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1.
This study examines midden selection and use by mountain gazelles Gazella gazella in central Saudia Arabia and the implications of middens (dung piles) for the conservation of this species. Specifically, we tested poachers' claims that mountain gazelles are easy to kill because midden use was predictable and conspicuous. We found that midden selection in mountain gazelles is non-random, with middens typically located at the base of the most conspicuous and largest trees, although the choice of midden sites is also influenced by tree species. Middens clearly have olfactory importance; the majority of mountain gazelles that visited middens were observed sniffing the ground. Mountain gazelles visit middens at night, which corroborates poachers' claims that the animals are easily hunted at night through spotlighting. Although the use of open habitats that are accessible to automobiles makes gazelles vulnerable to hunting and being run down, our data suggest that midden use is also an attribute that makes gazelles susceptible to hunting. Poachers can locate gazelles because of middens' predictable locations, as they are placed at prominent landmarks, are visually conspicuous as large dung piles, and are visited at night, which allows the animals to be found through spotlighting. Other taxa that use predictable and prominent landmarks, or communicate through visually conspicuous methods could also be susceptible to poaching.  相似文献   

2.
Mountain gazelles (Gazella gazella) rank among the most critically endangered mammals on the Arabian Peninsula. Past conservation efforts have been plagued by confusion about the phylogenetic relationship among various ‘phenotypically discernable’ populations, and even the question of species boundaries was far from being certain. This lack of knowledge has had a direct impact on conservation measures, especially ex situ breeding programmes, hampering the assignment of captive stocks to potential conservation units. Here, we provide a phylogenetic framework, based on the analysis of mtDNA sequences (360 bp cytochrome b and 213 bp Control Region) of 126 individuals collected from the wild throughout the Arabian Peninsula and from captive stocks. Our analyses revealed two reciprocally monophyletic genetic lineages within the presumed species Gazella gazella: one ‘northern clade’ on the Golan Heights (Israel/Syrian border) and one genetically diverse larger clade from the rest of the Arabian Peninsula including the Arava Valley (Negev, Israel). Applying the Strict Phylogenetic Species Concept (sensu Mishler & Theriot, 2000 Mishler, B. D. and Theriot, E. C. 2000. “The phylogenetic species concept (sensu Mishler and Theriot): monophyly, apomorphy, and phylogenetic species concepts”. In Species Concepts and Phylogenetic Theory. A Debate, Edited by: Wheeler, Q. D. and Meier, R. 4454. Columbia University Press, NY.  [Google Scholar]) allows assigning species status to these two major clades.  相似文献   

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5.
Dan  Baharav 《Journal of Zoology》1983,200(4):445-453
Observations of reproduction in four gazelle populations in the semi–arid and arid habitats of Israel during three years have revealed intra– and interspecific differences. In the eastern Lower Galilee of northern Israel, female Mountain gazelles (Gazella gazella gazella) reproduce during every month of the year, conceive first at six months of age and exercise long parental care. Females of a population 80 km to the north (Upper Galilee) maintain a seasonal reproductive pattern, conceive first at 18 months of age and have a short parental care period. The latter pattern is similar to the Dorcas gazelle (Gazella dorcas) females of the southern Negev Desert. Interspecific similarities in reproduction of these two populations is attributed to the lack of free water during lactation in both environments where females rely on water available in plant tissue only. The importance of the daily accessibility to water during lactation in female gazelles is discussed. It is suggested that the timing of births and the ability of female gazelles to conceive while lactating are not species-specific characteristics but simply a matter of short-term adaptation to changing environmental conditions common understanding today that animal reproductive strategies are a function of prevailing environmental conditions.  相似文献   

6.
Eight microsatellite loci were isolated from a genomic DNA library created from Grant's gazelle (Gazella granti). Observed and expected levels of heterozygosity were computed utilizing 20 individuals from a population in Central Kenya. Tests for Hardy–Weinberg equilibria were conducted and found that two of the eight loci deviated from equilibrium in this population. These markers were developed to analyse the genetic effects of culling and isolation on a game preserve in Kenya.  相似文献   

