Department of Anthropology, Stony Brook University, Stony Brook, NY, 11794-4364, USA.
Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, USA.
Primates. 2021 Jan;62(1):11-17. doi: 10.1007/s10329-020-00852-z. Epub 2020 Aug 17.
Hybridization is increasingly recognized as an important mechanism of evolutionary change in the order Primates. Here, we present the first observational data supporting natural hybridization between the critically endangered purple-faced langur (Semnopithecus vetulus philbricki) and the threatened tufted gray langur (Semnopithecus priam thersites) in Kaludiyapokuna Forest Reserve in Sri Lanka. In one case study, we observed a long-term (> 1 year) mixed-species group consisting of one adult tufted gray langur male coexisting with seven adult purple-faced females. Although copulations were not observed, two infants were conceived during the male's tenure, and the coat color of one of these infants transitioned into that intermediate between those of the two langur species. The tufted gray langur male was also aggressive toward extra-group males of both species, as well as towards purple-faced juveniles within his group. However, we never witnessed the male exhibiting aggression towards the infants conceived during his tenure. In a second case study, a female purple-faced langur visited and sexually solicited a tufted gray langur male in a known study group of this species over the course of 2 days, in what resembled a sexual consortship. Taken together, the observed mixed-species association and attempted interspecific mating suggest that hybridization is very likely in these sympatric species. Genetic data are needed to confirm and determine the extent of hybridization in the dry zone of Sri Lanka where purple-faced langurs live in sympatry with tufted gray langurs.
杂交被越来越多地认为是灵长目动物进化变化的一个重要机制。在这里，我们首次提供了支持在斯里兰卡 Kaludiyapokuna 森林保护区的濒危紫脸长尾猴（Semnopithecus vetulus philbricki）和受威胁的冠毛长尾猴（Semnopithecus priam thersites）之间发生自然杂交的观察数据。在一个案例研究中，我们观察到一个长期（>1 年）的混合物种群体，其中包括一只成年冠毛长尾猴雄性与七只成年紫脸长尾猴雌性共存。虽然没有观察到交配，但在雄性的任期内，有两只婴儿受孕，其中一只婴儿的毛色介于两种长尾猴之间。这只冠毛长尾猴雄性也对两个物种的外群雄性以及其群体内的紫脸长尾猴幼崽表现出攻击性。然而，我们从未目睹雄性对其任期内孕育的婴儿表现出攻击性。在第二个案例研究中，一只雌性紫脸长尾猴在两天的时间里访问并向一只已知的冠毛长尾猴雄性求爱，这类似于性伴侣关系。总的来说，观察到的混合物种关联和尝试的种间交配表明，在这些同域物种中，杂交很可能发生。需要遗传数据来确认和确定在斯里兰卡干燥地区紫脸长尾猴与冠毛长尾猴同域生活的情况下杂交的程度。
