Dogs Gone Wild: Feral Dog Damage in the United States

Feral dogs have been documented in all 50 states and estimates of damage in the U.S. from these animals amount to >$620 million annually. In Texas alone, it is estimated that over $5 million in damage to livestock annually can be attributed to feral dogs. We reviewed national statistics on feral dog damage reported to USDA, APHIS, Wildlife Services for a 10-year period from 1997 through 2006. Damage by feral dogs crossed multiple resource categories (e.g., agriculture, natural resources); some examples of damage include killing and affecting the behavior and habitat use of native wildlife; killing and maiming livestock; and their role as disease vectors to wildlife, domestic animals, and humans. We review the role of dog damage in the U.S., synthesize the amount of damage between resource categories (agriculture, human health and safety, disease, and natural resources), and report trends in dog damage during the 10-year period. Results showed an increase in dog damage across all resource categories indicating the importance of management.

Biology and Impacts of Pacific Island Invasive Species. 5. Eleutherodactylus coqui, the Coqui Frog (Anura: Leptodactylidae)

The nocturnal, terrestrial frog Eleutherodactylus coqui, known as the Coqui, is endemic to Puerto Rico and was accidentally introduced to Hawai‘i via nursery plants in the late 1980s. Over the past two decades E. coqui has spread to the four main Hawaiian Islands, and a major campaign was launched to eliminate and control it. One of the primary reasons this frog has received attention is its loud mating call (85–90 dB at 0.5 m). Many homeowners do not want the frogs on their property, and their presence has influenced housing prices. In addition, E. coqui has indirectly impacted the floriculture industry because customers are reticent to purchase products potentially infested with frogs. Eleutherodactylus coqui attains extremely high densities in Hawai‘i, up to 91,000 frogs ha-1, and can reproduce year-round, once every 1–2 months, and become reproductive around 8–9 months. Although the Coqui has been hypothesized to potentially compete with native insectivores, the most obvious potential ecological impact of the invasion is predation on invertebrate populations and disruption of associated ecosystem processes. Multiple forms of control have been attempted in Hawai‘i with varying success. The most successful control available at this time is citric acid. Currently, the frog is established throughout the island of Hawai‘i but may soon be eliminated on the other Hawaiian Islands via control efforts. Eradication is deemed no longer possible on the island of Hawai‘i.

A Tool Box Half Full: How Social Science can Help Solve Human–Wildlife Conflict

There is a growing recognition among wildlife managers that focusing management on wildlife often provides a temporary fix to human–wildlife conflicts, whereas changing human behavior can provide long-term solutions. Human dimensions research of wildlife conflicts frequently focuses on stakeholders’ characteristics, problem identification, and acceptability of management, and less frequently on human behavior and evaluation of management actions to change that behavior. Consequently, little information exists to assess overall success of management. We draw on our experience studying human–bear conflicts, and argue for more human dimensions studies that focus on change in human behavior to measure management success. We call for help from social scientists to conduct applied experiments utilizing two methods, direct observation and self-reported data, to measure change in behavior. We are optimistic these approaches will help fill the managers’ tool box and lead to better integration of human dimensions into human–wildlife conflict management.

Effects of a synthetic gonadotrophin-releasing hormone agonist, leuprolide, on rut-associated events in male red deer

This study examined the effectiveness of leuprolide, a gonadotrophin-releasing hormone agonist, in suppressing rut-associated events in farmed male red deer. In mid-January (~6 weeks before the rut period in the southern hemisphere) adult red deer (Cervus elaphus scoticus) stags that had been allocated to three groups (n = 10 per group) received leuprolide, administered subcutaneously in a 90-day release formulation, at zero (control), low (22.5 mg) or high (45 mg) doses. Following treatment with leuprolide there was evidence of suppression of mean plasma luteinising hormone concentration that was significant (P < 0.05) at 9 weeks. Mean plasma testosterone concentration of all three groups rose following treatment, then declined prematurely in the low- and high-dose leuprolide-treated groups, so that it was significantly (P < 0.05) suppressed (0.66 ± 0.29 and 2.0 ± 0.88 ng mL–1, low and high dose respectively) in early April when the peak value (9.0 ± 1.94 ng mL–1) was recorded from control stags. A reduction in mean liveweight occurred in all three groups through February–April and this did not differ among treatments. However, a corresponding reduction in mean body condition score was greater in the control stags (P < 0.05). There was little effect of leuprolide treatment on aggressive behaviours, but it lowered roaring frequency in the latter period of the rut. The results indicate that this gonadotrophin-releasing hormone agonist has potential for application in the deer farming industry to suppress undesirable effects of the rut.

