Zejun Zhang

Molecular censusing doubles giant panda population estimate in a key nature reserve

The giant panda (Ailuropoda melanoleuca), a flagship species for conservation, once inhabited most of China and its neighboring countries in Southeast Asia. Nowadays, giant pandas are confined to fragmented mountain habitats in Western China because of ecological and anthropogenic pressure 1 and 2. In order to establish effective conservation strategies, it is critical to know the number and distribution of giant pandas in the wild. However, accurately censusing panda populations remains problematic, because individuals are elusive, wary and very difficult to observe in their complex habitat. Previously, a number of indirect censusing methods have been used 1, 2 and 3 D. Lindburg and K. Baragona, Giant Pandas: Biology and Conservation, University of California Press, London (2004).3. These methods were essentially based on transect lines and proved poor at identifying individuals, resulting in a questionable precision of estimates. Considering the keen interest of the conservation community and the millions of dollars already spent on three major national surveys, it is important to find an accurate method for censusing giant pandas. Recently, microsatellite analysis using fecal DNA has proven effective in estimating population size of elusive animals 4 and 5. Large numbers of fecal samples can be easily obtained from giant panda habitat without disturbance due to its diet and high deposition rates [2]. Here, we conducted for the first time an exhaustive non-invasive genetic survey of giant pandas in a key reserve and found that the molecular census was double that previously estimated.

Obligate herbivory in an ancestrally carnivorous lineage: the giant panda and bamboo from the perspective of nutritional geometry

Summary Herbivores face various nutritional challenges in their life cycles, challenges that may become increasingly acute under ongoing environmental changes. Here, focusing on calcium, phosphorus and nitrogen, we used nutritional geometry to analyse individual-based data on foraging and extraction efficiencies, and combined these with data on reproduction and migratory behaviour to understand how a large herbivorous carnivore can complete its life cycle on a narrow and seemingly low quality bamboo diet. Behavioural results showed that pandas during the year switched between four main food categories involving the leaves and shoots of two bamboo species available. Nutritional analysis suggests that these diet shifts are related to the concentrations and balances of calcium, phosphorus and nitrogen. Notably, successive shifts in range use and food type corresponded with a transition to higher concentrations and/or a more balanced intake of these multiple key constituents. Our study suggests that pandas obligatorily synchronize their seasonal migration and reproduction with the disjunct nutritional phenologies of two bamboo species. This finding has potentially important implications for habitat conservation for this species and, more generally, draws attention to the need for understanding the nutritional basis of food selection in devising management plans for endangered species.

Old-growth forest is what giant pandas really need

Giant pandas (Ailuropoda melanoleuca) are an iconic conservation species, but despite significant research effort, do we understand what they really need? Estimating and mapping suitable habitat play a critical role in conservation planning and policy. But if assumptions about ecological needs are wrong, maps with misidentified suitable habitat will misguide conservation action. Here, we use an information-theoretic approach to analyse the largest, landscape-level dataset on panda habitat use to date, and challenge the prevailing wisdom about panda habitat needs. We show that pandas are associated with old-growth forest more than with any ecological variable other than bamboo. Other factors traditionally used in panda habitat models, such as topographic slope, are less important. We suggest that our findings are disparate from previous research in part because our research was conducted over a larger ecological scale than previous research conducted over more circumscribed areas within individual reserves. Thus, extrapolating from habitat studies on small scales to conservation planning on large scales may entail some risk. As the Chinese government is considering the renewal of its logging ban, it should take heed of the pandas dependency on old growth.

Winter microhabitat separation between giant and red pandas in Bashania faberi bamboo forest in fengtongzhai nature reserve

Abstract We studied microhabitat use of the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) from November 2002 to March 2003 at Fengtongzhai Nature Reserve, Baoxing County of Sichuan Province, China, where the 2 species are sympatric. The means of discriminant scores between the 2 species differed, suggesting each had a distinct microhabitat selection pattern, consistent with 1-way ANOVA and Kruskal-Wallis tests. We found that 6 of 19 microhabitat variables differed significantly between these species. Four variables were associated with preferences of the giant panda and 2 from preferences of the red panda. We suggest that environmental factors (slope, fallen log, etc.) other than food availability were primarily responsible for microhabitat separation between the 2 pandas. We hypothesize that the pattern of microhabitat separation did not result from ecological or evolutionary adjustment to reduce interspecific competition but from differences in physiological and ecological requirements. With abundant food resources, slope appeared to be a more important microhabitat feature to the giant panda than any single food factor. The presence of fallen logs and tree stumps was similarly an important microhabitat feature selected by red pandas.

Ecological scale and seasonal heterogeneity in the spatial behaviors of giant pandas

We report on the first study to track the spatial behaviors of wild giant pandas (Ailuropoda melanoleuca) using high-resolution global positioning system (GPS) telemetry. Between 2008 and 2009, 4 pandas (2 male and 2 female) were tracked in Foping Reserve, China for an average of 305 days (± 54.8 SE). Panda home ranges were larger than those of previous very high frequency tracking studies, with a bimodal distribution of space-use and distinct winter and summer centers of activity. Home range sizes were larger in winter than in summer, although there was considerable individual variability. All tracked pandas exhibited individualistic, unoriented and multiphasic movement paths, with a high level of tortuosity within seasonal core habitats and directed, linear, large-scale movements between habitats. Pandas moved from low elevation winter habitats to high elevation (>2000 m) summer habitats in May, when temperatures averaged 17.5 °C (± 0.3 SE), and these large-scale movements took <1 month to complete. The peak in panda mean elevation occurred in Jul, after which they began slow, large-scale movements back to winter habitats that were completed in Nov. An adult female panda made 2 longdistance movements during the mating season. Pandas remain close to rivers and streams during winter, possibly reflecting the elevated water requirements to digest their high-fiber food. Panda movement path tortuosity and first-passage-time as a function of spatial scale indicated a mean peak in habitat search effort and patch use of approximately 700 m. Despite a high degree of spatial overlap between panda home ranges, particularly in winter, we detected neither avoidance nor attraction behavior between conspecifics.

