滇金丝猴0 - 3 岁个体的社会玩耍行为

2012 年7 月到2013 年4 月,对云南白马雪山国家级自然保护区一个人工辅助投食的滇金丝猴群进行观察,采用全事件取样法对该群全部0-3 岁30 只个体(雄性12 只、雌性18 只) 的社会玩耍行为进行了研究。研究结果表明:不同年龄段的社会玩耍频次存在显著差异,且玩耍频次与年龄段呈明显负相关;0-3 岁的滇金丝猴倾向于选择相同年龄段的个体作为玩耍伙伴;0-1 岁的个体更喜欢追逐(67.5%) 的玩耍行为,1-2 岁内的个体主要采取抓打(26.6% )、撕咬(25.3% )、追逐(40.5% )的玩耍行为;2 -3 岁的个体各种玩耍行为的频次有明显差异。0-3 岁的雄性个体比雌性个体的玩耍频次更高。研究结果表明,0-3 岁滇金丝猴的社会玩耍行为符合年龄阶段假说、性别差异假说和运动技能训练假说。     

Phylogeography and population structure of the Yunnan snub-nosed monkey (Rhinopithecus bieti) inferred from mitochondrial control region DNA sequence analysis

Rhinopithecus bieti, the Yunnan snub-nosed monkey, is the nonhuman primate with the highest altitudinal distribution and is also one of the 25 most globally endangered primate species. Currently, R. bieti is found in forests between 3000 and 4500 m above sea level, within a narrow area on the Tibetan Plateau between the Yangtze and Mekong rivers, where it is suffering from loss of habitat and shrinking population size (approximately 1500). To assess the genetic diversity within this species, its population structure and to infer its evolutionary history, we sequenced 401 bp of the hypervariable I (HVI) segment from the mitochondrial DNA control region (CR) for 157 individuals from 11 remnant patches throughout the fragmented distribution area. Fifty-two variable sites were observed and 30 haplotypes were defined. Compared with other primate species, R. bieti cannot be regarded as a taxon with low genetic diversity. Phylogenetic analysis partitioned haplotypes into two divergent haplogroups (A and B). Haplotypes from the two mitochondrial clades were found to be mixed in some patches although the distribution of haplotypes displayed local homogeneity, implying a strong population structure within R. bieti. Analysis of molecular variance detected significant differences among the different geographical regions, suggesting that R. bieti should be separated into three management units (MUs) for conservation. Based on our results, it can be hypothesized that the genetic history of R. bieti includes an initial, presumably allopatric divergence between clades A and B 1.0-0.7 million years ago (Ma), which might have been caused by the Late Cenozoic uplift of the Tibetan Plateau, secondary contact after this divergence as a result of a population expansion 0.16-0.05 Ma, and population reduction and habitat fragmentation in the very recent past.     

First direct evidence of infanticide and cannibalism in wild snub-nosed monkeys (Rhinopithecus bieti)

Although infanticide has been witnessed in many species of Colobinae, and a case was observed in a captive group of golden snub-nosed monkeys (Rhinopithecus roxellana), observed cases of infanticide in wild snub-nosed monkeys (Rhinopithecus spp.) have not previously been recorded. Here we describe the killing of a 1-month-old infant by a male in a black-and-white snub-nosed monkey (R. bieti) group at Xiaochangdu in Tibet. The infanticidal attack was witnessed as part of a long-term observational study of ecology and behavior that began in June 2003. The male was observed killing and eating the infant. The literature proposes three main explanations for infanticide: two adaptive hypotheses (sexual selection and resource competition), and one nonadaptive hypothesis (social pathology). Individual cases of infanticide, such as this one, are important for comparative purposes, but when examined on their own they are difficult to interpret in relation to established theoretical frameworks. The cases we describe here show some consistency with the sexual selection hypothesis, but the lack of critical information (i.e., as to paternity) makes it impossible to draw a firm conclusion. This is also the first described case of cannibalism in snub-nosed monkeys.     

