Human–Wildlife Interactions

Using predator exclosures to protect ground nests from red fox

Ben C. West et al. — Fri, 12 Mar 2010 13:53:52 PST

Nest predation often is cited as a primary cause for low recruitment and subsequent population decline of many ground-nesting bird species. In response, managers and researchers have developed a myriad of techniques to reduce rates of predation on ground nests. Fences to exclude predators from nesting areas have reportedly been a successful, albeit expensive, strategy to reduce predation rates. Although many studies have evaluated the use of exclusionary fences as a management tool, nearly all of these studies have evaluated the impact of fences in terms of nest success rather than by actual fence penetration by predators. Many authors, for example, assumed that particular fence designs would repel meso-predators like red fox. During a study to assess fences as a management tool to manage predation on duck nests, we documented that red foxes routinely penetrated fences that were designed based on recommendations in the literature. Our observations call into question many fence design recommendations, particularly in areas with red fox populations. More research is needed to assess the ability of various fence designs to repel specific predators.

Developing people skills in the human–wildlife conflict community

Ben C. West — Fri, 12 Mar 2010 13:51:31 PST

As I travel across the country talking with wildlife professionals about leadership and communication, I often ask groups this question: “How many of you decided to become a wildlife biologist because you just love working with people?” Believe it or not, I’ve never witnessed the raising of a single hand.

Expanding bear populations bring new challenges to state wildlife agencies

Robert Southwick — Fri, 12 Mar 2010 13:49:17 PST

In the 1800s, bears were almost eliminated from the United States because they were seen as a threat to humans and livestock and were labeled pests. Now, bear populations are growing and becoming more widely dispersed. Their numbers are increasing and continually extending into new territories, including suburban areas. Suburban developments also are expanding into already established bear territory. This helps to explain that while state wildlife agencies estimate bear populations have increased 12% nationally during the past 5 years, bear complaints have increased 19%, personnel hours to resolve complaints have increased 22%, and state agency expenditures to control bear damage have increased 40% (Figure 1).

Deer–human conflict and hunter access in an exurban landscape

Daniel J. Storm et al. — Fri, 12 Mar 2010 13:47:20 PST

Exurban development (non-metropolitan, residential development) poses unique challenges for wildlife managers through increases in human–wildlife interactions. However, little is known about hunting activity and human attitudes toward white-tailed deer (Odocoileus virginianus) in exurban areas. In 2004, we surveyed exurbanites near Carbondale, Illinois, regarding their experiences with and attitudes toward deer, whose population in the study area was at or above cultural carrying capacity. Deer–vehicle collisions (DVC) were common and a concern for most respondents (84%). However, DVCs were less influential than plant damage in determining landowner tolerance of deer. Only 19% of respondents allowed hunting on their property, and this reluctance resulted in substantial amounts of habitat acting as a de facto refuge for deer. Due to the closure of land to hunting, traditional deer management alone is not likely to control deer populations in exurban areas without significant outreach and education programs aimed at both increasing hunter recruitment and retention and encouraging more landowners to allow hunting.

Scent deterrence to reduce southern flying squirrel kleptoparasitism of red-cockaded woodpecker cavities

Jonathon M. Stober et al. — Fri, 12 Mar 2010 13:44:08 PST

When establishing new populations of endangered red-cockaded woodpeckers (RCW; Picoides borealis), cavity kleptoparasites can pose a considerable obstacle to successful restoration. Southern flying squirrels (SFS; Glaucomys volans) are the principal kleptoparasite of RCW roost and nest cavities. Managers restoring RCW populations primarily use labor-intensive, direct removal to mitigate cavity competition by SFS. We field tested the use of red fox (Vulpes vulpes) urine and rat snake (Elaphe spp.) musk as predator scents to examine if SFS could be deterred from using RCW cavities and to observe RCW roost behavior at cavities treated with red fox urine. Scent deterrence proved ineffective in preventing SFS use of RCW cavities, while RCWs showed no behavioral response to scent treatment. Managers should continue using squirrel excluder devices, and direct removal to mitigate SFS kleptoparasitism of RCW cavities when restoring critically endangered populations.