Giant panda conservation science: how far we have come

The giant panda is a conservation icon, but science has been slow to take up its cause in earnest. In the past decade, researchers have been making up for lost time, as reflected in the flurry of activity reported at the symposium Conservation Science for Giant Pandas and Their Habitat at the 2009 International Congress for Conservation Biology (ICCB) in Beijing. In reports addressing topics ranging from spatial ecology to molecular censusing, from habitat recovery in newly established reserves to earthquake-induced habitat loss, from new insights into factors limiting carrying capacity to the uncertain effects of climate change, this symposium displayed the vibrant and blossoming application of science to giant panda conservation. Collectively, we find that we have come a long way, but we also reach an all-too-familiar conclusion: the more we know, the more challenges are revealed. While many earlier findings are supported, many of our assumptions are debatable. Here we discuss recent advancements in conservation science for giant pandas and suggest that the way forward is more direct application of emerging science to management and policy.

Giant panda scent-marking strategies in the wild: role of season, sex and marking surface

Scent marking entails significant energetic and opportunity costs that demand efficiency. Signal detection theory offers a theoretical framework that generates testable hypotheses regarding where animals should place scent signals in the environment in a way that maximizes their probability of detection by target receivers while minimizing costs of production and distribution. Solitary and reliant on chemical communication, the giant panda, Ailuropoda melanoleuca, offers an interesting model to test these ideas. We studied scent-marking patterns in wild giant pandas in the Foping Nature Reserve by surveying areas containing a high density of scent posts. Pandas did not deploy scent marks randomly in this environment, but targeted trees with specific characteristics that promoted signal persistence, range and/or likelihood of detection. Variables affecting selection of scent-marking sites included bark roughnesss, presence of moss on the tree trunk, tree diameter and distance to the trail. That pandas should be efficient with their use of chemosignals comes as no surprise, as mounting evidence is suggesting that many aspects of giant panda life history are constrained by their energetically poor diet. We also found seasonal and sex differences in marking patterns, indicating a role for scent marking in reproduction and competition. Males scent-marked throughout the year, whereas females scent-marked predominantly during the mating season, suggesting functional differences in scent marking between the sexes.

Giant Pandas Are Not an Evolutionary cul-de-sac: Evidence from Multidisciplinary Research

The giant panda (Ailuropoda melanoleuca) is one of the worlds most endangered mammals and remains threatened by environmental and anthropogenic pressure. It is commonly argued that giant pandas are an evolutionary cul-de-sac because of their specialized bamboo diet, phylogenetic changes in body size, small population, low genetic diversity, and low reproductive rate. This notion is incorrect, arose from a poor understanding or appreciation of giant panda biology, and is in need of correction. In this review, we summarize research across morphology, ecology, and genetics to dispel the idea, once and for all, that giant pandas are evolutionary dead-end. The latest and most advanced research shows that giant pandas are successful animals highly adapted to a specialized bamboo diet via morphological, ecological, and genetic adaptations and coadaptation of gut microbiota. We also debunk misconceptions around population size, population growth rate, and genetic variation. During their evolutionary history spanning 8 My, giant pandas have survived diet specialization, massive bamboo flowering and die off, and rapid climate oscillations. Now, they are suffering from enormous human interference. Fortunately, continued conservation effort is greatly reducing impacts from anthropogenic interference and allowing giant panda populations and habitat to recover. Previous ideas of a giant panda evolutionary cul-de-sac resulted from an unsystematic and unsophisticated understanding of their biology and it is time to shed this baggage and focus on the survival and maintenance of this high-profile species.

Factors Predicting Den Use by Maternal Giant Pandas

Abstract We studied the denning ecology of giant pandas (Ailuropoda melanoleuca) in the Foping Nature Reserve, China. We identified 17 used and 21 unused cavities of appropriate size to accommodate denning and measured several variables potentially affecting the suitability of these cavities for panda denning. Principal component analysis, combined with traditional univariate tests, indicated that maternal females preferred deeper cavities with a high interior-to-entrance ratio for height and width, suggesting a preference for narrow entrances and roomy chambers. Microhabitat features, including slope and distance to water, were also useful in predicting den use by maternal females. We believe that the availability of suitable dens may limit population size, especially in areas where tree dens have been eliminated by logging of old growth forests. Conservation managers in giant panda reserves can use our data to determine the number of suitable panda dens that are in an area, estimate whether there are enough for the adult female population to use as birthing dens, and—if needed—construct suitable artificial dens to increase the rate of reproduction.

Can science save the giant panda (Ailuropoda melanoleuca)? Unifying science and policy in an adaptive management paradigm

The giant panda (Ailuropoda melanoleuca David, 1869) is an iconic species for global conservation, yet field research has only recently advanced to the point where adaptive management is possible. Here, we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation forward. Because of scientific, funding, political, and logistical hurdles, few endangered species management programs have embraced adaptive management, wherein management decisions are shaped iteratively by targeted scientific research. Specific threats, such as habitat destruction, anthropogenic disturbance and fragmented nonviable populations, need to be addressed simultaneously by researchers, managers and policy-makers working in concert to understand and overcome these obstacles to species recovery. With the backing of the Chinese Government and the conservation community, the giant panda can become a high-profile test species for this much touted, but rarely implemented, approach to conservation management.