Human Wildlife Conflict II

Contributed Oral Presentations

Contributed paper sessions will be available on-demand for the duration of the conference, then again at the conclusion of the conference.


Anthropogenic Toll: Relative Effects of Forest Edge and Free-Roaming Dogs and Cats on Threatened Carnivores
Erin M. Wampole; Zach J. Farris; Prisca Razafy; Brian D. Gerber
Globally, forest dependent carnivores are threatened by intensifying land conversion, creating hard forest edges that interface anthropogenic and natural landscapes. Free-roaming dogs and cats facilitated by anthropogenic activity range along forest edges and wander into core forest habitat. These non-native predators can negatively affect prey availability, increase disease risk, and predate on or spatially/temporally exclude native carnivores. Rare endemic carnivores of Madagascar are threatened at the peripheries of remaining intact forests by these pressures. Understanding the effects of forest edges and dogs/cats on habitat use of threatened carnivores in the last strong holds of natural forest is critical to conservation planning. We established monitoring stations using remote trail cameras, along existing trails within Andasibe-Mantadia National Park. Stations were placed along a continuum from forest edge to interior core forest. We used a single season multispecies occupancy model to evaluate the effects of distance to forest edge and the presence of free-ranging dogs and cats on five species of threatened endemic carnivores in Madagascar. We found anthropogenic disturbance at the peripheries of protected forest boundaries reduces threatened carnivore’s habitat use and increases their exposure to negative effects of free-ranging dogs and cats. Additionally, we found presence of dogs and cats in interior core forest overlapping with native carnivores. Our results are the first in Madagascar to provide independent and combined effects of forest edges and free-ranging dogs and cats on native carnivores. This information improves current knowledge of species habitat use and provides measures for forecasting species occurrence under intensifying anthropogenic conditions. Importantly, our findings help identified under current conditions where carnivores are most vulnerable and can direct limited conservation resources. This could include integrating a buffer zones between protected forest boundaries and abutting villages housing dogs/cats or prioritizing control efforts of dogs and cats within core forest.
Effects of Anthropogenic Activity and Structures on the Spatiotemporalactivity Patterns of the Carnivore Community on a Temperate, Protected Archipelago
Morgan J. Farmer; Maximilian L. Allen; Erik R. Olson; Julie Van Stappen; Timothy R. Van Deelen
Anthropogenic impacts on wildlife have well-documented, varied effects, and understanding both the magnitude and direction of these effects is necessary for conservation of wildlife species. While protected areas are often considered to be strongholds for wildlife populations, recent research on anthropogenic impacts on wildlife in protected areas has highlighted that even nonconsumptive activities can be detrimental. To determine how anthropogenic activity and structures affect the spatiotemporal activity of the carnivore community on the Apostle Islands National Lakeshore, we monitored the community using a grid of camera traps from 2014 to 2018. We used generalized linear mixed effects models (GLMMs) to test whether carnivore community and carnivore species relative abundance (RAB) at the camera site is related to distance from nearest structure or type of nearest structure. At the community-level, all structure types tested were significant and negatively related to RAB of carnivores, except for campgrounds, which was significant and positively related to the RAB of the carnivore community. Responses of individual species to anthropogenic structures varied depending on structure type. Since human activity on the island is likely correlated with season, we replicated the GLMMs using a subset of the data to determine whether the relationship between carnivore RAB and human structures was dependent on season. Based on the differences between the seasonal models and the human structures models, seasonality does influence human effects on the carnivore community. To determine whether anthropogenic activity has affected the temporal activity patterns of the carnivore community, we compared carnivore nocturnality along a gradient of anthropogenic activity, and our results indicate no difference in nocturnality. Within the Apostle Islands National Lakeshore the carnivore community displayed no increase in nocturnality due to human activity but did display spatial avoidance of anthropogenic structures, potentially reducing the effectiveness of the protected area near human structures.