Social organization of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Deqin, China

Data on social organization of two bands of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were collected when the monkeys were crossing an open spot at Nanren and Bamei (northwest of Yunnan, China) using a sampling rule where individuals within one social unit are spatially closer to each other than individuals between social units. The typical pattern of social organization in this sample was multiple adult females (AFs) and their offspring with one adult male (AM) in a one-male unit (OMU), similar to that of many other colobines. In such units, on average one male is associated with 4.0 AFs and 2.5 of their offspring. Moreover, there are multimale/multifemale units and monogamous units besides OMUs. All bisexual units traveled together with at least one all-male unit as a cohesive band. In two bands of monkeys, 87% of AMs in bisexual units were within OMUs, 7.8% within monogamous units and 5.2% within multimale, multifemale units. In the Bamei band, 6.7% of AMs were in the all-male unit. The size of OMUs in the Nanren band was larger than that of the Bamei band, with more AFs and juveniles, which may be related to better conservation in the Nanren band's habitat. For the Nanren band, the average number of AFs in OMUs varied across time, increasing from 4.3 in 1994 to 5.1 in 2001, and then decreasing to 3.8 in 2005. This article suggests three possible explanations for this variation, but more data are needed for these hypotheses to be tested.     

云南富合山地区滇金丝猴游走模式的季节性差异

从 2 0 0 0年 11月至 2 0 0 2年 1月 ,我们在云南富合山 (99°2 0′E ,2 6°2 5′N)记录了滇金丝猴 (Rhinopithe cusbieti)的游走以及其他行为 ,以描述猴群行为模式的季节性变化及其对温带环境的适应。由于季节间行为方式的相似 ,我们将冬季和春季、夏季和秋季的数据合并表述。猴群终年以取食树叶为主 ,多在过夜地附近活动。在冬 -春季 ,猴群一般在低海拔的南部地区活动 ,同时缩短日行走距离 ,花费较多的时间取食树叶、竹叶和竹笋 ;而在夏 -秋季猴群的活动模式与冬 -春季相反 ,并取食大量果实。我们将富合地区猴群的季节性游走模式以及食性看作是食物供给和温度变化之间折中的结果 ,这些行为特征和其它温带灵长类的相似。此外 ,过夜地的分布也会影响猴群利用家域内各方格的方式     

白马雪山自然保护区响古箐滇金丝猴（Rhinopithecus bieti）的交配行为

灵长类交配模式是灵长类社群结构和婚配制度的重要表征之一,其研究有助于了解灵长类社群结构和两性交配策略。2013年11月至2014年10月,我们对云南白马雪山国家级自然保护区一人工辅助投食滇金丝猴群进行了观察研究,采用焦点动物取样法和全事件记录法收集了雌雄个体的交配相关的行为数据,主要包括邀配对象、交配过程、持续时间和回合数,以及参与交配的雌雄对在交配结束后的相互理毛的持续时间和回合数。研究结果表明：研究群滇金丝猴全年均有交配行为,交配高峰期在7-9月,两性参与交配的积极性和对季节变化的响应不同;交配主要由雌性通过邀配发动（76%）,交配高峰期也是雌性邀配的高峰期;雄性爬跨频次（年均0.43次/月,n=5）和射精爬跨比（年均19%,n=5）则在全年无显著变化。交配行为发生的典型表现为：雌性通过小跑或跳跃进入雄性视线范围内,爬伏呈臀向雄性邀配;雌猴爬伏时离雄猴的远近距离不同（<1m vs. 2-5m ： 69% vs. 31%）会影响其邀配成功率（<1 m vs. 2-5 m ：68% vs. 40%）;若一次邀配失败,雌猴可能会连续爬伏邀配（最多4次）,连续多次邀配的成功率显著高于单次邀配（79% vs. 52%）。交配结束后雌性会主动为雄性理毛,但雌性主动理毛与交配是否射精无关。     

Dominance hierarchy and social relationships in a group of Captive black-and-white snub-nosed monkeys (Rhinopithecus bieti)

Different types of dominance hierarchies reflect different social relationships in primates. In this study, we clarified the hierarchy and social relationships in a one-male unit of captive Rhinopithecus bieti observed between August 1998 and March 1999. Mean frequency of agonistic behaviour among adult females was 0.13 interactions per hour. Adult females exhibited a linear hierarchy with a reversal of 10.9%, indicating an unstable relationship; therefore, R. bieti appears to be a relaxed/tolerant species. The lack of a relationship between the agonistic ratio of the adult male towards adult females and their ranks indicated that males did not show increased aggression towards low-ranking females. Differentiated female affiliative relationships were loosely formed in terms of the male, and to some extent influenced by female estrus, implying that relationships between the male and females is influenced by estrus and not rank alone. A positive correlation between the agonistic ratio of adult females and their ranks showed that the degree to which one female negatively impacted others decreased with reduction in rank. Similarly, a positive correlation between the agonistic ratio of females and differences in rank suggests that a female had fewer negative effects on closely ranked individuals than distantly ranked ones. These data indicate that rank may influence relationships between females. A steeper slope of regression between the agonistic ratio and inter-female rank differences indicated that the extent of the power difference in high-ranking females exerting negative effects on low-ranking ones was larger during the mating season than the birth season, suggesting that rank may influence the mating success of females.     

