CORRESPONDENCE
Focus on Red Wolf Reproductive Barriers, Not Coyote Demography Richard Fredrickson Missoula, MT (E-mail:
[email protected])
Received 6 January 2016 Accepted 3 February 2016
doi: 10.1111/conl.12235
After many years of effort, the U.S. Fish and Wildlife Service recently suspended its red wolf recovery program. The reintroduced population in North Carolina has failed to thrive, leading to questions of whether red wolves are recoverable. In an effort to “ . . . inform the ongoing program review and potential future direction of red wolf recovery” Murray et al. (2015) examined demographic data from the red wolf reintroduction program. They posited that for the reintroduced red wolf population to be viable, it must have higher survival or productivity than that of coyotes and hybrids in the area. And red wolves must kill coyotes and hybrids as part of their territorial aggression. They found that red wolves, coyotes, and hybrids had similar demographic rates. They also found that while red wolf deaths due to gunshot did not increase in 2009–2014 relative to that in 1999–2007, other forms of illegal take did. Among coyotes and hybrids, they noted that there were no deaths attributed to natural causes in the latter period suggesting red wolves appeared not to kill coyotes and hybrids as part of territorial interactions. Fredrickson & Hedrick (2006), however, found that the most important factors determining the success of red wolf populations were the extent to which two reproductive barriers operated, displacements of coyotes and hybrids by red wolves and positive assortative mating between red wolves and coyotes. Nearly as important was the survival of adult red wolves. In contrast, coyote demography had little effect on population outcomes suggesting that red wolves do not need to demographically outperform coyotes and hybrids to be successful. These
simulations assumed that coyotes would be a constant presence, and red wolves did not kill displaced coyotes and hybrids. These results are consistent with a large body of work concluding that reproductive barriers are essential for parental species to persist in the face of hybridization (Coyne & Orr 2004). Fortunately, evidence from the reintroduced red wolf population suggests that these reproductive barriers are operating. Gese & Terletzky (2015) found that there was an average 3.4 displacements annually of coyotes and hybrids by red wolves from 1999 to 2013. And Bohling & Waits (2015) found evidence suggesting positive assortative mating among red wolves. But they also found that high rates of human-caused mortality among red wolves, particularly gunshot mortality during the deer hunting season, drove hybridization. Assessing the strength of reproductive barriers and addressing factors weakening these barriers should be a major focus of the Service’s review. Murray et al. (2015) further noted habitat in the current reintroduction area may be inadequate to support a viable population of red wolves. If the current recovery area is likely incapable of contributing to recovery, the next step should be to examine the suitability of alternative areas for red wolf recovery. Dellinger et al. (Unpublished manuscript) may provide a starting point. They identify 21 additional areas that may be suitable for reintroduction. Thus, it is premature to conclude that red wolves should be relegated to being a “conservation reliant” species or that they are unrecoverable.
C 2016 The Authors. Conservation Letters published by Wiley Periodicals, Inc. 309 Conservation Letters, July/August 2016, 9(4), 309–310 Copyright and Photocopying: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Red wolf reproductive barriers
References Bohling, J.H. & Waits, L.P. (2015). Factors influencing red wolf–coyote hybridization in eastern North Carolina, USA. Biol. Conserv., 184, 108-116. Coyne, J.A. & Orr, H.A. (2004). Speciation. Sinauer Associates, Sunderland, MA. Dellinger, J.A., Shores, C.R. & Newsome, T.M. (In Press). Identifying sites for continued red wolf (Canis rufus) reintroduction in the eastern United States.
Fredrickson
Fredrickson, R.J. & Hedrick, P.W. (2006). Dynamics of hybridization and introgression in red wolves and coyotes. Conserv. Biol., 20, 1272-1283. Gese, E.M. & Terletzky, P.A. (2015). Using the “placeholder concept to reduce introgression of an endangered carnivore. Biol. Conserv., 192, 11-19. Murray, D.L., Bastille-Rousseau, G., Adams, J.R. & Waits, L.P. (2015). The challenges of red wolf conservation and the fate of an endangered species recovery program. Conserv. Lett., 8, 338-344.
C 2016 The Authors. Conservation Letters published by Wiley Periodicals, Inc. 310 Conservation Letters, July/August 2016, 9(4), 309–310 Copyright and Photocopying:
