Wildlife Damage Management I

Contributed Paper
ROOM: HCCC, Room 21

8:10AM Foraging Ecology and Depredation Impact of Scaup on Commercial Baitfish and Sportfish Farms in Eastern Arkansas
Stephen A. Clements; Brian Davis; Brian S. Dorr; Katie C. Hanson-Dorr; Luke A. Roy; Anita M. Kelly; Carole Engle; Scott C. Barras
Research is needed to address the growing concerns of Arkansas’ commercial baitfish and sportfish producers regarding the perceived increase in consumption of fish by lesser scaup (Aythya affinis) and greater scaup (Aythya marila); hereafter, scaup. The goals of our study were to estimate the distribution and abundance of piscivorous waterbirds, including scaup, on bait- and sportfish farms during fall-winters 2016-2017, and compare our contemporary results with unpublished surveys conducted from 2004 to 2005. Additionally, we aimed to estimate the amount of fish consumed by scaup foraging on commercial bait- and sportfish ponds. We surveyed approximately 800 baitfish and sportfish ponds (n = 15 individual farms) in Lonoke and Prairie Counties, Arkansas in winter 2016-2017. Primary fish species produced on surveyed farms were golden shiners (Notemigonus crysoleucas), fathead minnows (Pimephales promelas), bluegill (Lepomis macrochirus), and goldfish (Carassius auratus). Accompanying these surveys, we also collected 294 foraging scaup from ponds. We removed and identified all food items in the gastrointestinal tract above the gizzard and taxonomically sorted, dried, and weighed each sample. All gizzards were examined for presence or absence of fish parts. We detected fish parts in 2% of scaup examined. A generalized linear mixed model fitted to previous and current survey data showed that scaup abundances were significantly higher on golden shiner ponds than ponds containing fathead minnows, goldfish, or sportfish. Our model indicates a significant decrease in scaup abundances during the contemporary surveys. We attribute the apparent low consumption of fish by scaup and low scaup abundances to the mild 2016-2017 winter. Our data will provide an important framework for developing potential management strategies for reducing fish predation by scaup on commercial aquaculture farms in Arkansas and will inform an estimate of the total economic impact of scaup foraging on Arkansas’ bait- and sportfish producers.
8:30AM The Influence of Landfills and Landscape Composition on the Bird Strike Rate at Civil Airports
Morgan B. Pfeiffer; Brad F. Blackwell; Travis L. DeVault
Municipal solid waste landfills (MSWLFs) are an anthropogenic food resource for many species and can alter species densities and movement patterns. The establishment of MSWLFs within 8 kilometers of an airport is discouraged by the U.S. Federal Aviation Administration because of their ability to attract large numbers of birds to the flight path of aircraft, which could result in a bird-aircraft collision (bird strike) and loss of human life. We hypothesized that bird-strike rates would differ across airports because of the arrangement and composition of MSWLFs and surrounding landscape mosaics. We predicted a higher strike rate at 113 large hub airports if: 1) airports were surrounded by a high density of MSWLFs, 2) landfills only handled municipal waste, as opposed to municipal and construction waste, 3) there was high landscape heterogeneity of land uses surrounding the airport, and 4) mosaics comprised intermediate levels (20-50%) of impervious surfaces and high human population densities. We tested our predictions via generalized linear models. We found that presence of a landfill within 8 km of an airport did increase the bird-strike rate, however other variables such as density, number, and type of landfill were not significant. Coupling MSWLF characteristics with attributes of the surrounding landscape matrix were important. These results can be used by land-use planners to evaluate the establishment of MSWLFs near airports to prevent bird strikes.
8:50AM Assessing Owl Collisions with U.S. Civil and U.S. Air Force Aircraft
Brian E. Washburn; Kimberly E. Linnell
Wildlife-aircraft collisions (wildlife strikes) with civil and military aircraft pose notable risks and economic losses. Previous research on wildlife strikes has emphasized a variety of birds and mammals, but no comprehensive evaluation of owl-aircraft incidents has been conducted. We queried the Federal Aviation Administration’s National Wildlife Strike Database and the U.S. Air Force’s Birdstrike Database from 1990 to 30 June 2014 to characterize owl-aircraft collisions within the USA and foreign countries. We found 2,531 owl-aircraft collisions involving more than 20 individual species of owl. Barn Owls were the most frequently struck species, accounting for 42% of all reported owl-aircraft collision events. Almost 75% of owl-aircraft collisions occurred during night-time hours. Owl-aircraft collisions typically occur within the airfield environment itself; 86% of owl strikes occurred when the aircraft was at or below 30 m above ground level. Some mitigation tools and techniques are currently available to reduce the frequency and severity of owl-aircraft collisions. An important area of future research will involve the development and evaluation of effective, publically acceptable methods of reducing owl-human conflicts.
9:10AM Assessing Hunter Involvement in Reducing Overabundant Lesser Snow Goose Populations
Craig A. Miller; Adam C. Landon
North American snow goose populations are over-abundant. To address this problem the U.S. Fish and Wildlife Service established conservation orders permitting hunters unlimited take during certain periods in winter and spring using previously unlawful methods (i.e., use of electronic calls, unlimited shell capacity, and hunting after sunset). Success in achieving reductions of snow goose populations is a function of hunters’ abilities to harvest geese. Understanding factors that determine hunters’ participation and harvest during the conservation order is needed. In this study we measured snow goose hunting participation, harvest, and constraints. Data were drawn from a statewide survey of snow goose hunters in Illinois following the 2017 spring conservation order hunt (n=871). Data were limited to hunters who participated during the conservation order. Specifically, we hypothesized that snow goose hunting participation, operationalized as number of days hunted during the conservation order, is a function of hunters’ involvement in waterfowl hunting, perceived skill as a snow goose hunter, and constraints to participation. We hypothesized that successful snow goose harvest can me modeled as a function of number of days hunting snow geese, involvement, skill, constraints to participation, and use of specialized equipment that facilitates harvest. Involvement in waterfowl hunting and perceived skill were found to positively influence hunting participation. Participation accounted for the majority of variance in snow goose harvest. However, subjective skill, perceived constraints, and specialized equipment use all exerted independent effects on snow goose harvest, and accounted for meaningful amounts of variance. Opportunities for fostering participation, increasing harvest, and furthering snow goose conservation efforts are discussed.


Contributed Paper
Location: Huntington Convention Center of Cleveland Date: October 10, 2018 Time: 8:10 am - 9:50 am