Comparison of 2 vegetation-height management practices for wildlife control at airports

Thomas W. Seamans et al. — Fri, 12 Mar 2010 13:40:54 PST

Vegetation-height management is a potential method to reduce bird numbers at airports. Based on studies in Europe, researchers recommended vegetation heights around 25 cm; however, preliminary studies in the United States produced conflicting results regarding the effect of tall (18 to >25 cm) vegetation on bird numbers at airports. From 1999 to 2002, we compared birds and other wildlife use of 4 short-vegetation plots (mean maximum height of 15.6 cm ± 5.1 SE and visual obstruction reading of 4.6 ± 3.0 cm) and 4 tall-vegetation plots (mean maximum height of 26.9 ± 8.4 cm and visual obstruction reading of 10.0 ± 5.0 cm) in Ohio. We surveyed bird use of the plots 2 to 3 times/week and observed 6,191 birds in short-vegetation plots and 5,962 birds in tall-vegetation plots. We detected no difference between short-vegetation and tall-vegetation plots in the probability of avian use of the plots when evaluated as a binary response of presence and absence. Small mammal capture rates in 100 adjusted trap nights were 0.0 in short-vegetation plots and 0.3 in tall-vegetation plots. We found no difference in the number of deer observed in the plots during sunset and spotlighting counts. There was slightly greater insect biomass in tall- than in short-vegetation plots. Mowing negatively affected small mammal use. The generalization that tall vegetation (18 to >25 cm) alone would reduce bird use of an airport is not supported by the results of this study. Further research on vegetation density, composition, palatability, and nutritional value is necessary to accommodate airfield requirements for habitat that is pleasing to the public and repellent to wildlife.

Population viability analysis of monk parakeets in the United States and examination of alternative management strategies

Stephen Pruett-Jones et al. — Fri, 12 Mar 2010 13:37:27 PST

In the United States, monk parakeets (Myiopsitta monachus) are expanding their geographical distribution, and their overall population size is growing exponentially. Monk parakeets are causing widespread economic damage in the United States by nesting on utility structures, which leads to electrical fi res and power outages. Although few life history data are available for the species from North America, extensive data are available from the species’ native range in South America. Incorporating data from South America into the population viability analysis program VORTEX, we simulated population growth in United States monk parakeets to determine whether it is likely that the United States population shows life history patterns similar to those in the native range. The answer was, no. The intrinsic rate of growth (r) of monk parakeets in the United States (r = 0.119 during the period 1976–2003) was almost double the rate of population growth (r = 0.064) for the simulated population. Modifying the South American data to allow for reduced mortality, higher fecundity, or a greater proportion of breeding females resulted in population growth rates similar to those in the United States. We extended the simulations to examine the effectiveness of alternative control measures on the monk parakeet population by using the modifi ed life history data. Simulations revealed that it would be necessary to remove 20% of the adult population or to destroy 50% of the nests each year to reduce the population size of monk parakeets. In practical terms, such massive management efforts are unlikely to be sustainable. Instead, control of monk parakeets will likely require an integrated approach including removal of local problem nests on a case-by-case basis and long-term population reduction through trapping or chemical sterilization.

A review of Shiga toxin Escherichia coli and Salmonella enterica in cattle and free-ranging birds: potential association and epidemiological links

Kerri Pedersen et al. — Fri, 12 Mar 2010 13:33:54 PST

Cattle are the main reservoir for human infection by pathogenic Escherichia coli and Salmonella enterica. To prevent entry of these food-borne pathogens into the human food chain, management factors at the farm level must be identified and controlled. External sources of contamination, such as birds, should be considered as potential sources of transmission over long distances. In this review, we focus on the epidemiology of infection by E. coli and S. enterica and the consequences of birds acting as disseminators of these pathogens at dairy farms in terms of cattle health and the subsequent effects on human health.