Historic and Contemporary Use of Catfish Aquaculture Ponds by Double-Crested Cormorants in Northwest Mississippi
Paul C. Burr; Jimmy L. Avery; Garrett M. Street; Bronson K. Strickland; Brian S. Dorr
Double-crested cormorants (Phalacrocorax auritus) are the main source of catfish (Ictalurus spp.) depredation at aquaculture facilities in northwestern Mississippi, costing aquaculture producers millions of dollars annually. Historical research conducted in the early 2000s estimated cormorant use of aquaculture ponds in the region, but aquaculture area has decreased by more than 70% since those estimates were made. In addition, the larger breeding population of cormorants has also been increasing. With less aquaculture available and potentially more cormorants, we predicted cormorant densities on aquaculture would be greater today than historically. Applying similar methodology as in historical studies, we used aerial surveys to collect data on cormorants at night roosts and using catfish aquaculture ponds during three consecutive winter seasons, beginning in 2015. We found the mean annual number of cormorants at roosts during our study was 64% less than historically, and we found no significant change in densities on aquaculture, suggesting that aquaculture area is likely the factor influencing cormorant occurrence in northwestern Mississippi. We also examined pond selection of cormorants to increase management efficiency and our understanding of cormorant foraging behavior at aquaculture facilities. We constructed occupancy models using 1,187 unique ponds to estimate the probability of cormorant presence on catfish ponds against multiple variables associated with each pond’s physical surroundings and internal conditions. Our results show cormorants to have a higher probability of using larger pond, ponds nearer the edge of pond cluster, and ponds located farther away from trees and activity centers. Specific pond contents influenced cormorant use as well, including fish species cultured, pond systems, and fish types. The relationships described here can be used by producers and wildlife managers to predict pond use of cormorants at aquaculture facilities and to design efficient management plans to mitigate potential impacts of depredation and disease.
White-Tailed Deer Damage to Alfalfa during Growing and Dormant Seasons in Southeastern Minnesota
Gino J. D’Angelo; Ryan G. Tebo
In the farmland region of Minnesota, the majority of complaints about white-tailed deer (Odocoileus virginianus) damage involve standing row crops and alfalfa in the field. Farmers who enter into a cooperative damage management agreement with Minnesota Department of Natural Resources are eligible for cost-sharing to install exclusion fencing and to take other mitigation measures. However, funds for deer damage assistance are limited and verification of damage is required. The amount and timing of deer damage to alfalfa can be difficult to ascertain and few accounts exist in the primary literature. For example, overwinter damage to alfalfa crown buds may appear minimal, but could stunt plant growth during the following growing season. Our objective was to quantify the amount of damage caused by white-tailed deer to standing alfalfa crops during the dormant and growing seasons. We conducted our study on 6 private farms in southeastern Minnesota during 2014-2016 including 2 growing seasons and 2 dormant seasons. We constructed removable deer exclosures in established fields, and periodically harvested and weighed alfalfa to estimate proportional yield losses due to deer browsing. Yield losses varied widely among properties, ranging 0-100% and averaging 17.5% (SE = 13). Deer damage to alfalfa was greatest in our study during winter 2015-2016 (average = 38.4%, SE = 23) when winter conditions were historically mild with minimal snow cover. In southeastern Minnesota, deer damage to alfalfa can be expected to occur in most fields with levels of damage varying with local conditions. Our results indicated that deer damage to alfalfa during the dormant season can be significant, and fields with the least overwinter damage had greater yields during the following growing season. Mitigation strategies should be offered to alfalfa producers throughout the year to minimize damage and to ensure the longevity of alfalfa plantings.
