Social information and community dynamics: nontarget effects from simulating social cues for management.
Artificially creating social stimuli may be an effective tool for facilitating settlement by rare and/or declining species into suitable habitat. However, the potential consequences for other community members have not been explored and should be considered when evaluating the overall utility of using such management strategies. I report on nontarget, community-wide effects that occurred when manipulating social cues of two competitors that are species of concern in the western United States, the dominant Least Flycatcher (Empidonax minimus) and the subordinate American Redstart (Setophaga ruticilla). The experiment consisted of surveying birds during a pretreatment year, which allows for the control of baseline communities, and a treatment year, in which treatments were applied just prior to settlement by migratory birds. Treatments included broadcasting songs of flycatchers and redstarts and were compared to controls. While the addition of redstart cues did not significantly influence community structure, the addition of flycatcher cues reduced species richness of migratory birds by approximately 30%. This pattern was driven by an absence of local colonizations of small-bodied migrants to sites with added flycatcher cues, rather than by local extinctions occurring from manipulations. The artificial flycatcher stimuli were more responsible for declines in species richness than were changes in actual flycatcher densities. I conclude by identifying some fundamental issues that managers and conservation practitioners should weigh when considering simulating social cues for species conservation prior to implementation.
Department of Wildlife Ecology and Conservation, P.O. Box 110430, 110 Newins-Ziegler Hall, University of Florida, Gainesville, Florida 32611-0430 USA. robert.fletcher@ufl.edu
Robert J
RJ
Fletcher
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D009009:Montana; D012919:Social Behavior; D020308:Songbirds / Q000502:physiology*