7.
动物通过集群降低个体警戒时间,从而增加采食等行为时间,这种现象被称为" 群体效应" 。除群体大小
外,社会及环境因子如季节与性别也可能影响个体警戒水平。本文于2007 年至2009 年在新疆卡拉麦里山有蹄类
野生动物保护区采用焦点动物取样法,通过测定鹅喉羚警戒行为比例、平均每次警戒持续时间及10 min内警戒频
率,研究了季节、性别及群体大小对鹅喉羚个体警戒水平的影响,并验证群体效应。结果表明:由于季节更替
而产生的生物量的变化对鹅喉羚个体警戒水平无显著影响;在秋冬季除雄性外,鹅喉羚个体警戒水平均有随群
体增大而降低的趋势,但这种趋势并不十分明显。性别则显著影响其警戒水平,夏季由于雌性羚羊处于哺乳期,
因而其警戒水平显著高于雄性(P < 0.05);受繁殖行为影响,冬季雄性比雌性警觉性更高(P > 0. 05);春秋季
两性间警戒水平没有差异(P >0.05)。不同生理周期是导致鹅喉羚育幼期雌性及繁殖期雄性个体警戒水平发生
显著变化的重要因子。  相似文献   

8.
During serological surveillance of peste des petits ruminants (PPR) disease, it required capture of randomly selected herds of gazelles as part of a study to determine the epidemiological role of these species in the circulation of peste des petits ruminants virus (PPRV). The study targeted capturing 135 Grant's gazelles (Gazella granti) from the Serengeti ecosystem, Tanzania. A modified netting technique was used aiming at providing safe, efficient and cost‐effective method for capture of gazelles. Locally available materials were used, and wildlife professionals guided the process of manufacturing supporting frame for the nets. Twenty (20) black metal pipes, 20 metal bars, four nets and three vehicles were used in the procedure. A total of 136 Grant's gazelles and nine Thomson's gazelles were captured in three missions. The Grant's gazelles were captured as per sample size calculated in all locations: Loliondo (n = 25), Serengeti National Park (n = 44) and Ngorongoro Conservation Area (NCA) (n = 67) using less time and minimum cost than estimated. Injuries of three fawns (2%) inadvertently captured with the groups of adults and sub‐adult animals were recorded. Comparing with 2014 and other studies, modified netting technique showed high animal and operator safety levels with minimal injuries. With this technique, it was possible to capture even flighty animals that behave nervously because of hunting and other human activities, including Thomson's gazelles, a species previously found to be difficult to capture by netting.  相似文献   

9.
Azaperone can reduce stress caused by weaning and relocation of breeding sows, but its effects on reproductive processes are still poorly understood. The primary aim of this study was to describe and compare the endocrine and ovarian activity in ultrasonographically monitored second parity sows, with or without azaperone treatment at weaning (2 mg/kg BW i.m.). The intervals from weaning to the onset of estrus and ovulation were both greater (P<0.05) in azaperone-treated (n=12) than in control sows (n=12) by ~12 h. Mean daily growth rates of identified antral follicles were less (P<0.05) in azaperone-treated than in control sows (1.08±0.17 v.1.23±0.18 mm/day; mean±SD) and treated animals exceeded (P<0.05) controls in the mean ovulation rate (13.7±1.3 v. 12.6±1.2). A transient suppression of cortisol release was observed in the treatment group (at 10 and 30 min after azaperone injections) but circulating cortisol concentrations were variable in both groups of sows for the remainder of the study. The preovulatory rise in LH and estradiol secretion was delayed (P<0.05), and the duration of the LH surge was greater (P<0.001) in azaperone-treated sows compared with their control counterparts. The amplitude of episodic fluctuations in serum cortisol concentrations was correlated with the number of stillborn piglets in control sows (r=0.63, P=0.04). The amplitude and concentration of the preovulatory rise in estradiol secretion were negatively correlated with ovulatory response and litter size (r=−0.63 to −0.82, P<0.05), whereas the time at which the LH surge ended was directly related to the number of live-born piglets (r=0.82, P=0.002) in azaperone-treated animals. The present results indicate that administration of azaperone at weaning had a profound effect on preovulatory LH secretion as well as growth kinetics and estrogenicity of ovarian antral follicles. However, the causative associations among various characteristics of the preovulatory LH discharge, ovarian and adrenal steroid secretion post-weaning, and reproductive variables in sows remain equivocal.  相似文献   

