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Combining lines of evidence of paleontology and zoogeography of Asian langurs, we here offer a hypothesis of ancestral origin and evolution of China’s white-headed langur, divided into four phases. In the initial phase, during the extreme glaciation period in the Early Pleistocene Epoch, some ancient Javan langurs took the opportunity to emigrate northwards and entered the small land mass sandwiched between Zuo Jiang and Ming Jiang Rivers in Southwest China. Barricaded by the rivers, the Javan langur ancestors evolved independently into Chongzuo langurs (Trachypithecus chongzuosis). In the second phase, under the pressure of predacious animals, the Chongzuo langurs were forced to abandon their exclusive arboreal life and find natural refuges on the numerous precipices of Guangxi’s karst topography. In the third phase, on that extensive infertile land with a scant human population, the early white-headed langurs (T. leucocephalus) found sufficient suitable habitat to further evolve locally, adapting to coexist with humans. In a short, anthropogenic phase 4, from the 1950s to the year 2000, trees were brutally chopped and forests were recklessly exploited, which devastated the white-headed langurs’ natural habitat. Along with the rampant poaching activities, white-headed langurs were driven to an evolutionary bottleneck, at the brink of extinction.

From November 1996 to May 2015, we registered in detail the total range of eight resident family troops and two transitory troops and discovered that their home ranges became smaller as vegetation biomass, and thus food, was more abundant. We estimated that 0.26 km2 is the optimum home range size for white-headed langur families. The langurs would pick different kinds of food in different forage quarters according to seasonal changes. The langurs were highly territorial, maintaining both fixed and drifting territories. The fixed territory of each family amounts to about 12% of their home range. Females of the family are restricted to that area, which is inherited from earlier generations. The role of protection of the fixed territory befalls the resident alpha male. Typically the alpha male’s territorial behavior includes monosyllabic “Ga” barks, jumping, shaking branches, and successive braying to threaten intruders. When the intruder goes beyond what the alpha male perceives as a safe distance, male offspring older than 3 years would help the alpha male to protect their territory. When a white-headed langur troop is confronted with competitors on its way to forage, they would show temporary territory defending behaviors. This kind of temporary “drifting territory” is about half the size of the core area.

In a limestone karst cave (Sanhe Cave) in Nongguan Mountains in Chongzuo, Guangxi, China, we unearthed in the sediments 82 mammal fossils in a Gigantopithecus fauna of 1.4 mya, including fossils of Gigantopithecus blacki, Ailuropoda milanoleuca wulingshanensis, Megatapirus augustus, Rhinoceros sinensis, and Stegodon preorientalis, the ancestor species of the white-headed langur, named Chongzuo langur (Trachypithecus chongzuosis), and the ancestor species of the Sumatran striped rabbit (Nesolagus sp.). The animals were buried during the middle phase of the Early Pleistocene Epoch, which coincided with the first extreme glaciations in the Quaternary Period. The glaciations caused the sea level to drop, and the continental shelf was thus exposed. As a result, the coastal areas surrounding Java Island and Sumatra Island became land, which connected with the Malay Peninsula, Indochina Peninsula, and the coastal lowlands around Beibu Gulf in southern Guangxi. This provided land passages for Javan Langurs (Trachypithecus sp.) to disperse northward, enter the karst hill district on the south bank of Zuo Jiang River, and gradually evolve into the present-day white-headed langur (Trachypithecus leucocephalus).

White-headed langurs have sexual contacts with one another year-round, but there are distinct reproductive peak seasons. Copulations peak between July and August, while the peak season for parturitions is between December and January. The mean age of the female’s first parturition is at 5.4 years, with the youngest at 4.8 years and the oldest at 6.2 years. We observed 16 female langurs giving birth to 78 pups, and accurately registered 61 inter-birth intervals of adult females. The average inter-birth interval is 784.3 days or 25.8 months. That is to say, each adult female white-headed langur is able to reproduce 0.93 infants in a year. The length of the suckling period of white-headed langurs is 456 ± 28 days, which is equivalent to 15 ± 0.9 months. Two pieces of data registered from field observations show that the pregnancy period of a female white-headed langur is 138–139 days.

