Use of Bait to Increase Archery Deer Harvest in an Urban–Suburban Landscape

Abstract: Hunting is the primary tool for managing white-tailed deer (Odocoileus virginianus) populations. Effectiveness of hunting in suburban areas may be reduced due to limited hunter access to small properties, firearms-discharge laws, and public safety concerns. In Connecticut, USA, hunting over bait on private land was recently legalized to increase harvest opportunities. Our objective was to assess bow-hunter willingness to use bait and effects of bait type, hunter disturbance, time spent hunting, and property size on deer-harvest potential in a suburban landscape. We mailed a prebaiting survey in February 2002 and a postbaiting survey in February 2004 to the same group of hunters. Hunters using bait were more successful and harvested more deer than hunters using no bait. Hunters using bait on small properties observed similar numbers of deer within shooting range as hunters using bait on larger properties. Hunters using bait met their venison needs, whereas hunters using no bait did not meet their needs. Resource managers should implement strategies that increase hunter success when developing urban deer-management programs for communities.     

Assessment of Shock Collars as Nonlethal Management for Wolves in Wisconsin

ABSTRACT Lethal control alone has not proven entirely effective in reducing gray wolf (Canis lupus) depredations in chronic problem areas. Opponents of lethal control argue that more emphasis should be placed on integrating nonlethal strategies into current management. However, few evaluations have tested the effectiveness of nonlethal options. We compared behavior patterns in terms of frequency and duration of bait station visits for 5 wolves fitted with shock collars to 5 control animals inhabiting wolf pack territories in northern Wisconsin during summers of 2003 and 2004. Shock collared wolves spent less time and made fewer visits to bait station zones than did control animals. During and after shocking, wolves shifted 0.7 km away from the bait station zone. Although active shocking did restrict wolf access, which could be useful in controlling wolf depredations during a limited time period, conditioning was not clearly demonstrated once shocking ceased. The effect of shock collar design and operation on long-term conditioning and shock-conditioned wolves on pack behavior needs further study. If long-term conditioning is possible, shock collars could be used by wildlife managers as a nonlethal wolf management method in chronic problem areas where lethal control has proven ineffective.     

Fox‐baiting in agricultural landscapes in south‐eastern Australia: a case‐study appraisal and suggestions for improvement

Summary In south‐eastern Australia, the introduced Red Fox (Vulpes vulpes) is a major predator of native wildlife and livestock. Fox control in agricultural landscapes is heavily reliant on the laying of poisoned baits by private landholders, yet there have been few assessments of the application or success of landholder‐baiting practices. We evaluated a community‐based fox‐baiting campaign, typical of programs employed throughout the agricultural regions of south‐eastern Australia to control foxes. We recorded the spatial coverage of 1080 baits deployed by landholders, assessed baiting procedures, monitored the survival of six radio‐collared foxes during and after baiting, and compared the spatial coverage and likely effectiveness of the baiting program with two alternative (theoretical) baiting strategies. Relative to other baiting programs, coordination among neighbours was reasonably high, with 37.5% of baited properties (n = 40) adjoining ≥3 neighbouring properties that also contained baits. Nevertheless, the maximum distance from the centre of a baited property to the nearest edge of an unbaited property was <750 m (mean = 380 m ± 147 m SD). On average, 33% (±17% SD) of each fox’s home range overlapped with baited properties, but only two foxes died during the baiting program. The remaining four foxes were still alive 10 weeks after baiting ceased. Modelling of simulated fox home ranges showed that 13.5% contained no bait stations based on the community baiting program, whereas alternative roadside‐ and grid‐baiting strategies (theoretically) delivered baits to all simulated home ranges. Some landholders employed practices that could reduce the effectiveness of baiting programs such as not removing decayed baits before deploying new ones or placing bait stations too close together. Our research illustrates the difficulties of managing a coordinated baiting program on private land that effectively controls foxes. Alternative baiting strategies such as roadside baiting need to be considered to improve fox control in agricultural landscapes.     