10.
Fecal reproductive progestagen monitoring in the mountain gazelle (Gazella gazella) provided a non-invasive method for tracking reproductive cycling, estimating age of sexual maturity and diagnosing pregnancy in this species of gazelle. Fresh fecal samples were collected from eight female mountain gazelle (Gazella gazella) for a period of two months. Two of the animals were pregnant while the other six were not. Using the progestagen profile the luteal phase, interluteal (follicular) phase and estrous cycle in adult female gazelles were determined to be 12.5 ± 1.2, 5.9 ± 0.59 and 18.8 ± 0.98 days respectively. Significant inter-animal differences in fecal progestagen concentration were observed in both the luteal and follicular phases. Significant differences were observed in the levels of fecal progestagen between cycling females and females in late pregnancy. Low concentrations of fecal progestagen in females aged less than 18 months old indicated that sexual maturity in captivity is not attained before that age.  相似文献   

11.
Gazella羚羊是"三趾马动物群"中常见成员,在晚中新世至更新世地层中广泛分布,演化速率相对较快,具有重要的生物地层学及生态指示意义,但在我国尚未有保德期之前的化石报道。本文研究的化石发现于陕西蓝田灞河组中部,磁性地层学资料显示其年代为晚中新世灞河期。化石标本包括了5个近乎完整的头骨、下颌以及颅后骨骼。根据发现的标本装架起第一个完整的Gazella羚羊骨架。形态对比与测量数据表明,蓝田标本与巴基斯坦西瓦里克发现的Gazella lydekkeri非常相近,而不同于欧洲晚中新世常见的Gazella各种以及我国发现的种类。从肢骨的形态分析与测量比例数据来看,Gazella cf.G.lydekkeri适合快速奔跑运动,可能生活在相对开阔的环境中,与灞河期动物群的生态类型以及与灞河组沉积学、同位素地球化学等研究所指示的相对干旱、半干旱的开阔草原环境相一致。  相似文献   

12.
新疆准噶尔盆地东部鹅喉羚采食地的特征   总被引:8,自引:1,他引:8  
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。  相似文献   

13.
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.  相似文献   

14.
15.
Cattle on the Golan Heights are kept in enclosures and some of these enclosures have guard dogs. We studied the effect of such dogs on the behavior and breeding success of mountain gazelles Gazella gazella living within enclosures. We found that guard dogs have both direct and indirect effects on gazelles. Gazelles living in enclosures with dogs spent more time in vigilance behavior and running, and less time resting and walking, in comparison with gazelles in dog-free enclosures. In the absence of dogs, gazelle female herds in enclosures tended to stay closer to the cattle, but shunned away from them in the presence of the dogs, which, in turn, remained near the cattle. The percentage of fawns per female was higher in enclosures without dogs in comparison with those with dogs, but the difference was not significant. However, the largest of the enclosures with dogs, which had the largest number of gazelles, had only an average number of dogs in it. Hence, the gazelles in this enclosure were better able to avoid the dogs in comparison with those in smaller enclosures. Removing this enclosure from the overall calculation revealed that guard dogs have a significant negative effect on gazelle reproductive success. In two of the four enclosures with dogs no fawn still survived 6 months after birth, while in each of the four enclosures without dogs some fawns did survive to that age and beyond, suggesting that the dogs themselves may predate the fawns.  相似文献   

16.
17.
No published information exists on the chemical immobilization of free-ranging dholes (Cuon alpinus), binturongs (Arctictis binturong), or yellow-throated martens (Martes flavigula). We chemically immobilized these species in Thailand using a mixture of ketamine hydrochloride with xylazine hydrochloride (KH–XH) and tiletamine hydrochloride with zolazepam hydrochloride (TH–ZH). Mean (±SD) dose of KH–XH was 18.1±5.3 and 0.9±0.1 mg/kg for dholes (n=2), 19.7±4.1 and 1.3±0.4 mg/kg for binturongs (n=8), and 28.7±3.3 and 1.1±0.1 mg/kg for yellow-throated martens (n=5), respectively. Mean dose of TH–ZH was 4.1±0.1 mg/kg for dhole (n=2). Induction time, duration of anesthesia, and recovery time were satisfactory for standard field research procedures including radio-collaring, although the effects on yellow-throated martens and binturongs were more variable. Respiration and muscle rigidity were monitored during sedation with no observed adverse physiological effects. Individuals were released after full recovery and monitored via radio telemetry for 4–23 months with no observed detrimental effects due to chemical immobilization. We conclude that KH–XH and TH–ZH are safe and effective immobilization agents for these carnivores; however, we suggest testing different KH–XH ratios and dosages, and other immobilizing agents for these species.  相似文献   

18.
Neonate ruminants produce distress calls when captured by a predator and discomfort milk begging calls when hungry. In many neonate ruminants, the distress and discomfort calls are high‐frequency vocalizations, in which the fundamental frequency is the key variable for recognition of their emotional arousal by caregivers. In contrast, in this study, we examine the low‐frequency open‐mouth distress and discomfort calls in the neonates of two species of wild‐living ungulates, which clearly highlight vocal tract resonances (formants). In the goitred gazelle (Gazella subgutturosa), the distress calls were higher in fundamental frequency (f0) and in the first and third formants than the discomfort calls. The accuracy of classifying individuals by variables of distress calls with discriminant function analysis (67%) was significantly lower than that of discomfort calls (85%). In the saiga (Saiga tatarica), only the third formant was higher in the distress calls than in the discomfort calls. The accuracy of classifying individuals by variables of distress calls (89%) did not differ significantly from that of discomfort calls (94%). Thus, the use of acoustic cues to vocal identity and to the degree of arousal differs between the two species. Calls were significantly more individualistic in the saiga, probably because this species lives in large herds and neonates use a ‘following’ antipredatory strategy, in which vocal individuality is crucial for mother–offspring communication. In contrast, goitred gazelles live in smaller groups and neonates use a ‘hiding’ antipredatory strategy. Accordingly, mothers can rely on additional environmental cues for spotting their young and this may decrease the necessity for individualization of the calls of neonates.  相似文献   

19.
Long-term storage of semen by cryopreservation, with high recovery rates on thawing, is essential for the establishment of genetic resource banks of endangered species. The purpose of the present study was to evaluate various diluents for the cryopreservation of spermatozoa from three species of gazelles (genus Gazella) in a captive breeding program. The diluents compared were Tes (N-tris(hydroxymethyl)methyl-2 aminoethane sulfonic acid)-Tris with 5% egg yolk and 6% glycerol (TEST) and Triladyl, yolk-citrate, Tris-trehalose, and Tris-lactose-all of them with 20% egg yolk and 6% (Triladyl) or 8% glycerol. Semen was obtained by electroejaculation from 12 G. cuvieri, 12 G. dama, and 13 G. dorcas males. Samples with less than 50% motile sperm, positive endosmosis, or acrosome integrity were not used. Diluted samples were loaded into 0.25-ml straws, cooled slowly to 5 degrees C over 1.5 h (-0.16 degrees C/min), equilibrated at that temperature for 2 h, frozen in nitrogen vapors for 10 min, and plunged into liquid nitrogen. Subsamples were assessed fresh, after refrigeration-equilibration, after freezing and thawing, and 2 h after thawing. Differences were seen between diluents, with best overall recovery rates after freezing and thawing found with Triladyl, TEST, and Tris-trehalose in G. cuvieri, TEST in G. dama, and Triladyl and TEST in G. dorcas. Differences were observed between species in the ability to withstand freezing and thawing, with best results seen in G. dorcas, intermediate results in G. dama, and worst results in G. cuvieri. These differences were inversely related to the average values of inbreeding of these populations. The underlying mechanism responsible for these differences may be a differential resistance to osmotic shock.  相似文献   

20.
Gazella is one of the most species‐rich genera within horned ruminants. Despite overall similarity in body size and morphology, gazelles show variability in coloration and horn morphology. Unfortunately, however, species differentiation based on these characters, or on discrete skull characters, is very difficult due to high intraspecific variability. Furthermore, most species have fragmented and allopatric distributions, so that species boundaries were hard to define in the past. Mitochondrial DNA sequences have proven useful for investigating gazelle taxonomy in recent years, but especially for old museum material, i.e. type specimens, destructive sampling is often impossible. We provide a comprehensive morphometric framework for the genus Gazella based on linear skull measurements reconciled with results from molecular phylogenetic analysis based on the largest dataset available so far. In particular for males, the skull morphology shows interspecific differences concurrent with DNA data and provides a reliable tool for species identification. Based on morphometric data we synonymize G. karamii with G. marica, and confirm the identification of the G. arabica and G. a. rueppelli type skulls from analyses of mitochondrial DNA sequences. © 2013 The Linnean Society of London  相似文献   

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