Poets in Ming Dynasty and Qing Dynasty portrayed the white-headed langur in the Longrui Mountains during the fifteenth–nineteenth century as “Thousands of monkey hoots fill the forsaken land.” But the late twentieth century and the early twenty-first century had become a catastrophe for the white-headed langur. In 1977, three Guangxi researchers pointed out that the white-headed langurs were distributed in six karst mountain districts on the south bank of Zuo Jiang River with a total area of 500–600 km2. In 1988, Pan Wenshi and his research team ventured into all the white-headed langur habitats and found a still rich biodiversity. They estimated the number of white-headed langurs between 1000 and 1200. In November 1996, Pan Wenshi set up the Peking University Biodiversity Research Base in the Nongguan Mountains. At that time, we witnessed rampant poaching activities in Nongguan Mountains, which shattered the white-headed langur families. From 1999 to 2002, Ran Wenzhong penetrated deep into and surveyed the known distribution range of white-headed langur, spending a total of 2359 h studying the vastly reduced langur communities while interviewing forest guards and local residents. He discovered that four out of six regional populations had been virtually wiped out. Apart from blasting mountains and burning wasteland for agricultural reclamation, it was rampant poaching that had decimated the species in just a few decades. The enormous demand for tonics extracted from langur organs and for langur bushmeat put the white-headed langur on the road to extinction.

In 2012, we worked in the bush for 357 days and recorded the all-day activities of a white-headed langur family with high-definition video cameras, in both “Sampling All Occurrences of Some Behaviors” method and “Focal-Animal” method. Activities of white-headed langurs follow a constant 24 h diurnal cyclical pattern. In this chapter, we present a detailed summary of their diurnal activities. White-headed langurs periodically adjust the timing of their activities and rests according to seasonal cycles. Their inherent circadian clock keeps biological activities synchronized with the seasonal photoperiod changes in the Northern Hemisphere. We also researched on the “roles” of individuals in a family troop with respect to different sexes and ages and found that the duty of defending the family rested primarily on the resident alpha male, while sub-adult male and adolescent male served as assistance to their father. All females acted in roles of reproducing or nursing pups. Yellow-haired pups and infants spent a lot of time playing with family members.

In Nonguan Mountain area, there are 220 hills scattered in the dense jungle. Due to the restriction of the landform, we tracked the white-headed langur troops on fixed spots, along with line transect surveys, to estimate their numbers. From April till December 2015, we surveyed white-headed langur distribution in the Nongguan Mountains and divided it into three districts. According to our survey, we estimated a total of 798 (216 + 425 + 157) individuals. Since 1996, the langur population has been growing rapidly. The sex ratio within phase 1 and 2 was 1:1, but the phase 3 sex ratio after maturity was strongly biased toward females, with a ♀:♂ ratio of 22:3 (overall mean 7.3:1). Old white-headed langurs accounted for 6.5% of the population, adults at reproductive ages accounted for 32.3%, and the pups, juveniles, and adolescents made up 61.3%. Age distribution as such indicates that the age structure of the FJC white-headed langur population is balanced. Meanwhile, the net rate of annual population increase of six families during the last 20 years ranged from 4.0% to 54.5%, with a mean value of 40%.

From 1996 to 2015, we surveyed the composition of diets of white-headed langurs during three sampling periods. According to plant species verified in their diets, we found that when the biomass of plants in the environment was low (1996–2001), white-headed langurs would make up the quality and quantity deficiencies in diets by extending their choices. When vegetation biomass started to restore, langurs showed a preference for particular species (2002–2006). During the period (2008–2015) when the plant community was fully restored, we found an increased number of plant species in their diets, indicating their choice of food had increased. Nonetheless, in all three periods, 21 species could be reckoned as the main diets of white-headed langurs. Among them were Iodes vitiginea, Pueraria Montana, Broussonetia papyrifera, Ficus tinctoria subgibbosa, Pteroceltis tatarinowii, Sterculia nobilis, and Radermachera sinica, which were vital to the survival of white-headed langurs. According to our detailed direct observations of daily diets of white-headed langurs and the chime found in the stomach of a 4.5-year-old male that died from electrocution, the mass of the food adults consume every day is estimated at around 800–900 g.

