Hinton Joseph W, Gittleman John L, van Manen Frank T, Chamberlain Michael J
Warnell School of Forestry and Natural Resources University of Georgia Athens GA USA.
Odum School of Ecology University of Georgia Athens GA USA.
Ecol Evol. 2018 Mar 23;8(8):3927-3940. doi: 10.1002/ece3.3950. eCollection 2018 Apr.
Anthropogenic hybridization of historically isolated taxa has become a primary conservation challenge for many imperiled species. Indeed, hybridization between red wolves () and coyotes () poses a significant challenge to red wolf recovery. We considered seven hypotheses to assess factors influencing hybridization between red wolves and coyotes via pair-bonding between the two species. Because long-term monogamy and defense of all-purpose territories are core characteristics of both species, mate choice has long-term consequences. Therefore, red wolves may choose similar-sized mates to acquire partners that behave similarly to themselves in the use of space and diet. We observed multiple factors influencing breeding pair formation by red wolves and found that most wolves paired with similar-sized conspecifics and wolves that formed congeneric pairs with nonwolves (coyotes and hybrids) were mostly female wolves, the smaller of the two sexes. Additionally, we observed that lower red wolf abundance relative to nonwolves and the absence of helpers increased the probability that wolves consorted with nonwolves. However, successful pairings between red wolves and nonwolves were associated with wolves that maintained small home ranges. Behaviors associated with territoriality are energetically demanding and behaviors (e.g., aggressive interactions, foraging, and space use) involved in maintaining territories are influenced by body size. Consequently, we propose the hypothesis that size disparities between consorting red wolves and coyotes influence positive assortative mating and may represent a reproductive barrier between the two species. We offer that it may be possible to maintain wild populations of red wolves in the presence of coyotes if management strategies increase red wolf abundance on the landscape by mitigating key threats, such as human-caused mortality and hybridization with coyotes. Increasing red wolf abundance would likely restore selection pressures that increase mean body and home-range sizes of red wolves and decrease hybridization rates via reduced occurrence of congeneric pairs.
历史上隔离的分类群的人为杂交已成为许多濒危物种面临的主要保护挑战。事实上，红狼（Canis rufus）和郊狼（Canis latrans）之间的杂交对红狼的恢复构成了重大挑战。我们考虑了七个假设，以评估通过两种物种之间的配对关系影响红狼和郊狼杂交的因素。由于长期的一夫一妻制和对多功能领地的防御是这两个物种的核心特征，配偶选择具有长期影响。因此，红狼可能会选择体型相似的配偶，以获得在空间利用和饮食方面行为与自己相似的伴侣。我们观察到多种影响红狼繁殖对形成的因素，发现大多数狼与体型相似的同种个体配对，而与非狼（郊狼和杂交种）形成同属配对的狼大多是雌性狼，即两性中体型较小的一方。此外，我们观察到相对于非狼，红狼数量较少以及没有帮手增加了狼与非狼交配的可能性。然而，红狼与非狼之间的成功配对与维持小家园范围的狼有关。与领地性相关的行为在能量上要求很高，而维持领地所涉及的行为（如攻击性互动、觅食和空间利用）受体型影响。因此，我们提出假设，配对的红狼和郊狼之间的体型差异影响正选型交配，可能代表了这两个物种之间的生殖障碍。我们认为，如果管理策略通过减轻关键威胁，如人为造成的死亡和与郊狼的杂交，来增加红狼在景观中的数量，那么在有郊狼存在的情况下，有可能维持红狼的野生种群。增加红狼数量可能会恢复选择压力，从而增加红狼的平均体型和家园范围大小，并通过减少同属配对的发生来降低杂交率。
