雄性黄山短尾猴攻击行为和粪便睾酮水平季节性变化

睾酮对启动和维持雄性动物的性行为及保持雄性第二性征有重要作用,高浓度的睾酮还可促进雄性的攻击性。但是长时期维持高的睾酮水平还会使雄性付出很高的能量代价,所以雄性不会长时期地维持高的睾酮水平。本研究对黄山短尾猴鱼鳞坑YA2群雄性个体交配期（2006年9月-12月）与产仔期（2007年1月-4月）攻击行为进行研究,同时收集研究个体的新鲜粪便,并用放射免疫分析法测定粪便睾酮水平,以探讨雄性黄山短尾猴不同时期睾酮水平差异及睾酮水平与攻击行为的关系。结果表明,成年雄性黄山短尾猴攻击行为发生频次在交配期显著高于非交配期;成年雄性粪便睾酮水平在交配期显著高于非交配期;交配期成年雄性的粪便睾酮水平与攻击行为发生频次有较显著的正相关关系,而在非交配期无显著相关;低顺位个体在交配期和非交配期都没有观察到攻击行为。本研究的结果支持了“繁殖竞争假说”。     

非优势顺位雄性黄山短尾猴的交配策略

在多雄多雌、顺位决定交配机会、雄性偏斜繁殖的非人灵长类社会中,低顺位雄性为提高自己的繁殖成功率,通常采取多样的交配策略以获得较多的交配机会。对非优势顺位雄性交配策略的研究可以增加对灵长类社会性行为复杂性的理解,对于深入探讨动物的婚配制度及繁殖策略具有十分重要的科学意义。本研究采用目标动物取样法和全事件记录法,在2012年9-12月(交配期)记录了安徽黄山短尾猴鱼鳞坑YA1群中4只成年雄性个体的交配及有关的行为。研究发现:(1)非优势顺位雄性个体在远离优势顺位雄性视野范围的交配频次和交配时间显著高于优势顺位视野范围内;(2)与优势顺位雄性个体相比,非优势顺位雄性的强行交配(forced copulation)和隐秘交配(clandestine copulation)比例较高;(3)就交配对象而言,对成功生育的雌性个体,优势顺位雄性在选择交配对象时具有明显的倾向性,非优势顺位雄性在选择时倾向性不显著;对未生育的雌性,优势顺位雄性更倾向于选择没有生殖经历的亚成年雌性个体,非优势顺位雄性则倾向于选择处于哺乳后期的成年雌性个体;(4)在具体交配策略上,优势顺位雄性选择跟随(follow)雌性,非优势顺位雄性则通过做鬼脸(grimacing)和性追求(sexual chasing)直接获取交配机会。本研究结果表明黄山短尾猴中非优势雄性个体形成了多变的交配策略,更多采取强制性方式,以获得更多的交配机会,多数的交配都是机会性的。     

成年雌性短尾猴的社会联系强度及影响因素

灵长类动物社会中,个体间的社会关系是维系群体稳定的重要基础,也影响个体的寿命和繁殖成功。本研究以栖息于安徽黄山的短尾猴YA1群为对象,采用焦点动物取样法和行为取样法观察成年雌性个体在交配期(2015.9-2015.12)和非交配期(2016.3-2016.5)的社会行为,通过理毛和近距行为计算社会联系强度,探讨群体成员之间的社会关系及影响因素。结果表明:在交配期和非交配期,雌性短尾猴的社会联系强度无显著差异(t=0.181,P=0.857);亲缘关系和社会联系强度呈显著正相关(交配期:r=0.534,P=0.001;非交配期:r=0.469,P=0.001);个体间的等级距离和社会联系强度呈显著负相关(交配期:r=-0.288,P=0.014;非交配期:r=-0.238,P=0.048);年龄差异和社会联系强度无显著相关性(交配期:r=-0.176,P=0.181;非交配期:r=-0.192,P=0.151)。本研究提示成年雌性短尾猴个体间会形成稳定的社会关系,亲缘关系和等级顺位是影响个体之间社会关系的重要因素。     