More than 60 years ago, based on a black and white piebald pelt, a formerly unknown primate species, the “Piebald langur” Presbytis leucocephalus (Tan 谭邦杰 1955) was described from the Chongzuo area, in China’s Guangxi Province. It was later reassigned to the genus Trachypithecus, but further controversies arose regarding its systematics. Some propose that it is a geographic subspecies of the black langur T. francoisi, while others hold the view that the white-headed langur is a distinct species.

The Nongguan Mountains in Guangxi Province have a landform of peak cluster depression and peak forest valley, which has been formed since the Early Pleistocene. This karst landscape is located at the south of the Tropic of Cancer at the junction of tropical and subtropical monsoon belts. The subtle synchronization of water availability and heat in this area is beneficial to the growth of lush vegetation, many perennial, and provides sufficient food for white-headed langurs year-round. From 1053 AD to 1956 AD, the Nongguan Mountain area was a region with still scant population and rich biodiversity, which provided ample space for the white-headed langur to coexist with human communities. However, since 1956, within 10 years, intense human activities have led to the insularization of the white-headed langur’s habitats. Two interspersed but relatively discrete ecosystems gradually formed: an agro-ecosystem established on the peak cluster depression and peak forest valley, and the karst tropical monsoon rainforest ecosystem that remained in primeval state on the talus and karst hills. Rich humus and rainwater storage make the soil in the talus the most fertile in the Nongguan Mountain range, which allows seeds to germinate and prosper into forests. It is the karst hills and talus that have provided a natural refuge for the white-headed langurs.

We used the Vortex Population Viability Analysis (PVA) model to simulate the changes of the white-headed langur population over the past 20 years and verified it with field observation data from 1997 to 2016. We found that the population numbers calculated by the two methods are very close, with a fitting degree of R2 = 0.99792. According to our field investigation, the number of white-headed langurs in the Nongguan Mountains has increased from 105 in 1997 to 797 in 2015, while VORTEX 9.99c, after 500 iterations of simulations, shows that in the 19 years from 1996 to 2016, the population of white-headed langurs would grow from 105 to 858, with an extinction probability of 0% and a survival probability of 100%. Taking into account the effective breeding population size, age distribution, breeding strategy, mortality, population diffusion, environmental capacity, and other factors of the population in 2016, a positive future for the population is predicted through the PVA model. The effective breeding population size will increase with time, and the inbreeding rate will gradually be reduced. When the natural habitat of the whole Nongguan Mountain area of 13.2 km2 is supposed to sustain a maximum of 1800 white-headed langurs, it is expected to reach carrying capacity in 2027 and, if current conditions persist, remain stable in the future. From the perspective of growth trend, 2003–2021 is the key period for the rapid recovery and growth of this population and thus the golden period that saved the population from extinction.

The restoration of the white-headed langur population in the Nongguan Mountains has undergone several phases. In February 1997, only six family troops and three all-male troops survived the anthropogenic calamities (Chap. 4), with an aggregate of 105 white-headed langurs. In 2002, the population increased to 12 family troops and seven all-male troops, with a population density of 42.5 langurs/km2. From 2006 to 2015, the population increased to above 800, and the all-male troops started to migrate and disperse all over the Nongguan Mountains. We divide the lifespan of a white-headed langur into six age stages: infant (≤0.5 years old), yellow-haired pup (0.5–1.3 years old), juvenile (1.3–2.5 years old), adolescent (2.5–4 years old), sub-adult (4–5 years old), adult (>5 years old), and old (♂ >13 years; ♀ >25 years). The social structure of the white-headed langurs could be summarized into four basic systems: ante-family troop, family troop, transitory troop, and all-male troop. The white-headed langur does not show obvious sexual dimorphism, but the canine teeth of adult males are noticeably larger than in females. During the family troop phase, the white-headed langurs are strictly polygynous, but in their lifetime, they are polygamous.

In mammals, bitter taste is mediated by TAS2Rs, which belong to the family of seven transmembrane G protein-coupled receptors. Since TAS2Rs are directly involved in the interaction between mammals and their dietary sources, it is likely that these genes evolved to reflect species-specific diets during mammalian evolution. Here, we analyzed the amino acids responsible for the difference in sensitivities of TAS2R16s of various primates using a cultured cell expression system. We found that the sensitivity of TAS2R16 varied due to several amino acid residues. Mutation of amino acid residues at E86T, L247M, and V260F in human and langur TAS2R16 for mimicking the macaque TAS2R16 decreased the sensitivity of the receptor in an additive manner, which suggests its contribution to the potency of salicin, possibly via direct interaction. However, mutation of amino acid residues 125 and 133 in human TAS2R16, which are situated in helix 4, to the macaque sequence increased the sensitivity of the receptor. These results suggest the possibility that bitter taste sensitivities evolved independently by replacing specific amino acid residues of TAS2Rs in different primate species to adapt to species-specific food.