Comparison of sampling strategies to estimate abundance of double-crested cormorants in western Mississippi

Aaron T. Pearse et al. — Fri, 12 Mar 2010 13:30:38 PST

We compared 2 sampling strategies designed to estimate abundance of double-crested cormorants (Phalacrocorax auritus, hereafter cormorants) on aquaculture ponds in western Mississippi. Cormorants are a major predator of cultured channel catfish (Ictalurus punctatus) in this region; thus, estimating cormorant abundance is needed to better determine their economic impact. We independently designed a species-specific survey (i.e., cluster sampling) and a general survey (i.e., transect sampling) based on robust probability sampling theory to estimate abundance of this target population. During winters 2002–2003 and 2003–2004, we conducted 8 pairs of surveys and compared estimates of cormorant abundance and associated precision using conventional paired t-tests and complimentary equivalency tests. Abundance estimates from sampling methods did not differ given a minimum important effect size of 1,420 individuals. Precision of estimates for both survey protocols was poor (the coefficient of variation [CV] was 39.5% for cluster samples and 45% for transect samples), and we were unable to definitively conclude if precision was similar between sampling methods (due to low sample size and high variability). We found sample sizes must increase 222% for cluster sampling and 538% for transect sampling to detect a 15% change in abundance on average. Thus, neither method met our goals of detecting a given effect size at a desired level of precision. We recommend investigating additional sampling designs that may provide precise estimates of abundance more efficiently than the methods compared in this study.

In Memory, Spring 2007

Human-Wildlife Conflicts — Fri, 12 Mar 2010 13:20:35 PST

Kenny Acord lost his year-long battle with cancer on June 30, 2006. He was 25. Kenny was the son of Bobby Acord, the former deputy administrator of USDA/APHIS/Wildlife Services. Kenny earned an M.S. degree in anthropology/archeology at Northern Arizona University in 2005. He was employed by the National Park Service as an archeologist at Navajo National Monument. He is survived by his true love and partner DeeAnn Tracy, his parents Bobby and Anna Acord, and his sister Leigh Anna Willard.

20,25-Diazacholesterol as an oral contraceptive for black-tailed prairie dog population management

Paul Nash et al. — Wed, 10 Mar 2010 14:26:23 PST

Black-tailed prairie dog (Cynomys ludovicianus) colonies can become overcrowded, and the colonies, landscape, and people affected by them may benefit from controlled populations. Contraception is a method that may be useful, particularly where lethal control is inappropriate or illegal. We investigated if oral administration of 20,25-diazacholesterol (DiazaCon®), an inhibitor of cholesterol and reproductive steroid hormone production, could reduce reproductive success of treated black-tailed prairie dogs in a fi eld trial. Ten treatments of approximately 45-mg DiazaCon per black-tailed prairie dog yielded a 47% reduction of young:adult ratios compared to control sites. Over a 3-month period, desmosterol, a cholesterol precursor used as an indicator of DiazaCon effects, was not detectable in any black-tailed prairie dogs trapped at control sites, whereas elevated levels were detectable in 33 of 35 blood samples from black-tailed prairie dogs trapped at treated sites. Average cholesterol levels were lower in treated animals than in control animals. DiazaCon administration may be a useful tool to control populations of black-tailed prairie dogs, especially in light of the desire for conservation while still managing populations.

Use of snares to live-capture beavers

Lance B. McNew, Jr. et al. — Wed, 10 Mar 2010 14:20:03 PST

Wildlife managers, researchers, and nuisance-control operators often require a nonlethal means of capturing beavers (Castor canadensis). Historically, live-capture has relied on enclosure-type traps such as Bailey or Hancock traps. We describe the live-capture of 231 beavers using snares in southern Illinois from 2002 to 2005. Capture success averaged 5.4 beavers/100 trap-nights. Capture success did not differ between sexes (P = 0.57) or age-classes (P = 0.68). We captured most beavers in haul-out slide sets, surface run sets, or channel sets. Recaptures accounted for 28% (n = 65) of all captures. Mortality rate using snares was 10% and decreased annually during the study period. Snares are advantageous over enclosure-type traps because they have a high capture:cost ratio and are less heavy and cumbersome than traps. However, mortality rates are relatively high, limiting the utility of this technique for some research.

