Cedar Waxwings

Prevention and control of cedar waxwing (Bombycilla cedrorum) damage to small fruits such as blueberry, cherry, and strawberry is vexing to growers in many parts of the United States. Cedar waxwings (Figure 1) travel in flocks and descend in large numbers on berry crops, especially during winter and migration. In short feeding bouts, waxwings eat, peck, or knock substantial amounts of fruit from the plants. These frugivores are difficult to discourage once they become established at a given location. Harassment early and often using pyrotechnics or other sudden noisemakers can help prevent flocks from being established. The most effective preventative measure is exclusion using an appropriate netting system. Visual and auditory deterrents have limited effectiveness as flocks rapidly habituate. Chemical repellents based on methyl anthranilate as the active ingredient are readily available. Permits for lethal control can be difficult to obtain

Diverse examples from managing invasive vertebrate species on inhabited islands of the United States

A wide array of sizes, ecosystems, cultures, and invasive wildlife are represented among inhabited islands. Here, six cases from the United States of America (US) are selected to illustrate the high diversity of invasive animal management issues and objectives. We outline the background, define the problems and management objectives. We identify the management approaches and discuss the results and influences as they specifically relate to inhabited islands. The examples are: (1) Gambian giant pouched rats on Grassy Key, Florida; (2) coqui frogs on Kaua’i, Hawai’i; (3) feral swine on Cayo Costa Island, Florida; (4) rodents and monitor lizards on Cocos Island, Guam; (5) black spiny-tailed iguanas (ctenosaurs) on Gasparilla Island, Florida; and (6) mongooses on Puerto Rico. The outcomes of the programs are discussed, particularly in relation to the impact of human habitation on success

The Development of a Program to Reduce Damage from European Starlings at Dairies Using DRC-1339

In the winter in Michigan, European starlings (Sturnus vulgaris) congregate, sometimes in large numbers, at dairies to feed on the high energy components of cattle feed. Damage is incurred not only with the extensive consumption of the feed but also in a corresponding loss in milk production. Starlings are also suspected in the spread of diseases harmful to cattle. Effective control of starlings in these situations is limited to DRC-1339 which has been registered for this use for many years. However, it was rarely used, largely under the perception that effective control was difficult to achieve. In 1999, WS-MI launched a pilot project to see if the use of DRC-1339 could be re-invented for use on a broad scale. Foremost among the tasks of the pilot project was to identify a bait that was universally accepted by starlings, readily available in large quantities and compatible with DRC-1339. The answer to this search was found in a high-fat additive to cattle feed. This key discovery allowed for considerable expansion of this program which presented new challenges for business practices, personnel, logistics and public affairs. The answers to these challenges allowed WS-MI to conduct starling damage control on an unprecedented scale with a high degree success. Since the initiation of the pilot project, 219 dairies have been treated with DRC-1339 in which 181 farms (83%) have seen starlings reduced by 75% or more

Eradication of a Bovine Tuberculosis-Positive Captive Cervid Herd in Northeast Michigan

In December 1997, bovine tuberculosis was detected in a white-tailed deer taken at a commercial deer hunting ranch in Presque Isle County, Michigan. Since captive cervidae are considered agricultural livestock in Michigan, the Michigan Department of Agriculture (MDA) ordered the depopulation of the herd. In 1998, USDA, Wildlife Services (WS) entered into a cooperative agreement with MDA to depopulate the herd from the ranch. The facility covered approximately 1500 ac of natural vegetation, including 400 ac of dense cedar swamp. The captive herd was thought to contain approximately 600 animals, most of which were white-tailed deer. This project presented two significant challenges: 1) removing no less than 100% of the deer and, 2) providing verification to MDA that 100% depopulation had been achieved. The depopulation effort began in February 1998 and was completed in March 1999 with the removal of 325 cervids. The successful depopulation strategy which included various shooting techniques, fencing, dogs and helicopters is described as well as the verification efforts