雄性黄山短尾猴(Macaca thibetana)攻击支持雌性以换取交配回报

生物市场理论认为动物个体之间通过某种协定交换有价值的商品,使双方均受益。该研究采用目标动物法、行为取样法和连续记录法,对浮溪黄山野生猴谷鱼鳞坑短尾猴(Macaca thibetana)A1群(YA1群)和A2群(YA2群)成年个体在非繁殖季节(2011年8月—12月)和繁殖季节(2012年2月—5月)的雄性攻击支持雌性行为和交配行为进行研究,探讨雄性攻击支持雌性与交配之间的关系。两猴群在繁殖季节和非繁殖季节雄性攻击支持雌性与交配行为均呈显著正相关;YA2群繁殖季节与非繁殖季节攻击支持后交配频次均显著高于随机交配;YA1群在繁殖季节攻击支持后交配频次与随机交配频次差异不显著,但在非繁殖季节攻击支持后交配频次显著高于随机交配,说明短尾猴成年雄性攻击支持雌性可以换取与该雌性个体的交配回报。本研究验证了生物市场理论中社会行为存在交换,首次证明了雄性攻击支持可以换取雌性的交配回报,为进一步研究雄性性竞争与雌性选择提供了实例。     

黄山短尾猴交配叫声及其影响因素

哺乳动物在交配过程中经常会发出独特且有节奏的交配叫声（Copulation call）,这通常被认为是雌雄双方交配策略的一种体现。交配叫声的发生及其影响因素在不同物种间差异较大,对其深入研究有助于比较和揭示不同动物交配策略的差异及其适应性功能。为了阐明交配叫声的生物学和社会学因素,我们在安徽黄山记录了野生黄山短尾猴（Macaca thibetana）交配行为中雄性和雌性发出叫声的过程,分析了影响交配叫声的相关因素,探讨了伴随叫声的交配行为对后续友好行为的影响。结果表明,在交配过程中,高顺位成年雄性短尾猴比其他性别—顺位组个体更易发出叫声,而优势个体雌性和从属个体雌性在交配过程中的发声频次无显著差异。此外,交配叫声能促进参与者之间在交配后表现出更多的友好行为和更近的空间距离。本研究为理解多雄多雌婚配制度的短尾猴群体交配策略提供了声音通讯方面的理论支持。     

黄山短尾猴对游人攻击行为比较

为探讨黄山短尾猴对游人攻击行为与猴(行为发起者)和游人(行为承受者)年龄/性别组的关系,于2008年11-12月和2009年4-5月以黄山短尾猴鱼鳞坑YAl群和YA2群为研究对象,将其攻击行为按照危害程度大小划分为3类,采用全事件取样法和连续取样法观察记录猴对游人攻击行为类型、发生攻击行为的短尾猴和受到攻击的游人年龄/性别组,并统计猴群和游人数最.研究发现,成年雄猴所有攻击行为发生的比例显著高于期望值(P<0.01),成年雌猴和未成年猴攻击行为Ⅲ(威胁)发乍的比例显著低于期望值(P<0.01);在游人中,成年男性受到所有攻击发生的比例显著高于期望值(P<0.01),成年女性和末成年人受到攻击行为Ⅲ发生的比例显著低十期单值(P<0.01).结果表明,黄山矩尾猴对游人的攻击行为在人猴年龄/性别组中存在差异.成年雄性比成年雌性和未成年猴更易攻击游人,成年男性游人比成年女性和未成年人更易受剑短尾猴攻击.建议在管理过程中重点监控管理成年雄猴和提醒成年男性游人,这为进一步探讨人猴之间关系提供科学基础,并为其他类似地区生态旅游监管提供案例以供借鉴.     