Infants of many primate species have extensive interactions with group members other than their mothers, which can affect an infant’s fitness. Patterns of nonmaternal infant handling vary according to the mother’s response as well as the number, sex, age, and dominance ranks of social partners. The primary goal of this study was to identify the basic pattern and explore the function of nonmaternal infant handling behavior in wild white-headed langurs (Trachypithecus leucocephalus) at the Nongguan Hills in Guangxi, Southwest China. We report nonmaternal interactions in the first 3 mo after birth for 15 infants born during six birth seasons in a 67-mo field study. The nonmaternal infant handling we observed was generally in the form of caregiving, and mothers permitted most handling attempts. Infants were handled by nonmothers from the first day after birth. Infants spent 20–30% of the daytime associated with nonmothers during the first month of life, and time in contact with nonmothers decreased with infant age. Rates of nonmaternal infant handling varied significantly with the sex and age of handlers. Juvenile and subadult females handled infants significantly more than expected from their proportional representations in the group, whereas adult females did so less frequently than expected. Older male infants and juvenile males rarely handled infants, and adult males never did so. Infant handling behavior showed no correlation with the dominance rank of handlers relative to the mothers. Our data, although limited in some analyses, are in line with the predictions of the learning-to-mother hypothesis, but do not support the female competition or alliance formation hypotheses.

Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.

There are few detailed descriptions of parturition behavior in wild primates. Here we report for the first time birth-related behaviors in a highly endangered colobine monkey endemic to southwest China, the white-headed langur (Trachypithecus leucocephalus). We video recorded three complete birth events in three parturient females living in one reproductive group. The births occurred during the night at one of the group’s sleeping sites. One parturient was primiparous, while the other two were multiparous. All three delivered close to other group members. Common behaviors among the parturients included adopting a raised-rump posture during contractions, manual inspection of the anogenital area followed by hand-licking, manual self-assistance as the infant emerged, holding and licking the infant immediately after the birth, and ingesting the placenta. However, we found considerable individual variation in birth-related behaviors. The primiparous female had the longest prepartum phase and more contractions than the two multiparous females. All three mothers ingested the placenta, but the primipare took much longer than the two multiparous mothers to deliver the placenta, start to ingest it, and consume it. Other group members had little interaction with the parturients during the prepartum phase, but showed intense interest in the neonates. The newly born infants were held by nonmaternal adult females of the group within 5–9 h of their birth. Our case studies stress the importance of the social context at parturition in group-living primates, and suggest that parity of parturients may influence birth-related behavior.

Infanticide by males is common in mammalian species such as primates in which lactation lasts much longer than gestation. It frequently occurs in one-male groups following male takeovers and is likely a male reproductive strategy. Reported female countertactics include abrupt weaning of infants, dispersal, or paternity confusion. Here, we estimated costs of female countertactics in terms of weaning ages and interbirth intervals. We observed a population of white-headed leaf monkeys (Trachypithecus leucocephalus) in Nongguan Nature Reserve, China (1995–2006) mainly composed of one-male groups. Takeovers (N = 11) coincided with the peak conception period. Detailed data are presented for five takeovers (34 females, 29 infants, and 47 group-years) leading to six infant disappearances (42.9% of infant mortality). All presumed infanticides were in accordance with the sexual selection hypothesis. Following a takeover, females without infants or with old infants stayed with the new males, incurring no or low costs (via abrupt weaning). Females with young infants dispersing with the old males also experienced low costs. High costs (due to infant loss) were incurred by pregnant females and those with young infants who stayed with the new males indicating that paternity was not confused. Costs in terms of long interbirth intervals were also high for females leaving with the old males to later join the new males, despite infant survival. Female countertactics reflected female philopatry mediated by infant age. Presumably due to the seasonal timing of takeovers, most countertactics seemed successful given that 32.3% of females apparently incurred no costs and 41.2% incurred only low costs.

