49 research outputs found

    Applications of Sensory Ecology for Wildlife Damage Management

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    Human-wildlife conflicts typically involve fundamental processes associated with the feeding behavior and/or the spatial behavior of wildlife. Thus, most human-wildlife conflicts arise from wildlife consuming products and/or wildlife occupying places valued by humans. For mammals, taste is the most important sensory cue for selecting nutrients and avoiding toxins. Most birds use both flavor (i.e. taste, odor, texture) and visual cues for their food selection process. We previously learned that an ultraviolet visual cue can enhance the repellency of an anthraquinone-based repellent for blackbirds, starlings, Canada geese and wild turkeys. Although the ultraviolet cue is not itself aversive, novel repellent formulations including ultraviolet cues have provided repellent efficacy at reduced concentrations of the repellent active ingredient. Ultraviolet repellent formulations are currently being developed for the protection of ripening agricultural crops from bird depredation. With regard to spatial behavior, exteroceptive sensory cues (e.g. visual, auditory, tactile cues) are reliably used for patch selection. We suggest that sensory cues and their paired consequences can be exploited for the development and application of effective strategies for wildlife damage management

    A molecular analysis to assess codling moth \u3ci\u3eCydia pomonella\u3c/i\u3e L. (Lepidoptera: Tortricidae) predation by orchard birds

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    The codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is a major economic pest in organic apple orchards. Observational methods, prey removal experiments and correlative experiments with exclosures or nest boxes have demonstrated that birds contribute to the removal of this insect pest. However, the majority of research conducted in the last several decades has taken place outside of the United States and methods for studying biological pest control have advanced dramatically and now include molecular techniques. We conducted a proof-of-concept study to test a DNA-based approach to detect C. pomonella prey in the diets of birds occupying organic apple orchards. We tested published Tortricidae primers, polymerase chain reaction (PCR) and sequencing for detection of C. pomonella in avian feces. We also tested the quality of DNA isolated and purified from fecal samples using two DNA extraction kits. Finally, we field-tested this tool to identify the presence or absence of C. pomonella in the laboratory and from field samples. C. pomonella DNA was amplified in less than 1% of field samples and was successfully sequenced in 0.5%. A single species, the brown-headed cowbird Molothrus ater (Boddaert), had fecal samples positive for C. pomonella DNA. While our results do not provide evidence that birds play a strong role in the control of C. pomonella in western Colorado organic apple orchards, the approach we present is a new tool for understanding bird-mediated ecosystem services, avian feeding ecology, and supporting management decisions for sustainable agricultural practices and farmland biodiversity

    Rooting Out Genetic Structure of Invasive Wild Pigs in Texas

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    Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 40 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently in California and Florida, USA, which have similarly long-established populations and high densities of wild pigs. Our goals were to use molecular approaches to elucidate invasion and migration processes shaping wild pig populations throughout Texas, compare our results with patterns of genetic structure observed in California and Florida, and provide insights for effective management of this invasive species. We used a high-density single nucleotide polymorphism (SNP) array to evaluate population genetic structure. Genetic clusters of wild pigs throughout Texas demonstrate 2 distinct patterns: weakly resolved, spatially dispersed clusters and well-resolved, spatially localized clusters. The disparity in patterns of genetic structure suggests disparate processes are differentially shaping wild pig populations in various localities throughout the state. Our results differed from the patterns of genetic structure observed in California and Florida, which were characterized by localized genetic clusters. These differences suggest distinct biological and perhaps anthropogenic processes are shaping genetic structure in Texas. Further, these disparities demonstrate the need for location-specific management strategies for controlling wild pig populations and mitigating associated ecological and economic costs

    Addressing the Gender Gap in Distinguished Speakers at Professional Ecology Conferences

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    Keynote and plenary speakers at professional conferences serve as highly visible role models for early-career scientists and provide recognition of scientific excellence. This recognition may be particularly important for women, who are underrepresented in senior positions in the biological sciences. To evaluate whether conferences fulfill this potential, we examined distinguished speakers at North American ecology conferences between 2000 and 2015 and compared these data with the percentage of women ecologists at diverse career stages. We found that 15%–35% (x = 28%, n = 809) of the distinguished speakers were women, which is significantly lower than the percentage of female ecology graduate students (x = 55%, n = 26,802) but consistent with the percentage of women in assistant- and associate-faculty positions. We recommend that conference organizers institute policies to enhance speaker gender balance, to provide support for speakers with family responsibilities, and to actively monitor gender-related trends in their societies to achieve the equitable representation of women in distinguished speaking roles

    Addressing the Gender Gap in Distinguished Speakers at Professional Ecology Conferences