白马雪山自然保护区格花箐滇金丝猴夜宿地的季节性选择

2005年9月至2006年9月,在白马雪山自然保护区南端的格花箐,对一群(约250只)滇金丝猴的夜宿地选择与利用情况进行调查.整个调查历时13个月,确认研究群的夜宿点54个,共记录夜宿地的利用次数137次,提示研究群在其中一些地点多次夜宿.滇金丝猴夜宿地在平均海拔分布上存在明显的季节性差异:夏季猴群夜宿地的平均海拔为3 352 m,为一年中夜宿地分布最高的时期;春季猴群则多选择在低海拔地区夜宿,平均海拔在一年中最低(3 082 m).猴群夜宿地集中分布于3 200～3 400 m的海拔范围,随季节变化,不同海拔梯度上的夜宿地数量和利用频次差异明显.虽然猴群夜宿地主要位于针阔混交林中,但是不同季节猴群夜宿地植被的组成明显不同.猴群明显偏好在位于南坡面和西坡面的地点过夜,在夏季和秋季尚未发现北坡向的夜宿地.研究还表明,不同季节,猴群都会不同程度地在少数几个地点多次过夜,但大多数夜宿地在一年中仅利用一次.滇金丝猴为什么会对某些地点多次利用尚需进一步研究证实.     

Sleeping sites of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Baima Snow Mountain, China

Data on sleeping sites of a group of black-and-white snub-nosed monkeys Rhinopithecus bieti (Colobinae, Primates) were collected between April–July and September–December 2001 to try to determine the factors affecting site selection at Nanren (99°04'E, 28°34'N, Baima Snow Mountain, China). Sleeping trees were tall emergents (27.5±3.2 m) with large diameter at breast height (57.9±16.9 cm) and broad crown diameters (6.3±1.4 m), and significantly larger than other trees. The use of large sleeping trees could provide effective shelters from attacks of terrestrial and aerial predators, heavy snow and rain. Sleeping sites were changed nightly and located at significantly lower altitudes in winter months than in other seasons, which might be a thermoregulatory adaptation or related to snow covering. Such sites tended to be at the middle of sun-oriented slopes, possibly trading off predator avoidance and foraging efficiency.     

First evidence of prey capture and meat eating by wild Yunnan snub-nosed monkeys Rhinopithecus bieti in Yunnan,China

Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey Rhinopithecus bieti in a wild, habituated group between 2004 and 2009 in Yunnun, China. At present,only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum.     

中国云南塔城滇金丝猴的社会结构

在云南塔城附近的山地森林中,我们利用摄象机记录了一群滇金丝猴通过山谷和在水源地饮水的过程。我们利用这些记录分析这群滇金丝猴的种群大小、组成成员以及个体的空间分布,并利用连续通过个体之间的时间间隔来揭示社会结构。塔城滇金丝猴群由366个个体组成,是目前所知最大的滇金丝猴群体。猴群内雌性个体较多。猴群可以分为26个单位,其中有19个单雄多雌单位、5个多雄多雌单位和2个全雄单位。统计结果表明单位内个体间的时间间隔显著比单位间的短。2/3以上的亚成年雄性个体和全雄单位一起活动。猴群在地面活动时全雄单位位于猴群的外围,充当前卫和后卫。塔城猴群的生命表组成结构与吾牙普亚猴群的大致一样,同样是多层社会结构,单雄多雌和全雄单位构成猴群的主体。亚成年雄性多数与全雄单位一起活动,表明雄性可能会从其出生的单雄多雌单位中迁移出来。     

