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Corpus Christi, TX, United States

Van Dyke F.,Wheaton College at Illinois | Van Dyke F.,Sable Environmental | Fox A.,Wheaton College at Illinois | Harju S.M.,Hayden Wing Associates LLC | And 3 more authors.
Environmental Management

Elk (Cervus elaphus) are known to shift habitat use in response to environmental modifications, including those associated with various forms of energy development. The specific behavioral responses underlying these trends, however, have not been effectively studied. To investigate such effects, we examined elk response to habitat alteration near natural gas wells in Las Animas County, Colorado, USA in 2008-2010. We created 10 1-ha openings in forests adjacent to 10 operating natural gas wells by removing standing timber in 2008, with concomitant establishment of 10 1-ha control sites adjacent to the same wells. On each site, we estimated elk use, indexed by pellet density, before and after timber removal. Concurrently, we measured plant production and cover, nutritional quality, species composition and biomass removed by elk and other large herbivores. Species richness and diversity, graminoid and forb cover, and graminoid and forb biomass increased on cut sites following tree removal. Differences were greater in 2010 than in 2009, and elk and deer removed more plant biomass in 2010 than 2009. Elk use of cut sites was 37 % lower than control sites in 2009, but 46 % higher in 2010. The initially lower use of cut sites may be attributable to lack of winter forage on these sites caused by timber removal and associated surface modification. The increased use of cut sites in 2010 suggested that elk possessed the behavioral capacity, over time, to exploit enhanced forage resources in the proximity of habitat modifications and human activity associated with maintenance of operating natural gas wells. © 2012 Springer Science+Business Media, LLC. Source

DeJong L.N.,Calvin College | Cowell S.D.,Sable Environmental | Nguyen T.N.N.,Calvin College | Proppe D.S.,Calvin College | Proppe D.S.,Sable Environmental
Behavioral Ecology

The presence of conspecifics is an indicator of good habitat for a number of songbird species; a cue positively associated with territory selection. Thus, conspecific playback may be a cost-effective tool for attracting songbirds to particular, preselected sites of high-quality habitat. Previous studies have used conspecific playback to encourage the establishment of a single species; however, few have researched the potential for the simultaneous attraction of multiple species. Furthermore, empirical studies on the effect of song playback for nonfocal species are sparse. We investigated whether 6 migratory songbird species are more likely to establish nesting territories in response to multispecies playback. To evaluate the effect on the greater songbird community, we assessed the responses of 22 nonfocal species. Three of 6 focal species increased their use of areas near playback speakers, and none became less common. However, several nonfocal species were less likely to use playback sites. Phylogenetic comparison revealed that species closely related to playback species were those most likely to be affected. Our results suggest that conspecific attraction can be used to attract multiple songbird species simultaneously, but that its impact on nonfocal species should be considered before implementation. © The Author 2015. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. Source

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