Zhi-Gao Zeng

Lack of mtDNA control region variation in Hainan Eld's deer: Consequence of a recent population bottleneck?

We find no genetic variation at 550bp ofmtDNA control region among 55 Hainan Elds deerin an island population that has sufferedrecent population contractions. Congenericspecies show high levels of variation at thislocus. We use a simulation approach to test thelikelihood of various bottleneck scenarios, andshow, in the context of what is known about therecent demographic history of this population,that there are credible scenarios for abottleneck driven by hunting pressure in the1960s that could account for the lack ofvariation at this locus.

Eld's Deer Translocated to Human-Inhabited Areas Become Nocturnal

As human populations expand and nonhuman animals decline, understanding the interactions between people and wildlife is essential. For endangered species, appreciating the effect of human disturbance can be important for their conservation. However, a human disturbance angle is often absent from ecological research, despite growing evidence of the negative impact of nonfatal human interference. Here, we monitored Hainan Eld’s deer living within a reserve and translocated animals living amongst villagers. We show that translocated deer deviated from a crepuscular activity pattern and became increasingly nocturnal, and most active when villagers were not. It appears that translocated deer adapted over time to human disturbance and this pattern is similar to that of other species during periods of hunting. People do not pose an actual threat to Eld’s deer, but their presence triggered a response akin to predator avoidance and may be interfering with broader aspects of their biology and conservation.

Shifts in activity patterns of Microtus gregalis : a role of competition or temperature?

Abstract Although temporal partitioning has long been viewed as a valid mechanism in reducing competition, direct field evidence is rare, and the temporal niche is often considered less important than other factors in promoting coexistence. Furthermore, the relative importance of biotic and abiotic factors in shaping diel activity patterns of animals is poorly understood. We conducted controlled experiments in a little-studied area (Hulunbuir meadow steppe, China) to explore the effects of presence of a larger species, Spermophilus dauricus, and ambient temperature in shaping diel activity patterns of Microtus gregalis. Our results suggest that although interference competition existed between S. dauricus and M. gregalis, the presence of S. dauricus did not significantly affect the diel activity patterns of M. gregalis (P > 0.05). Timing of activity of M. gregalis, however, was always significantly correlated with ambient temperature (P < 0.001). As winter approached, ambient temperature appeared to be a major factor in shaping activity patterns of M. gregalis. To our knowledge, this is the 1st experimental study conducted in an East Asian steppe to integrate the roles of both biotic and abiotic factors in shaping rodent activity patterns.

Life history pattern and fitness of an endangered Hainan Eld's deer population

Understanding life history patterns, individual fitness and population fitness can assist with conservation of endangered species. Field data on life history traits (i.e. age specific fecundity, age specific mortality, age at first reproduction, litter size and adult life expectancy) were collected from 121 Hainan Elds deer (Cervus eldi hainanus Thomas, 1918), an in situ herd of an endemic, rare and endangered cervid inhabiting Bangxi Natural Reserve of Hainan Island, from 1990 to 2002. First, we constructed a dynamic life table to analyze the life history pattern of the population, which showed that the difference between the average lifespan of males and females was not significant (P > 0.05), and that the difference between the average lifespan of the whole Hainan Elds deer population and that of other Elds deer populations living in South Asia (P > 0.05), North America (P > 0.05) and Europe (P > 0.05) was not significant. Second, we used individual reproductive success or number of offspring of a male over its lifetime to estimate male individual fitness. Statistic analysis showed that male individual fitness was not significantly correlated with total antler velvet mass. Third, we used the population intrinsic rate of increase to measure population fitness, and population fitness of Hainan Elds deer was compared with similar indexes of 5 other cervid species. Hainan Elds deer population fitness index was 0.012, the second lowest value relative to other cervids. Results indicated that this rare species is still endangered and is in need of additional protection.

Isolation and characterization of eight microsatellite loci for the vulnerable Hainan Eld’s deer (Cervus eldi hainanus) in China

We report on the isolation and characterization of eight microsatellite markers in the Hainan Eld’s deer (Cervus eldi hainanus) from genomic DNA-enriched libraries. Thirty-three microsatellites were screened from the libraries, and 8 of the screened microsatellites were polymorphic. The number of observed alleles for each locus in 47 individuals ranged from 2 to 9, and the expected and observed heterozygosity was 0.141–0.792 and 0.128–0.957, respectively. Three loci (CEH-2, CEH-6 and CEH-8) of eight deviated from Hardy-Weinberg expectation and no significant linkage association was found among all these loci. These microsatellite markers provide useful tool for population genetic studies of the Eld’s deer.

