Coombs Keenin R, Weladji Robert B, Holand Øystein, Røed Knut H
Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montreal, QC, H4B1R6, Canada.
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Oluf Thesens vei 6, 1433 Ås, Norway.
Curr Zool. 2022 Jul 8;69(4):377-384. doi: 10.1093/cz/zoac054. eCollection 2023 Aug.
In polygynous systems, such as that exhibited by reindeer , mate choice can be difficult to disentangle from male intrasexual competition because male behavior may constrain female choice. Multiple mating may provide an avenue for female mate choice, though it is difficult to identify using behavioral estimators alone. Molecular techniques address this issue by affording ecologists an opportunity to reassess mating systems from a genetic perspective. We assessed the frequency and possible explanations for multiple mating in reindeer using a genetic approach to determine the success of observed copulations in a semi-domesticated herd in Kaamanen, Finland. Behavioral and genetic data were synthesized with population characteristics over a 7-year period to test the hypothesis that, if present, polyandry in reindeer is driven by sexual harassment from sub-dominant males. We observed multiple mating in 42% of females, with as many as 60% exhibiting multiple mating in certain years. We found no evidence that multiple mating resulted from sexual harassment by sub-dominant males, suggesting that it is likely a deliberate strategy among females. Conversion rate of copulations into paternities varied with male size, with smaller males more likely to experience mismatch than larger males. Female preference for larger males persisted despite the occurrence of multiple mating, possibly suggesting a mechanism for cryptic post-copulatory selection. We suggest further research to delineate the possible influence of cryptic post-copulatory selection and multiple mating to defend against infertility in exhausted males.
在一夫多妻制的系统中，比如驯鹿所表现出的那种，配偶选择可能很难与雄性间的竞争区分开来，因为雄性行为可能会限制雌性的选择。多次交配可能为雌性配偶选择提供一条途径，不过仅靠行为估计很难识别。分子技术通过为生态学家提供从基因角度重新评估交配系统的机会来解决这个问题。我们利用一种基因方法评估了驯鹿多次交配的频率及可能的原因，以确定在芬兰卡马宁一个半驯化鹿群中观察到的交配成功率。在7年时间里，将行为和基因数据与种群特征相结合，以检验这样一个假设：如果驯鹿存在一妻多夫制，那么它是由次优势雄性的性骚扰所驱动的。我们观察到42%的雌性存在多次交配情况，在某些年份，多达60%的雌性表现出多次交配。我们没有发现证据表明多次交配是由次优势雄性的性骚扰导致的，这表明多次交配可能是雌性的一种有意策略。交配转化为父权的比率因雄性体型而异，体型较小的雄性比体型较大的雄性更有可能出现错配情况。尽管存在多次交配，但雌性对体型较大雄性的偏好依然存在，这可能暗示了一种隐秘的交配后选择机制。我们建议进一步开展研究，以阐明隐秘的交配后选择和多次交配可能对抵御疲惫雄性的不育情况产生的影响。