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    Keynote and plenary speakers at professional conferences serve as highly visible role models for early-career scientists and provide recognition of scientific excellence. This recognition may be particularly important for women, who are underrepresented in senior positions in the biological sciences. To evaluate whether conferences fulfill this potential, we examined distinguished speakers at North American ecology conferences between 2000 and 2015 and compared these data with the percentage of women ecologists at diverse career stages. We found that 15%–35% (x = 28%, n = 809) of the distinguished speakers were women, which is significantly lower than the percentage of female ecology graduate students (x = 55%, n = 26,802) but consistent with the percentage of women in assistant- and associate-faculty positions. We recommend that conference organizers institute policies to enhance speaker gender balance, to provide support for speakers with family responsibilities, and to actively monitor gender-related trends in their societies to achieve the equitable representation of women in distinguished speaking roles

    Muc2 Protects against Lethal Infectious Colitis by Disassociating Pathogenic and Commensal Bacteria from the Colonic Mucosa

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    Despite recent advances in our understanding of the pathogenesis of attaching and effacing (A/E) Escherichia coli infections, the mechanisms by which the host defends against these microbes are unclear. The goal of this study was to determine the role of goblet cell-derived Muc2, the major intestinal secretory mucin and primary component of the mucus layer, in host protection against A/E pathogens. To assess the role of Muc2 during A/E bacterial infections, we inoculated Muc2 deficient (Muc2βˆ’/βˆ’) mice with Citrobacter rodentium, a murine A/E pathogen related to diarrheagenic A/E E. coli. Unlike wildtype (WT) mice, infected Muc2βˆ’/βˆ’ mice exhibited rapid weight loss and suffered up to 90% mortality. Stool plating demonstrated 10–100 fold greater C. rodentium burdens in Muc2βˆ’/βˆ’ vs. WT mice, most of which were found to be loosely adherent to the colonic mucosa. Histology of Muc2βˆ’/βˆ’ mice revealed ulceration in the colon amid focal bacterial microcolonies. Metabolic labeling of secreted mucins in the large intestine demonstrated that mucin secretion was markedly increased in WT mice during infection compared to uninfected controls, suggesting that the host uses increased mucin release to flush pathogens from the mucosal surface. Muc2 also impacted host-commensal interactions during infection, as FISH analysis revealed C. rodentium microcolonies contained numerous commensal microbes, which was not observed in WT mice. Orally administered FITC-Dextran and FISH staining showed significantly worsened intestinal barrier disruption in Muc2βˆ’/βˆ’ vs. WT mice, with overt pathogen and commensal translocation into the Muc2βˆ’/βˆ’ colonic mucosa. Interestingly, commensal depletion enhanced C. rodentium colonization of Muc2βˆ’/βˆ’ mice, although colonic pathology was not significantly altered. In conclusion, Muc2 production is critical for host protection during A/E bacterial infections, by limiting overall pathogen and commensal numbers associated with the colonic mucosal surface. Such actions limit tissue damage and translocation of pathogenic and commensal bacteria across the epithelium

    Synergistic effect of an ultraviolet feeding cue for an avianrepellent and protection of agricultural crops

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    Application strategies for avian repellents are needed to maintain efficacious repellentconcentrations throughout the period of needed crop protection. We investigated the repellency of an ultraviolet (UV) feeding cue in the absence of postingestive consequences, thecombination of the UV feeding cue and an UV-absorbent, postingestive repellent (i.e., arepellent that causes negative postingestive consequences), and a non-UV feeding cue com-bined with the UV-absorbent, postingestive repellent in red-winged blackbirds (Agelaiusphoeniceus). In the absence of negative postingestive consequences, 0.2% of the UV feed-ing cue (wt/wt) was not aversive relative to untreated food (i.e., baseline preference test; P = 0.1732). Relative to the repellency of food treated only with the anthraquinone-basedrepellent, synergistic repellency (i.e., 45–115% increase) was observed when 0.2% of the UVfeeding cue was combined with 0.02% or 0.035% anthraquinone (wt/wt). In contrast, \u3c10%repellency was observed for 0.2% of a non-UV feeding cue (red #40 aluminum lake disper-sion) paired with 0.02% anthraquinone. Aversion performance was therefore not attributedto characteristics of either conditioned or unconditioned stimuli but their combinations,and enhanced repellency of anthraquinone plus the UV-absorbent cue was attributed toUV wavelengths. Thus, the addition of an UV feeding cue can enhance avian repellencyat repellent concentrations realized from previous field applications on agricultural crops(e.g., ≀1000 ppm anthraquinone)
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