新疆鹅喉羚的种群结构

１９９２年８～９月和１９９３年９月,作者在新疆北部鹅喉羚北疆亚种（ＧａｚｅｌｌａｓｕｂｇｕｔｔｒｏｓａＳａｉｒｅｎｓｉｓ）分布区（天山以北）设置１９条样带,总长８１８ｋｍ,观测点至动物的平均垂直距离２４８．３ｍ,面积４０５．８ｋｍ２的调查统计,见鹅喉羚６２群次,共２２１只。样带中动物的平均密度为０．７１±０．１７只／ｋｍ２。对能判别性别和成幼的１６条样带中的３７群次１１３只统计,雌：雄＝１：１．０５,成：幼＝２．４：１。对８条样带中的１６群次５０只统计,母：仔＝１：１．４。１９９３年２月和１０月,我们还在新疆南部鹅喉羚南疆亚种（Ｇ．ｓ．ｙａｒｋａｎｄｅｎｓｉｓ）分布区（天山以南）,设置８条样带,长２３０ｋｍ,平均垂直距离２９９ｍ,面积１１６ｋｍ２的调查统计,见鹅喉羚１７群次５１只,平均密度０．５７±０．２６只／ｋｍ２。     

鹅喉羚的年龄鉴定

本文以鹅喉羚为材料,采用双重附贴磨片法及蚀刻法确定角磨片上显示的生长层与角鞘上凸“嵴”的关系,并以第一下门齿(I_1)作切片所显示的年轮线进行验证。证明其角鞘上的凸“嵴”数量多少并不表示年龄大小,在一龄内无凸“嵴”,二、三龄均包含有4—5个凸“嵴”,四龄后亦为2—3个凸“嵴”组成一龄,真正的年龄线是角表凸“嵴”之后有一粗糙微凹的环纹。实验结果可应用于野外生态学调查,用以判断种群年龄及结构。     

新疆准噶尔盆地东部鹅喉羚采食地的特征

2001—2003年5月和9月,通过野外亘接观祭米样的方法,我们对新疆准噶尔盆地东郡木垒地区鹅喉羚的采食地进行了研究。在研究区南部,分布着以盐生假木贼和蒿为主的低矮小半灌木,其间散布有木本猪毛菜和驼绒藜为优势种的条块状高灌丛。鹅喉羚多在灌丛块中采食。Mann-WhitneyU检验表明,采食地内的植物种数、植被盖度和植被高度都显著高于对照地中相应成分。主成分分析表明,影响鹅喉羚采食地选择的主要环境因子是植物种数和植被盖度。在研究区北部,分布着以沙生针茅和木地肤为主的植被,其问散布有固定和半固定沙丘。沙丘上各种灌木发育较好,鹅喉羚多在沙丘上觅食。Mann-WhitneyU检验表明,采食地内的植物种数、植被盖度、植被高度,以及蛇麻黄、木地肤和驼绒藜的盖度都显著高于对照地中相应成分。主成分分析表明,影响鹅喉羚采食地选择的主要环境因子是蛇麻黄、木地肤、扁果木蓼盖度和植物种数。     

蒙古野驴、鹅喉羚和家畜的食物重叠

采用粪样显微分析技术研究了新疆卡拉麦里山有蹄类自然保护区及周边区域蒙古野驴、鹅喉羚及家羊、家马和家骆驼3种家养有蹄类春季、秋季和冬季食性组成及食物生态位。结果发现：（1）蒙古野驴、鹅喉羚和家畜主要采食针茅、驼绒藜、蒿和梭梭,但是,它们采食的植物科数和种数都不相同,各植物种类在食谱中所占的比例不同;（2）各个季节有蹄类动物两两之间的食物生态位重叠均在0．8以上,最低为0．832（冬季鹅喉羚和家马）,最高达到0．986（秋季蒙古野驴和家羊;秋季家马和家羊）,五种有蹄类之间的食物生态位重叠度也达到了0．3以上。表明在卡拉麦里山有蹄类自然保护区,上述野生动物及季节性进入该自然保护区的家畜之间均存在食物竞争;冬季积雪深,食物短缺,荒漠有蹄类易因冻饿及疾病等造成死亡。因此,应采取限制秋冬季进入该自然保护区,家畜数量及调整放牧区域等保护管理措施,对该区域荒漠有蹄类动物实施有效保护[动物学报54（6）：941-954,2008]。     

