世界的鹿

鹿是地球上一类经济价值较大的有蹄类动物,现在生存的鹿,已记录有44种,中国有17种,约占全球总种数的40%.随着动物分类学和分子生物学的发展,鹿的分类系统亦有很大的变化,如体形很小的鼷鹿(Tragulus spp.)、长脖子的长颈鹿(Giraffa sp.)、分泌麝香的麝(Moschus spp.)等都因其形态和进化特征皆已独立成科.现在,鹿科(Cervidae)下分4个亚科,即鹿亚科(Cervinae)17种,獐亚科(Hydropotinae)1种,麂亚科(Muntiacinae)8种及空齿鹿亚科(Odocoileinae)18种(参见表1).

用于太空舱外作业的机器人

在前一期中我们学习了中蹄类动物行走时的动画。不知大家感觉如何，这一期来学习爪类动物行走的动画。相对之前的两足动物动画而言四足动物动画稍微有点复杂，不过只要你持之以恒，相信不久你就会发现自己有了显著的进步。

Restoration Prospects for Heitutan Degraded Grassland in the Sanjiangyuan

In many ecosystems ungulates have coexisted with grasslands over long periods of time. However, high densities of grazing animals may change the floristic and structural characteristics of vegetation, reduce biodiversity, and increase soil erosion, potentially triggering abrupt and rapid changes in ecosystem condition. Alternate stable state theory provides a framework for understanding this type of dynamic. In the Sanjiangyuan atop the Qinghai-Tibetan plateau (QTP), grassland degradation has been accompanied by irruptions of native burrowing animals, which has accentuated the loss of ground cover. Severely degraded areas of alpine meadows are referred to as 'Heitutan'. Here, using the framework of alternate stable state theory, we describe the proximate and ultimate drivers of the formation of Heitutan on the QTP, and we assess prospects for recovery, in relation to the degree of biophysical alteration, of these alpine meadows. Effective rehabilitation measures must address the underlying causes of degradation rather than their symptoms. Heitutan degradation is not uni-causal. Rather it reflects different mechanisms operating at different spatio-temporal scales across this vast region. Underlying causes include overly aggressive exploitation of the grasslands (e.g. overgrazing), amplification of grazing and erosion damage by small mammals when outbreaks occur, and/or climate change. Given marked variability in environmental conditions and stressors, restorative efforts must vary across the region. Restoration efforts are likely toyield greatest success if moderately and severely degraded areas are targeted as the first priority in management programmes, before these areas are transformed into extreme Heitutan.

Ungulate Mortality due to Fencing and Perceptions of Pasture Fences in Part of the Future Qilianshan National Park

Fencing is an important part of husbandry for pastoral communities;however, these same fences can have unintended consequences for wildlife populations by restricting movement, reducing connectivity, and causing direct mortality. This paper assesses the current status and effects of fencing present in Yanchiwan National Nature Reserve, soon to be part of the recently proposed Qilianshan National Park. A questionnaire survey was conducted among 70 households to gauge local herders’ perceptions of fences, threats of fencing to native ungulates, and the number of wildlife found entangled in fencing. We found that local communities rely on fencing for livestock management and individuals who had encountered wildlife entangled in fences were more likely to perceive fences as having negative effects. Furthermore, those who perceived fencing as harmful to wildlife were more likely to support the dismantling of fences. On the other hand, families who needed to hire others to tend to their livestock were less likely to support dismantling efforts. However, the best model was only able to account for some of the data variability, suggesting that while perceptions of fences are important, other factors could be influencing support for fence dismantling. Hence, increasing awareness of threats alone may not be enough to generate community support of a fence dismantling program. Therefore, outreach and community collaboration to reduce the impacts of fence alterations upon livestock management will be necessary for a successful fence dismantling program within the new national park. Finally, those surveyed reported finding kiang, argali, and Tibetan gazelle dead in fences, with kiang found more often than the other two. This suggests that these three species may be more vulnerable to fence entanglement and that they are good targets for future studies and dismantling efforts.

Using the movement patterns of reintroduced animals to improve reintroduction success

Despite their importance to conservation, reintroductions are still a risky endeavor and tend to fail, highlighting the need for more efficient post-release monitoring techniques. Reintroduced animals are released into unfamiliar novel environ ments and must explore their surroundings to gain knowledge in order to survive. According to theory, knowledge gain should be followed by subsequent changes to the animal＇s movement behavior, making movement behavior an excellent indicator of reintroduction progress. We aim to conceptually describe a logical process that will enable the inclusion of behavior （in particular, movement behavior） in management decision-making post-reintroductions, and to do so, we provide four basic components that a manager should look for in the behaviors of released animals. The suggested components are release-site fidelity, recurring locations, proximity to other individuals, and individual variation in movement behavior. These components are by no means the only possible ones available to a manager, but they provide an efficient tool to understanding animals＇ decision-making based on ecological theory; namely, the exploration-exploitation trade-off that released animals go through, and which underlies their behavior. We demonstrate our conceptual approach using data from two ungulate species reintroduced in Israel： the Persian fallow deer Dama mesopotamica and the Arabian oryx Oryx leucoryx [Current Zoology 60 （4）： 515-526, 2014] .

