On the sexual dimorphism in the skull of the tiger (Panthera tigris)

Sexual dimorphism in the skull of the tiger (Panthera tigris) is reviewed and described in detail. The most significant diagnostic differences between the sexes are absolute length of the cranium, breadth of interorbital region and muzzle, zygomatic arch, and occipital region, length of upper carnassial, and the degree of the development of the cranial prominences. The degree of sexual dimorphism is closely related to geographic variation, and its form is rather complex.     

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.     

基于SwissPdbViewer和MATLAB对东北虎Sox蛋白三级结构建模及分析

SOX蛋白具有一个与DNA特异结合的高保守HMG-box结构域。为研究东北虎SOX蛋白三级结构的分子机理,利用MATLAB的Bioinformatics工具从GenBank中下载东北虎SOX蛋白序列信息,以三级结构已知的SOX2为模板,联合SwissPdbViewer与MATLAB,采用同源建模方法对SOX蛋白HMG-box进行建模、预测;利用MATLAB的Visualization Tool分析预测结果的三维结构。结果显示PtSox蛋白的HMG-box由3个α-螺旋和2个loop区构成;热稳定性分析表明PtSox蛋白loop区的热力学结构不稳定;表面静电分布显示出PtSox蛋白C-端的中间有一个可能与其它小分子或蛋白质的相互作用位点的N/C腔,上述空间结构可能与其活性与功能的调控有关。     

一具东北虎尸体同时制作剥制和完整骨骼标本的试验

制作大型哺乳动物的剥制标本和完整的骨骼标本,通常都各需要一完整的个体为材料.本试验是以一具东北虎尸体为材料,探索出用同一具东北虎尸体制作剥制和完整的骨骼标本各一具的方法.     

东北虎3个部位针毛表面超微结构的观察分析

应用扫描电镜技术对东北虎的头部、背部和尾部针毛的表面超微结构进行了观察和比较研究.结果表明,东北虎3个部位针毛均近似为纺锤形;3个部位针毛的3个典型节段之间在鳞片类型、鳞片排列方式、高度和密度差异及游离缘平滑度上均具有较高的相似性和一致性.3个不同部位针毛的近根部鳞片均为扁平型;主体部分鳞片均为杂波型;近梢部鳞片均为冠...     

Interbirth interval and litter size of free-ranging Bengal tiger (Panthera tigris tigris) in dry tropical deciduous forests of India

We studied the interbirth interval (IBI) and litter size of the population of free-ranging Bengal tigers (Panthera tigris tigris) in dry tropical deciduous forests in Ranthambhore Tiger Reserve (RTR), Rajasthan, and Pench Tiger Reserve (PTR), Madhya Pradesh, between April 2005 and June 2011. Data on 15 breeding females in RTR and nine breeding females in PTR were collected using camera trapping, direct observation and radio-telemetry. The mean?±?standard error of IBI (months) in RTR was 33.4?±?3.7 and in PTR was 25.2?±?1.8. A significant difference was observed between the mean IBI of tigresses in RTR and those in PTR (df?=?9, P?=?0.04). The estimated mean litter size in RTR was 2.3?±?0.1 and that in PTR was 2.9?±?0.2. There was a significant difference between the litter size in RTR and that in PTR (χ ²?=?12.04, P?=?0.017, df?=?4). Since RTR and PTR are the important source populations of tigers in the Western and Central Indian landscapes, we propose that the tigers in these reserves be monitored, particularly for reproductive traits that are essential for understanding aspects of their population ecology.     

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.     