A Tiered Management Approach to Reduce Raven Impacts on Sensitive Species
Seth J. Dettenmaier; Peter S. Coates; Shawn T. O’Neil; Brianne E. Brussee; Pat J. Jackson; Mark A. Ricca; Jonathan B. Dinkins
Common raven (Corvus corax) populations have increased drastically in recent decades within the Great Basin, primarily in association with landscape alterations and anthropogenic resources that provide perching, nesting, and alternative food subsidies. Despite growing evidence of ravens adversely impacting numerous sensitive prey species, detailed assessments of raven impacts on ecosystem processes and subsequent management approaches aimed at addressing these impacts are deficient. Although lethal removal of ravens can provide short-term positive responses for prey populations, a multi-faceted approach that encompasses habitat improvements and reduces anthropogenic subsidies may facilitate a more effective long-term management strategy. Here, we provide an applied example of a multi-tier management approach that employs a rapid survey design coupled with ecological predator-prey thresholds to help guide management actions aimed at ameliorating predicted impacts of ravens on sensitive prey species. We focus our example on greater sage-grouse (Centrocercus urophasianus), as this species is often considered an indicator for the health of sagebrush ecosystems and is central to many state and federal land management actions. Our example framework is objective-based and engages three tiers of management actions, namely: (1) improvement to sensitive prey habitat that reduces probability of predation by ravens; (2) reduction of access to anthropogenic resource subsidies that provide alternative food sources (e.g., roadkill, landfills) and perching and nesting substrates (e.g., power lines); and (3) lethal techniques at various life stages (e.g., egg-oiling techniques and application of DRC-1339). We demonstrate the use of multiple quantitative tools that guide the assignment of tiers and facilitates movement among tiers based on key post-management raven assessments, with the ultimate goal of reducing impacts of ravens on greater sage-grouse populations at broad spatial scales. This information is preliminary and is subject to revision. It is being provided as an example to meet the need for timely best science.
Comparing Management Programs to Reduce Red-Tailed Hawk? Aircraft Collisions
Brian E. Washburn; Travis L. Guerrant; Craig K. Pullins; Scott F. Beckerman
Wildlife-aircraft collisions (wildlife strikes) pose a serious safety risk to aircraft. Raptors (i.e., hawks and owls) are one of the most frequently struck guilds of birds within North America. Although raptors [most notably red-tailed hawks (Buteo jamacensis)] are commonly managed at most airports and military bases, there is no scientifically valid information available regarding comparisons of the efficacy of raptor management programs for reducing raptor-aircraft collisions. Therefore, we conducted a study to examine the efficacy of 2 integrated wildlife damage management programs implemented at Chicago’s O’Hare International Airport (ORD). The first raptor management program occurred during August 2010 – June 2013 (Phase I) and was characterized by intensive and sustained live-trapping and translocation efforts. The second raptor management program occurred during July 2013 – November 2016 (Phase II) and involved live-trapping and translocation of specific age classes and increased levels of lethal control. Compared to Phase I, there were 37% fewer red-tailed hawk strikes (41 in Phase I and 26 in Phase II) and 67% fewer damaging red-tailed hawk strikes (6 in Phase I and 2 in Phase II) during Phase II. Our findings demonstrate that airport wildlife management decisions based on scientific data and biological information can aid in reducing wildlife strikes, financial losses, and ultimately airport liability while increasing human safety. The decision matrix regarding the components of an airport raptor management program involves a variety of biological, geographic, logistical, economic, and socio-political variables. This study represents an important scientific foundation for informing such management decisions
Identifying Raven Demographic Characteristics Using Movement Data
Julia C. Brockman; Peter S. Coates; Pat J. Jackson; John Tull; Perry J. Williams
Anthropogenic modifications to sagebrush ecosystems have contributed to increasing common raven (Corvus corax) numbers across the Great Basin. Population increases have substantial negative impacts on prey species including species of conservation concern such as greater sage-grouse (Centrocercus urophasianus). Effects on prey species may vary depending on raven demographic characteristics. As such, understanding intraspecific variation in ravens is crucial to raven population management and conservation of sensitive prey. However, it is often challenging to identify demographic characteristics such as age and breeding status in the field. Our objective is to identify the demographic characteristics of individual ravens based on movement data. We captured and radiomarked 98 individuals at multiple sites across Nevada from 2015-2020 to investigate differences among breeding adults, juveniles, and individuals of unknown breeding class. Specifically, we developed discrete-time animal movement models that use and/or estimate attraction points to estimate the probability of breeding based on movement. As a result, we provide a method to (1) identify breeding status, (2) create spatial maps of attraction points for each individual, and (3) estimate breeding propensity of different age classes. The classification of individual breeding status allows for a more thorough investigation of differences in space use between breeding and non-breeding birds, and spatial maps highlight areas of attraction for the two breeding classes. This information can ultimately highlight intraspecific variation in raven impacts on prey species while also identifying target management areas based on points of attraction. Finally, estimates of breeding propensity by age class can be incorporated into population models for a complete understanding of the dynamics underlying raven population growth. The method we outline forms a foundation for investigating population dynamics and intraspecific variation in resource use based on movement data. This information is preliminary and provided as timely best science.