Understanding the reproductive parameters of endangered primate species is vital for evaluating the status of populations and developing adequate conservation measures. This study provides the first detailed analysis of the reproductive parameters of wild white-headed langurs (Trachypithecus leucocephalus), based on demographic data collected over an 8-year period in the Nongguan Karst Hills in Chongzuo County, Guangxi, China. From 1998 to 2002, a total of 133 live births were recorded in the population based on systematic censuses. Births occurred throughout the year, but the temporal pattern was highly correlated with seasonal variation in temperature and rainfall, with the birth peak coinciding with the dry and cold months of November–March. The average birthrate was 0.47±0.13 births per female per year and mortality for infants younger than 20 months was 15.8%. From 1998 to 2006, 14 females gave birth to 41 infants in four focal groups. The average age at first birth for female langurs was 5–6 years (n=5) and the interbirth interval (IBI) was 23.2±5.2 months (median=24.5 months, n=27). Infants are weaned at 19–21 months of age. The IBI for females with infant loss before weaning was significantly shorter than those for females whose infants survived. It appears that birth seasonality in the white-headed langurs is influenced by seasonal changes in food availability. The timing of conceptions was found to coincide with peak food availability. The reproductive parameters for white-headed langurs reported here are quite similar to those reported for other colobine species. One major difference is our observation of lower infant mortality in Trachypithecus. Am. J. Primatol. 71:558–566, 2009. © 2009 Wiley-Liss, Inc.

Numerous hypotheses have been developed to explain sex allocation. In male-dispersing, female cooperatively breeding species, the local resource competition model predicts male-biased birth sex ratio, the local resource enhancement model predicts female-biased birth sex ratio, and the population adjustment model predicts that biased birth sex ratio should not be favored if the two sexes are equally costly to rear. The male quality model predicts that, in polygynous species, females in better physical condition will either produce more sons than daughters or invest more heavily in sons than in daughters. White-headed langurs are a female philopatry and female cooperatively breeding species. During a 11-yr study, a total of 133 births were recorded, among which birth sex ratio (M:F = 73:49) was significantly male-biased. This is consistent with the prediction of the local resource competition model. On the other hand, if mothers balanced their investment between the two sexes, according to Fisher's population adjustment model, males should be the less-costly-to-rear sex. However, we found no sex difference for infant mortality (12.3% in males and 12.2% in females), and sons induced slightly longer interbirth interval (son: 26.4 ± 1.1 mo, daughter: 24.1 ± 0.6 mo) and lactational period (son: 20.9 ± 1.0 mo, daughters: 19.6 ± 0.5 mo) for their mothers. Thus, the population adjustment model was not supported by this study. The local resource enhancement model was not supported because birth sex ratio did not bias to females who provided more reproductive assistance. On the individual level, probit regression showed no relation between birth sex ratio and group size. Because the group size was considered to be negatively related to female physical condition, our study did not support the male-quality model. We suggested several possibilities to explain these results.

The number of males per group is the most variable aspect of primate social organization and is often related to the monopolizability of females, which is mainly determined by the number of females per group and their reproductive synchrony. Colobines show both inter-specific and intra-specific variations in the number of males per group. Compared with other colobine species, little is known about the social organization of white-headed langur (Trachypithecus leucocephalus), despite its endangered status and unusual limestone habitat. As a part of a long-term study of the white-headed langurs in the Nongguan Karst Hills, Guangxi, China, we quantitatively investigated their social organization by analyzing census data from 1998 to 2003. The population censuses revealed that the predominant social organization of bisexual groups was the one-male group, similar to a previous report on this species and many other Asian colobines. In such groups, one adult male associated with 5.1 adult females, 0.1 sub-adult males, 2.6 juveniles and 2.9 infants on average, with a mean group size of 11.7 individuals. In addition, three multi-male groups were recorded, consisting of 2-3 adult males, 1-5 adult females, 0-2 sub-adult males, 0-7 juveniles and 0-2 infants. They did not contain more adult females than the one-male groups and were unstable in group membership. The langurs outside bisexual groups were organized into small nonreproductive groups or lived as solitaries. The nonreproductive groups averaged 1.3 adult males, 1.3 sub-adult males and 2.6 juveniles. Juvenile females were present in such groups on 52.4% of all occasions. As predicted by the monopolization model, the prevalence of the one-male pattern in this species may mainly be attributed to the small number of females in the group. The possible reasons for the occurrence of multi-male groups and the presence of juvenile females in nonreproductive groups are also discussed.

