Indirect Effects of Elk Harvesting on Ravens in Jackson Hole, Wyoming

摘要: Harvesting of marine and terrestrial animals by humans produces animal biomass byproducts that many scavenger species exploit. Effects food from harvesting on the ecology has rarely been measured, especially in systems. Such nutritional subsidization scavengers needs to be monitored because increases their populations may influence population dynamics other alter natural community dynamics. I quantified effects distribution elk (Cervus elaphus) gutpiles generated an intensive harvest program Jackson Hole, Wyoming, USA, local raven (Corvus corax) foraging behaviors, daily seasonal movements, distribution. During Hole's 2001 fall harvest, found ravens most abundant vertebrate scavenging gutpiles, number detected during fixed-width transect surveys positively correlated with concurrent, sympatric gutpile densities. abundance, estimated via point-count habitat-paired zone reference plots, increase significantly conjunction only plots. Furthermore, abundance nest density spring were higher plots than Results indicate exploit provided harvesting, corresponds immediate across landscape, is associated overall a given area fall, are density. Collectively, these findings suggest high concentration Hole significant supplemental resource for ravens, wildlife environment capable influencing species. Wildlife managers must consider nontarget when evaluating efficacy regulatory programs work minimize unintended caused management surrounding ecological community. regulation model ungulate due its long-term success, while at same time continually addressing how affect considering alternative strategies more effectively conserve region's diversity. here provide baseline information relation current comparison areas programs, later within as managing change future. This study also draws attention toward monitoring anthropogenic byproduct resources that, despite inconspicuousness literature, can substantially opportunistic scavengers; it points out several influenced access or foods abundant, reliable, nutritious. Finally, having determined clear link between ravens—an influential community—this sets stage future research, testing strength extent trophic cascade initiated availability propagated Hole.