新疆卡拉麦里山保护区鹅喉羚的社群结构

2005年11月至2007年5月,在新疆卡拉麦里山有蹄类保护区对鹅喉羚的社群结构进行了初步研究.将其集群划分为雌性群、雄性群、亚成体群、独羚、雌雄混合群和不明群6种类型.共统计鹅喉羚564群,总计3186只.春季鹅喉羚以雄性群居多(45.7%);夏秋两季则以雌性群为主(52.9%和70.4%);冬季以混合群居多(60%).卡方独立性检验表明,四个季节间三种社群类型的百分比组成差异显著(x2=68.45,P<0.01),受繁殖周期和季节变化影响.鹅喉羚集群大小范围为1～95只,其中3只群出现最多(20.0%);2～5只的群占54.3%;6～10只的群占23.1%;11～20只的群占9.2%;>20只的群占2.3%.春夏秋冬四季平均群大小分别为(4.45±4.07;4.94±4.20;6.66±10.12;6.0±5.66),其中春季平均集群大小分别与秋季和冬季差异显著.     

鹅喉羚的求偶交配行为

于2009~2010年研究了卡拉麦里山有蹄类自然保护区鹅喉羚Gazella subgutturosa的求偶交配行为。共记录4大类17种求偶交配行为。鹅喉羚的发情期分为2个阶段:发情准备期和高峰期。从发情准备期开始,雄羚开始沿雌羚每日移动路线建立领域并在整个白昼呆在领域内。高峰期持续时间较短,但雄羚整个高峰期始终停留在领域内。排泄物标记是鹅喉羚采用最多的领域标记方式,而角标记则持续时间更长。小跑是鹅喉羚圈雌时采用频率最高的步法,其次是走动和奔跑,走动步法持续时间最长,不同步法的组合使用是圈雌成功率和能量节约的最优化权衡。鹅喉羚的求偶交配过程可分为3个阶段,第一阶段为试探接近阶段,若雌羚已作好交配准备,则进入第二阶段,雄羚以直立行走或碎步行走接近雌羚,第三阶段为爬跨交配阶段。鹅喉羚的交配模式属于Dewsbury交配行为模式分类系统的第13类和Dixson分类系统的第14类。鹅喉羚成功交配后,并不存在个体配偶看护,而是通过守卫领域以提高总体配偶看护水平。     

鹅喉羚夏季和冬季卧息地选择

2007年夏季(6—8月)及冬季(11—2008年1月),在卡拉麦里山有蹄类自然保护区研究了鹅喉羚(Gazella subgutturosa sairensis)的卧息生境选择。夏季测定了49个卧迹样方,36个对照样方;冬季测定了75个卧迹样方,75个对照样方。卡拉麦里山有蹄类自然保护区的鹅喉羚夏季主要选择平滩、下坡位,海拔910 m以上、与水源距离较远、远离道路、远离居民点、高隐蔽级、中低植被密度和中高草本密度的区域作为卧息地; 而冬季鹅喉羚主要选择山坡、阳坡和半阴半阳坡、中上坡位和下坡位、900—1 000 m的高度范围、离道路501—1 000 m以及大于2 000 m的距离、靠近居民点、中低隐蔽级、中等雪深(1.1—3 cm)、中高植被密度和中高草本密度的区域作为卧息地。主成分分析表明,鹅喉羚夏季卧息样方前4个主成分的累积贡献率达到86.57%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅(Stipa spp.)密度、至最近居民点距离、至永久水源最近距离和海拔的影响。冬季鹅喉羚卧息样方前4个主成分的累积贡献率达到73.88%,第1主成分主要反映卧迹样方的植物密度、草本密度、针茅密度和坡度的影响。     

