地区墨脱县、林芝县、工布江达县、米林县及朗县东部。墨脱弯脚虎夜间活动,白天藏匿于石下,属夜行性动物。截至目前,有关墨脱弯脚虎的生物学资料极少,有关繁殖生物学方面的数据缺失(赵尔宓等1987,1999,李丕鹏等2010)。2015年5月30日在西藏林芝地区林芝县八一镇(29°36′14.72″N,94°24′35.17″E,海拔2 970 m)采得墨脱弯脚虎数尾,解剖其中2只雌性个体,腹内分别有卵1枚和2枚。2015年8月29日,在米林县卧龙镇(29°8′17.2″N,     

变化环境下的生物多样性保护——第四届“一个星球”峰会述评

2021年1月11日,由联合国、世界银行和法国共同发起的第四届“一个星球”峰会通过线上线下相结合的方式在巴黎举行,本次峰会主题为生物多样性保护。峰会针对4个议题展开,分别是：(1)保护陆地和海洋生态系统;(2)促进生态农业;(3)生物多样性与资金筹措;(4)保护人类健康、物种和热带森林。对变化背景下的生物多样性保护主要有以下几个方面的启示：(1)识别优先保护区域,提高保护区有效性;(2)开展变化背景下的生态修复规划,提高自然-社会生态系统抗风险能力;(3)加强模型预测与情景分析,发展生物多样性与生态系统服务集成模型;(4)发展基于自然的解决方案,可持续利用自然资源;(5)加强后疫情时代国际间交流合作,开展生物多样性保护资金筹措工作。     

MHC class I and MHC class II DRB gene variability in wild and captive Bengal tigers (Panthera tigris tigris)

Bengal tigers are highly endangered and knowledge on adaptive genetic variation can be essential for efficient conservation and management. Here we present the first assessment of allelic variation in major histocompatibility complex (MHC) class I and MHC class II DRB genes for wild and captive tigers from India. We amplified, cloned, and sequenced alpha-1 and alpha-2 domain of MHC class I and beta-1 domain of MHC class II DRB genes in 16 tiger specimens of different geographic origin. We detected high variability in peptide-binding sites, presumably resulting from positive selection. Tigers exhibit a low number of MHC DRB alleles, similar to other endangered big cats. Our initial assessment—admittedly with limited geographic coverage and sample size—did not reveal significant differences between captive and wild tigers with regard to MHC variability. In addition, we successfully amplified MHC DRB alleles from scat samples. Our characterization of tiger MHC alleles forms a basis for further in-depth analyses of MHC variability in this illustrative threatened mammal.     

华南虎、东北虎、孟加拉虎的D-100p和ND5序列及其在系统进化分析中的应用

本文采用PCR和质粒克隆测序方法,获得了华南虎线粒体D-loop区的480bp序列和东北虎、孟加拉虎线粒体D-loop区的503bp序列;同时还获得了这三个虎亚种和金钱豹线粒体ND5基因5’端309bp的部分序列。根据D-loop序列分析,华南虎与孟加拉虎、东北虎的平均距离(p-distance)分别为0．11088和O．11087,而东北虎与孟加拉虎间的平均距离为0．00994;根据ND5序列分析,华南虎与孟加拉虎、东北虎的平均距离分别为0．11434和0．11758,而东北虎与孟加拉虎间的平均距离为0．00324。三个虎亚种的mtDNA D-loop和ND5序列比较表明,华南虎是这三个虎亚种中最为古老的亚种。     

Noninvasive genetic monitoring of tiger (Panthera tigris tigris) population of Orang National Park in the Brahmaputra floodplain, Assam, India

