title: Undesirable evolutionary consequences of trophy hunting.
abstract: Phenotype-based selective harvests, including trophy hunting, can have important implications for sustainable wildlife management if they target heritable traits. Here we show that in an evolutionary response to sport hunting of bighorn trophy rams (Ovis canadensis) body weight and horn size have declined significantly over time. We used quantitative genetic analyses, based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns, to explore the evolutionary response to hunter selection on ram weight and horn size. Both traits were highly heritable, and trophy-harvested rams were of significantly higher genetic 'breeding value' for weight and horn size than rams that were not harvested. Rams of high breeding value were also shot at an early age, and thus did not achieve high reproductive success. Declines in mean breeding values for weight and horn size therefore occurred in response to unrestricted trophy hunting, resulting in the production of smaller-horned, lighter rams, and fewer trophies.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK. d.coltman@sheffield.ac.uk
authors.forename: David W
authors.initials: DW
authors.lastname: Coltman
authors.forename: Paul
authors.initials: P
authors.lastname: O'Donoghue
authors.forename: Jon T
authors.initials: JT
authors.lastname: Jorgenson
authors.forename: John T
authors.initials: JT
authors.lastname: Hogg
authors.forename: Curtis
authors.initials: C
authors.lastname: Strobeck
authors.forename: Marco
authors.initials: M
authors.lastname: Festa-Bianchet
mesh_terms: D000416:Alberta; D000818:Animals; D005075:Biological Evolution; D005260:Female; D006686:Hobbies; D006733:Horns / Q000033:anatomy & histology*; D008297:Male; D010375:Pedigree; D012418:Ruminants / Q000033:anatomy & histology* / Q000235:genetics; D013177:Sports