短尾猴种群生态学研究Ⅱ.繁殖方式

黄山短尾猴鱼鳞坑群为季节性繁殖,属产仔节律型。据１９８８、１９９０和１９９２年有全年婴猴出生日期的记录,计算出平均产仔日期在４月２日。雌猴性成熟年龄为５．４±０．５岁,其繁殖率受年龄和个体在群内的社会顺位的不同而有所不同。顺位高的繁殖率高,产仔时间亦早。本文还首次提出了雌性产仔经历对一年度产仔影响的数据。     

两种性比类群的雄性黄山短尾猴繁殖行为和攻击行为比较

有效性比（operational sex ratio, OSR）是指性成熟雄性数量与发情雌性数量的比值,可作为测量性选择强度的指标。本文对两种有效性比的黄山短尾猴(Macaca thibetana)鱼鳞坑YA1群和YA2群成年雄性在交配期（2007年8—12月）内的繁殖行为和攻击行为进行研究,采用目标动物取样法、随机取样法和连续记录法记录行为,探讨有效性比对雄性黄山短尾猴交配竞争的影响。研究期间,YA1群的有效性比为0.4:1,YA2群的有效性比为0.9:1,YA2群的有效性比大于YA1群。在繁殖行为上,高顺位成年雄性的性检查、做鬼脸、性追赶和交配行为在两群间均存在显著差异,YA1群高于YA2群（P＜0.01）;中等顺位成年雄性的性检查、做鬼脸、性追赶在两群间均存在显著差异,YA1群高于YA2群（P＜0.01）,交配行为在两群间存在显著差异,YA1群高于YA2群（P＜0.05）;低顺位成年雄性在两群间不存在显著差异。在攻击行为上,高顺位成年雄性在两群间存在显著差异,YA2群高于YA1群（P＜0.01）;中等顺位成年雄性在两群间存在显著差异,YA2群高于YA1群（P＜0.05）;YA1群低顺位成年雄性攻击行为发生频次为零。结果表明,雄雌有效性比越大,雄性黄山短尾猴的交配机会越少,繁殖行为发生频次下降,竞争压力增大,攻击行为频次上升,因此YA2群成年雄性交配竞争强度高于YA1群。本研究结果支持性选择理论中有效性比对交配竞争作用的预测。     

黄山短尾猴的冬季产仔

动物的繁殖时间是动物在长期进化过程中对其栖息环境适应的结果。黄山的短尾猴属于季节性繁殖的动物,其产仔期一般在1～5月。但在2001年,记录了一例短尾猴在冬季产仔,产仔日期为11月29日。为分析其原因,依据1988～2001年连续14年的产仔数据及当地连续14年的气象资料(年平均气温、降水量及日照长度),统计学检验结果表明,黄山短尾猴产仔时间的推移与栖息地年平均气温显著相关(P<0 05),而与年平均降水量及日照长度无显著相关(P>0 05)。     

秦岭野生雌性川金丝猴粪便睾酮水平与邀配频次的季节性变化

为研究野生雌性川金丝猴(Rhinopithecus roxellana)不同季节体内睾酮水平与性行为频次的变化及二者的关系,我们以秦岭一野生川金丝猴种群为研究对象,通过长时间连续跟踪观察,完成了该种群中所有87只金丝猴的个体识别。用无损伤取样法采集了三只成年雌性川金丝猴不同季节的粪样,对粪样中的睾酮进行抽提测定,同时对采样个体的性行为进行记录。结果显示:1)成年雌猴在交配盛期与非交配盛期,粪样中睾酮水平均呈明显的周期性波动,交配盛期时睾酮水平的变化周期为24.56 d±4.07 d,非交配盛期时为43.67 d±2.89 d,显著长于交配盛期;2)成年雌猴在交配盛期的粪样睾酮水平为2.85 ng±1.12 ng/g,邀配频次为0.98±1.04次/d,非交配盛期时睾酮水平为1.71 ng±0.77 ng/g,邀配频次为0.28±0.53次/d,与交配盛期相比,非交配盛期的睾酮水平和邀配频次均明显降低;3)交配盛期各成年雌猴的粪样睾酮水平与邀配频次均有较显著的正相关关系(相关系数分别为0.631、0.683和0.659),而在非交配盛期这种相关关系并不存在(相关系数分别为0.091、0.493和0.205)。本研究表明,成年雌性川金丝猴体内睾酮水平、睾酮水平变化周期及邀配行为频次均具有明显的季节性差异,这种季节性差异可能是川金丝猴行季节性繁殖的内在原因和外在表现之一。本研究亦表明交配盛期雌猴的性行为频次在一定程度上可能受体内睾酮水平的控制,而在非交配盛期这种控制作用较弱。     

Long-Term Trends in Matrilineal Inbreeding Among the Japanese Macaques of Arashiyama B Troop

In a long-term study of sexual behavior in Japanese macaques, we found that matrilineal inbreeding accounted for 2.9% of the copulations recorded for the Arashiyama B troop during 7 mating seasons between 1968 and 1984. Of the 906 copulatory dyads, 46 (5.1%) occurred among kin. Close matrilineal kin dyads (r = 1/2–1/8, 1.1% of the total of copulatory dyads) strongly avoided matrilineal inbreeding, but for remote kin dyads (r > 1/8, 4.0% of the total) the tendency was weaker in some years. Among the possible determinants of matrilineal inbreeding, we found that it tended to occur among younger and lower-ranking males as an effect of troop demographic changes. There is no significant association between female rank and matrilineal inbreeding. Our results are consistent with the hypothesis that different degrees of kin relatedness are discriminated by individuals with respect to mate choice.     

Inbreeding avoidance in rhesus macaques: Whose choice?

Whether nonhuman primates avoid copulating with close kin living in their social group is controversial. If sexual aversion to relatives occurs, it should be stronger in females than in males because of females' greater investment in each offspring and hence greater costs resulting from less viable offspring. Data presented here show that adult male rhesus macaques breeding in their natal groups at Cayo Santiago experienced high copulatory success, but copulated less with females of their own matrilineages than with females of other matrilineages. Adult females were never observed to copulate with males of their own matrilineage during their fertile periods. Although natal males sometimes courted their relatives, examination of two measures of female mate choice showed that females chose unrelated natal males over male kin. Female aversion to male kin was specific to the sexual context; during the birth season, females did not discriminate against their male relatives in distributing grooming. Evolved inbreeding avoidance mechanisms probably produce different outcomes at Cayo Santiago than in wild rhesus macaque populations. Gender differences in sexual aversion to relatives may be partly responsible for differences between studies in reported frequency of copulations by related pairs. © 1993 Wiley-Liss, Inc.     

Female‐biased dispersal alone can reduce the occurrence of inbreeding in black grouse (Tetrao tetrix)

Although inbreeding depression and mechanisms for kin recognition have been described in natural bird populations, inbreeding avoidance through mate choice has rarely been reported suggesting that sex‐biased dispersal is the main mechanism reducing the risks of inbreeding. However, a full understanding of the effect of dispersal on the occurrence of inbred matings requires estimating the inbreeding risks prior to dispersal. Combining pairwise relatedness measures and kinship assignments, we investigated in black grouse whether the observed occurrence of inbred matings was explained by active kin discrimination or by female‐biased dispersal. In this large continuous population, copulations between close relatives were rare. As female mate choice was random for relatedness, females with more relatives in the local flock tended to mate with genetically more similar males. To quantify the initial risks of inbreeding, we measured the relatedness to the males of females captured in their parental flock and virtually translocated female hatchlings in their parental and to more distant flocks. These tests indicated that dispersal decreased the likelihood of mating with relatives and that philopatric females had higher inbreeding risks than the actual breeding females. As females do not discriminate against relatives, the few inbred matings were probably due to the variance in female dispersal propensity and dispersal distance. Our results support the view that kin discrimination mate choice is of little value if dispersal effectively reduces the risks of inbreeding.     