The Brahmaputra Valley of Assam, India, is one of the prime habitats for the endangered Royal Bengal tiger Panthera tigris tigris. With dwindling global population, estimation of the minimum number of tigers has always been a curiosity to wildlife researchers as well as to protected area managers. In the present study, DNA-based techniques were used for identifying individual tigers present in Orang National Park of Assam, from 57 faecal samples collected during February 2009. Orang National Park stands as an island of a single forest patch along the north bank of river Brahmaputra. The present study confirms the presence of 17 individual tigers in Orang National Park, with five male and 12 female. DNA-based capture–recapture analysis yielded minimum range estimate of 18 and 19 individuals, with possible overestimates of population size following two models of capture probability in CAPWIRE. The results of our genetic counting of tigers are compared with the estimates of 19 tigers based on pugmark analysis by the state Forest Department in 2000 and an independent capture–recapture estimate of 14 (±3.6) individuals based on photographic identity study in 2009. Looking at high mortality of tigers in the area, with 19 reported deaths during 2000 to 2009, our results indicate high individual turnover in the area. This study shows that Orang National Park harbours a healthy breeding population of tigers. However, the possibility of a source-sink dynamics operating in the landscape could not be ruled out, with possible immigration from nearby Kaziranga National Park on the south bank of Brahmaputra, which has the highest reported density of the species in the world.     

Living on the Edge: Attitudes of Rural Communities toward Bengal Tigers (Panthera tigris) in Central India

To date, most studies of the Bengal tiger (Panthera tigris) are of biological research, techniques, conservation, population modeling, or tiger– human conflicts. Few studies have attempted to understand the rural population that share a region with the tigers, and some of the villages are even displaced in the name of conservation. Hence, we undertook a survey of 10 villages that are located in the buffer zone of the Bor Tiger Reserve (BTR). Most of the villagers interviewed had encountered tigers, most considered them a boon and beneficial to their livelihood, and almost all displayed environmental awareness and stressed the necessity to conserve tigers in order to ensure their own continued survival. Some stressed the religious connotation and significance because the tiger is the animal of transport of the Goddess Durga. A minority expressed a negative attitude that resulted not from damages incurred by the tigers, but from discontent following inept handling of property losses by the authorities, who did not provide compensation in time, or paid only a small part of the original value of the loss. We conclude that in order to ensure the continued goodwill of the local stakeholders, it is important that the state and national governments react in a timely manner and ensure that the farmer is compensated in full. Support of the villagers who cohabit with tigers will ensure the continued survival of the two entities.     

华南虎现状及谱系分析

华南虎目前处于极危状态。野生个体已极为少见,只有中国一些动物园内饲养着 53只。按其亲缘关系分为上海系和贵阳系,上海系的华南虎携带优秀的多子基因,但其子代的生活力不强;而贵阳系的虎虽然产子率不高,但子代的生活力很强,现存的6只贵阳系华南虎具有极高的基因保存与基因研究价值,应建立基因库。这些虎分散饲养于22个单位,大大降低了适龄虎的交配繁殖机会,浪费了本已有限的珍贵资源,是抑制其种群发展的最主要因素。目前其种群的年龄结构非常合理,育龄虎占种群的62.3％,幼龄虎为28.3％,高龄虎很少,仅为9.4％,今后种群的发展乐观。     

Prey selection by the Indian tiger (Panthera tigris tigris) in Nagarjunasagar Srisailam Tiger Reserve, India

Very little is known about prey selection by the Indian tiger Panthera tigris tigris in tropical dry deciduous forests or in wild herbivore-depleted habitats with high livestock pressures. We undertook a short-term study in a large south Indian tiger reserve and examined two intensive study areas (SA's) from October 1998 – June 1999. In each area, herbivore sightings were recorded, scats were collected, and wild prey and livestock kills documented. Chital, wild boar and sambar were the most abundant among the wild herbivores in the study area. Scat analysis revealed wild boar (Sus scrofa) being the most common prey followed by chital (Axis axis) and sambar (Rusa unicolor). Livestock comprised less than 7% of diet intake. Here, the tigers consumed a lower mean prey mass (56.3 kg) than in other reserves. Our study suggests that in tropical dry deciduous forests with low natural prey density, smaller prey species, and high livestock biomass, tigers preferentially kill smaller prey and generally avoid livestock predation.     

Philopatry and Dispersal Patterns in Tiger (Panthera tigris)

Background

Tiger populations are dwindling rapidly making it increasingly difficult to study their dispersal and mating behaviour in the wild, more so tiger being a secretive and solitary carnivore.