Many Asian colobine monkey species are suffering from habitat destruction and population size decline. There is a great need to understand their genetic diversity, population structure and demographic history for effective species conservation. The white-headed langur (Trachypithecus leucocephalus) is a Critically Endangered colobine species endemic to the limestone karst forests in southwestern China. We analyzed the mitochondrial DNA (mtDNA) control region sequences of 390 fecal samples from 40 social groups across the main distribution areas, which represented one-third of the total extant population. Only nine haplotypes and 10 polymorphic sites were identified, indicating remarkably low genetic diversity in the species. Using a subset of 77 samples from different individuals, we evaluated genetic variation, population structure, and population demographic history. We found very low values of haplotype diversity (h = 0.570 ± 0.056) and nucleotide diversity (π = 0.00323 ± 0.00044) in the hypervariable region I (HVRI) of the mtDNA control region. Distribution of haplotypes displayed marked geographical pattern, with one population (Chongzuo, CZ) showing a complete lack of genetic diversity (having only one haplotype), whereas the other population (Fusui, FS) having all nine haplotypes. We detected strong population genetic structure among habit patches (Φ ST = 0.375, P < 0.001). In addition, the Mantel test showed a significant correlation between the pairwise genetic distances and geographical distances among social groups in FS (correlation coefficient = 0.267, P = 0.003), indicting isolation-by-distance pattern of genetic divergence in the mtDNA sequences. Analyses of demographic history suggested an overall stable historical population size and modest population expansion in the last 2,000 years. Our results indicate different genetic diversity and possibly distinct population history for different local populations, and suggest that CZ and FS should be considered as one evolutionarily significant unit (ESU) and two management units (MUs) pending further investigation using nuclear markers.

In primates, male–immature interactions are always multifacetted. We studied male–immature interactions of white-headed langur during our long-term study in Nongguan White-Headed Langur Reserve, Guangxi, China. Male–immature interactions obviously differed between one-male groups and male–immature groups. In one-male groups, adult males behaved tolerantly or aggressively towards immatures and never carried out sociopositive behaviors. Sexual selection theory supports this phenomenon because males are predicted to bias to compete for more mating chances but not to invest in any single offspring. In male–immature groups, however, adult males carried out sociopositive behaviors and never behaved aggressively towards immatures. This is supported by kin selection theory because it will be beneficial for the males to increase the survival of the immatures if they are likely the fathers of them. Thus, we conclude that male–immature interactions differ between one-male groups and male–immature groups because the mating status of males are different between the two kinds of groups.

The giant panda ( Ailuropoda melanoleuca ) is among the more familiar symbols of species conser- vation. The protection of giant panda populations has been aided recently by the establishment of more and better-managed reserves in existing panda habitat located in six mountain ranges in western China. These re- maining populations are becoming increasingly isolated from one another, however, leading to the concern that historic patterns of gene flow will be disrupted and that reduced population sizes will lead to diminished genetic variability. We analyzed four categories of molecular genetic markers (mtDNA restriction-fragment- length polymorphisms (RFLP), mtDNA control region sequences, nuclear multilocus DNA fingerprints, and mi- crosatellite size variation) in giant pandas from three mountain populations (Qionglai, Minshan, and Qin- ling) to assess current levels of genetic diversity and to detect evidence of historic population subdivisions. The three populations had moderate levels of genetic diversity compared with similarly studied carnivores for all four gene measures, with a slight but consistent reduction in variability apparent in the smaller Qinling population. That population also showed significant differentiation consistent with its isolation since historic times. From a strictly genetic perspective, the giant panda species and the three populations look promising insofar as they have retained a large amount of genetic diversity in each population, although evidence of re- cent population reduction—likely from habitat loss—is apparent. Ecological management to increase habi- tat, population expansion, and gene flow would seem an effective strategy to stabilize the decline of this en- dangered species.