西藏红拉雪山滇金丝猴的夜宿地与夜宿树选择

树栖灵长类动物要在夜宿地度过半生以上的时光,因此选择合适的夜宿地及夜宿树对其存活尤为关键。影响夜宿地以及夜宿树选择的主要因素是逃避天敌捕食,但对于栖息在温带森林的灵长类而言,还必须面对低 温以及食物缺乏等因素的影响。2003 年6 月至2005 年3 月,采用跟踪猴群,记录夜宿地并依据地面粪便颗粒数确定夜宿树,在西藏红拉雪山自然保护区对小昌都滇金丝猴的夜宿地及夜宿树进行了研究。结果表明:在主要 研究时间段196 d 夜宿地记录中猴群使用了101 个夜宿地,使用2 次以上的夜宿地有67 个,夜宿162 d。夜宿地全部位于针叶林中,冬季夜宿地主要分布在向阳、背风和低海拔处。比较重复利用夜宿次数多与夜宿次数少的树发现:夜宿多的树高大,底枝长,而与底枝高没有差异。比较夜宿和不过夜的树发现:夜宿树高大、底枝长。这些特点表明小昌都猴群夜宿地及夜宿树的选择可能受到逃避天敌和体温调节的影响。     

传统文化和社会经济活动对生物保护的正面影响: 来自西藏黑白仰鼻猴的实例研究(英文)

黑白仰鼻猴(Rhinopithecus bieti)是仅存于滇西北和藏东南的横断山脉的濒危灵长类动物,目前仅有野外15群约2500只个体,并且西藏红拉雪山自然保护区的小昌都群也许是自1988年调查以来唯一数量保持稳定的种群。通过调查访问、以及分析社会经济数据中隐含的保护信息,该文通过实例研究探讨了传统文化和社会经济发展模式对红拉雪山自然保护区小昌都猴群的影响,试图探讨传统文化和人类活动对该猴群种群保持稳定的正面影响:1)研究结果表明传统的生产方式对黑白仰鼻猴的生境保护有益,例如主要依靠畜牧业和非木材的林产品而不是毁林开荒种植青稞;2)受印度教和佛教影响的藏传佛教对生灵的敬畏,避免当地村民对黑白仰鼻猴的猎杀;3)一妻多夫的大家庭,其人均资源消耗(特别是薪柴,建房木材等)明显比一夫一妻的小家庭少,这种婚俗也许可以缓解人类索取相应自然资源时对黑白仰鼻猴的生境破坏。因此,考虑到小昌都是唯一种群稳定的群,我们认为是当地的社会生产方式、宗教文化以及婚俗习惯让小昌都群长期维持在该生境的最大容纳量。     

Changes of urinary steroid conjugates and gonadotropin excretion in the menstrual cycle and pregnancy in the Yunnan snub-nosed monkey (Rhinopithecus bieti).

The Yunnan snub-nosed monkey (Rhinopithecus bieti) is one of the most endangered species in the world, and it is endemic to China. According to our knowledge, there was no information on reproduction for this species. The present study was designed to understand the characteristics of reproductive hormone secretion during the menstrual cycle and pregnancy of this species by monitoring urinary estrone conjugate (E1C), pregnanediol-3-glucuronide (PdG), bioactive follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The urine samples were collected each day from four adult females for eight menstrual cycles, and once in 3 days during pregnancy (three full-term pregnancies, one mid-term abortion). The steroid conjugate was tested by radioimmunoassays (RIAs), and bioactive FSH and LH levels were measured in vitro by the sensitive bioassays granulosa cell aromatize bioassay (GAB) and rat interstitial cell testosterone (RICT), respectively. The results showed that: 1) E1C presented a preovulatory peak (183.9 +/- 8.6 ng/mgCr) followed by a definite elevation of PdG; 2) PdG in the luteal phase (754.4 +/- 30.6 ng/mgCr) was three- to fivefold higher than during the corresponding follicular phase (198.3 +/- 11.4 ng/mgCr); 3) the peaks of bio-LH and bio-FSH were on the same day, while the E1C peak was 1 or 2 days before the peaks for these two hormones; 4) bio-FSH levels were higher in the follicular phase than in the luteal phase, and bio-LH levels elevated slightly in the luteal phase; 5) the mean cycle length was 23.6 +/- 3.5 days (n = 3) based upon successive urinary LH peaks; 6) based on the interval from the day of E1C peak to the day of parturition, the gestation was 203.7 +/- 2.5 days (n = 3); and 7) both E1C and PdG increased and remained high after pregnancy, with a sharp decrease in basal levels following parturition or mid-term abortion. The results suggested that the pattern of reproductive hormones for R. bieti is similar to that of other Old World monkeys, but the concentration of the hormones is different from that of other species. This species has a longer progestation period, which may be related to its classification status.     