Translocation of nine-banded armadillos

During the last 150 years, nine-banded armadillos (Dasypus novemcinctus) have increased their range and abundance in the southeastern United States. When foraging, armadillos cause damage to agricultural crops as, as well as cause structural damage to driveways and foundations. Homeowners frequently use translocation to reduce local armadillo abundance. Despite its popularity with the general public, however, the appropriateness of nuisance wildlife translocation presents concerns for biologists. Our objective was to address some of these concerns by examining survival and movements of translocated armadillos. We translocated 12 armadillos (9 male, 3 female) equipped with radio-transmitters and compared their survival and movements to that of 29 (11 male, 18 female) resident armadillos. Most (92%) of the translocated animals dispersed from their release site within the fi rst few days after release. Resident armadillos generally maintained stable home ranges. We found evidence that translocated animals were abl to return to their original capture sites. We, therefore, recommend against translocating nuisance armadillos.

Comparison of Endocrine Response to Stress Between Captive-Raised and Wild-Caught Bighorn Sheep

Stress hormones in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), produced in response to environmental changes, road development, or high population density, may impact their immune systems to a threshold level that predisposes them to periodic, large-scale mortality. We compared the stress response to a novel environmental situation and repeated handling between bighorn sheep born and raised in captivity (CR) and bighorn sheep born in the wild (WC) and brought into captivity. We measured plasma epinephrine, norepinephrine, cortisol, and fecal glucocorticoid metabolites (FGM). Three weeks after each group’s arrival we used a one-time drop-net event to elicit an acute stress response, and we collected blood samples from each sheep over 35 minutes, as well as one fecal sample. We collected blood and fecal samples from both groups on 7 other occasions over the subsequent 6 months. We also collected fecal samples from the pen at approximately 24-hour intervals for 3 days following every handling event to monitor the stress response to handling. We found that CR sheep had a stronger autonomic nervous system response than WC sheep, as measured by epinephrine and norepinephrine levels, but we found a very similar hypothalamic–pituitary–adrenal axis (HPA) response, measured by cortisol levels, to the acute stress event of a drop-net restraint. We also found that once the WC sheep had acclimated, as indicated by the return to the initial baseline FGM levels within 12 weeks, the CR and WC groups’ HPA responses to sampling events were not significantly different from one another. Fecal samples can provide a noninvasive mechanism for managers to monitor baseline FGM for a given herd. Using long-term monitoring of FGM rather than values from a single point in time may allow managers to correlate these levels to outside influences on the herd and better understand the impacts of management changes, population density, or increased human developments on the health of the sheep population.

Sapro-Zoonotic Risks Posed by Wild Birds in Agricultural Landscapes

There are over 1400 catalogued human pathogens, with approximately 62% classified as zoonotic (Taylor et al., 2001). Most evidence of direct transmission of pathogens to humans involves domestic and companion animals, whereas the reservoir for most zoonoses is wildlife; yet there are relatively few well-documented cases for the direct involvement of transmission from wildlife to humans (Kruse et al., 2004). In part, this absence of evidence reflects the mobility of wildlife, the difficulty accessing relevant samples, and the smaller number of studies focused on characterizing wildlife pathogens relative to the human and veterinary literature (McDiarmid, 1969; Davis et al., 1971; Hubalek, 2004).

An Overview of Historical Beaver Management in Arizona

In the mid-1820s, Anglo-American fur trappers, known as "mountain men," entered Arizona and began trapping beaver (Castor canadensis). In Arizona there have been a number of famous mountain men such as Sylvester and James Pattie, Ewing Young, Jededia Smith, and Bill Williams who trapped along the waterways in northern and southern Arizona. Although the heyday of mountain men lasted only a few decades due to a population decline of beaver, management of these animals continues to this day. The purpose of managing beavers shifted from monetary gain to controlling wildlife damage. During the late 1900s, beaver were still widely distributed in limited numbers throughout much of the state. We provide a historical overview of beaver management in Arizona with emphasis on the mountain men, recreational trapping, wildlife damage management, and beaver research in Arizona.