Environmental Factors Affecting Productivity of Brown-Headed Nuthatches

Abstract: Understanding the link between habitat use and components of fitness can yield useful insight into the environmental conditions necessary for population maintenance and can help promote effective habitat management. This information is especially important for species that are in decline or otherwise of conservation concern. Populations of brown-headed nuthatches (Sitta pusilla), an obligate cavity nester, have declined throughout their range, primarily due to extensive habitat loss and degradation. To help guide habitat management for this species, we identified habitat features associated with variation in the number of offspring fledged within 2 populations in southern Florida, USA. The most important predictor of productivity was the date on which a nest attempt began, with earlier nests producing more fledglings. The number of large pine (Pinus elliottii var. densa) snags and, to a lesser extent, the number of small pine trees surrounding a nest site were positively associated with productivity. We recommend that land managers in southern Florida focus on providing abundant large pine snags because doing so will increase productivity and also may increase nest-site availability and the percentage of individuals that breed each year. Prescribed burning may be an effective way to increase the abundance of large pine snags; however, land managers should exercise caution when doing so because of the trade-off between snag recruitment and snag consumption that accompanies the use of fire. We lack the data required to predict the fire-return interval that optimizes this trade-off, but until these data are available we recommend increasing the spatial heterogeneity in fire-return interval and lengthening the fire-return interval in some areas to 5-6 years.     

Bait Uptake and Caching by Red Foxes and Nontarget Species in Urban Reserves

Abstract: The management of biodiversity in urban areas provides a challenge for conservation managers who are interested in the recovery of native species by controlling exotic species. Exotic-animal control programs using poisons can be contentious in terms of the health and safety of nontarget species, including people. Managing exotic predators in urban areas must be effective at 2 levels: controlling the target species and minimizing impacts to nontarget species. We investigated the feasibility of instigating a poison-baiting program to control nonindigenous European red foxes (Vulpes vulpes) in city conservation reserves (Perth, Australia). We selected 3 reserves to assess the safety and efficacy of baiting for foxes by maximizing bait uptake by the target species, and minimizing uptake by nontarget species. We tested 2 types of meat bait using 4 bait presentation methods (untethered, uncovered; untethered, covered; tethered, uncovered; tethered, covered). Bait uptake by foxes was highest in urban reserves compared to that in a peri-urban reserve. Bait type and presentation method equally explained bait uptake by foxes. Untethered and uncovered baits were removed 10% more often by foxes, and untethered baits had been cached more often than tethered baits. Baits cached by foxes for up to 1 week were not removed by species other than foxes. Domestic dogs and native birds were common nontarget species to remove baits. Dogs showed no aversion to removing any bait type, nor did bait presentation method influence bait removal. Birds removed fewer baits that had been tethered and covered. We provide an evidence base to demonstrate that bait uptake by nontarget species can be minimized, although we suggest that a fox control program is likely to be more of an organizational challenge to change public attitudes toward responsible dog ownership rather than a technical challenge to poison foxes.     

Spatial sampling to detect slug abundance in an arable field

Overuse of molluscicides by farmers in arable systems can lead to environmental and product contamination. Here we assess a simple and inexpensive surface trapping method for monitoring populations of slugs (Deroceras reticulatum and Arion intermedius). This method was biased against small slugs, and against A. intermedius, when compared to direct soil sampling. Regression was used to model the relationship between the results of surface trapping and soil sampling methods. Spatial Analysis by Distance IndicEs (SADIE) algorithms were used to describe the spatial relationships between the two sets of samples. Using both traditional statistical methods and spatial statistics, the spatial information collected from surface traps was sufficient to identify patches and gaps in slug numbers and possibly to allow the spot application of slug control, and thus provide land managers who experience slug damage with a way of reducing molluscicides use, whilst maintaining slug control. Further improvements and applications of the model are discussed.     

Multidimensional biases,gaps and uncertainties in global plant occurrence information

Plants are a hyperdiverse clade that plays a key role in maintaining ecological and evolutionary processes as well as human livelihoods. Biases, gaps and uncertainties in plant occurrence information remain a central problem in ecology and conservation, but these limitations remain largely unassessed globally. In this synthesis, we propose a conceptual framework for analysing gaps in information coverage, information uncertainties and biases in these metrics along taxonomic, geographical and temporal dimensions, and apply it to all c. 370 000 species of land plants. To this end, we integrated 120 million point‐occurrence records with independent databases on plant taxonomy, distributions and conservation status. We find that different data limitations are prevalent in each dimension. Different metrics of information coverage and uncertainty are largely uncorrelated, and reducing taxonomic, spatial or temporal uncertainty by filtering out records would usually come at great costs to coverage. In light of these multidimensional data limitations, we discuss prospects for global plant ecological and biogeographical research, monitoring and conservation and outline critical next steps towards more effective information usage and mobilisation. Our study provides an empirical baseline for evaluating and improving global floristic knowledge, along with a conceptual framework that can be applied to study other hyperdiverse clades.     

