Efficacy of a two-ingredient fumigant on Richardson's ground squirrel

In July 1981, efficacy data were obtained on a new two-ingredient gas cartridge by field testing against Richardson's ground squirrels (Spermophilus richardsonii) in a sagebrush-rangeland pasture. The gas cartridge contained 97 g of a sodium nitrate (65%) and charcoal (35%) mixture and upon ignition generated mainly carbon monoxide with a small quantity of carbon dioxide. We live-trapped 53 (24 male and 29 female) ground squirrels, equipped each with a 164 MHz radio transmitter, and then released each at the point of capture. Later we located each ground squirrel and treated its main burrow and all burrows within 3 m by inserting ignited gas cartridges. After treatment the location of each radio-equipped ground squirrel was plotted. Ground squirrels showing no movement were presumed dead; death was confirmed by burrow excavation. Success rate was 84% as 41 of 50 (18 males and 23 females) died (82%) and 8 survived (16%). The radio transmitter on 1 (2%) failed immediately after treatment. Efficacy was estimated at 83.7%, which exceeds the 70% minimum standard established by the EPA. Thirty-eight ground squirrels died in burrows at depths ranging from 7.6 to 132.1 cm (mean = 74.7 ± SE 5.2 cm), and 3 died in nests at depths ranging from 94.0 to 182.9 cm (mean = 133.0 ±SE 26.2 cm). Seven of the eight survivors were retrapped. Factors contributing to survival are discussed, including soil porosity and moisture content, as well as squirrel body weight. Recommendations for further testing are presented

Wildlife Fertility Control

Huge flights of Canada geese turn off local park visitors with their messy, smelly business cards. The superabundant white-tailed deer we love to watch also can do a number on your car at night and host the ticks that carry Lyme Disease. Blackbirds and gulls and coyotes and other critters bring their own problems when their numbers get out of hand. Most such problems reach their highest profile in urban/suburban areas where traditional animal-control techniques such as hunting and trapping are frowned upon or illegal. More and more people are calling for wildlife managers to use fertility control –-but is that concept really feasible on populations of free-ranging wildlife? The definitive answers–in the form of the latest science–are contained in a new Technical Review titled Wildlife Fertility Control. The 29-page Review notes that in the past, fertility control has been far less successful than observers had hoped, but thanks to new findings about animal reproductive systems, the technology is advancing rapidly and is being tested on several species on a small scale. Hurdles include the need to develop and commercialize effective vaccines or baits, cost-effective delivery systems, and public-agency acceptance of the technique. The new publication states that birth control will undoubtedly play a role in the science of wildlife management in the future. Managers face two major challenges: integrating contraceptive tactics with more conventional ways of managing critter numbers, and giving the public accurate information about the feasibility of using fertility control vs. lethal methods to reduce populations of deer and other long-lived species

Mitigating Impacts of Terrestrial lnvasive Species

Human beings have introduced other species around the world both accidentally and intentionally. Accidental introductions resulted from escape from captivity (monk parakeets [Myiopsitta monachus] in Florida), stowaways (rats [Ranus spp.] and house mice [Mus musculus] worldwide; brown tree snakes [Boiga irregularis] in Guam), or expansion of species\u27 ranges. Intentional introductions occurred for various reasons including: 1) aesthetics (songbirds into Hawaii, grey squirrel [Sciurus carolinensis] into Europe, and European songbirds imported by British colonists into North America, Australia, and New Zealand); 2) economics (nutria [Myocastor coypus] introduced in the eastern US., and Arctic fox [Alopex lagopus] onto Aleutian Islands for development of fur industries); 3) recreation (pheasants [Phasianus colchicus] and cbukar [Afectoris chukar] introduced as game species from Asia to North America, and red deer [Cervus elaphus] introduced into New Zealand); 4) food (domestic livestock worldwide, rabbits [Oryetolagus cunniculus] into Australia, pigs [Sus scrofa] into Hawaii); 5) for biological control (mongooses [Herpestes auropunctatus] to control rats in Hawaii, fox [Vulpes vulpes] to control rabbits in Australia, and giant toad [Bufo marinus] to control cane beetles in Australia); or 6) releases from captive populations (bulbuls [Pycnonotus jocosus] in Florida and domestic ferrets [Mustela putorius] in California, mink [Mustela vison] and muskrat [Ondntra zibethicus in Europe, and horse [Equus caballus], donkey [Equus minus], and other ungulates into Australia and western North America). The majority of biological introductions fail. Of those that succeed, only a small fraction become serious pests. Many introductions, like livestock or pheasants into the US., have been generally beneficial; however, some introduced species become invasive, defined as nonnative species which cause substantial economic or ecological h m . The U.S. has at least 221 nonnative terrestrial vertebrate species[1] and New Zealand has 35 introduced birds and 33 mammals, where previously the only mammals consisted of 3 bats. [2] About 44 mammals have been introduced into Australia, of which 27 have become established, 13\u27 along with 3 species of amphibians and reptiles and numerous birds. Ten species of terrestrial mammals on the Galapagos are aliens

Measurement of direct nitrous oxide emissions from microalgae cultivation under oxic and anoxic conditions

2011 Summer.Includes bibliographical references.Lifecycle assessments (LCA) of microalgae-based biofuels have demonstrated net greenhouse gas (GHG) emissions reductions, but limited data exist on direct emissions of GHG's from microalgae cultivation systems such as open raceway ponds (ORP) or photobioreactors (PBR). For example, nitrous oxide (N2O) is a potent GHG that has been detected from microalgae cultivation. However, N2O emissions have not been experimentally quantified to determine their impact on overall lifecycle assessment of the microalgae-to-biofuels process. Theoretical calculations using the Intergovernmental Panel on Climate Change standards for terrestrial crops (1% of available nitrogen applied as fertilizer is converted to N2O) suggest the potential for significant levels of N2O from microalgae cultivation. In this study, microalgae species Nannochloropsis salina was cultivated with nitrate under conditions representative of PBR and ORP growth conditions with diurnal light-dark cycling. To examine the effect of dissolved oxygen on N2O emissions, experiments were conducted with an air headspace and nitrogen headspace, respectively. During these experiments N2O emissions were quantified utilizing Fourier Transform Infrared spectrometry. Under a nitrogen headspace, N2O emissions were elevated during dark periods and minimal during light periods. Under an air headspace, N2O emissions were negligible for both the light and dark periods. The experimental results show that N2O production was induced by anoxic conditions with nitrate present in the growth media, suggesting that N2O was produced by denitrifying bacteria within the microalgal growth media. The presence of denitrifying bacteria was verified through PCR-based detection of norB genes, which encode bacterial enzymes that produce N2O. Furthermore, antibiotic treatments inhibited N2O emissions. Application of these results to LCA and potential strategies for management of growth systems to reduce N2O emissions are discussed

Black-footed ferret areas of activity during late summer and fall at Meeteetse, Wyoming

Black-footed ferrets (Mustela nigripes; hereafter, ferret) were formerly widespread in central North America. Their populations decreased throughout the last century to near extinction by the late 1970s as a result of extermination of prairie dogs (their main prey) and the spread of disease (Biggins and Godbey 1995; Biggins et al. 1998). In 1973 the ferret was the least known endangered mammal in the United States because of its nocturnal, semifossorial habits and the few known populations (Erickson 1973). In 1981 a small population was discovered in a complex of white-tailed prairie dog (Cynomys leucurus) colonies near Meeteetse, Wyoming. During 1983 and 1984 we used radiotelemetry to collect information on areas of activity for ferrets in this population. Our overall objective was to develop data on ferret activity and spatial use among sex and age groups. The Meeteetse population of ferrets was decimated by canine distemper (Morbillivirus) and plague (Yersinia pestis) in 1985 (Forrest et al. 1988), and 18 individuals were brought into captivity, forming the foundation for a captive-breeding program. We present data on sequential areas of activity (using minimum convex polygons) during 1983–1984 for Meeteetse ferrets monitored intensively for short periods of time between August and December. We compare the sizes of activity areas and shifts in centers of activity for male and female and adult and juvenile ferrets

The Use of Toxicants in Black-Tailed Prairie Dog Management: An Overview

Black-tailed prairie dogs pose management challenges to landowners and resource managers. They are viewed as either a pest when they cause damage to vegetation or property or pose a disease hazard or, conversely, as a valuable Akeystone@ species representative of reasonably intact prairie ecosystems. When conflicts arise with prairie dog colonies, the two main options are capture and relocation or lethal removal. There are a number of vertebrate toxicants registered for field use in the United States, but few are currently registered for prairie dog control. Only one, zinc phosphide, can be applied above ground as a grain bait. The other toxicants (aluminum phosphide pellets, fumigant gas cartridges, and acrolein) are applied in the burrow system as lethal fumigants. Most of these rodenticides are restricted use compounds and can be applied only by a certified pesticide applicator. The rodenticide label must be followed carefully to assure the safety of the applicator and to minimize non-target hazards. We present a brief summary of the toxicants registered for prairie dog control, including history and use patterns, general characteristics and mode of action, toxicity, efficacy, non-target hazards, and environmental fate

Foreword

The effects of invasive vertebrate species on agriculture, human health and safety, and the environment are a growing concern around the world. The number of incidents of invasive species causing harm continues to climb with increased worldwide travel and transportation of goods. The focus for many decades was on invasive pathogens, plants, and invertebrates because they can greatly affect human and animal health and food supplies. In recent years, invasive vertebrate species, such as rats, feral pigs, and feral cats, have garnered more attention because the magnitude of their impacts have been repeatedly highlighted in the media. In response, better methods of prevention, detection, and management of invasive species have been developed. For example, several eradications of invasive vertebrates on islands have been successful, although management on mainland settings is generally much more challenging