Las enfermedades del venado cola blanca en Norteamérica: situación actual y desafíos.

Desde hace mucho tiempo, los administradores de vida silvestre han buscado conocer acerca de la ecología de las enfermedades y parásitos que afectan al venado cola blanca (Odocoileus virginianus ) (por ejemplo vea Whitlock 1939). Este es un importante campo de estudio porque las enfermedades y parásitos pueden afectar nocivamente las poblaciones de venados, otros animales silvestres, el ganado y humanos (Davidson et al. 1981). El venado cola blanca ha recibido mucha atención en la literatura acerca de sus enfermedades y parásitos y tratados completos se han dedicado al tema (por ejemplo, vea Davidson et al. 1981). Los avances recientes en nuestra comprensión de la ecología de las enfermedades y parásitos del venado cola blanca han sido realizados por científicos de las universidades y organismos estatales y federales. Una gran cantidad de enfermedades y parásitos causan morbilidad y mortalidad en el venado cola blanca. También se han observado alteraciones en la conducta del venado, el éxito reproductivo y sobrevivencia (Matschke et al. 1984).

Feral swine damage and damage management in forested ecosystems

Invasive feral swine (Sus scrofa) cause deleterious impacts to ecosystem processes and functioning throughout their worldwide distribution, including forested ecosystems in the United States. Unfortunately, many feral swine damage management programs are conducted in a piecemeal fashion, are not adequately funded, and lack clearly stated or realistic objectives. This review paper identifies damage caused by feral swine to forest resources and presents techniques used to prevent and control feral swine damage. Concluding points related to planning a feral swine damage management program are: (1) the value of using a variety of techniques in an integrated fashion cannot be overstated; (2) there is value in using indices for both feral swine populations and their damage pre and post management activities; (3) innovative technologies will increasing be of value in the pursuit of feral swine damage reduction; and (4) though not appropriate in every situation, there is value in involving the public in feral swine damage management decisions and activities.

Evaluation of Sodium Lauryl Sulfate as a Blackbird Wetting Agent

New and improved strategies are needed for managing overabundant blackbird (Icteridae spp.) populations in some areas of the United States. From 2004 to 2007, we evaluated sodium lauryl sulfate (SLS) as a wetting agent during controlled outdoor cage and flight pen tests in Colorado and small-scale field tests at urban blackbird roosts in Missouri. In the outdoor cage tests (ambient temperature -5 to 2° C), mortality of male red-winged blackbirds (Agelaius phoeniceus) sprayed with 1, 2, and 5 ml of SLS on the back feathers only, on the breast feathers only, or on both breast and back feathers ranged from 25% to 100%. A SLS spray on male red-winged blackbirds at 2° C ambient temperature with 1 ml of SLS sprayed on breast feathers and back feathers resulted in 90% mortality in less than 60 minutes. In a flight pen test (-12 to -5° C ambient temperature ), SLS sprayed at 20 l per 3,400 l of water with a single ground-based sprinkler-head system over 35 male red-winged blackbirds roosting in cedar trees (Juniperus virginiana) resulted in 53% mortality. There was no mortality in the control group exposed to the same treatment without the SLS. Small-scale field tests conducted in Missouri at 6 sites with a single ground-based sprinkler-head spray system and at 2 sites with 4 sprinkler-head spray systems resulted in mortality that ranged from 0 to 4,750 and 4,500 to 15,000 blackbirds and starlings, respectively. Spray operations lasted from 28 to 208 minutes. Each spray covered about 200 m2 . At all sites, mortality of blackbirds sprayed with the SLS occurred as soon as 30 minutes post-SLS application. Mortality at two sites where pump problems precluded completing the spray ranged from 0 to 800 birds. Air leaving the system as the system was activated caused birds to flush from the roost trees. Poor water quality and pump durability were problems at some sites.

