Hazards to golden-mantled ground squirrels and associated secondary hazard potential from strychnine baiting for forest pocket gophers

Radio telemetry and capture-recapture techniques were used to evaluate the hazards to golden-mantled ground squirrels (Spermophilus lateralis) from hand baiting with 0.5% strychnine-treated oats for western pocket gophers (Thomomys mazama) on conifer plantations in eastern Oregon. Toxicology data were collected on field-killed and caged ground squirrels and on caged mink (Mustela vison), great horned owls (Bubo virginianus), and red-tailed hawks (Buteo jamaicensis). Ground squirrel populations were reduced 50 to 75% following underground baiting for pocket gophers. Maximum amount of strychnine alkaloid found in cheek pouches and carcass of a field-killed golden-mantled ground squirrel was 2.88 mg. Mean amount of strychnine in carcasses was 0.35 mg; almost all occurred in the gut. The estimated LD50 for mink was 0.6 mg/kg. The lowest lethal dose for great horned owls and red-tailed hawks was 7.7 mg/kg and 10.2 mg/kg, respectively. The LD50 for owls and hawks was not determined. Long-term effects on golden-mantled ground squirrel populations and secondary hazard potential to owls and hawks were judged to be minimal. Wild mustelids as large as mink could be adversely affected by consuming the gut content of strychnine-killed golden-mantled ground squirrels

Slug grazing effects on seedling and adult life stages of North American Prairie plants used in designed urban landscapes

Designed vegetation is a major contributor to ecosystem service provision incities, and as such the study of how herbivory and other ecological factors determine its capacity to deliver such services, is long overdue. This study investigated the effect of slug grazing on the establishment and development of 26 species of North American prairie forbs and grasses used in sown or planted naturalistic communities in urban greenspace. The experiment was designed to provide slugs with the opportunity to choose between the plant species used, to mirror the situation that prevails in public greenspace. Slug density was manipulated through baiting with metaldehyde at different frequencies. Seedlings of prairie species were more palatable to slugs than adults. Seedling establishment was significantly reduced in most species by slug grazing, with only seven species showing no significant increase in establishment in response to baiting with metaldehyde. In many species successful establishment was based on moderate-high unpalatability and large or fast growing seedlings. Adult prairie plants were typically more able to withstand slug damage, and once their shoots reached a certain size, grazing declined. This was not true of the most palatable species, which even as adults were eventually eliminated by grazing in the absence of baiting. Phenology plays an important role in the survival of adults, with early emerging species potentially subject to severe damage due to the limited availability of alternate food plants. As a group, prairie forbs are typically palatable to slugs, and unlikely to be persistent in the most slug-rich urban situations

Rabies Surveillance Identifies Potential Risk Corridors and Enables Management Evaluation

Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV management strategies, and identify surveillance gaps. ORV management has resulted in a decrease in RABV cases over time within vaccination zones (from occupancy (ψ) of 0.60 standard error (SE) = 0.03 in the spring of 2006 to ψ of 0.33 SE = 0.10 in the spring 2017). RABV cases also reduced in the enzootic area (from ψ of 0.60 SE = 0.03 in the spring of 2006 to ψ of 0.45 SE = 0.05 in the spring 2017). Although RABV occurrence was related to habitat type, greater impacts were associated with ORV and trap–vaccinate–release (TVR) campaigns, in addition to seasonal and yearly trends. Reductions in RABV occupancy were more pronounced in areas treated with Ontario Rabies Vaccine Bait (ONRAB) compared to RABORAL V-RG®. Our approach tracked changes in RABV occurrence across space and time, identified risk corridors for potential incursions into Canada, and highlighted surveillance gaps, while evaluating the impacts of management actions. Using this approach, we are able to provide guidance for future RABV management

Experimental population suppression of Richardson's ground squirrels (Spermophilus richardsonii) in Alberta

Richardson's ground squirrel is one of the most economically harmful rodents in east central Alberta. In an effort to develop an effective, safe, economical and practical method of long-term population control over large areas, experimental field testing was begun in 1970 to evaluate a variety of potential control techniques. Although tests with a machine bait applicator proved unsuccessful due to the unique soil structure, its potential in other areas of the province is discussed. Use of portable baiting stations is limited by the manufacturing and maintenance costs as well as the limited attractability of the stations. Attractability of the stations to ground squirrels was not increased with the use of reflector tops; however, it did have a repellent influence on raptors feeding in the area. Disposable baiting tubes appeared to have greater potential for large acreages and possible aerial application. Initial tests conducted with diethylstilbestrol and mestranol as chemosterilants are outlined. The potential of using techniques to regulate reproductive rate as opposed to increasing mortality rate is discussed. The potential of using amphetamines to reduce body weight and increase winter mortality during hibernation is also discussed

