Essay Selecting for Tolerance against Pathogens and Herbivores to Enhance Success of Reintroduction and Translocation MATTHEW D. VENESKY, ∗ † JOSEPH R. MENDELSON III,‡§ BRITTANY F. SEARS, ∗ PETER STILING, ∗ AND JASON R. ROHR ∗ ∗ Department of Integrative Biology, The University of South Florida, 4202 East Fowler Avenue, SCA 110, Tampa, FL 33620, U.S.A. ‡Zoo Atlanta, 800 Cherokee Avenue SE, Atlanta, GA 30315, U.S.A. §Georgia Institute of Technology, School of Biology, 301 Ferst Drive, Atlanta, GA 30332, U.S.A. Abstract: Some species have insufficient defenses against climate change, emerging infectious diseases, and non-native species because they have not been exposed to these factors over their evolutionary history, and this can decrease their likelihood of persistence. Captive breeding programs are sometimes used to reintroduce individuals back into the wild; however, successful captive breeding and reintroduction can be difficult because species or populations often cannot coexist with non-native pathogens and herbivores without artificial selection. In captive breeding programs, breeders can select for host defenses that prevent or reduce pathogen or herbivore burden (i.e., resistance) or traits that limit the effects of parasitism or herbivory on host fitness (i.e., tolerance). We propose that selection for host tolerance may enhance the success of reintroduction or translocation because tolerant hosts generally have neutral effects on introduced pathogens and herbivores. The release of resistant hosts would have detrimental effects on their natural enemies, promoting rapid evolution to circumvent the host resistance that may reduce the long-term probability of persistence of the reintroduced or translocated species. We examined 2 case studies, one on the pathogenic amphibian chytrid fungus ( Batrachochytrium dendrobatidis [Bd]) and the other on the herbivorous cactus moth ( Cactoblastis cactorum) in the United States, where it is not native. In each case study, we provide recommendations for how captive breeders and managers could go about selecting for host tolerance. Selecting for tolerance may offer a promising tool to rescue hosts species from invasive natural enemies as well as new natural enemies associated with climate change-induced range shifts. Keywords: artificial selection, Batrachochytrium dendrobatidis, Cactoblastis cactorum, cactus moth, captive breeding, chytridiomycosis, non-native species, tolerance Selecci´ on de Tolerancia a Pat´ ogenos y Herb´ıvoros para Incrementar el ´ Exito de la Reintroducci´ on y la Translocaci´ on Resumen: Algunas especies no tienen suficientes defensas contra el cambio clim´ atico, enfermedades in- fecciosas emergentes y especies no nativas porque no han sido expuestas a estos factores a lo largo de su historia evolutiva, y esto puede disminuir su probabilidad de persistencia. El ´exito de la reproducci´ on en cautiverio y de la reintroducci´ on puede ser dif´ıcil porque las especies o poblaciones a menudo no pueden coexistir con pat´ ogenos y herb´ıvoros no nativos sin selecci´ on artificial. En programas de reproducci´ on en cau- tiverio, los criadores pueden seleccionar defensas que prevengan infecciones o herbivor´ıa o que reducen la carga de pat´ ogenos o herb´ıvoros atacando directamente al pat´ ogeno o herb´ıvoro (i.e., resistencia) o atributos que limitan los efectos del parasitismo o la herbivor´ıa sobre la adaptabilidad del hu´esped (i.e., tolerancia). †email mvenesky@usf.edu Paper submitted August 16, 2011; revised manuscript accepted January 13, 2012. 586 Conservation Biology, Volume 26, No. 4, 586–592 C 2012 Society for Conservation Biology DOI: 10.1111/j.1523-1739.2012.01854.x