雌性黄山短尾猴回避近亲交配

Inbreeding avoidance by female Tibetan macaques Macaca thibetana at Huangshan,China

本研究分别在交配期(2006年9月-2006年12月)和产仔期(2007年1月-2007年4月)对黄山短尾猴鱼鳞坑YA1群中5只雄猴和5只雌猴成年个体采用目标动物法、随机取样法和连续记录法记录行为参数。研究期间记录交配行为336例:母子交配0例;母系兄妹交配7例(占2.1%),其中强行交配4例;非亲缘关系交配329例(占97.9%),非亲缘关系交配频次显著高于亲缘关系。在交配期,雄猴对亲缘雌猴跟随、性检查频次均低于非亲缘雌猴,接近指数(PMI)在亲缘和非亲缘雌猴间无显著性差异;雌猴对亲缘雄猴交配拒绝率显著高于非亲缘雄猴,接近指数在交配期显著低于非亲缘雄猴,产仔期接近指数在亲缘和非亲缘雄猴间无显著性差异。尽管雄猴在交配选择上趋于避免与亲缘雌猴交配,但某些雄猴仍会主动对有亲缘关系的雌猴邀配或强行交配,雌猴则主动回避。这些结果表明:黄山短尾猴母系亲属间可以通过行为倾向抑制近亲交配发生,且雌猴更主动回避交配,支持了近交回避的双亲投资理论。

Mating with close relatives generally results in reduced reproductive success （inbreeding depression ） because it increases the risk that rare deleterious recessive alleles will be expressed in offspring, and such matings decrease the viability of resulting offspring. Parental investment theory suggests that if sexual aversion to close relatives does occur, it should be stronger in females than males because of females＇ greater investment in each offspring and hence greater potential costs resulting from less viable offspring. In this study, we collected data on the sexual behavior of adult males and females, using focal animal sampling, ad libitum sampling and continuous recording in YA1 troop at Huangshan from September 2006 to April 2007. Overall, 336 copulations were recorded during the study period in the focal troop. None of copulations involved in mother-son dyads; 7 （2.1% ） of copulations were among siblings; 329 （97.9%） of copulations were among non-kin dyads. During the mating season, males followed and sex-inspected their matrilineal females less than non-kin dyads. However, there was no significant difference in male＇ s Proximity Maintenance Index between kin and non-kin dyads. In females, the frequency of refusals of mating to kin was higher than non-kin males. There was a significant difference in female＇s Proximity Maintenance Index between kin and non-kin dyads in mating season. However, there was no significant difference during the birth season. Although males showed behavioral propensities inhibiting copulation between matrilineal relatives and matings with their kin females less than non-kin females in mating season, they occasionally sought copulations or force matings with kin dyads, but were always refused by females. However, the hourly rate of social grooming and proximity in matrilineal relatives was higher than that in non-kin dyads during the mating and birth seasons. These results strongly suggest that behavioral propensities inhibit copulations between matrilineal relatives in wild Thibetan macaques. Females appear to be more averse than males to copulating with relatives. Our results are consistent with parental investment theory