Wildlife Conflicts

Whenever the needs both of humans and wildlife overlap, there is a potential for wildlife damage to occur. Wildlife damage has been an issue throughout human history. Typical history essays about wildlife damage management (WDM) examine a chronology of events on the topic. This paper takes a different approach. Looking through the history of WDM, we considered the driving factors behind changes in the management of wildlife damage. Based on the events of WDM history, we defined 4 factors that underlie major shifts in the management of wildlife damage: human population needs, economic stability, social paradigms, and tools and techniques. To illustrate how these factors affect WDM, we first explained their interplay using the example of knights and dragons. We then considered how these factors changed throughout actual human history by subdividing history into 6 time periods of WDM. We found that managers' tactics for dealing with wildlife damage do matter; understanding the factors that affect management is important for wildlife damage managers to handle future challenges.

Management programs aimed at reducing wildlife damage to row crops rely on information concerning the spatial nature of wildlife damage at local and landscape scales. In this study we explored spatial patterns of wildlife damage within individual corn and soybean fi elds by describing relationships between specifi c locations where wildlife damage was recorded and distances from such locations to various habitat types that presumably infl uenced animal abundance and movements in our study area. Using stratifi ed random sampling, we conducted depredation surveys of 100 corn fi elds and 60 soybean fi elds from May through October both in 2003 and 2004 and recorded the specifi c global positioning satellite (GPS) coordinates of wildlife damage to individual corn and soybean plants. We then generated random point locations in the same fi elds using a geographic information system (GIS) and evaluated whether damage point locations and random point locations differed with respect to distances to the nearest patches of forest, developed area, or grassland and shrubland habitats. For both crop types, damage point locations were signifi cantly closer to forest patches than were random point locations, but farther from developed areas than random point locations. Logistic regression analyses further indicated that distance to forest infl uenced the probability of wildlife damage within fi elds, although pseudo r 2 values of the best models were low (0.15). Our results clearly indicated that fi eld portions that were nearest to forested habitats were more likely to suffer wildlife damage than fi eld portions farther from forested habitats. We suggest that targeted removals of depredating species, concentrated along crop-forest interfaces, may be an effective, cost-effective means of reducing corn and soybean damage in areas where wildlife damage is especially problematic.

harvest data suggest that feral hog (Sus scrofa) populations in western Louisiana are increasing, and population control in this region is complicated by the mixing of feral and domestic free-ranged hogs. Aggressive management may be warranted as feral and domestic hogs appear to be having unexpected effects on their ecosystem. We present the results of 3 recent investigations of genetic source-tracking to link waterborne bacteria with bacteria from feral hogs. We integrate our most recent fi ndings with data regarding: (1) water quality in a watershed without hog management and (2) aquatic biota of the same watershed. Hog activity substantially increased waterborne bacteria, which often exceeded state and federal surface water guidelines. Aquatic biota, specifi cally freshwater mussels and aquatic insects of the collector and scraper feeding guilds, declined in stream reaches with hog activity. Finally, PCR (polymerase chain reaction)-based DNA source-tracking revealed a >95% si...

Texas harbors the largest population of feral hogs (Sus scrofa) in the United States, with populations estimated at >2 million. Depending on one’s perspective, feral hogs are either a pariah (from the farmer’s standpoint) or a popular sporting animal (from a hunter’s standpoint). As feral hogs increase in range and density, confl icts among stakeholders are sure to increase. Texas Cooperative Extension (TCE) initiated educational programs in 1991 to address concerns regarding the presence and management of feral hogs. Since that time, we have developed various workshops, symposia, and educational materials (e.g., print, videotape, and website) as means of addressing “the good, the bad, and the ugly” aspects of feral hogs in Texas. Texas Cooperative Extension involves various stakeholder groups, including agriculturalists, biologists, hunters, and wildlife damage management professionals in its efforts to provide a thorough, balanced approach to management of feral hogs. Our goal ...

Abstract: The Utah prairie dog (Cynomys parvidens), a federally listed threatened species, causes damage to agricultural operations, yet little incentive exists for private landowners to conserve them. Therefore, we surveyed Utah residents to identify stakeholder attitudes regarding ...

The purpose of this project was to assess the mussel (Mytilus edulis) food requirements of oystercatcher (Haematopus ostralegus) in the Exe Estuary, which has been designated a Special Protection Area for overwintering waterbirds, including oystercatcher. The overwintering oystercatcher population of the Exe Estuary has been well-studied, and the birds are known to feed predominantly upon mussels in intertidal areas. There have been recent declines in the population size of oystercatcher in the Exe Estuary, mirroring wider declines throughout Europe, the reasons for which are unknown.

