Size‐assortative choice and mate availability influences hybridization between red wolves (Canis rufus) and coyotes (Canis latrans)

Abstract

Anthropogenic hybridization of historically isolated taxa has become a primary conservation challenge for many imperiled species. Indeed, hybridization between red wolves (Canis rufus) and coyotes (Canis latrans) 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.

Taxonomic status of the Australian dingo: the case for Canis dingo Meyer, 1793

“…As a result, samples do not always reflect dingoes that do not encounter dogs. (3) There are some behavioural barriers that hinder hybridisation in canids (Hinton et al 2018). It is difficult for a feral domestic dog to integrate and compete with a large dingo population that has a stable pack structure (Corbett 2001b).…”

Rediscovery of Red Wolf Ghost Alleles in a Canid Population Along the American Gulf Coast

“…For red wolf ghost alleles to persist, a remnant Gulf Coast population would need to be relatively isolated from frequent interbreeding with coyotes [14]. Although red wolves that co-occur with coyotes in the NCEP exhibit assortative mating patterns [20], a geographic island would promote genetic isolation and the persistence of red wolf alleles. We report evidence that Galveston Island, Texas (TX) may represent one such location.…”

High genomic diversity and candidate genes under selection associated with range expansion in eastern coyote (Canis latrans) populations

“…As such, coyote hybridization with remnant populations of eastern (C. lycaon) and/or gray wolves (C. lupus) has been documented along the northeastern expansion route (Kays et al, 2010;Rutledge, Garroway, Loveless, & Patterson, 2010;vonHoldt et al, 2011;vonHoldt, Kays, Pollinger, & Wayne, 2016), as well as with red wolves (C. rufus) in the southeastern expansion front (Nowak, 2002). In particular, red wolves are believed to be extirpated outside of the North Carolina recovery area, but hybridization between red wolves and coyotes is well documented within that area (Bohling et al, 2016;Hinton, Gittleman, Manen, & Chamberlain, 2018). Further, several previous studies have also shown that eastern coyote populations have interbred with domestic dogs (Adams, Leonard, & Waits, 2003;Wilson, Rutledge, Wheeldon, Patterson, & White, 2012;Wheeldon, Rutledge, Patterson, White, & Wilson, 2013;Monzõn, Kays, & Dykhuizen, 2014).…”