环境因子对新疆鹅喉羚群体遗传多样性的影响

环境因素在物种进化和遗传变异过程中起着非常重要的作用。为探讨新疆鹅喉羚遗传多样性与环境因子的关系,本研究采用聚合酶链式反应（PCR）和直接测序的方法,测定了新疆鹅喉羚11个群体84份样本的线粒体DNA Cyt b基因（1140 bp）和D-loop区（1100 bp）序列,分析各群体遗传多样性及环境因子对遗传多样性的影响。结果显示新疆鹅喉羚具有较高的单倍型多样性,较低的核苷酸多样性,表明其遗传多样性处于较低水平。环境因子与群体遗传多样性的相关性分析结果表明,海拔、年均降水量、年均气温、人口数量是影响新疆鹅喉羚遗传多样性的主要环境因子,其中海拔是最关键的环境因子。本研究结论为新疆鹅喉羚群体有效合理的保护与管理提供理论依据。     

新疆卡拉麦里山有蹄类自然保护区鹅喉羚遗传多样性及系统发育地位

鹅喉羚是生活于亚欧大陆荒漠、半荒漠地区重要的有蹄类动物。2010年春季,新疆卡拉麦里山有蹄类自然保护区遭遇了60年不遇的雪灾,我们采集了野外救灾发现的130头死亡鹅喉羚肌肉样本,采用PCR和测序技术,研究了鹅喉羚线粒体 DNA 的 Cyt b 基因 1143 bp 核酸序列,发现新疆卡拉麦里山有蹄类自然保护区生存的鹅喉羚单倍型多样性较高(Hd=0.855),核苷酸多样性较低(π=0.00224)。采用邻接法(NJ)、最大似然法(ML)构建单倍型之间的系统发育树,以及network所构建的单倍型间中介网络图都显示出2个遗传分化程度很大的分支,且这2个分支都出现过明显的群体扩张和持续增长。将本研究获得的单倍型H1与Genebank检索获得的瞪羚属其他12个物种Cyt b基因进行了比较,分别采用邻接法(NJ)和最大似然法(ML)构建分子系统树,证明与鹅喉羚最接近的物种为印度瞪羚(Gazella bennettii),鹅喉羚与瞪羚属内物种的分歧时间大约为1.08-2.5百万年(Mya)(Million years ago, Mya)。     

鹅喉羚线粒体D-loop和Cytb序列遗传多样性分析

[目的]为了探讨新疆天山野生动物园17只鹅喉羚的遗传多样性、亲缘关系和群体来源。[方法]对这些鹅喉羚线粒体控制区(D-loop)和细胞色素b(Cytb)基因序列进行了PCR扩增和测序,分别计算了群体单倍型多样度(H)和核苷酸多样性(Pi)以及个体间的遗传距离,并构建了单倍型NJ(Neighbor-Joining)聚类图。[结果]D-loop区和Cytb分别获得了978bp和543bp的基因片段,D-loop区识别出11个单倍型,Cytb区识别出3个单倍型;D-loop和Cytb的单倍型多样度(H)和核苷酸多样性(Pi)分别为0.863、0.01028和0.330、0.00077;个体之间最大遗传距离为0.024,最小遗传距离为0.001;17只鹅喉羚分别聚为2个分支。[结论]该鹅喉羚群体D-loop区多态性较丰富,在野外可能来自两个不同的群体。     

Sex ratio in goitered gazelles (Gazella subgutturosa Guldenstaedt, 1780)

We studied the sex ratio of goitered gazelles in the naturally arid environment of Kazakhstan over a 6-year period. The main methods in our study were taking transect counts and focal observations. The sex ratio of adult goitered gazelles has demonstrated a female bias due to a much higher mortality of males of all ages, especially during years with unusually severe winters. This phenomenon is typical for many polygynous ungulates, as well as other gazelle species. Surprisingly, our data demonstrated monthly fluctuations in sex proportions, along with a bias shift from a female-dominant population during most of the year to a male-dominant population during spring. We discovered, though, that our data did not reflect any real changes in the sex ratio of the population but, instead, revealed the radical changes in behavior of pregnant females before giving birth—hiding from danger in thick shrubs or broken terrain rather than fleeing. As a result, we were not able to see many pregnant females in our spring samples (before birthing), and so received a male-biased population. During the rest of the year (after birthing), females returned to their usual behaviors of fleeing from danger that then gave us a female-biased sex ratio that reflected a more accurate status in sex proportions of the population. So, our results discovered seasonal sex difference in hiding behavior which led to a bias based on visibility.     

