Weikang Yang

Social organization in goitered gazelle (Gazella subgutturosa Güldenstaedt 1780)

The population structure of goitered gazelles was investigated in Kazakhstan over several years. We found that the social organization of goitered gazelle changed over months mostly because of their birthing and rutting behaviour, and seasonal migrations. Female groups were smallest and solitary females were the most numerous during parturition in May and these groups were largest during rutting season in November–December. In contrast, male groups were smallest and solitary males were the most numerous during the rutting period, while during the rest of the year they formed considerably larger groups although male singletons were always common. Mixed-sex groups were typical for spring and autumn migration periods in March–April and in October. The month also influenced the population structure with larger groups more common during cold months and smaller groups frequently observed during hot months, but such impact was not as distinctive as in the case of biological events (birthing, mating and migration). Despite living in northern latitudes, goitered gazelles have a social organisation that is comparable with other gazelle species.

Grouping pattern of the goitered gazelle, Gazella subgutturosa (Cetartiodactyla: Bovidae) in Kazakhstan

Abstract The group size and composition of goitered gazelles were investigated over several years in Kazakhstan. Most gazelles formed groups of one to three individuals all year round. This small herd size recorded in our study area was probably a consequence of the feeding ecology of the goitered gazelle, which is a very selective ruminant of small body size. With respect to group composition, female and male groups were the most often noted (52.0% and 37.9%), while mixed herds and groups of yearlings were considerably rarer (4.6% and 5.5%). Moreover, mixed groups were the largest groups (mean±SE: 5.29±0.25 individuals per group), followed by female groups (2.40±0.03), male groups (2.14±0.05), and yearling herds (1.49±0.05). In addition, the grouping pattern varied seasonally and corresponded very closely to the yearly breeding cycle of the goitered gazelle. Nevertheless, it remains consistent with what is known of the grouping pattern of other gazelles.

Seasonal diet of Khulan (Equidae) in Northern Xinjiang, China

Abstract The natural diet of khulan (Equus hemionus Pallas, 1775) was observed over the period of a year in northern Xinjiang, China, using faecal analysis. The winter food habits of the khulan and domestic sheep were also compared. The faecal analysis method demonstrated that khulan ate 46 species of plants during the year. Diets varied seasonally, with the widest food breadth in winter (0.43) and the least in summer (0.10). Chenopodiaceae and Poaceae were major foods of khulan, and during spring, forbs were quite important as well. In contrast, Stipa glareosa was preferred during spring and summer, but consumed less during autumn and winter. Shrubs dominated the khulans natural diet during autumn and winter. The dietary overlap between khulan and domestic sheep was 48.3% during winter. As a grazer living in arid environments, khulan ate more shrubs than other equids living in grassland, and their winter diet was an adaptation to avoid competition from domestic sheep. The number of sheep in the reserve should be reduced to lessen the pressure of competition.

Diet of Gazella subgutturosa (Güldenstaedt, 1780) and food overlap with domestic sheep in Xinjiang, China

Abstract. The natural diet of goitred gazelle (Gazella subgutturosa) was studied over the period of a year in northern Xinjiang, China using microhistological analysis. The winter food habits of the goitred gazelle and domestic sheep were also compared. The microhistological analysis method demonstrated that gazelle ate 47 species of plants during the year. Chenopodiaceae and Poaceae were major foods, and ephemeral plants were used mostly during spring. Stipa glareosa was a major food item of gazelle throughout the year, Ceratoides latens was mainly used in spring and summer, whereas in autumn and winter, gazelles consumed a large amount of Haloxylon ammodendron. Because of the extremely warm and dry weather during summer and autumn, succulent plants like Allium polyrhizum, Zygophyllum rosovii, Salsola subcrassa were favored by gazelles. In winter, goitred gazelle and domestic sheep in Kalamaili reserve had strong food competition; with an overlap in diet of 0.77. The number of sheep in the reserve should be reduced to lessen the pressure of competition.

Influence of population density on group sizes in goitered gazelle (Gazella subgutturosa Guld., 1780)

We conducted our study in Ili depression, south-eastern Kazakhstan during 1981–1989 to investigate how group sizes and group class frequencies change with increasing population densities in goitered gazelles. In addition, we compared our study to data on group size and group class frequency of various goitered gazelle populations in Kazakhstan with very variable population densities. We found that mean group size was a more variable index than group class frequency. Population density had some effect on mean group sizes, but the strength of the influence was quite weak, and only in cases where densities of two populations varied more than sevenfold did group sizes start to change. Group class frequency was not correlated with population density at all. The impact of the yearly breeding cycle on group size was bigger than population density. The density-dependent response of goitered gazelle population was curvilinear in fashion, and it may be classified as intermediate between social-dwelling ungulate species, living in large groups and demonstrating continuous (linear) increases of group size with population density and those that are solitary or territorial ungulate species with no relationship between population size and group size, though the goitered gazelle population’s weak response was distinctively closer to the one of solitary ungulate species.