Different elevational patterns of rodent species richness between the southern and northern slopes of a mountain

Studies on elevational gradients in biodiversity have accumulated in recent decades. However, few studies have compared the elevational patterns of diversity between the different slopes of a single mountain. We investigated the elevational distribution of rodent diversity (alpha and beta diversity) and its underlying mechanisms along the southern and northern slopes of Mt. Taibai, the highest mountain in the Qinling Mountains, China. The species richness of rodents on the two slopes showed distinct distribution patterns, with a monotonically decreasing pattern found along the southern slope and a hump-shaped elevational pattern evident along the northern slope. Multi-model inference suggested that temperature was an important explanatory factor for the richness pattern along the southern slope, and the mid-domain effect (MDE) was important in explaining the richness pattern along the northern slope. The two slopes also greatly differed in the elevational patterns of species turnover, with the southern slope demonstrating a U-shaped curve and the northern slope possessing a roughly hump-shaped pattern. Our results suggest that even within the same mountain, organisms inhabiting different slopes may possess distinct diversity patterns, and the underlying mechanisms may also differ. The potential role of the factors associated with slope aspect in shaping diversity, therefore, cannot be ignored.

Phylogeographical structure and demographic expansion in the endemic alpine stream salamander (Hynobiidae: Batrachuperus ) of the Qinling Mountains

The Qinling Mountains of China provide an excellent study area for assessing the effect of Pleistocene climatic oscillations and paleogeological events on intraspecific diversification. To assess genetic diversity of an endemic stream salamander, Batrachuperus tibetanus, for its conservation, a phylogeographical survey was performed based on mitochondrial DNA and morphological data. The mitochondrial data revealed three lineages of B. tibetanus in the Qinling Mountains. A lineage present in the northwestern Qinling Mountains groups with the Tibet lineage of B. tibetanus, and the remaining Qinling populations are eastern and western lineages that separated ~3–4 million years ago (Ma). The eastern and western Qinling lineage delineation is supported by three morphological variables (snout length, eye diameter and axilla-groin length). The divergence of the two major lineages was likely caused by orogenesis of the Qinling Mountains during the late Cenozoic, and the two lineages were subsequently affected at different levels by Pleistocene climatic oscillations showing different signals of demographic expansion. A large suitable area of B. tibetanus through the Qinling Mountains since the last glacial maximum (LGM) indicated the adaptation of this species to the climatic changes. However, low genetic diversity within populations indicate the urgency of preserving the vulnerable populations and endemic lineages.

Effects of cattle grazing on small mammal communities in the Hulunber meadow steppe

Small mammals play important roles in many ecosystems, and understanding their response to disturbances such as cattle grazing is fundamental for developing sustainable land use strategies. However, how small mammals respond to cattle grazing remains controversial. A potential cause is that most of previous studies adopt rather simple experimental designs based solely on the presence/absence of grazing, and are thus unable to detect any complex relationships between diversity and grazing intensity. In this study, we conducted manipulated experiments in the Hulunber meadow steppe to survey small mammal community structures under four levels of grazing intensities. We found dramatic changes in species composition in native small mammal communities when grazing intensity reached intermediate levels (0.46 animal unit/ha). As grazing intensity increased, Spermophilus dauricus gradually became the single dominant species. Species richness and diversity of small mammals in ungrazed and lightly grazed (0.23 animal unit/ha) area were much higher than in intermediately and heavily grazed area. We did not detect a humped relationship between small mammal diversity and disturbance levels predicted by the intermediate disturbance hypothesis (IDH). Our study highlighted the necessity of conducting manipulated experiments under multiple grazing intensities.

Habitat Selection by Eld’s Deer following Relocation to a Patchy Landscape

An emerging issue in wildlife conservation is the re-establishment of viable populations of endangered species in suitable habitats. Here, we studied habitat selection by a population of Hainan Eld’s deer (Cervus eldi) relocated to a patchy landscape of farmland and forest. Hainan Eld’s deer were pushed to the brink of extinction in the 1970s, but their population expanded rapidly from 26 to more than 1000 individuals by 2003 through effective reserve protection. As part of a wider relocation and population management strategy, 131 deer were removed from the reserve and reintroduced into a farmland-forest landscape in 2005. Habitat use under a context of human disturbance was surveyed by monitoring 19 radio-collared animals. The majority of deer locations (77%) were within 0.6–2 km of villages. Annual home ranges of these collared deer averaged 725 ha (SD 436), which was 55% of the size of the reserve from which they had originated. The annual home ranges contained 54% shrub-grassland, 26% forest and 15% farmland. The relocated deer population selected landscape comprising slash-and-burn agriculture and forest, and avoided both intensively farmed areas and areas containing only forest. Within the selected landscape, deer preferred swiddens and shrub-grasslands. Forests above 300 m in elevation were avoided, whereas forests below 300 m in elevation were overrepresented during the dry season and randomly used during the wet season. Our findings show that reintroduced deer can utilize disturbed habitats, and further demonstrate that subsistence agroforest ecosystems have the capacity to sustain endangered ungulates.

Isolation and characterization of nine microsatellite loci for the takin (Budorcas taxicolor)

We report on the isolation and characterization of nine microsatellite markers in the takin (Budorcas taxicolor) from genomic DNA-enriched libraries. Twenty-eight microsatellites were screened from the libraries, and nine of the screened microsatellites were polymorphic. The number of observed alleles for each locus in 28 individuals ranged from two to seven, and the expected and observed heterozygosity was 0.105–0.758 and 0.071–0.821, respectively. Four loci (TK01, TK02, TK04 and TK08) of nine deviated from Hardy-Weinberg expectation and no significant linkage association was found among all these loci. These microsatellite markers provide useful tool for population genetic studies of the takin.