Habitat selection of black-and-white snub-nosed monkeys (Rhinopithecus bieti) in Tibet: implications for species conservation

As anthropogenic habitat changes are often considered a threat to natural ecosystems and wildlife, a sound understanding of the effects of habitat alteration on endangered species is crucial when designing management strategies or performing conservation activities. Black-and-white snub-nosed monkeys (Rhinopithecus bieti) are categorized as endangered on the IUCN Red List and are endemic to the trans-Himalayas in China. At present, there are only 15 groups and 2,500 individuals remaining in the wild, and they are facing intense habitat degradation with selective logging for house building and firewood. Habitat deterioration through wood extraction is occurring at Xiaochangdu, Tibet, where one stable group of R. bieti lives in a marginal habitat in the northernmost part of the species' distribution. To understand the species' response to selective logging in an extremely marginal habitat, data on habitat preference and diet composition of a group of R. bieti were collected at Xiaochangdu from 2003 to 2005. The monkeys used different habitats nonrandomly during the year. The selection index for secondary conifer forest (SC), where selective logging has occurred, was the highest of all habitat types (>1), suggesting that the groups strongly preferred SC. The monkeys fed more on buds/leaves, more on flowers/fruit/seeds, and less on lichen in SC than in primary conifer forest (PC). Dietary diversity was significantly higher in SC than in PC. These results indicate that over the short term, low-intensity disturbances may result in increased foliage diversity that enable groups of R. bieti to survive in this marginal habitat.     

Effects of anthropogenic intermixing on the genetic structure of Dybowski's frog populations in northeast China

The Dybowski's frog (Rana dybowskii) is mainly distributed in northeast China and the Russian Far East. Its dried oviduct, or frog oil, has been used in traditional Chinese medicine for thousands of years. Frogs from different geographic regions exhibit variations in their body mass and oil productivity. As a result, farmers usually import high quality breeding stock from different areas to increase oviduct productivity. This practice could alter the genetic structure of the frog populations. We used 10 microsatellite loci to investigate the level of genetic variation for 10 frog populations in the context of human-mediated disturbance. The study populations comprised the following: the Hebei, Tieli, and Jiamusi populations from the Lesser Khingan Mountains; the Mudanjiang, Jilin, Jiaohe, and Huadian populations from the north central Changbai Mountains; and the Tonghua, Benxi, and Xiuyan populations from the southern Changbai Mountains. Our results showed that the 3 Lesser Khingan Mountain populations exhibited highly significant differentiation values (F_ST = 0.047–0.071, P < 0.001). In addition, the Tonghua population differentiated significantly from the other 6 populations of the Changbai Mountains (P < 0.001). The genetic differentiation coefficient (F_ST) and gene flow (N_em) estimates showed that the Benxi and Jiaohe populations had a high degree of genetic similarity despite being geographically separated by mountains and river systems. We obtained similar results for the Xiuyan and Tieli populations. Furthermore, the degree of gene flow between the Jiamusi and the north central Changbai Mountain populations was greater than that observed between the Jiamusi and the other Lesser Khingan Mountain populations. These results therefore suggest that the Benxi, Xiuyan, and Jiamusi populations have undergone substantial intermixing because of human-mediated relocation. Economic demands make completely stopping the geographical relocation of Dybowski's frog in northeast China virtually impossible. Consequently, effective management strategies are now a high priority to ensure that conservationists and local economies can work together to guarantee the long-term survival of this species. © 2013 The Wildlife Society.     

基于景观遗传学的滇金丝猴栖息地连接度分析

结合景观遗传学,应用最小费用距离模型对物种栖息地进行连接度分析,能够为生物多样性保护和自然保护区管理提供更加真实准确及可实践操作的指导。选取滇金丝猴这一珍稀濒危物种,结合景观遗传学,应用最小费用距离模型对其栖息地进行了连接度和潜在扩散廊道分析。并且通过连接度的分析和制图绘制出了更为准确的种群间潜在扩散廊道,确定了受人工障碍影响的廊道及敏感区域。结果表明,研究区内的5个亚群中,仅S3亚群内的5个猴群保持着较好的连接度,总体来说,各亚群内的连接度相对于各亚群间连接度保持的较好。除S3亚群中猴群间的潜在扩散廊道较为理想外,其余种群间的潜在扩散廊道均受人工斑块的影响,多数廊道被人工障碍阻断,或面临即将被阻断的情况,对于滇金丝猴的扩散交流影响较大。敏感区域多集中在中南部的3个亚群间,这些敏感区域应作为景观恢复及保护区规划的重要优先区域。     