The Director’s desk

Bruce D. Leopold — Wed, 10 Mar 2010 14:17:04 PST

Well, this is truly a momentous occasion for the Berryman Institute: publication of the inaugural issue of its scientific journal, Human– Wildlife Conflicts (HWC). This issue has been long in the making (over 2 years), but well worth the wait!!!!!! Oh my oh my oh my!! Wildlife-damage management, and more generally, human–wildlife conflict resolution, continues to grow in prominence, and the Berryman Institute is ready and able to work with all of its state, federal, and private partners to address these issues through sound empirical research and outstanding outreach programs. HWC is designed to place wildlife damage management in the same forefront as other fields of study in wildlife. With the leadership of Dr. Michael Conover as its editor, we are confident that our journal will provide practicing scientists, field personnel, and wildlife biologists with critical information necessary to address the diverse issues that face us concerning human–wildlife conflict resolution. We all are so proud of this accomplishment that is so greatly needed by our clientele!!!!

In The News, Spring 2007

Michael R. Conover — Wed, 10 Mar 2010 14:13:47 PST

High Country News reported that on November 8, 2006, the body of 22-year-old Joel Carnegie was found at Points North Landing in the northern boreal forest of Saskatchewan, Canada. Investigators believe Carnegie was attacked by a group of 2 to 4 wolves when he was walking alone near a mining exploration company camp. The attack is the first documented case of a fatal wolf attack in North America since 1900, but a nonfatal wolf attack occurred a year earlier in the same area. In that incident, wolves attacked and injured a jogger. Wildlife biologists linked the attacks to the presence of garbage in the area and to the wolves’ decreasing fear of humans.

Land-use pattern, urbanization, and deer–vehicle collisions in Alabama

Anwar Hussain et al. — Wed, 10 Mar 2010 14:08:59 PST

With the rise in deer–vehic^le collisⁱons across the United States, the associated costs also have risen. Increasingly, however, researchers are learning that these collisions are not a random phenomena but ^follow a syst^ematic pattern. Bu_ilding on this in_sight, we explored the role of county characteri^stics in influencing the pattern and incidence of w^hite-tailed deer- (Odocoileus virginianus) related auto c^ollisions. Using county level data from 1994 to 2003 in Alabama, we tested several data models with the above mentioned facto^rs as covariates. Our resul^ts showed that county characteristics, such as (1) having a deer population density (≥31/km2), (2) being part of a metropolitan statistical area, (3) having a high proportion of pasture, urban and other land relative to woodland, and (4) having greater vehicle density per road km were more likely to increase the odds of deer–vehicle collisions. In contrast, high proportion of cropland relative to woodland, and wildlife management tools, such as increase in hunting license sales, and high deer bag limits, reduced the frequency of deer–vehicle collisions. These findings suggested that urban planners need to consider the impact of urban development and infrastructure activities on deer habitat and densities, and how wildlife management strategies (e.g., judicious manipulation of bag limits and ways to promote hunting license sales) can be used along with other mitigation techniques to reduce deer–vehicle collisions.

Successful use of neck snares to live-capture red foxes

S. Nicole Frey et al. — Wed, 10 Mar 2010 14:00:26 PST

Box traps and ^foot-hold snares are common methods to live-c^apture study animals. However, these methods are frequent^ly ineffective due to factors such as weather constraints, food availabi^lity, and target an_imal behavior. Duri_ng a study of red fox (Vulpes vulpes) behavior, we examined the use of neck snares to live-trap study anima^ls. We m^odified the neck snare using swi^vel cam-locks, d^eer stops to minimize damage to the animal. Additionally, we utilized our knowledge of red-fox behavior to set traps in a way that would reduce trauma to the captured animals. We snared 21 red foxes during the 3-year study with only 2 fatal injuries. Sixteen of these animals were followed with radio-telemetry for 3 to 28 months. With the data we collected during the radio-telemetry, we calculated home ranges. Home range size estimates calculated during the first few months for each fox were not different than those collected during the rest of the season. Most of the estimated home ranges for these red foxes did not encompass the snare location, suggesting either avoidance of the trap location or that the foxes were caught while investigating the status of another territory. Because captured red foxes were active the evening immediately after capture and all captured females reared young that spring, we determined that neck snares did not greatly affect their behavior. Thus, this method is a successful alternative way to live-capture red foxes for radio-telemetry studies.