Strategic male mating effort and cryptic male choice in a scorpionfly

In animal species with high male mating effort, males often find themselves in a dilemma: by increasing their mating effort, the gain from each copulation increases but simultaneously reduces available resources and, thus, the opportunity for future copulations. Therefore, we expect males to spend less reproductive resources on matings that provide low reproductive potential, thereby saving resources for future copulations, possibly with high-quality females, a sort of cryptic male choice. However, the strength of the trade-off between investment in a current mating and resources available for future matings must not be the same for all males. Males with relatively high mating costs should allocate their limited resources more cautiously than males with more plentiful resources. Here, we examine this prediction in the scorpionfly Panorpa cognata. Prior to copulation, males produce a large salivary mass on which females feed during copulation. We show that the production of larger salivary masses leads to longer copulations. Moreover, the size of the salivary gland and salivary mass increases with increasing male condition. However, males in poor condition make a relatively higher mating investment than males in good condition. We therefore expect male condition to influence cryptic male choice. In accordance with our hypothesis, only males in poor condition choose cryptically, producing larger salivary masses in copulations with females of high fecundity.     

Homosexual incest avoidance among females in captive Japanese macaques

This paper reports a systematic pattern of homosexual incest avoidance among females in a captive group of Japanese macaques (Macaca fuscata) culled from the Arashiyama-West troop known for its high rates of female homosexuality. The study group included three matrilines and two generations. Between eight and 11 females were sexually active over four consecutive mating seasons, and all engaged in both heterosexual and homosexual activity. While all females performed homosexual acts with almost all possible non-kin partners, they systematically avoided homosexual interactions with their mother, daughters, and sisters. This pattern could not be explained either in terms of kin not being simultaneously in estrus, kin avoiding affiliative interactions in general, or non-kin utilizing the tension-reducing effect of estrus to affiliate exclusively with each other. In contrast to homosexual females, heterosexual pairs of relatives (brother-sister, mother-son) were sometimes incestuous. Assuming that female homosexuality expresses the reproductive strategy of females unconstrained by male influence, the present results point to the strong tendency of females to avoid incest and suggest that males are primarily responsible for the reported exceptions to incest avoidance.     

A life-history perspective on strategic mating effort in male scorpionflies

In species with high male mating effort, there is a trade-offbetween mating effort spent in a current mating and resourcesleft for future matings. Consequently, to maximize their reproductivesuccess, males have to invest strategically, saving resourcesin matings with low reproductive gain for future, more valuablematings. However, as males age, the expected future reproductivesuccess constantly declines. Thus, the importance of resource rationing may drastically change during a lifetime. Males ofthe scorpionfly Panorpa cognata offer females a costly nuptialgift before copulation, which functions as male mating effort.Resources for the production of these salivary masses are severelylimited for males in poor condition. We found that males investedmore in copulations with high-quality females than in copulationswith low-quality females. However, males ceased to discriminateas they became older. Old males, with a relative small numberof expected future matings, did not invest differentially incopulations with high- versus low-quality females. In copulationswith low-quality females, males invested more in late thanin initial matings, whereas in matings with high-quality females,time of mating had no influence on mating effort. These resultsimply that males adaptively change their resource allocationstrategy during the course of the season. Initial matings seemto be characterized by male prudence; in later matings, malesseem to adopt a more opportunistic mating strategy.     

Affiliative relations among male Japanese macaques (Macaca fuscata yakui) within and outside a troop on Yakushima Island

Male Japanese macaques (Macaca fuscata yakui) in a troop on Yakushima Island frequently groom other males. However, previous studies have not compared the social relations of troop males to those of non-troop males. I followed all troop males and non-troop males in and near a troop during a mating season and during the following non-mating season and recorded their neighbors, grooming, and agonistic interactions. Comparisons of the social relations of troop males and non-troop males with other troop members revealed that grooming and agonistic interactions with females during the mating season were similar between troop and non-troop males. However, troop males groomed each other more often and had fewer agonistic interactions among themselves than did non-troop males. Compared to what occurred in the mating season, troop males groomed females less often and exchanged grooming bouts more often with other troop males during the non-mating season. One non-troop male groomed females more frequently than did any troop male in both seasons, and this male groomed troop males more frequently than did any troop male in the non-mating season. This male immigrated into the troop during the following mating season. Regardless of their competition with respect to reproduction, male Japanese macaques on Yakushima Island maintain affiliative relations, probably to cooperatively defend fertile females from non-troop males.     