Successful information exchange between restoration science and practice

The science‐practice gap is often cited as a limitation to successful restoration outcomes; however, the existence of such a gap in information exchange is rarely measured. Here, we quantify the gap by focusing on common recommendations from both scientists (i.e. researchers) and managers (i.e. practitioners, land managers) on what is needed for successful restoration. We surveyed 45 managers associated with 244 invasive species (Tamarix spp.) removal projects across the southwestern U.S. to determine the degree to which they have utilized four strategies advocated by scientists: (1) collaborate widely, (2) monitor beyond cursory visual methods, (3) use a variety of information sources, and (4) consider project goals beyond invasive species removal. Half of these managers were also interviewed to assess managers' perceptions of the role of science in restoration. Twenty‐three scientists specializing in Tamarix‐related research in this region were also surveyed to assess how much they understood and/or shared the concerns of land managers. We found that managers were following scientists' recommendations and that managers' perceptions of the role of science in land management did not have any bearing on the management actions taken. Scientists reported being influenced by managers, and the concerns of scientists and managers were more overlapping than expected. Boundary organizations and river‐wide partnerships were often cited as important in facilitating effective communication between land managers and scientists. A lack of funding for monitoring and for longer‐term projects was cited by both groups as a limitation to incorporating scientists' recommendations into restoration.     

Bait Stations for Detection and Control of Alien Rats in Galapagos

ABSTRACT Alien rats have impacted native systems worldwide, yet wildlife managers lack techniques to efficiently monitor for rodent invasions where native rodents are present and to control alien rodents sympatric with native rodents. We tested the ability of vertical bait stations to exclude native rodents in the Galapagos Islands, Ecuador. Norway rats (Rattus norvegicus) appeared able to enter all station sizes, whereas black rats (R. rattus) were excluded from larger stations. The endemic rodents Oryzomys bauri and Nesoryzomys narboroughi were unable to enter bait stations of any size, but N. swarthi entered the smallest station. Differences in climbing technique contributed to the advantage of alien rodents over endemic species. Our technique provides wildlife managers in the Galapagos, and potentially other islands with native rodents, a means for early detection and control of alien rats.     

Use of an ungulate‐specific feed structure as a potential tool for controlling feral goats in Australian forest ecosystems

The feral Goat (Capra hircus) has successfully exploited a range of landscapes around the world with occurrences of overabundance resulting in significant damage to ecological values. In forested ecosystems in Australia, there are currently limited means to control the species when compared to the range of management techniques available for other pest animals. To redress this deficiency, we designed a feed structure combined with commercially available salt blocks to attract goats to set locations in a forested study area. Structures that exploited differences in the pedal morphology (foot size and shape) of native herbivores (kangaroos and wallabies) and ungulates (feral goats and deer) were found to be highly target‐specific, with feral goats freely able to access salt blocks, whilst nontarget native species were effectively excluded. Other introduced ungulate species, Fallow Deer (Dama dama) and Red Deer (Cervus elaphus), successfully accessed salt blocks in feed structures but at a considerably lower rate than feral goats. The capacity to present a range of bait types within a target‐specific feed structure, once matched with a humane toxicant, could provide land managers with an additional cost‐effective lethal control tool for future management of feral ungulates, particularly goats.     