Estimation of large herbivore densities in the tropical forests of southern India using distance sampling

Food habits of tigers Panthera tigris in terms of prey abundance were studied in the semi-arid deciduous forests of Ranthambhore National Park, western India, between November 2000 and April 2001. Wild prey availability was assessed by line transects ( n =8) and prey selection by the tigers was determined from analysis of scats ( n =109). Compared to some other parts of the country, prey abundance was found to be high at 96.65 animals km⁻². Chital Axis axis was the most abundant wild prey in the study area, followed by common langur Presbytis entellus , sambar Cervus unicolor , nilgai Boselaphus tragocamelus , wild pig Sus scrofa and chinkara Gazella bennetti. Chital ( c. 31%) and sambar ( c . 47%) constituted the bulk of the tigers' diet and were preferred prey. Nilgai and chinkara contributed minimally to the tigers' diet ( c . 5–7% and <1%, respectively) and were used less than their availability. Domestic livestock made up 10–12% of the tigers' diet. The average weight of an animal consumed was between 107 and 114 kg reflecting a preference for large prey. The analysis reveals that parts of Ranthambhore have high prey abundance, thus making it important for long-term tiger conservation. Despite the high prey abundance, tigers were still considerably dependent on domestic livestock, posing challenges for the park management to resolve potential areas of conflict.     

Use of oligonucleotide fingerprinting and faecal DNA in identifying the distribution of the Chinese tiger (Panthera tigris amoyensis Hilzheimer)

Chinese tiger (Panthera tigris amoyensis Hilzheimer) was once distributed in the Zhejiang Province, China, but there have not been any tiger sightings in this province since 1985. Fortunately, within the boundaries of the Fengyangshan-baishanzu State Natural Reserve, gamekeepers have found tiger footprints and tiger faeces many times since 1998. However, these tracks may have been left by the leopard or clouded leopard, which leave similar tracks. The presence of the Chinese tiger in Zhejiang Province was demonstrated using DNA fingerprinting and faecal DNA. The study not only revealed a new habitat for Chinese tigers, Zhejiang Province, but also provided an effective scatology method to identify the distribution of tigers and other wild felines.     

Long-term monitoring of a Bengal tiger (<Emphasis Type="Italic">Panthera tigris tigris</Emphasis>) population in a human-dominated landscape of Central India

Long-term monitoring of tiger population is essential in any human-dominated landscape as globally their population is showing a declining trend due to unrelenting stress or stochastic events. In view of that, Bengal tiger population was monitored in Pench Tiger Reserve (Pench), Madhya Pradesh of Central India between May 2006 and April 2013. The population, age-sex ratios, survival rate, growth rate, and recruitment pattern of adult (≥36 month), subadult (≥18 to 36 month), and cubs (≤15 month) were studied using camera trap and radio-telemetry techniques. Overall, tiger density ± SE/100 km² using Maximum Likelihood Spatial Explicit Capture Recapture method was 5.5 ± 1.6 in first trapping period or year and 3.7 ± 0.8 in last or seventh trapping year. The estimated survival rate of all tiger (n = 66) was 0.66 (±0.04), whereas mean annual growth rate (±SE) was 1.15 (±0.11) i.e. 15%. The sex ratio (male/female) found to be female biased and more than 80% of overall recruitment was contributed by female tiger. The dispersal of subadults in the tiger population contributed gradual fluctuation in survival rate and annual growth rate, as resident adult tiger population remained almost stable over the study period. As the overall tigers are surviving in a small population size and operating at carrying capacity, the important corridors connecting with neighboring population of Kanha Tiger Reserve and Satpura Tiger Reserve may ensure constant emigration and immigration to reduce the chances of genetic drift or inbreeding in the Pench tiger population.     

An unusual osteological formation in the posterior skulls of captive tigers (Panthera tigris)

Examination of pathologies in a series of felid skulls from a museum collection spanning the past century revealed distinctively malformed external occipital protuberances in zoo specimens of Panthera tigris, a condition that was not present in the skulls of wild-caught individuals. Myological studies and comparative dissections together support a conclusion that the condition most likely arose from heightened rotation of the head and neck in the lateral plane, combined with reduced jaw activities during the lives of the affected individuals. Historical records in turn indicate that such activities were possibly consequences of the nonnatural diets and increased grooming behaviors fostered in captive environments. Zoo Biol 17:135–142, 1998. © 1998 Wiley-Liss, Inc.