Aversive conditioning on horseback: A management alternative for grassland systems threatened by sedentary elk populations.

Loss of migratory behaviour in ungulates has been observed worldwide
and invites new tools for managing the habitat degradation that results from these
sedentary populations. We assessed use of aversive conditioning on horseback as
a means of reducing grazing pressure and restoring migratory behaviour in elk
(Cervus elaphus) at the Ya Ha Tinda ranch, which is an important wintering
range. We conditioned elk by herding them daily in the direction of their historic
migratory route and monitored changes in elk distribution and grassland biomass
each year. After three summers of aversive conditioning treatments, summer elk
presence on the targeted grassland had declined substantially and grassland
biomass had increased. Although elk use shifted in the desired direction, we did
not detect any longer-distance migration in targeted elk. Our research suggests
that aversive conditioning on horseback can temporarily reduce grazing pressure
on threatened grasslands, but is unlikely to change migratory behaviour.