Mapping Restoration Opportunity for Collaborating with Land Managers in a Carbon Credit‐Funded Restoration Program in the Makana Municipality,Eastern Cape,South Africa

Spatial prioritization techniques are commonly used in conservation planning, but are relatively new for planning restoration programs. Typically, ecological data, and more recently data on economic costs and vulnerability of sites, are used. However, the effectiveness of restoration action ultimately relies on a combination of the appropriate ecological restoration techniques and the human and social dynamics of social‐ecological systems. Surveys were conducted with 29 land managers within the Makana Municipality of the Eastern Cape, South Africa, to identify a range of human and social factors hypothesized to define the potential effectiveness of restoration action. Land managers with similar characteristics were grouped using a cluster analysis, and the groups ranked and mapped in geographical information system (GIS) to provide a spatial representation of restoration opportunity. The total number of questions were reduced by 35.6%, a step toward developing a rapid assessment approach for assessing land managers' potential participation in restoration initiatives. Identifying and incorporating human and social factors that directly influence restoration prioritization should promote efficient and effective implementation of restoration actions by the Working for Woodlands programme, who are looking to funding landscape‐scale restoration through carbon trading.     

Rapid recolonisation by the European red fox: how effective are uncoordinated and isolated control programs?

Uncoordinated and isolated control programs are often used by land managers, property owners and recreational hunters to control numbers and reduce the impacts of European red foxes (Vulpes vulpes). However, decades of such attempts to eradicate this significant agricultural and biodiversity pest in many countries have failed. We investigated the effectiveness of an uncoordinated and isolated shooting program to determine if it caused any change in red fox population density. We also determined whether shooting is more cost effective than poison baiting for fox control. First, we estimated the density of foxes on an agricultural study property using distance sampling and rates of bait uptake before and after a control program. Second, we estimated the costs associated with undertaking the control program and compared it to the estimated costs of undertaking poison baiting. Prior to control, we estimated a density of 4.18 foxes per square kilometre. After the control exercise, which removed 47 individuals in 12 nights, we estimated a density of 3.26 foxes per square kilometre. Our results provide evidence that one-off control programs are not effective in greatly reducing red fox density, even if the control effort is intensive. Where large-scale control programs cannot be coordinated, isolated programs should therefore involve follow-up campaigns to reduce population recovery. On a local scale, combinations of shooting and baiting may also provide maximum control impact at minimal cost.     

Invasive Snake Activity Before and After Automated Aerial Baiting

Aerially delivered toxic baits have proven effective for landscape-level control of numerous invasive vertebrate populations with major benefits for conservation and ecosystem function, but this technique has not been broadly adapted for control of invasive reptiles. Nonnative brown treesnakes (Boiga irregularis) on the Pacific island of Guam have caused severe ecological and economic damage and pose an invasion risk on other islands, making them a high-profile candidate for application of aerial baiting methods. Although terrestrial applications of traps, toxicants, and hand-removal are standard brown treesnake management practices, these methods are not cost-effective for control in the island's large tracts of remote, rugged forest. In 2016, the first major in situ evaluation of a helicopter-borne automated aerial bait delivery system applied snake-targeted toxic baits at an effective rate of approximately 120 baits/ha over a 110-ha forested test plot on Guam. We evaluated the extent and duration of the suppressive effect of this toxic bait application on brown treesnakes by measuring nontoxic bait take rates as a proxy index of relative snake abundance before and after toxic bait application in a treatment plot and surrounding reference area. We placed 4,420 nontoxic baits in random transects at georeferenced locations, from 1 month before until nearly 12 months after toxic bait application, allowing temporal analysis of the suppressive effect and spatial analysis of treatment plot reinvasion. Over the first 30 days after toxic bait application, average nontoxic bait take rate in the treatment plot was 41.2% lower than the pre-application rate, and there was no immediate decrease in bait take in the reference area. Reduced snake activity was still evident nearly 12 months after bait application. Roads forming a portion of the treatment boundary appeared to slow snake movement between treated area and surrounding untreated area. Trail cameras monitoring a subset of bait tubes showed that 97.5% of baits removed were taken by snakes rather than nontarget species. We indexed rodent abundance in the treatment plot and reference area, and found no indication of a rodent population increase following toxic bait application. Our results show that automated aerial bait applications can suppress brown treesnake abundance over a large area and that reinvasion from surrounding untreated habitat occurs over several months. We anticipate that repeated bait applications could achieve and maintain greatly reduced brown treesnake abundance on a landscape scale, potentially improving biosecurity and enabling experimental reintroduction of native birds extirpated by brown treesnake predation. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

A comparison of methods for estimating raccoon abundance: Implications for disease vaccination programs