Diversification and subspecies patterning of the goitered gazelle (Gazella subgutturosa) in Iran

Goitered gazelles, Gazella subgutturosa, exist in arid and semiarid regions of Asia from the Middle to the Far East. Although large populations were present over a vast area until recently, a decline of the population as a result of hunting, poaching, and habitat loss led to the IUCN classification of G. subgutturosa as “vulnerable." We examined genetic diversity, structure, and phylogeny of G. subgutturosa using mitochondrial cytochrome b sequences from 18 geographically distant populations in Iran. The median‐joining network of cyt b haplotypes indicated that three clades of goitered gazelles can be distinguished: a Middle Eastern clade west of the Zagros Mountains (and connected to populations in Turkey and Iraq), a Central Iranian clade (with connection to Azerbaijan), and an Asiatic clade in northeastern Iran (with connection to Turkmenistan, Uzbekistan, and other Asian countries as far as northeastern China and Mongolia). Based on our results, we argue that Iran is the center of diversification of goitered gazelles, due to the presence of large mountain ranges and deserts that lead to the separation of populations. In accordance with previous morphological studies, we identified the Asiatic clade as the subspecies G. s. yarkandensis, and the other two clades as the nominate form G. s. subgutturosa. The new genetic information for goitered gazelles in Iran provides the basis for future national conservation programs of this species.     

The postnatal ontogeny of the sexually dimorphic vocal apparatus in goitred gazelles (Gazella subgutturosa)

This study quantitatively documents the progressive development of sexual dimorphism of the vocal organs along the ontogeny of the goitred gazelle (Gazella subgutturosa). The major, male‐specific secondary sexual features, of vocal anatomy in goitred gazelle are an enlarged larynx and a marked laryngeal descent. These features appear to have evolved by sexual selection and may serve as a model for similar events in male humans. Sexual dimorphism of larynx size and larynx position in adult goitred gazelles is more pronounced than in humans, whereas the vocal anatomy of neonate goitred gazelles does not differ between sexes. This study examines the vocal anatomy of 19 (11 male, 8 female) goitred gazelle specimens across three age‐classes, that is, neonates, subadults and mature adults. The postnatal ontogenetic development of the vocal organs up to their respective end states takes considerably longer in males than in females. Both sexes share the same features of vocal morphology but differences emerge in the course of ontogeny, ultimately resulting in the pronounced sexual dimorphism of the vocal apparatus in adults. The main differences comprise larynx size, vocal fold length, vocal tract length, and mobility of the larynx. The resilience of the thyrohyoid ligament and the pharynx, including the soft palate, and the length changes during contraction and relaxation of the extrinsic laryngeal muscles play a decisive role in the mobility of the larynx in both sexes but to substantially different degrees in adult females and males. Goitred gazelles are born with an undescended larynx and, therefore, larynx descent has to develop in the course of ontogeny. This might result from a trade‐off between natural selection and sexual selection requiring a temporal separation of different laryngeal functions at birth and shortly after from those later in life. J. Morphol. 277:826–844, 2016. © 2016 Wiley Periodicals, Inc.     

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.     

The ontogeny of acoustic individuality in the nasal calls of captive goitred gazelles, Gazella subgutturosa

Individualistic voices are important for establishing personalized relationships among individuals. In young animals, individual vocal identity is affected by permanent changes of the acoustics due to the growth of their vocal apparatus. Different acoustic variables change uncoordinatedly, so vocal individuality should be repeatedly upgraded along development. We compared classifying accuracy of individuals and sexes by nasal calls in fast-growing goitred gazelles Gazella subgutturosa at two ontogenetic stages, juvenile (3-6 weeks of age) and adolescent (23-26 weeks of age). Juvenile "spring" nasal calls and adolescent "fall" nasal calls were examined in the same 35 calves (18 males, 17 females), wild-born in May and then hand-raised. Discriminate function analysis based on four formants, fundamental frequency, duration and three power quartiles, revealed an equally high potential of spring and fall calls to encode sex. The individuality was very high in both ages but significantly higher in fall calls. Classifying calls to individuals was based on the same three acoustic variables (fundamental frequency and third and fourth formants) in both ages, although their actual values changed uncoordinatedly from spring to fall in most subjects. Our results suggest updating acoustic individuality in nasal calls of adolescent goitred gazelles accordingly to the newly emerged acoustic variation.