Do lemurs know when they could be wrong? An investigation of information seeking in three species of lemur (<i>Lemur catta, Eulemur rubriventer, </i>and<i> Varecia variegata</i>)

Sixteen lemurs, including representatives from three species (Lemur catta, Eulemur rubriventer, Varecia variegata), were presented with a food seeking task where information about the rewards location, in one of two plastic tubes, was either known or not known. We evaluated whether lemurs would first look into the tube prior to making a choice. This information-seeking task aimed to assess whether subjects would display memory awareness, seeking additional information when they became aware they lacked knowledge of the rewards location. We predicted lemurs would be more likely to look into the tube when they had insufficient knowledge about the rewards position. Lemurs successfully gained the reward on most trials. However, they looked on the majority of trials regardless of whether they had all the necessary information to make a correct choice. The minimal cost to looking may have resulted in checking behaviour both to confirm what they already knew and to gain knowledge they did not have. When the cost of looking increased (elevating end of tube requiring additional energy expenditure to look inside - Experiment 2), lemurs still looked into tubes on both seen and unseen trials; however, the frequency of looking increased when opaque tubes were used (where they could not see the rewards location after baiting). This could suggest they checked more when they were less sure of their knowledge state

PREFERENSI KECOAK AMERIKA Periplaneta americana (L.) (Blattaria : Blattidae) TERHADAP BAITING GEL

Kecoak eriplaneta amricana merupakan jenis kecoak yang paling banyak terdapat di lingkungan permukiman di Indonesia. Kecoak bsa menjadi vektor mekanik berbagai patogen seperti jamur, virus, bakteri dan protozoa. Penelitian ini bertujuan untuk menganalisis perbedaan preferensi Periplaneta americana terhadap baiting gel komersial berbahan aktif imidaklorprid (BTX) dan fipronil (MFF). Penelitian ini di lakukan di Laboratorium Entomologi FKM Universitas Diponegoro. Desain penelitian yang digunakan adalah Ekserimen murni menggunakan olfactometer dengan pengulan sebanyak 3 kali. Data dianalisis dengan menggunakan t-test independent (a=0,05). Hasil pengamatan menunjukan bahwa preferensi pada stadium nimfa Periplaneta americana tidak ada perbedaan yang signifikan terhadap baiting gel BTX dan MFF dengan p value 0,710. Begitu juga pada stadium imago Periplaneta americana tidak ada perbedaan preferensi yang signifikan terhadap baiting gel BTX dan MFF dengan p value 0,849. Baiting gel lebih menarik dan efektif digunakan untuk pengendalian kecoa amerika dewasa dibandingkan nimfa. Kata Kunci: prefrensi, kecoa, baiting ge

Report of the Inter-American Tropical Tuna Commission for the year 1952

ENGLISH: The Inter-American Tropical Tuna Commission, established by a Convention between the United States and Costa Rica, has as its purpose the collection and interpretation of information which will facilitate maintaining, at levels of maximum sustained yield, the populations of tropical tunas in the Eastern Pacific and of the bait species used in their capture. To this end, the Commission is directed by the Convention to undertake investigations of the tunas and bait species, and to make recommendations for joint action by the member governments designed to attain the objectives of the Convention. The year 1952 is the second since the initiation of the investigations of the Commission. The Commission was organized in 1950. Its program of investigations ~as outlined and work commenced during 1951. The work during 1952 has been a continuation and logical development of the research commenced the previous year. SPANISH: La Comisión Interamericana del Atún Tropical, establecida por una Convención entra Costa Rica y los Estados Unidos de América, tiene como deberes recolectar e interpretar la información que facilite el mantenimiento, a niveles de una contínua producción máxima, de las poblaciones de las especies tropicales de atún en el Pacífico Oriental y de los peces de carnada que se emplean para su pesca. Con este propósito la Comisión se encarga, en conformidad con los términos de la antes expresada Convención de efectuar investigaciones sobre los atunes y mencionadas especies de carnada, y de hacer recomendaciones a los Gobiernos Miembros a fin de que pueden tomar una acción conjunta que les permita obtener los resultados que el citado Convenio persigue. El año 1952 es el segundo desde la iniciación de las investigaciones de la Comisión. Esta fué organizada en 1950. Durante 1951 se preparó el programa de estudios y se comenzaron los trabajos. La tarea realizada en el año 1952 ha sido una continuación y lógico desarrollo de las investigaciones empezadas en el año anterior. (PDF contains 61 pages.