Modeling Woodpecker Damage in Wooden Utility Pole Systems across the Southeast United States
Hannah C. Wright; Carlos Ramirez-Reyes; Scott A. Rush
Woodpecker activity in utility poles and subsequent costs to repair and replace these structures have been an ongoing source of wildlife-human conflict in the U.S. during the last 100 years. In the southeast United States, the Tennessee Valley Authority utility company has accrued an estimated $5 million dollar/year in costs through mitigation of woodpecker damage. With the goal of reducing the annual cost to the utility providers, we will be using species occurrence records spanning 475,000 km^2 of utility pole systems that have been affected by various woodpecker species. We are working to identify features (abiotic and biotic) associated with areas of heightened woodpecker damage through the use of an Ensemble Species Distribution Model. Using information obtained from this model, we will identify areas that are associated with the highest woodpecker activity and thus likely to accrue damage to the utility infrastructure. This ongoing work has the objective of recommending areas of increased surveillance due to landscape characteristics associated with dense clusters of woodpecker damage to allow mitigation tactics to be implemented before the power system is affected.
Highly Targeted Non-Lethal Predator Control Approach Using Intelligent Prey Decoys Equipped with Aversive Stimuli to Protect Endangered Species from Predation and Provide Data Insights
Caroline Kingsley; Kenneth Nussear; Michael King; Michael Jenkins
Approximately 42% of threatened or endangered species are at risk due to invasive species. Invasive species exacerbate threats on native species in a variety of ways, including habitat disruption, outcompeting for resources, causing or carrying disease, and notably, preying on native species. While a multifaceted approach involving the reduction of human subsidies to invasive species would help address the root of this issue, fusing the empirically established method of conditioned aversion with technological advancements in small form factor sensors, ruggedized electronics, and robotics, presents a novel opportunity to protect vulnerable species from unwanted predators in a targeted, non-lethal, non-toxic, and self-sustaining way. To this end, researchers and engineers completed a 6-month Phase I effort to demonstrate the feasibility of technology to detect, identify, and train targeted predators from preying on vulnerable species through intelligent decoy devices. These devices are designed to cue predators through natural predation cues (i.e., looks and smells like), detect and classify predator interaction through onboard sensor processing (i.e., matching sensor data to biologically-informed predator attack profiles), and deploy repeatable, flexible, non-lethal, predator-specific aversion stimuli which are randomized (i.e., by pattern, frequency, type) to reduce and/or mitigate habituation. Additionally, these devices provide the ability to collect device sensor data and provide researchers with novel insights into predator-prey relationships. The result from the Phase I effort is a ruggedized juvenile desert tortoise prototype that can classify notional raven and coyote predator profiles and deploy predator-specific combinations of light, sound, and electric shock. The next phase of this effort will involve testing these devices with coyotes and ravens in a controlled setting, refining the desert tortoise decoy, and expanding scope to target other predator-prey relationships, such as endangered bird species endemic to Hawaii threatened by nest predation by invasive species and farm chickens preyed on by protected bald eagles.


Contributed Oral Presentations
Location: Virtual Date: Time: -