The study comprised:
• The collection of new data on the area of mussel beds, the density and size distribution of mussels on these beds, and the numbers and behaviour of oystercatcher on these beds;
• The collation of existing data on the food supply of oystercatchers in the Exe Estuary;
• The development of models to predict the food requirements of oystercatcher;
• Running simulations of the models to predict whether there is / could be any effect on oystercatcher survival of the current / potential future ways of managing the mussel fishery on the Exe Estuary.

The current mussel fishery on the Exe provides a feeding resource for oystercatcher on intertidal lays that are exposed on spring tides. Two potential management options that could be effective at improving the feeding conditions of oystercatcher would be to increase the number and area of intertidal mussel lays, and / or to place mussel discards at a relatively high shore level close to the oystercatcher roost.

This project documented a number of changes that have occurred to the Exe Estuary mussel and oystercatcher populations including:
• The number and size of mussel beds have decreased since traditional methods of maintaining mussel beds in the estuary have ceased.
• The density of mussels within the size range consumed by the birds has generally decreased, but the density of the larger mussels within this size range, which are more profitable to oystercatcher, has generally increased.
• Oystercatcher lose a higher proportion of mussels to attacks by carrion crows and herring gulls than they have in the past.
• The number of oystercatcher wintering in the estuary has declined, but the number of birds feeding on the mussel beds has been relatively stable.

The models developed in the project predict that the present day mussel population is sufficient to support the number of oystercatcher that were observed to feed on mussels.

The presence of mussel lays provides extra food for oystercatcher when these lays are exposed on spring tides. The present area, or increases in the area of mussel lays could increase the survival rate of oystercatcher if the number of birds feeding on mussels was over 2000. Below this threshold, starvation was predicted to affect 0 % of the population and so additional food resources cannot further reduce the starvation. The effect over 2000 birds is relatively small because the lays are only exposed for a short time, and so oystercatcher will obtain the majority of their food from mussel beds that are higher on the shore, and hence exposed for longer. Simulations were not run in which lays were positioned higher on the shore because this would not be commercially viable from a fishery perspective; the growth rate of mussels declines as they are positioned further up the shore because they are inundated with water for less time and so have less time to feed.

Factors that would affect the beneficial effect of discards include the size of the discards, the size of the discard bed and the date from which discards are replenished. Our simulations predicted that larger discards spread at lower density over a larger bed increased oystercatcher survival by the greatest amount. This happened because interference competition excluded some birds from smaller patches, and oystercatcher can maintain high intake rate down to low mussel densities. It is unlikely that the size of discards could be increased, but the simulations suggest that the greatest benefit to oystercatchers could be achieved by spreading discards over a larger area. Our simulations predicted that making discards available from January increased oystercatcher survival by the same amount as making them available from September. This was because the feeding conditions of birds deteriorate through winter as, for example, the ash-free dry mass of prey declines, interference competition intensifies and day length shortens. The intake rate of birds feeding on discards was not measured during the study, but we recommend that this is done to between understand the potential benefit of discards. We recommend that the best place for the discard bed would be along the top of the shore on an area of gravel (and hence of relatively low food value to the birds), to the south of Cockwood. This is south of an area where discards have been laid and exploited by oystercatcher in the past, but would experience lower levels of disturbance from human activity.

In the northern suburbs of NYC, land managers have begun implementing bow-only hunts to reduce overabundant white-tailed deer (Odocoileus virginianus) herds in an effort to promote forest regeneration. However, there have been no attempts to model the impact of bow hunting on deer population growth. Using harvest statistics from the Mianus River Gorge Preserve in Westchester County, NY we simulated the impact of bow hunting on a population of female deer exhibiting density-dependent growth and explored a range of carrying capacities, immigration rates, and harvest intensities. Simulated bow hunting (adult harvest ≥ 1.8 females km −2 ) was capable of achieving deer densities believed necessary for forest regeneration (2.9 females km −2 ) in closed populations where carrying capacity = 13.8 females km −2 , representing the lower end of deer overabundance. At this carrying capacity and low immigration rates, the impact of bow hunting was more variable, producing population declines ranging from 20 to 70% contingent on harvest rates. Hours per harvest increased rapidly as the deer population declined requiring nearly 5 times the hourly effort as female density approached target levels. Sustaining harvests over multiple decades, particularly as effort per deer harvest increases, is one of the biggest challenges facing bow-only hunts. As controlled bow hunts are executed by volunteer sportsmen, reductions will be determined by hunters' capacity or willingness to increase effort and efficiency. Bow hunting will therefore likely result in deer densities lower than historical peak values, yet higher than is currently assumed necessary for forest regeneration.

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