Methods

We used non-invasively obtained genetic data to establish the presence of 28 tigers, 22 females and 6 males, within the core area of Pench tiger reserve, Madhya Pradesh. This data was evaluated along with spatial autocorrelation and relatedness analyses to understand patterns of dispersal and philopatry in tigers within this well-managed and healthy tiger habitat in India.

Results

We established male-biased dispersal and female philopatry in tigers and reiterated this finding with multiple analyses. Females show positive correlation up to 7 kms (which corresponds to an area of approximately 160 km²) however this correlation is significantly positive only upto 4 kms, or 50 km² (r  = 0.129, p<0.0125). Males do not exhibit any significant correlation in any of the distance classes within the forest (upto 300 km²). We also show evidence of female dispersal upto 26 kms in this landscape.

Conclusions

Animal movements are important for fitness, reproductive success, genetic diversity and gene exchange among populations. In light of the current endangered status of tigers in the world, this study will help us understand tiger behavior and movement. Our findings also have important implications for better management of habitats and interconnecting corridors to save this charismatic species.     

Connectivity of Tiger (Panthera tigris) Populations in the Human-Influenced Forest Mosaic of Central India

Today, most wild tigers live in small, isolated Protected Areas within human dominated landscapes in the Indian subcontinent. Future survival of tigers depends on increasing local population size, as well as maintaining connectivity between populations. While significant conservation effort has been invested in increasing tiger population size, few initiatives have focused on landscape-level connectivity and on understanding the effect different landscape elements have on maintaining connectivity. We combined individual-based genetic and landscape ecology approaches to address this issue in six protected areas with varying tiger densities and separation in the Central Indian tiger landscape. We non-invasively sampled 55 tigers from different protected areas within this landscape. Maximum-likelihood and Bayesian genetic assignment tests indicate long-range tiger dispersal (on the order of 650 km) between protected areas. Further geo-spatial analyses revealed that tiger connectivity was affected by landscape elements such as human settlements, road density and host-population tiger density, but not by distance between populations. Our results elucidate the importance of landscape and habitat viability outside and between protected areas and provide a quantitative approach to test functionality of tiger corridors. We suggest future management strategies aim to minimize urban expansion between protected areas to maximize tiger connectivity. Achieving this goal in the context of ongoing urbanization and need to sustain current economic growth exerts enormous pressure on the remaining tiger habitats and emerges as a big challenge to conserve wild tigers in the Indian subcontinent.     

Genotyping faecal samples of Bengal tiger <Emphasis Type="Italic">Panthera tigris tigris</Emphasis> for population estimation: A pilot study

Background

Bengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective for designing conservation measures and for evaluating those that are already in place. Due to the tiger's cryptic and secretive behaviour, it is not possible to enumerate and monitor its populations through direct observations; instead indirect methods have always been used for studying tigers in the wild. DNA methods based on non-invasive sampling have not been attempted so far for tiger population studies in India. We describe here a pilot study using DNA extracted from faecal samples of tigers for the purpose of population estimation.

Results

In this study, PCR primers were developed based on tiger-specific variations in the mitochondrial cytochrome b for reliably identifying tiger faecal samples from those of sympatric carnivores. Microsatellite markers were developed for the identification of individual tigers with a sibling Probability of Identity of 0.005 that can distinguish even closely related individuals with 99.9% certainty. The effectiveness of using field-collected tiger faecal samples for DNA analysis was evaluated by sampling, identification and subsequently genotyping samples from two protected areas in southern India.

Conclusion

Our results demonstrate the feasibility of using tiger faecal matter as a potential source of DNA for population estimation of tigers in protected areas in India in addition to the methods currently in use.

     

Activity of the hypothalamo-pituitary-adrenals axis in the Siberian tiger (<Emphasis Type="Italic">Panthera tigris altaica</Emphasis>) in captivity and in the wild,and its dynamics throughout the year

A noninvasive evaluation method of hypothalamo-pituitary-adrenals axis (HPA) activity in the Siberian tiger was verified. Comparison of the activity level of HPA in Siberian tigers in the wild and in captivity, and their alterations over the year was carried out. Significant seasonal differences between activity levels of HPA in tigers in captivity were not found. In the wild, this level was significantly higher, reaching the maximum from November to January, which can be related with an unfavorable influence on tigers in low temperatures and deep snow cover.