The dwarf blue sheep (Pseudois schaeferi) is an endangered species only inhabiting upper Jinsha River gorge (Zhubalong, south of Batang),Sichuan Province, China. From July to December 2007 and April to June 2008,we investigated group patterns of dwarf blue sheep by using transect censuses and fixed point observations in Zhubalong Nature Reserve. We observed 34 groups consisting of 217 individuals with a mean group size of 6.4 ± 4.9 in 2007 and 16 groups comprising 135 individuals with a mean group size of 8.4 ± 7.7 in 2008. Sheep groups can be classified into five types: male only (2007∶8.8% of total groups,2008∶ 6.3% ),female only (2007:2.9%, 2008:0),mixed (2007:70.6%, 2008:81.2% ), mother-offspring (2007:8. 8%,2008:12.5% ),and solitary individual (2007:8.8%, 2008:0). These group types varied in proportion seasonally (P <0.01). These types also differed in distribution (P < 0.01) and in size (P < 0.01). Groups of 2 -10 individuals were predominant (73.5% of all groups in 2007 and 75.0% in 2008). We collected population data from several recent articles (1997,1998,2000,2006) to analyze mean group size and sex ratio dynamics using the ANOVA. The results indicated that group size was highly variable (P < 0.05)and the mean group size was significantly larger in 2007 (P < 0.05)and in 2008 (P < 0.01) than in 2000. The adult:juvenile:lamb ratio were 100∶ 26.4∶28.6 in 2007, and 100∶24.7∶ 20.4 in 2008. The female : male ratio (100∶ 55.7 in 2007 and 100∶ 56.6 in 2008) remained stable (P > 0.05). Group patterns of the sheep can be influenced by benefits in group living, biological characteristics, breeding cycle, competition for resources, habitat type and topography, predation risk, and human disturbance, group patterns of the sheep implied a survival strategy.
Dominance hierarchy which influences male reproductive behavior and social behavior, has often been reported in non-human primates. We examined aspects of dominance hierarchy in the Tibetan macaque (Macaca thibetana) at Mt. Huangshan, China. Six adult males were assigned into 3 groups:the dominant group,medial group and subordinate group, respectively, as representing their dominance rank in the YA2 troop at Mt. Huangshan. Social behavior data were collected using focal animal sampling. Our results showed: (1)The dominant group participated most often in bridging behavior; the frequency of sending and receiving bridging behavior was significantly different among different ranks; (2)The subordinate group participated most often in social mount behavior, the frequency of sending and receiving social mount behavior was significantly different among different ranks;(3)The dominant group received present behavior the most often, while the subordinate group was most likely to present. Frequency of sending present behavior also varied significantly among different ranks, but there was no significant difference in receiving present behavior among the different ranks; and (4) Frequency of shaking tree behavior was significantly different among the different ranks. We speculate that amicable behaviors reflect the social dominance rank and are an important way to sustain social stability.
A survey on winter habitat selection of rhesus macaques (Macaca mulatta tcheliensis) was carried out from November 2007 to February 2008 in Taihang Mountains (35°11′N,112°16′E ) in Jiyuan, Henan Province, China. 180 plots of 10 m × 10 m were set up and 10 factors were selected to analyze the habitat selection of the macaque. These factors include slope terrain, altitude of the plot, slope position, slope face, slope degree, the distance from water resource, concealment, human disturbance, canopy, and average DBH (diameter breast height). The results showed that, for their activities, the macaque usually chose a certain habitat with characteristics as follows:1)the average tree whose DBH is over 15 cm;2) the distance from human disturbance is less than 2 000 m;3) the distance to water is less than 1 000 m; 4) the gradient of slope ranges from 15° to 40°;5)the altitude of the monkey ranging sites ranged from 1 000 m to 1 300 m;6) the canopy cover was less than 60%. In addition, the macaques preferred south-faced and southwest-faced slopes in winter. The principal component analysis indicated that these five factors will contribute 70.713% of the total variance, while the others might have less impact on habitat selection.