Vigilance in Black-Necked Cranes: Effects of Predation Vulnerability and Flock Size

Abstract We studied Black-necked Cranes (Grus nigricollis), a Globally Vulnerable species and the only alpine breeding cranes in the world, to test whether and how predation vulnerability and flock size affect vigilance. Crane flocks were defined as high predation vulnerability (parents with juveniles) and low predation vulnerability (adults without juveniles). Both predation vulnerability and flock size influenced vigilance of Black-necked Cranes. High predation vulnerability flocks were significantly more vigilant than low predation vulnerability flocks at both the group scan level (t  =  2.379, df  =  66, P  =  0.02) and group scan frequency (t  =  3.208, df  =  66, P  =  0.002). Predation vulnerability and flock size affected vigilance in Black-necked Cranes (ANCOVA: group scan level, flock size: F  =  13.013, P  =  0.001, predation vulnerability: F  =  7.728, P  =  0.007); group scan frequency, flock size: F  =  13.873, P < 0.001, predation vulnerability: F  =  10.882, P  =  0.002).

Diurnal time budget of goitred gazelles (Gazella subgutturosa Güldenstaedt, 1780) in Xinjiang, China

Abstract It is considered that four factors influence ungulate activity budget: (a) seasonal biomass and quality, (b) temperature, (c) yearly life cycle, and (d) livestock movements and human activity. In order to test them, the diurnal time budget of goitred gazelles was studied using the focal sampling method in Xinjiang Province (China) during a two-year period (2007–2009). According to our results, in all seasons goitred gazelles spent more than half (up to 68.9%) of their daytime feeding on pastures, and more than one-third resting in spring, autumn, and especially summer (up to 42.1%); in winter their resting time decreased to 29.0% for males and 19.0% for females. Though other activities were very important in the gazelles’ lives, the diurnal time budget for these activities was low (<8.0%). Goitred gazelles showed a trimodal feeding activity in most seasons, and a bimodal in summer (females). Females in summer and males during rutting season devoted more significant time to other activities (suckling, moving, courting and agonistic behaviour). However, the portion of time was still notably lower than for feeding and resting.

Seasonal dynamics of agonistic displays in territorial and non-territorial males of goitered gazelle.

Aggression serves a great variety of social functions, one of which is protection of individual territories from intruders. Territorial males of many antelope species show aggressive noncontact displays, and only rarely fight. It has been suggested that ungulate males tend to have more frequent and longer aggressive interactions with rivals of similar age or social status than with males of dissimilar status. In the present paper, we test whether territorial and non-territorial males behave in a similar manner and avoid fights, and whether or not they preferentially direct aggressive and longer agonistic interactions towards males of similar age or social status, rather than towards other classes of males. We found that territorial males usually avoided straight fights with peers, and instead mainly used noncontact displays in aggressive interactions. In contrast, non-territorial males used fights considerably more often, especially during the onset of territoriality in April to May, when these males had their most frequent aggressive interactions. Territorial bucks aggressively interacted most frequently with non-territorial males and significantly less often with other territorial males, but agonistic noncontact displays between territorial males lasted the longest. In contrast, non-territorial males addressed their aggressive noncontact displays and fights most often to peers and less frequently to sub-adults. Asymmetry in the social status of territorial vs. non-territorial males was likely responsible for the distinctively different agonistic behaviors shown by the two types of males, which in turn are likely due to the different costs and benefits each male can accrue from these aggressive interactions.

Roaring function in male goitered gazelles

Most of the vocalizations of Antilopinae males are soft and usually only heard from a very close distance. The goitered gazelle is a rare exception to this rule, and during the rutting period territorial males of this species are among the noisiest antelopes. Rutting vocalization is such an essential part of the rutting behavior in goitered gazelle that adult males have a hypertrophic larynx, the muscle tissues of which increase considerably in size during the rut. We were interested in the frequency and variance with which male goitered gazelles emit their calls depending on an animals age, reproductive status and time of the year in order to understand the main function of the rutting vocalizations. We found that roaring was mostly related to courting displays, while vocalizations during aggressive displays were less frequent in male-male interactions. Acoustic signals likely enhance courtship displays and also may aid in accelerating female ovulation, promoting synchronization of breeding cycles during the mating and birthing periods, which last only several days for most of the females in our population. We discuss the potential benefits of such behaviors and compare it to other species living in similarly extreme environments.

Play behaviour in goitered gazelle, Gazella subgutturosa (Artiodactyla: Bovidae) in Kazakhstan

Abstract. In this paper, play behaviour of goitered gazelles is considered for the first time. Young gazelles demonstrated play activity most often, followed by adult males and sub-adults, then adult females. Locomotor play (running, jumping) was the most frequently observed play behaviour, while social play (fighting, sexual play) was noted considerably less often and mostly with males. Adult gazelles played mainly in May and gazelle young in June, and primarily in the evenings (19:00–20:00). Most acts of play lasted from several seconds to a half-minute. Young gazelles played often during their suckling period or, at least in the presence of their mothers. Adult females frequently became involved in their youngs play, while males played during grazing or butting. In describing goitered gazelle play patterns, we tested five hypotheses: practice-exercise, surplus energy, locomotor play ontogeny, different play types for specific stages of aging, and the social function of play. Our data for playful behaviour of goitered gazelles supported four of the five hypotheses, but contradicted the fourth listed above, which states, at least for Cuviers gazelles, that locomotor play appears and disappears earlier than social play. The cause of this difference in results may lie in the different conditions under which groups were observed or the different extent of the studies.