Phylogeography and population structure of the golden monkeys (Rhinopithecus roxellana): inferred from mitochondrial DNA sequences

The golden monkey (Rhinopithecus roxellana) is one of the most endangered primate species due to its dramatically shrinking distribution during the past 400 years. Its populations are restricted to three isolated regions, Qinglin (QL), Sichuan/Gansu (SG), and Shennongjia (SNJ) in China. As with other snub-nosed monkeys in China and Vietnam, the biology and evolution of this species is still poorly known. To assess genetic differentiation and explore the relationships among populations of golden monkeys from different geographic locations, 379 bp of mitochondrial DNA control region (CR) hypervariable segment I (HVI) was studied from 60 individuals. Twelve haplotypes were identified from seven populations within the three regions. Haplotype diversity was high (0.845), whereas nucleotide diversity among all haplotypes was low (0.0331). The most recent common ancestor (TMRCA) among mtDNA haplotypes was estimated to have lived approximately 0.48-0.32 million years ago. None of the haplotypes is shared among any of the three regions. Phylogenetic analysis and AMOVA revealed clear and significant phylogeographic structure between the three regions. However, only SG contained haplotypes of the two main clades, indicating either incomplete random sorting of haplotypes or a complex history with phases of population subdivisions and merging of populations. The phylogeographic structure implies that R. roxellana should be regarded as separate management units (MUs) for each of the three regions. It is likely that recent phylogeographic history has shaped the pattern of genetic differentiation observed in the golden monkey and that its populations have suffered significant demographic fluctuation.     

Contemporary genetic structure of Xantus's Hummingbird (Basilinna xantusii) in the Baja California peninsula

Genetic structure and phylogeographic patterns of natural populations are of great importance in assessing the conservation status of species. These population properties can be estimated using molecular markers of either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) to understand the historical, ecological and dispersal patterns that influence genetic exchange within and between populations. Basilinna xantusii is a sexually dimorphic hummingbird endemic to the Baja California Peninsula (BCP). It comprises three ancestral mitochondrial lineages linked to vicariant events, late Pleistocene climate changes and the geographical distribution of oases. This study aimed to determine and understand the current population genetic structure of this hummingbird. The genotypes of 16 microsatellite loci from 100 individuals collected across the geographical range of this species were compared with mtDNA sequences previously published. Cluster analyses identified five populations, two with almost no genetic admixture in the northern part of the BCP and three others with varying levels of admixed ancestry across the BCP. In San José de Magdalena, at the northernmost end of the range of Xantus's Hummingbird, 40% of individuals collected belong to one genetic cluster and the remaining 60% to another, both genetic clusters showing very little admixed ancestry. We hypothesize that, despite being in sympatry, these individuals do not interbreed, unlike the other populations where individuals showed ancestry coefficients of the other genetic groups. The philopatric behaviour of males and the long-range dispersal capacity of females probably determine the observed genetic differentiation pattern. The mito-nuclear discordance detected could be due to the molecular markers used and to female-biased dispersal. Gene flow is asymmetric in this species, being greater from north to south than vice versa, which is probably related to differences in the seasonality of precipitation across the BCP and to urbanization of the oases.     

Effects of structural connectivity on fine scale population genetic structure of muskrat,Ondatra zibethicus

In heterogeneous landscapes, physical barriers and loss of structural connectivity have been shown to reduce gene flow and therefore lead to population structuring. In this study, we assessed the influence of landscape features on population genetic structure and gene flow of a semiaquatic species, the muskrat. A total of 97 muskrats were sampled from three watersheds near Sudbury, Ontario, Canada. We estimated population genetic structure using 11 microsatellite loci and identified a single genetic cluster and no genetic differences were found among the watersheds as a result of high levels of gene flow. At finer scales, we assessed the correlation between individual pairwise genetic distances and Euclidean distance as well as different models of least cost path (LCP). We used a range of cost values for the landscape types in order to build our LCP models. We found a positive relationship between genetic distance and least cost distance when we considered roads as corridors for movements. Open landscapes and urban areas seemed to restrict but not prevent gene flow within the study area. Our study underlines the high‐dispersal ability of generalist species in their use of landscape and highlights how landscape features often considered barriers to animal movements are corridors for other species.