FLOTATION MATERIALS FOR AERIAL DELIVERY OF ACETAMINOPHEN TOXIC BAITS TO BROWN TREESNAKES

Polyvinyl chloride (PVC) tubes are effective bait stations for delivering dead neonatal mice (DNM) treated with the oral toxicant, 80 mg acetaminophen, to brown treesnakes (Boiga irregularis) in accessible jungle forest on Guam. However, PVC tubes are not practical for delivery of baits to remote areas of jungle or the forest canopy. Further, it is important that baits entangle in the canopy and not fall to the ground where they can be scavenged by non-target animals such as crabs. Data from helicopter aerial deployment of untreated DNM with radio transmitters that landed on the ground in areas of high coconut crab (Birgus latro) and hermit crab (Coenobita spp.) abundance showed that 67% of DNM were taken by crabs and 11% by monitor lizards (Varanus indicus). In contrast, in low crab abundance areas crabs took 24% of the DNM that landed on the ground. It is evident from these data that a flotation system that delivers DNM to the canopy is needed; otherwise non-target animals will remove DNM, making them unavailable for snakes. Seven aerial flotation devices were evaluated. Promising aerial devices are two types of commercial cardboard paper streamers that resulted in 75% - 85% of the DNM becoming entangled in the canopy

STATUS OF COMPOUND DRC-1339 REGISTRATIONS

Compound DRC-1339 is a restricted-use, slow-acting avicide that is registered to control a number of avian pests. It is unique because of its selective high toxicity to most pest birds, low-to-moderate toxicity to most mammals and predatory birds, and lack of known secondary hazards when used on baits. The most widely known product containing DRC- 1339 is Purina Mills’ Starlicide Complete®, a pelleted bait used to control blackbirds and starlings in feedlots. Other DRC- 1339 registrations are held by the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA/APHIS), for the use of nonpelletized baits at feedlots and for the control of gulls in or near their nesting colonies. Over 20 State Special Local Need 24(c) registrations have also been issued to APHIS for special DRC-1339 uses. To consolidate these registrations, APHIS has submitted data to amend its feedlot registration for blackbirds and starlings, and applied for three registrations for control of 1) raven and crow depredations on livestock and for wildlife protection, 2) pigeons in and around structures, and 3) blackbirds, starlings, and crows at preroosting staging areas. Because most of the submitted data were collected in the 1960s and 1970s, none of it was produced under the Environmental Protection Agency\u27s (EPA) Good Laboratory Practices (GLP) regulations; therefore, new data will probably be needed to support these registrations. Future data needs and procedures for collecting valid information for DRC-1339 are suggested

Nicarbazin OvoControl G Bait Reduces Hatchability of Eggs Laid by Resident Canada Geese in Oregon

Expanding populations of resident Canada geese (Branta canadensis) are resulting in increased conflicts with humans. Nonlethal and humane means are needed for managing Canada goose flocks at a variety of sites, including golf courses, industrial parks, government sites, and city parks. Decreased egg production and hatching are side effects of nicarbazin, a veterinary drug used to treat coccidiosis in chickens. Capitalizing on these effects, we developed nicarbazin as a reproductive inhibitor for Canada geese and conducted a field efficacy study. We recruited study sites in 2002 and 2003. Following laboratory testing, we conducted a field efficacy trial of nicarbazin for reducing the hatchability of Canada goose eggs in spring 2004 in Oregon, USA. The study began in February 2004 at 10 sites in Oregon, with 2 control and 3 treated sites on each side of the Cascades. We fed bait daily to resident Canada geese for approximately 6 weeks. We located and monitored nests until hatching or ≥5 days beyond the expected hatching date to determine hatchability. We completed data collection in May 2004. Geese consumed 8,000 kg of bait, with 5,100 kg of OvoControl G* (Innolytics, LLC, Rancho Santa Fe, CA) 2,500-ppm nicarbazin bait consumed among 6 treated sites and 2,900 kg of untreated bait consumed among 4 control sites. We monitored 63 nests at treated sites and 46 nests at control sites to determine hatching success of eggs. There was a 62% reduction in the percentage of nests with 100% hatchability at treated sites as compared to controls. There was a 93% increase in the percentage of nests at treated sites with 0% hatchability as compared to nests with no eggs hatching at control sites. Hatchability from treated sites versus control sites was reduced 36%(F=5.72, P=0.0622). We submitted results from this study to support Environmental Protection Agency registration of nicarbazin as a reproductive inhibitor for use in Canada geese. We have shown that treatment of resident Canada geese with OvoControl G 2,500-ppm nicarbazin bait by licensed, trained applicators immediately prior to and during the breeding season can reduce hatchability of eggs laid by treated geese, thereby reducing recruitment of goslings into problem resident Canada goose populations. ( JOURNAL OF WILDLIFE MANAGEMENT 71(1):135–143; 2007