Public opinion, the Leopold Report, and the reform of federal predator control policy

James W. Feldman — Wed, 10 Mar 2010 13:54:43 PST

This paper explores the role of public opinion in a landmark shift in the federal predator control pro^gram. In 1963, the Le^opold Committee recommended extensive reform in the federal predator c_ontrol program, predicting that growing p_ublic support for the environmen_tal movement would force such a move if the government did not initiate a change. In the years following the publication of the Leopold Report, the U.S. Division of Wildlife Services reformed its predator control program and tried to improve its public image. Meanwhile, both environmentali_sts and ranchers fought to control publ_ic opinion about the issue. The 1972 ban on pre_dacides (poisons for predators) in fed_eral predator control programs resulted as much from the environmentalists’ ability to control public opinion as from the changing scientific understanding of predators.

Perceptions of wildlife damage and species conservation: lessons learned from the Utah prairie dog

R. Dwayne Elmore et al. — Wed, 10 Mar 2010 13:49:41 PST

The Utah praⁱrie dog (Cynomys parvidens), a federa^lly ^list^ed threatened species, causes damage to a^gricultur^al operations, yet ^little incentive exists for priv_ate la_ndowners to conserve them. Therefore, we surveyed Utah resi_dents to identify stakeho^lder attitud^es regarding prairie dog mana^gement. We assessed how perceptions of wildlife d^amage affect respondent attitudes regarding conservation among agricu^ltural producers, rural residents, and urban residents. Higher levels of perceived wildlife damage were reported for agriculture respondents (79%) than for urban (20%) or rural (45%) respondents. Compensation for damage caused by Uta_h pr_airie dogs was supported by those engaged in agricultural production but not by rural or urban respondents. Agricultural producers, rural residents and urban residents all stated a preference for pri_vate cons_ervation orgaⁿizations t^o fund damage compensa^tion rat^her than a government agency. Most agrⁱcultural respondeⁿts (61%) and rural respondents (64%) believed that Utah prairie do^gs should be only on public lands. Some agricultural responden_ts (23%) th_ought they shoul^d be ^on no land. Attitudes regarding the Utah prairie dog varied, _with agr_icul_tural producers being the most negative and urban respondents the most positive. The negative attitude of rural residents and agricultural producers probably results from bot_h the damage caused by Utah prai^rie dogs and land-use restrⁱctions resulting from the species bein^g listed as t^hreatened. Accep^tance of Ut_ah prairie dogs by private la_ndowners may be key to the recovery of the species, and our fin_dings suggest that alleviation of damage issues may increase lando^wner acceptance of conse^rvation measures to pr^otect Utah prairie dogs.^ng

Long Time Coming

Michael R. Conover — Tue, 09 Mar 2010 14:19:52 PST

Welcome to this inaugural issue of Human– Wildlife Conflicts. Much has changed during my lifetime. I can remember when there were no deer on my family’s farm in Illinois. I can remember in 1979 seeing Canada geese feeding in a golf course in New Haven, Connecticut, and thinking they were a lost family of geese from the Arctic. I can remember going to a wildlife conference and seeing a presentation in the program, titled “Turkey problems in Wisconsin,” and wondering if the turkeys they were referring to had wings or wore overalls. I can remember the editor of The Journal of Wildlife Management refusing even to consider publishing my first manuscript on human– wildlife conflicts because animal damage control (as it was called in those days) was outside the purview of the journal and not a part of the field of wildlife management.

Evolution of the field of wildlife damage management in the United States and future challenges

James E. Miller — Tue, 09 Mar 2010 14:15:28 PST

Through the early twentieth century, people in rural areas of North America either dealt with problems caused by wildlife by killing the problem species, eliminating its habitat, changing crops or husbandry practices, tolerating the damage, or moving to a new area devoid of such problem animals. However, many of these solutions are impractical today with the increase in human populations, the increased expansion of development into previously rural landscapes, the increased fragmentation of land ownership, and the increasing movement of people into metropolitan areas. Because of current local, state, and federal ordinances and regulations, along with the impacts of animal rights and activist groups on public sensitivities, there are more rigid constraints on the tools, techniques, and capabilities that an individual or community in urban or rural areas can utilize to address a wildlife damage problem. The great majority of individuals today care about the humane treatment of animals and are sensitive to some of the claims, whether correct or not, made by animal activists, but they are much more likely to expect someone else to handle their problems as a community service or for a fee. This paper provides highlights of a historical perspective on the evolution of wildlife damage management in the United States, insight about the development of the Berryman Institute, and some future challenges for the profession.