Overhead Gridline Systems to Exclude Waterfowl From Large Bodies of Water

The presence of birds at retention/detention basins on or adjacent to an airport increases the probability of experiencing a wildlife strike. Overhead gridline systems have proven effective for reducing the presence of birds on small water bodies. While there are several line materials available to address bird hazards associated with small basins, the list of options decreases quickly as the distance to be spanned increases. The Michigan Wildlife Services program (WS) tested 4 types of line material on 3 large detention basins to determine which materials could span up to 675 m (2214.5 ft) without center supports. Additionally, the line material could not sag substantially because of water fluctuations of up to 1.5 m (5 ft). If a line would contact the surface of the water, the surface tension would hold it in place reducing the effectiveness and causing potential damage to the grid, especially during freezing and thawing periods. We found that a braided fishing line made of Spectra® fiber called PowerPro proved superior in our tests. We suspended grid lines in perpendicular directions on 30 m (100ft) spacing. Preliminary results show a notable reduction in usage by Canada geese (Branta canadensis), mallards (Anas platyrhynchos), mute swans (Cygnus olor), herring gulls (Larusargentatus) and ring-billed gulls (Larus delawarensis)

Diverse examples from managing invasive vertebrate species on inhabited islands of the United States

A wide array of sizes, ecosystems, cultures, and invasive wildlife are represented among inhabited islands. Here, six cases from the United States of America (US) are selected to illustrate the high diversity of invasive animal management issues and objectives. We outline the background, define the problems and management objectives. We identify the management approaches and discuss the results and influences as they specifically relate to inhabited islands. The examples are: (1) Gambian giant pouched rats on Grassy Key, Florida; (2) coqui frogs on Kaua’i, Hawai’i; (3) feral swine on Cayo Costa Island, Florida; (4) rodents and monitor lizards on Cocos Island, Guam; (5) black spiny-tailed iguanas (ctenosaurs) on Gasparilla Island, Florida; and (6) mongooses on Puerto Rico. The outcomes of the programs are discussed, particularly in relation to the impact of human habitation on success

The devil you know and the devil you don’t: current status and challenges of bovine tuberculosis eradication in the United States

Abstract Having entered into its second century, the eradication program for bovine tuberculosis (bTB, caused by Mycobacterium bovis) in the United States of America occupies a position both enviable and daunting. Excepting four counties in Michigan comprising only 6109 km2 (0.06% of US land area) classified as Modified Accredited, as of April 2022 the entire country was considered Accredited Free of bTB by the US Department of Agriculture for cattle and bison. On the surface, the now well-described circumstances of endemic bTB in Michigan, where white-tailed deer (Odocoileus virginianus) serve as a free-ranging wildlife maintenance host, may appear to be the principal remaining barrier to national eradication. However, the situation there is unique in the U.S., and far-removed from the broader issues of bTB control in the remainder of the country. In Michigan, extensive surveillance for bTB in deer over the last quarter century, and regulatory measures to maximize the harvest of publicly-owned wildlife, have been implemented and sustained. Prevalence of bTB in deer has remained at a low level, although not sufficiently low to eliminate cattle herd infections. Public attitudes towards bTB, cattle and deer, and their relative importance, have been more influential in the management of the disease than any limitations of biological science. However, profound changes in the demographics and social attitudes of Michigan’s human population are underway, changes which are likely to force a critical reevaluation of the bTB control strategies thus far considered integral. In the rest of the U.S. where bTB is not self-sustaining in wildlife, changes in the scale of cattle production, coupled with both technical and non-technical issues have created their own substantial challenges. It is against this diverse backdrop that the evolution of whole genome sequencing of M. bovis has revolutionized understanding of the history and ecology of bTB in Michigan, resolved previously undiscernible epidemiological puzzles, provided insights into zoonotic transmission, and unified eradication efforts across species and agencies. We describe the current status of bTB eradication in the U.S., how circumstances and management have changed, what has been learned, and what remains more elusive than ever

The devil you know and the devil you don’t: current status and challenges of bovine tuberculosis eradication in the United States

Having entered into its second century, the eradication program for bovine tuberculosis (bTB, caused by Mycobacterium bovis) in the United States of America occupies a position both enviable and daunting. Excepting four counties in Michigan comprising only 6109 km2 (0.06% of US land area) classified as Modified Accredited, as of April 2022 the entire country was considered Accredited Free of bTB by the US Department of Agriculture for cattle and bison. On the surface, the now well-described circumstances of endemic bTB in Michigan, where white-tailed deer (Odocoileus virginianus) serve as a free-ranging wildlife maintenance host, may appear to be the principal remaining barrier to national eradication. However, the situation there is unique in the U.S., and far-removed from the broader issues of bTB control in the remainder of the country. In Michigan, extensive surveillance for bTB in deer over the last quarter century, and regulatory measures to maximize the harvest of publicly-owned wildlife, have been implemented and sustained. Prevalence of bTB in deer has remained at a low level, although not sufficiently low to eliminate cattle herd infections. Public attitudes towards bTB, cattle and deer, and their relative importance, have been more influential in the management of the disease than any limitations of biological science. However, profound changes in the demographics and social attitudes of Michigan’s human population are underway, changes which are likely to force a critical reevaluation of the bTB control strategies thus far considered integral. In the rest of the U.S. where bTB is not self-sustaining in wildlife, changes in the scale of cattle production, coupled with both technical and non-technical issues have created their own substantial challenges. It is against this diverse backdrop that the evolution of whole genome sequencing of M. bovis has revolutionized understanding of the history and ecology of bTB in Michigan, resolved previously undiscernible epidemiological puzzles, provided insights into zoonotic transmission, and unified eradication efforts across species and agencies. We describe the current status of bTB eradication in the U.S., how circumstances and management have changed, what has been learned, and what remains more elusive than ever