Protein Hydrolysates Are Avoided by Herbivores but Not by Omnivores in Two-Choice Preference Tests

Background: The negative sensory properties of casein hydrolysates (HC) often limit their usage in products intended for human consumption, despite HC being nutritious and having many functional benefits. Recent, but taxonomically limited, evidence suggests that other animals also avoid consuming HC when alternatives exist. Methodology/Principal Findings: We evaluated ingestive responses of five herbivorous species (guinea pig, mountain beaver, gopher, vole, and rabbit) and five omnivorous species (rat, coyote, house mouse, white-footed mouse, and deer mouse; N = 16–18/species) using solid foods containing 20% HC in a series of two-choice preference tests that used a nonprotein, cellulose-based alternative. Individuals were also tested with collagen hydrolysate (gelatin; GE) to determine whether it would induce similar ingestive responses to those induced by HC. Despite HC and GE having very different nutritional and sensory qualities, both hydrolysates produced similar preference score patterns. We found that the herbivores generally avoided the hydrolysates while the omnivores consumed them at similar levels to the cellulose diet or, more rarely, preferred them (HC by the white-footed mouse; GE by the rat). Follow-up preference tests pairing HC and the nutritionally equivalent intact casein (C) were performed on the three mouse species and the guinea pigs. For the mice, mean HC preference scores were lower in the HC v C compared to the HC v Cel tests, indicating that HC’s sensory qualities negatively affected its consumption. However, responses were species-specific. For the guinea pigs, repeated exposure to HC or C (4.7-h sessions; N = 10) were found to increase subsequent HC preference scores in an HC v C preference test, which was interpreted in the light of conservative foraging strategies thought to typify herbivores. Conclusions/Significance: This is the first empirical study of dietary niche-related taxonomic differences in ingestive responses to protein hydrolysates using multiple species under comparable conditions. Our results provide a basis for future work in sensory, physiological, and behavioral mechanisms of hydrolysate avoidance and on the potential use of hydrolysates for pest management.

Review of issues concerning the use of reproductive inhibitors, with particular emphasis on resolving human-wildlife conflicts in North America

This manuscript provides an overview of past wildlife contraception efforts and discusses the current state of research. Two fertility control agents, an avian reproductive inhibitor containing the active ingredient nicarbazin and an immunocontraceptive vaccine, have received regulatory approval with the Environmental Protection Agency and are commercially available in the USA. OvoControl G Contraceptive Bait for Canada Geese and Ovo Control for pigeons are delivered as oral baits. An injectable immunocontraceptive vaccine (GonaCon Immunocontraceptive Vaccine) was registered with the Environmental Protection Agency for use in female white-tailed deer in September 2009. An injectable product (GonaCon Immunocontraceptive Vaccine) is registered for use in female white-tailed deer. Both products are labeled for use in urban/suburban areas where these species are overabundant. Several other compounds are currently being tested for use in wildlife in the USA, Europe, Australia and New Zealand that could have promise in the future. The development and use of reproductive inhibitors for resolving human–wildlife conflicts will depend on a number of factors, including meeting the requirements of regulatory agencies for use in the environment and on the biological and economical feasibility of their use. Use will also be dependent on health and safety issues and on public acceptance of the techniques.

“Species Pollution” in Florida: A Cross-Section of Invasive Vertebrate Issues and Management Responses

The state of Florida as among the two worst invasive species problems in the USA. Besides the sheer numbers of established exotic species in Florida, many present novel difficulties for management, or have other characteristics making effective management extremely challenging. Moreover, initiation of management action requires more than recognition by experts that a potentially harmful species has become established. It also requires the political will along with concomitant resources and appropriate personnel to develop effective methods and apply them. We illustrate various aspects of the situation in Florida with examples of invasive vertebrates, the problems they pose(d), and management approaches to the problems.

Ctenosaura similis (Black Spiny-Tailed Iguana), ,i>Gopherus Polyphemus (Gopher Tortoise) Concurrent Burrow Use

Ctenosaura similis is exotic to Florida (Meshaka et al. 2004. The Exotic Amphibians and Reptiles of Florida, Krieger Publ. Co., Malabar, Florida. 155 pp.), whereas Gopherus polyphemus is listed as a species of special concern by the state of Florida (Florida Wildlife Code Chap. 39 F.A.C.), and as a threatened species by the Florida Committee on Rare and Endangered Plants and Animals (FCREPA) (Moler 1992. Rare and Endangered Biota of Florida: Volume III, Reptiles and Amphibians. University Press of Florida, Gainesville, Florida. 291 pp.).