Reproductive activities of six giant panda females (Ailuropoda melanoleuca) living in the Qinling Mountains of China (Shaanxi Province) were recorded from 1989 into early 1995. Data on mating and birth dates, litter size, cub sex and den use were collected for three of the pandas. At this site, pregnant females migrated to lower elevations in advance of other pandas to seek dens for birthing. One dam was videotaped in the den with her cub from birth to the end of the denning phase at 94 days of age. This cub was repeatedly handled during the dam's absences to obtain data on development and weight. During the early part of the denning phase, the cub was maintained on the dam's body virtually continuously. Post-partum fasting for up to 3 weeks was noted. Dams invariably moved cubs to new dens three or four times during the birth season. By the time cubs left the den at about 3–4 months, they were fully furred and capable of surviving winter temperatures without further shelter. Reproductive parameters for the wild population fell within the range of values for captive pandas, based on information in the literature and in the giant panda studbook. The combined data on length of gestation, intervals between births, litter size and weight, infant development, and reproductive life span reveal a range of life-history variables that strongly resemble the Ursidae.

Infanticide was first observed in langurs nearly 50 years ago, and this rare phenomenon has been inferred to have either an evolutionarily adaptive function or to be a pathological and non-functional behavior. In this study, we report 5 male takeover events in one-male groups of white-headed langurs in the Nongguan Karst Hills, Guangxi, China from 1998 to 2006. We recorded 13 attacks on 9 infants by extra-group males or new resident males. During the male takeovers, all of the infants younger than 6 months (with an average age of 3.6 months [N = 11]) in the groups disappeared. The infant death rate during the 4.2 months after takeover by a new male was significantly higher than the infant death rate calculated for most of the year. Older infants that were still nursing (with an average age of 14.1 months [N = 7]) were often attacked and seriously wounded by the extra-group males or new resident males, but all of them survived. The interbirth intervals of females whose infants were assumed to be killed by males were significantly reduced relative to those of females in groups with stable male tenure (mean = 10 months vs 25 months). Our data suggest that males kill unrelated and unweaned infants during the takeover period to decrease the time until the infants’ mothers resume fertility. Thus, infanticide would support sexual selection theory in white-headed langurs. The data also show that infanticidal behavior was directed toward the infants, especially those who were still nursing. Female dispersal may function as a counter-strategy to avoid infanticide.

In mammals, bitter taste is mediated by TAS2R genes, which belong to the large family of seven transmembrane G protein-coupled receptors. Because TAS2Rs are directly involved in the interaction between mammals and their dietary sources, it is likely that these genes evolved to reflect species-specific diets during mammalian evolution. Here, we investigated the sensitivities of TAS2R16s of various primates by using a cultured cell expression system, and found that the sensitivity of each primate species varied according to the ligand. Especially, the sensitivity of TAS2R16 of Japanese macaques to salicin was much lower than that of human TAS2R16, which was supported by behavioural tests. These results suggest the possibility that bitter-taste sensitivities evolved independently by replacing specific amino acid residues of TAS2Rs in different primate species to adapt to food items they use.

Asian leaf-eating monkeys have flexible, environmentally adaptable feeding strategies. The diet and food choices of white-headed langurs (Trachypithecus leucocephalus) have, however, not yet been studied in the Nongguan Karst Hills in China, where one of the two main surviving populations of this endangered species lives. From 2000 to 2002 inclusive, we adopted an innovative video playback analysis method to identify the food species used by the langurs and to calculate the corresponding feeding frequency for each species. The video-aided methodology was shown to be efficient. It provided high-quality images, and the plant species could be identified in 98.3% of the feeding records. Based on this analysis, we found that the langurs in Nongguan fed on 70 species of plants, among which 24 were identified as their staple food species. The cumulative curve for the staple food species reached a plateau at 255 (43.7%) feeding records. This result indicated that most of the langurs’ staple food species had been identified by the analysis.