Evaluation of Bait Station Density for Oral Rabies Vaccination of Raccoons in Urban and Rural Habitats in Florida

Efforts to eliminate the raccoon variant of the rabies virus (raccoon rabies) in the eastern United States by USDA, APHIS, Wildlife Services and cooperators have included the distribution of oral rabies vaccine baits from polyvinyl chloride (PVC) bait stations in west-central Florida from 2009 to 2015. Achieving sufficient vaccine bait uptake among urban raccoons is problematic, given limitations on aerial and vehicle-based bait distribution for safety and other reasons. One or three bait stations/km2 were deployed across four 9-km2 sites within rural and urban sites in Pasco and Pinellas Counties, Florida. Based on tetracycline biomarker analysis, bait uptake was only significantly different among the urban (Pinellas County) high and low bait station densities in 2012 (p = 0.0133). Significant differences in RVNA were found between the two bait station densities for both urban 2011 and 2012 samples (p = 0.0054 and p = 0.0031). Landscape differences in terms of urban structure and human population density may modify raccoon travel routes and behavior enough for these differences to emerge in highly urbanized Pinellas County, but not in rural Pasco County. The results suggest that, in urban settings, bait stations deployed at densities of >1/km2 are likely to achieve higher seroprevalence as an index of population immunity critical to successful raccoon rabies control

Progress towards Bait Station Integration into Oral Rabies Vaccination Programs in the United States: Field Trials in Massachusetts and Florida

Bait stations for distribution of oral rabies vaccine baits are designed for rabies management in highly-developed areas where traditional distribution of oral rabies vaccine baits may be difficult. As part of national efforts to contain and eliminate the raccoon (Procyon lotor) variant of the rabies virus (raccoon rabies) in the eastern United States, the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services program, distributed vaccine baits by bait stations experimentally and operationally in Massachusetts during 2006-present, and in Florida during 2009–2015. In Massachusetts, a rabies virus-neutralizing antibody (RVNA) response of 42.1% for raccoons captured in areas baited with high density bait stations during 2011–2015 was achieved, compared with 46.2% in areas baited by hand, suggesting the continuation of this as a strategy for the oral rabies vaccination (ORV) program there, and for similar locations. Non-target competition for vaccine baits is problematic, regardless of distribution method. In Massachusetts, bait station visitation rates for targeted raccoons and non-target opossums (Didelphis virginiana) were similar (1.18:1) during 2006–2009 (p > 0.05). Bait station modifications for reducing non-target uptake were tested, and in Massachusetts, reduced non-target bait access was achieved with two design alternatives (p < 0.001). However, no difference was noted between the control and these two alternative designs in Florida. Due to ongoing trials of new vaccines and baits, the bait station performance of an adenovirus rabies glycoprotein recombinant vaccine bait, ONRAB® bait (Artemis Technologies, Guelph, ON, Canada) and a vaccinia-rabies glycoprotein recombinant vaccine bait, RABORAL V-RG®bait (Merial Limited, Athens, GA, USA), was compared. While uptake of the ONRAB bait was greater in Massachusetts (p < 0.001) in this limited trial, both types performed equally well in Florida. Since bait station tampering or theft as well as potential human bait contacts has been problematic, performance of camouflaged versus unpainted white bait stations was analyzed in terms of internal temperatures and maintaining a stable bait storage environment. In Massachusetts, camouflaged bait station interiors did not reach higher average temperatures than plain white bait stations in partially- or fully-shaded locations, while in Florida, camouflaged bait stations were significantly warmer in light exposure categories (p < 0.05). As ORV operations expand into more heavily-urbanized areas, bait stations will be increasingly important for vaccine bait distribution, and continued refinements in the strategy will be key to that success