Rut-induced changes in the activity budgets of male tropical ungulates： Eld＇s deer on Hainan Island

Aspects of time budgets, activity patterns and rut-related changes in behavior are well documented in temperate un-gulates; however, the application of this understanding to tropical and sub-tropical ungulate species has attracted less attention and remains an area that may re-shape our knowledge of ungulate behavior. Eld＇s deer Cervus eldi hainanus has a tropical and sub-tropical distribution on Hainan Island, China, and males have an extended rut exceeding five months during which they do not maintain harems or defend resources. We studied males from the only remaining population on Hainan Island, and describe rut-related changes in behavior by collecting data on time budgets and activity patterns. We show that male Eld＇s deer do not fol- low a strict crepuscular activity pattern, do not spend the majority of their time foraging and do not increase foraging nor display rut-induced hypophagia during rut, in obvious contrast to temperate ungulates. These results are discussed in light of current hy- potheses explaining the proximate mechanisms governing feeding time in ungulates, while appreciating the need for further re-search .

Distributional congruence of mammalian herbivores in the Trans-Himalayan Mountains

Large-scale distribution and diversity patterns of mammalian herbivores, especially less charismatic species in alpine environments remain little understood. We studied distributional congruence of mammalian herbivores in the Trans-Himalayan region of Ladakh to see if the distributions of less prominent and smaller herbivores can be determined from those of larger and more prominent herbivores like ungulates. Using a similarity index, we assessed shared distributions of species in 20x20 km2 grid-cells in an area of about 80,000 km2. We used the Unweighted Pair-Group Method with Arithmetic Average （UPGMA） to classify mammalian herbivores into groups with similar distributions. We then used the G-test of independence to look for statistical significance of the groups obtained. We identified six groups of mammalian herbivores with distributions more similar than ex- pected at random. The largest group was composed of nine species whereas the other large group comprised six species. Canonical Correspondence Analysis （CCA）, used to relate the groups with environmental features, showed that the largest group occurred in higher and flatter areas, while the other large group occurred in lower and steeper areas. Large herbivores like ungulates can be used as surrogate for less prominent small herbivores while identifying areas for latter＇s protection in the inaccessible mountainous re- gions of the Trans-Himalaya [Current Zoology 59 （1）： 116-124, 2013].

Response of Asiatic ibex(Capra sibirica) under Climate Change Scenarios

We investigated the effects of climate change on the distribution of the Asiatic ibex(Capra sibirica)in eastern Tajikistan.No existing climate change studies have been conducted on the habitat of a wild goat species in Asia.We conducted ecological niche modelling to compare potential present and future distributions of suitable environmental conditions for ibex.Projecting to 2070,18%(2689 km^2)of the current suitable areas would be lost,mostly located in the southeastern and northwestern regions of the study area.However,new suitable habitats could expand outside the current ibex range—about 30%(4595 km^2)expansion until 2070.We found that the elevation,terrain roughness,seasonal temperature,and precipitation of warmest quarter were the most important factors in the models and had strong correlations to ibex distribution.The losses in the southeastern portion overlapped most of the current locations of ibex in that region.These losses were observed in the much lower elevations of the study area(3500 m to 4000 m).When considering both loss and gain,the ibex could see a net expansion to new suitable habitats.About 30%(1379 km^2)of the average habitat gains for the Asiatic ibex in 2070 showed a shift to northern lower temperature habitats.Our results are beneficial in planning for the potential effects on biodiversity conservation in the eastern mountain region of Tajikistan under climate change scenarios.Special attention should be given to the ibex populations in the southeastern region,where habitats could become unsuitable for the species as a result of the climate-induced effects on the mountain ecosystem.

Sexual dimorphism across 3 stages of development in polygynous Artiodactyls is not affected by maternal care

In polygynous mammals, mature males are usually much heavier than females. Competition for females is intense, and few males reproduce. Given the importance of the male＇s body size for the reproduction and social life of these species, levels of sexual dimorphism were studied in 27 species of polygynous terrestrial cetartiodactyls at the 3 most significant stages of development： birth, 6 months of age, and adulthood. Overall, there were 3 different types of changes in male-to-female （M/F） mass ratios between birth and adulthood, corresponding to the 3 categories of adult dimorphism. The change in mass ratio between birth and 6 months of age was inversely correlated to the degree of dimorphism at birth. Most adult dimorphism was acquired after weaning. On the whole, postnatal maternal care seems to have no or even an inverse effect on the evolution of dimorphism, which is apparently not consistent with the assumption of greater maternal investment in male than in female offspring among polygynous mammals.