The giant panda has captured the world’s imagination. Its seemingly harmless, playful nature, velvety black and white fur, flat face, softly rounded body and soulful black eye patches combine to make it resemble an oversized and loveable teddy bear (Fig. 1.1). Its upright posture and famous ‘panda’s thumb’ – an elongation of the wrist bone that allows it to grasp bamboo and other food much like people do – further adds to its widespread appeal. From the most prominent government authorities to young children, people are passionate about protecting the giant panda. This fervent interest has caused the panda to emerge as the most highly visible of all endangered species, even though few people have actually ever seen one in the wild. Furthermore, this single species has become a worldwide icon for the need to conserve animals, plants and habitats. Therefore, it is ironic that the giant panda, which evokes so much attention by the public, scientific and conservation communities, still remains such a mystery with so many pieces still missing from a biological jigsaw puzzle that, if solved, could improve species management, welfare and conservation. The purpose of this book is to provide, and then assemble, a few more pieces of this enormous puzzle.

Eight traditional subspecies of tiger (Panthera tigris), of which three recently became extinct, are commonly recognized on the basis of geographic isolation and morphological characteristics. To investigate the species' evolutionary history and to establish objective methods for subspecies recognition, voucher specimens of blood, skin, hair, and/or skin biopsies from 134 tigers with verified geographic origins or heritage across the whole distribution range were examined for three molecular markers: (1) 4.0 kb of mitochondrial DNA (mtDNA) sequence; (2) allele variation in the nuclear major histocompatibility complex class II DRB gene; and (3) composite nuclear microsatellite genotypes based on 30 loci. Relatively low genetic variation with mtDNA, DRB, and microsatellite loci was found, but significant population subdivision was nonetheless apparent among five living subspecies. In addition, a distinct partition of the Indochinese subspecies P. t. corbetti into northern Indochinese and Malayan Peninsula populations was discovered. Population genetic structure would suggest recognition of six taxonomic units or subspecies: (1) Amur tiger P. t. altaica; (2) northern Indochinese tiger P. t. corbetti; (3) South China tiger P. t. amoyensis; (4) Malayan tiger P. t. jacksoni, named for the tiger conservationist Peter Jackson; (5) Sumatran tiger P. t. sumatrae; and (6) Bengal tiger P. t. tigris. The proposed South China tiger lineage is tentative due to limited sampling. The age of the most recent common ancestor for tiger mtDNA was estimated to be 72,000–108,000 y, relatively younger than some other Panthera species. A combination of population expansions, reduced gene flow, and genetic drift following the last genetic diminution, and the recent anthropogenic range contraction, have led to the distinct genetic partitions. These results provide an explicit basis for subspecies recognition and will lead to the improved management and conservation of these recently isolated but distinct geographic populations of tigers., Genetic analysis provides the basis for subspecies recognition among tigers, and will lead to improved conservation strategies for these endangered animals

A population census of white-headed langurs (Trachypithecus leucocephalus) was conducted using sleeping-site counts and the line-transect method from July to August 2002 at the Longrui Karst Hills, Guangxi, China. This area had been the largest habitat of the langurs across their range before the 1990s. While our survey revealed 146 old sleeping-sites, no white-headed langurs or fresh sleeping-sites were found in this area. Our study indicated that there had previously been a large population of langurs at Longrui Karst Hills, but now the langurs are possibly locally extinct in this area. If langurs still exist within the area, the population density must be very low. Interviews with local people confirmed that the number of white-headed langurs has been decreasing since the 1980s. Poaching was very common in the past and continues to be a problem at present, and it is likely that this has caused the decrease in the white-headed langur population at Longrui Karst Hills.

1. A model was set up to simulate the dynamics of a giant panda Ailuropoda melanoleuca population. All parameters in the model were taken from an existing panda population in the Shuidonggou Valley area of the Qinling Mountains, China. 2. The model projects population dynamics and assesses population viability under changing conditions. 3. Small, fragmented populations face potential risks in terms of genetics and demographic processes. This study concerns the latter. 4. The simulation indicated that: (i) the population is stable under present conditions (but note that the model does not incorporate environmental stochasticity); (ii) the environmental carrying capacity is the most important factor restricting population increase; (iii) poaching would greatly affect the probability of population survival; (iv) increasing the survival of individuals under 1 year of age would increase population persistence substantially; (v) reducing subadult female mortality would accelerate population growth; (vi) shortening the interbirth interval would allow more rapid population growth, and its effect is greater than changing other parameters, but may not be practicable; and (vii) immigration and reduction in young male mortality are of limited benefit to this small population but may be important in practical conservation management: 5. The model suggests management strategies for giant panda conservation.