Birth-season interactions of adult female Japanese Macaques(Macaca fuscata) without newborn infants

The affiliative interactions of 11 adult female Japanese macaques that did not deliver an infant during the 1981 birth season of the Arashiyama West troop were examined. Consideration was given to the effects of kinship as a structuring element in these birth-season interactions and to the degree of association with various categories of troop members based on age, sex, and (in the case of adult females) whether or not the females were new mothers. Females without infants interacted predominantly with their yearling off-spring, although it was the behavior of the offspring that precipitated the interaction. These females were active in soliciting affiliation with nonkin new mothers, whereas female matrilineal relatives with new infants approached and remained in proximity to them more than did nonrelated new mothers. Females without newborns groomed and approached nonkin infants more than infants within their own matriline, and these infants were predominantly those of females in the highest-ranking matriline of the troop. Adult males were responsible for 40% of all grooming received from nonkin by the females without newborns, and these males approached them significantly more than did other adult females without infants. These patterns demonstrate that the structure of social relationships is influenced by the particular dynamics of troop contexts such as birth seasons, as well as by enduring, broad-based affinities which are less affected by cyclic changes in troop context.     

Avoidance of close consanguineous inbreeding in captive groups of rhesus macaques

In three captive groups of rhesus macaques (Macaca mulatto) the intensity of inbreeding avoidance was directly correlated with the closeness of kinship. The incidence of inbreeding between matrilineal relatives was lower than expected were mating to occur randomly with regard to matrilineal affiliation. The avoidance of mating between sons and their mothers and between matrilineal sibs contributed about squally to this outcome. The incidence of mating between more remote matrilineal relatives was lower than, but could not be shown to differ significantly from, that expected at the 0.05 level of probability. Familiarity fostered by interactions among matriline members probably provides a focus for avoidance of matrilineal inbreeding, and might influence male dispersal. Results of this study are consistent with reports of female rhesus macaques' avoidance of sexual activity with matrilineal male relatives as predicted by parental investment theory The observed incidence of inbreeding between patrilineal relatives was not different from that expected, but significantly fewer of the patrilineally inbred matings involved father/daughter matings than expected were mating random. Recognition of phenotypic similarities might provide a focus for avoidance of inbreeding between fathers and their daughters, but is loss reliable than strategies for avoiding matrilineal inbreeding. Adaptations for avoiding matrilineal inbreeding that are more effective than those for avoiding patrilineal inbreeding might have evolved because the risk of patrilineal inbreeding, and hence the resulting loss in fitness, is marginal compared to that for matrilineal inbreeding in free-ranging groups. © 1995 Wiley-Liss, Inc.     

Frequency of interspecific matings and of hybrid offspring in sympatric populations of Vtviparus ater and V. contectus (Mollusca: Prosobranchia)

In species pairs able to produce fertile hybrids, the amount of introgression can be limited by the frequency of interspecific copulations. We investigated the frequency of interspecific copulations between Kviparus ater and V. contectus and the proportion of hybrid offspring of V. ater females in natural populations in northern Italy. Although there was significant assortative mating, the frequency of interspecific copulations was substantial. At sites where V. contectus was rare, 5.9% of all matings, and up to 73% of matings in which V. contectus was involved, were interspecific. At sites where both species were abundant 14.8% of all matings were interspecific. Male-male matings occurred in approximately 3% of copulations. In 1993, 12 out of 325 V. ater females collected from 10 sympatric populations and held in isolation for two to five months gave birth to 25 hybrid offspring, out of a total of 2548 offspring produced by all females. The proportion of hybrid offspring (ranging from 0 to 2.3% depending on the site) was positively related to the proportion of V. contectus in the population. Since interspecific copulations are frequent and hybrid offspring are produced in nature, we conclude that assortative mating is not an effective isolating mechanism between V. ater and V. contectus.