The tree shrews (Tupaia belangeri) are an endemic group in the Indomalayan Region (Torrid Zone or subtropical zone). The morphological characteristics of the skulls and mandibles of T belangeri in four local ranges (Luquan,Jianchuan, Lijiang and Yunlong) in Yunnan Province were compared using geometric morphometric techniques,principal components analysis, discriminant analysis, thin plate spline and multidimensional scaling analysis. Using principal components analysis and discriminant analysis, it was shown that the morphological characteristics of the lateral cranium and the lateral mandible were more efficient for differentiating animals from Dianzhong Altiplano and Hengduan Mountains region. Using thin plate spline analysis,significant morphological differentiations were shown for both nose bone and molars, which may reflect adaptations to climate and environment. Using multidimensional scaling analysis, it was shown that the morphological characteristics of skulls allowed differentiations between animals from Dianzhong Altiplano and Hengduan Mountains region, that may be related to longitude or latitude of their habitations. In conclusion, the morphological characteristics of the skulls and mandibles of T. belangeri in Dianzhong Altiplano and Hengduan Mountains region can be distinguished at the level of population; this may correlate to the ecological adaptation.
The significance of plasticity in energy metabolism and behavioral patterns in response to variations of food availability was examined in adult male KM mice acclimated to random food deprivation (FD)for 4 weeks,in which animals were fed ad libitum for a randomly assigned 3 days each week,but were deprived of food for the other 4 days, and then refed ad libitum for another 4 weeks. Food intake was measured using the food balance method,and basal metabolic rate (BMR) and nonshivering thermogenesis (NST)were measured using a closed-circuit respirometer. Behavioral observations were made to examine behavioral patterns including activity, feeding, grooming and resting behavior. The data showed that food intake and gastrointestinal mass increased significantly, and BMR and NST decreased significantly in FD mice compared to controls. Moreover, FD mice had a significantly higher percentage of resting behavior and lower activity than control mice. These parameters were all recovered after 4 weeks of ad libitum re-feeding, indicating significant plasticity. These results suggest that animals can compensate for an unpredictable reduction of food availability by engaging in an energetic strategy, including an increase in energy intake related to food intake, and a decrease in energy expenditure associated with BMR, NST and activity, but not including body fat mobilization. Significant plasticity in energy metabolism and behavioral patterns is shown in mice over a short timescale, which plays an important role in adaptations to food shortage in unpredictable environments with relation to food availability.
We examined the body mass and physiological states related to solitary lifestyle and dominant-subordinate relationships in male striped hamsters (Cricetulus barabensis). Wild adult hamsters were captured from farmland in mountainous areas in southwest of Shandong province and caged singly in the laboratory during the breeding season. The experimental hamsters were subjected to 4 weeks staged dyadic encounters, and the faeces were collected every day for 28 consecutive days by pairing two unfamiliar and weight-matched males in a neutral arena. In order to determine dominant or subordinate status, aggressive behavior, defense, social and nonsocial behaviors were quantified every day. Animals were then necropsied and their physiological and reproductive state assessed. Our results suggested that 1) an increase of body mass could not be depressed by social conflict of male hamsters;2) adrenal gland index of subordinate animals increased significantly; 3) the concentration of faecal GCs was related to the social conflict’s time and an individual’s social status;4)the dominant individual maintained a high testosterone level, which favored its aggressive behavior and facillitated the dominant status; 5)the cortisol suppressed testosterone secretion within all treatment groups caused the testosterone to fall to the low level. These data show that formation of dominance-subordinate relationships could be determined by aggressive behavior; testosterone level improved the formation of dominance of males, but this was in turn depressed by cortisol level. Organ index data suggested that the HPA axis did not suppress the HPG axis. Subordinate animals were stressed, which benefited survival and reproduction of dominant male hamsters in the field.