Accurate estimates of demographic parameters are critical to the management of wildlife populations, including management programs focused on controlling the spread of zoonotic diseases. Rabies managers in the United States Department of Agriculture (USDA) have applied a simple raccoon (Procyon lotor) abundance index (RAI) based on cumulative catch of unique raccoons per unit area to determine vaccine-bait distribution densities. This approach was designed to allow for both the collection of biological samples and to index raccoon abundance to determine bait densities for oral rabies programs. However, post-baiting surveillance data indicate that, on average, only 30% of raccoons sampled have vaccine induced rabies antibody titers, suggesting that bait densities may not be well calibrated to raccoon densities. We trapped raccoons using both capture-mark-recapture (CMR) and the standard RAI to evaluate the accuracy of the current index-based methodology for estimating raccoon density. We then developed a resource selection function from spatial data collected from radio-collared raccoons to standardize trap placement within the existing RAI protocol, and evaluated the performance of this modified RAI approach relative to CMR for estimating raccoon population size. Both abundance and density estimates derived using the RAI consistently underestimated raccoon population sizes compared with CMR methods. Similarly, although the use of resource selection models to inform trap placement appeared to improve the accuracy of the RAI, the effectiveness of this method was inconsistent because of an inability to account for variance in detection probabilities. Despite the logistical advantages of using indices to estimate population parameters to determine vaccine bait distribution densities, our results suggest that adjustments may be necessary to more accurately quantify raccoon abundance, which should improve the effectiveness of rabies management in the United States. In particular, estimates of detection probabilities are needed to more precisely quantify abundance estimates and ensure appropriate vaccine coverage rates. © 2012 The Wildlife Society.     

Eradication of Feral Pigs From Pinnacles National Monument

Abstract: Feral pigs (Sus scrofa) have caused considerable damage where they have been introduced around the world. At Pinnacles National Monument, California, USA, managers were concerned that feral pigs were damaging wetland habitats, reducing oak regeneration, competing with native wildlife, and dispersing nonnative plant species through soil disturbance. To address these threats the National Park Service constructed an exclosure around 57 km² of monument land and through cooperation with the Institute for Wildlife Studies eradicated all feral pigs within the area. Trapping, ground-hunting, hunting dogs, and Judas techniques were used to remove feral pigs. Trapping techniques removed most pigs, but a combination of techniques was required to cause eradication. A series of bait sites and transects across the monument helped focus removal efforts and facilitated detection of the last remaining feral pigs in the exclosure. Consistent funding and cooperation from the National Park Service allowed for a seamless and comprehensive program that provided intensive removal of feral pigs. The successful eradication of feral pigs at Pinnacles National Monument should encourage managers in other areas to implement future control or eradication programs.     

Massasauga Home Range Patterns in the Midwest

Abstract: The massasauga (Sistrurus catenatus) has drastically declined throughout its range mainly due to habitat loss and human persecution. Populations of the massasauga that occur north and east of the Missouri River, USA, are currently candidates for listing under the United States Endangered Species Act. In areas where land managers wish to improve habitat for existing populations or create habitat for repatriation efforts, an understanding of massasauga spatial ecology is necessary to ensure that adequate sized blocks of habitat are created and properly managed. We studied spatial ecology of massasaugas at 2 sites in Wisconsin and 3 sites in Missouri over an 11-year period. Our results indicated that male massasaugas had larger spatial requirements than all other cohorts. Our study sites supporting viable populations indicated that managers interested in restoring or enhancing massasauga habitat should use 100 ha as a minimum restoration or management target. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):754–759; 2008)     

Field evaluation of imidacloprid as a systemic approach to flea control in black‐tailed prairie dogs,Cynomys ludovicianus

Epizootic outbreaks of sylvatic plague have dramatically influenced prairie dog (Cynomys sp.) populations across North America. While a great deal of debate surrounds the cause and persistence of plague, flea control can stop the spread of plague epizootic outbreaks and even increase prairie dog survival under non‐epizootic conditions. We investigated a newly‐developed imidacloprid‐treated grain bait that could potentially reduce flea infestations and mitigate the effects of plague on black‐tailed prairie dogs (C. ludovicianus). We used a study design involving randomly assigned experimental and control study plots to assess the effectiveness of the systemic flea control product. We observed a significant difference in flea prevalence and abundance between experimental and control sites on three of the four sites treated with a single application of imidacloprid‐treated grain bait for up to 90 days post‐treatment. We observed an even greater reduction in flea infestations following the double application of treatment bait on two of three additional experimental sites. While we were unable to reduce flea infestations to the extent reported for more commonly used topical insecticides containing deltamethrin, imidacloprid might still be effective at reducing the risk of plague and halting epizootics. In addition, this systemic product can be more rapidly applied than topical insecticides, providing managers with a tool to quickly reduce flea infestations. Future research is needed to evaluate the effectiveness of different application timing and rates, the utility of the product in limiting plague, and the potential effects on non‐target species that might also consume the treated bait.     

