Feeding adaptation of François' langurs (Trachypithecus francoisi) to the fragmented limestone habitats in Southwest China.

Limestone forests are an unusual habitat for primates, especially fragmented limestone habitats. However, while some research has been conducted on François' langurs (Trachypithecus francois) in these habitats, there is still a need to improve the understanding of their behavioral adaptations to the fragmented limestone habitat. We collected data on the diet of François' langurs in a fragmented limestone habitat in Encheng National Nature Reserve, southwestern Guangxi, China using instantaneous scanning sampling, and their feeding adaptations to the fragmented forest were examined. The results indicated that a total of 101 species of plants were consumed by the langurs. They also fed on two non-plant components, including cliff minerals and at least one species of insect. The langurs ate a higher number of food species in Encheng when compared with the other geographic populations, and they maintained a high level of food diversity and ate more vines. Moreover, they were highly selective in their use of vegetation in their home range, and fewer plants provided a high-quality food source. During the season when food resources were scarce, the consumption of fruits and young leaves decreased as their availability decreased. This led to the use of other food components, such as mature leaves and seeds. The findings support that François' langurs adjust their feeding behavior to cope with seasonal and micro-variations in their dietary requirements and to adapt to their particular environment.

Diet, food availability, and climatic factors drive ranging behavior in white-headed langurs in the limestone forests of Guangxi, southwest China.

Changes in abiotic and biotic factors can affect the efficiency of biological systems in animals, forcing them to adjust their behaviors in response to daily and seasonal variations. From September 2016 to August 2017, we collected ranging behavior data on four groups of white-headed langurs ( Trachypithecus leucocephalus) in the Guangxi Chongzuo White-Headed Langur National Nature Reserve, Guangxi, southwest China. We simultaneously analyzed how multiple ecological factors affect langur ranging behavior, which should facilitate our understanding of the potential mechanisms underlying their adaptation to limestone habitats. Results showed that langur ranging behavior was significantly affected by diet composition, food availability, and climatic factors. Specifically, moving time and daily path length increased with the increase in dietary diversity. Furthermore, moving time and daily path length were positively associated with the availability of fruit and relative humidity of the forest, and moderately associated with temperature and relative humidity of bare rock. Our study demonstrated that langurs maintain stable moving and feeding times and exhibit a short daily travel distance, likely adopting an energy-conserving behavioral strategy in response to food shortages and high temperatures in the fragmented karst forest. These results highlight the importance of food availability and temperature in shaping the ranging behavior of these karst-dwelling primates.

Comparative Analysis of Gut Microbiota in Captive and Wild Oriental White Storks: Implications for Conservation Biology.

The oriental white stork (Ciconia boyciana) is considered an endangered species based on the International Union for Conservation of Nature (IUCN) Red List. This study presents the first evidence on comparative analysis of gut microbial diversity of C. boyciana from various breeding conditions. To determine the species composition and community structure of the gut microbiota, 24 fecal samples from Tianjin Zoo and Tianjin Qilihai Wetland were characterized by sequencing 16S rRNA gene amplicons using the Illumina MiSeq platform. Firmicutes was found to be the predominant phylum. Analysis of community structure revealed significant differences in the species diversity and richness between the populations of the two breeding conditions. The greatest α-diversity was found in wild C. boyciana, while artificial breeding storks from Tianjin Zoo had the least α-diversity. Principal coordinates analysis showed that the microbial communities were different between the two studied groups. In conclusion, this study reveals the species composition and structure of the gut microbiota of oriental white storks under two breeding conditions, and our findings could contribute to the integrative conservation of this endangered bird.

Variations in diet composition of sympatric Trachypithecus francoisi and Macaca assamensis in the limestone habitats of Nonggang, China.

Comparative studies of sympatric species are essential for understanding behavioral and ecological adaptation as well as the mechanisms that can reduce resource competition to allow coexistence. François' langurs (Trachypithecus francoisi) and Assamese macaques (Macaca assamensis) are sympatric primate species found in the limestone seasonal rainforests of Nonggang Nature Reserve, southwestern Guangxi, China. To explore their different adaptation strategies, we collected data on diet using scan sampling at 15-min intervals. Our results revealed that François' langurs showed a more flexible diet composition than Assamese macaques. François' langurs increased dietary diversity and mature leaf consumption in response to seasonal scarcity of preferred young leaves and fruits, whereas Assamese macaques relied heavily on young bamboo leaves (Indocalamus calcicolus) in most months. These variations reflect the differences in digestive physiology, morphology, and the temporal and spatial distribution of food resources.

Complete mitochondrial genome of the crested black macaque (Macaca nigra).

The complete mitochondrial sequence of the crested black macaque (Macaca nigra) has been determined by mapping the raw data to previously published mitochondrial assemblies of the corresponding species. The total sequence length is 16,564 bp and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 D-loop control region. The base composition of mtDNA genome is 31.76% A, 25.27% T, 30.17% C, and 12.80% G, with an AT content of 57.03%. The arrangement of genes in M. nigra is identical to that of M. mulatta. All genes are encoded on the heavy strand with the exception of ND6 and eight tRNA genes. The mitochondrial genome of M. nigra presented here will contribute to a better understanding of the population genetics, help to protect its genetic diversity and resolve phylogenetic relationships within the family.

Attacks on adult females with infants by non-resident males in the François langur.

Infanticide by males is a common phenomenon in mammals, especially primates, as lactation lasts much longer than gestation in many species. Usually, infanticidal episodes occur soon after group takeovers, and are traditionally considered a male reproductive strategy (i.e., support the sexual selection hypothesis, Hrdy, 1974). To verify the validity of this conception, we observed one group of Francois' langurs in the Nonggang Nature Reserve, China, between August 2003 and July 2004. During the study period, a Francois' langur female with the youngest infant in the group was attacked three times by immigrating males, and later disappeared by the third day after the final attack. We suggest that these attacks on the female-infant dyad represent infanticide attempts by males, and may be the cause of the adult female and her infant's disappearance. Presumably, that female dispersed with her infant to avoid infanticide and was not killed. Though these observations do not completely verify the sexual selection hypothesis, they are not inconsistent with it.

[Habitat selection and use of Francois's langurs (Trachypithecus francoisi) in Guangxi Province, Fusui area].

To explore the influence of habitat fragmentation on the ecology of the Francois's langur (Trachypithecus francoisi), data on habitat use were collected from a group of Francois's langurs living in an isolated hill in the Fusui Rare Animal Nature Reserve, Guangxi Province, from March to December 2001. To identify the effect of human activities on vegetation, 10 vegetation quadrats were sampled in the habitat, including 5 on the slopes with more human disturbance, and 5 on the hill-tops with less human disturbance. Because of human destruction, not only the number of plant species, diversity and density, but also the densities of preferred foods for Francois's langurs were less on the slope than those on the hill-top. Analyses of habitat use indicated that the langurs showed preference for the hill-top with abundant food resources and less human disturbance, and avoided to use the slope with more human disturbance. In the rainy seasons, langurs spent significantly more time on the hill-top rather than on the cliff. Therefore, habitat selection and use of the species may be resulted from the balance of feeding benefit and human disturbance. Francois's langurs used the platforms and caves on the cliffs as sleeping sites. They reused some sleeping sites, and tend to use the same caves on consecutive nights.