Feasibility of oral rabies vaccination campaigns of young foxes (<Emphasis Type="Italic">Vulpes vulpes</Emphasis>) against rabies in summer

Oral vaccination of foxes (Vulpes vulpes) against rabies has been shown to be highly effective. Several baiting strategies to increase vaccination coverage of the target population have been developed. For example, to increase the vaccination coverage of the young fox population before dispersal an additional summer vaccination campaign has been suggested. The effectiveness of such a campaign was evaluated using field data on home range size and shape of young foxes and a simulation model for aerial bait distribution. The results indicated that the limited ranging behaviour of the young fox population during the summer months severely reduced bait accessibility and consequently such an additional vaccination campaign would be very cost-ineffective.     

Use of Rhodamine B to Reveal Patterns of Interspecific Competition and Bait Acceptance in Raccoons

Abstract: Passive treatment of raccoons (Procyon lotor) through distribution of vaccine-laden baits recently has emerged as a potential solution to address health and economic conflicts associated with raccoon rabies and may have applications in the management of other pathogens carried by raccoons if frequent bait deployments are used. Consumption of baits by nontarget species reduces the efficiency in which baits can be used to manage wildlife disease, although no study has explicitly evaluated the influence of bait competitor density on the ability to treat raccoons. Our objectives were to use the biomarker Rhodamine B (RB) to 1) evaluate patterns of raccoon bait acceptance as a function of competition with Virginia opossums (Didelphis virginiana), the dominant bait competitor; 2) characterize attributes of opossum bait acceptance to improve efficiency of raccoon treatment; and 3) evaluate the effect of repeated bait exposure on rates of bait acceptance as may be required in the management of wildlife disease issues beyond rabies. Identifying bait consumption by individuals based on the presence of an RB mark in a sample of whiskers, we used logistic regression to model raccoon and opossum bait acceptance as a function of bait availability, previous exposure to baits, demographic attributes, and an index of time spent in the baited area (residency index). For both raccoons and opossums, the best measure of bait availability was the variable number of baits per opossum. The most parsimonious logistic regression model for raccoon bait acceptance included the variables baits per opossum, exposure history, and residency index. The strength of the variable baits per opossum relative to competing measures of bait availability indicated bait consumption by opossums significantly limited the ability to treat raccoons. The most parsimonious model for opossum acceptance was composed of the variables baits per opossum, sex, weight, residency index, baits per opossum X sex, and weight X sex. Patterns of opossum bait acceptance likely were driven by effects of bait availability and sex-dependent differences in movement. Our results call attention to the importance of bait competition in limiting the ability to effectively treat raccoon populations through distribution of baits and suggest managers incorporate information on density of bait competitors, particularly opossums, in allocation of baits.     

Diazacon Inhibits Reproduction in Invasive Monk Parakeet Populations

Abstract: Throughout the United States, managers lack safe, effective methods to control expanding populations of the invasive monk parakeet (Myiopsitta monachus). Because the reproductive inhibitor diazacon (20,25 diazacholesterol) has been used effectively in captive monk parakeets, we provided diazacon-treated sunflower seeds to birds at electric utility substations inhabited by parakeets in south Florida, USA. Nest productivity (nestlings plus eggs with embryos) averaged 1.31 (SE = 0.45, n = 100 nests) at 6 treated sites compared to 4.15 (SE = 0.68, n = 50 nests) at 4 untreated sites, a 68.4% reduction. Exposure of native bird species to treated bait was infrequent. Diazacon is an effective means to reduce reproductive success of monk parakeets, and development of methods to limit exposure of nontarget birds will enable more widespread use of this useful population management technique.