The Use of Rodenticides for Conservation Efforts

Non-native rats (Rattus spp.) and mice have been introduced to more than 80% of the island groups around the world. They have caused ecosystem-wide impacts, including the extirpation and extinction of many native and endemic species which evolved in a mammalian predator-free environment. Fortunately, practitioners have developed techniques to eradicate introduced rodents, allowing ecosystems to recover. Rodenticides have proven an effective tool in eradications, having been used in over 300 successful eradications worldwide. Careful planning, adequate resources, and a sustained effort by competent field staff are needed to help ensure a successful eradication program. Island eradications are logistically complex and often quite expensive, requiring that once initiated, removal of 100% of rodents is paramount to facilitate support for future projects. However, efforts must be made to reduce potential rodenticide impacts to non-target animals, especially native birds and mammals. Standard considerations include confirming the species present, their behavioral characteristics and scale of risk, the legal status of species present, and population levels and distributions. To minimize risks, the type of rodenticide used, bait formulation, placement (stations or broadcast), timing of application, number of applications, and weather needs to be considered. It is important to recognize the great value of a successful invasive rodent eradication to island resources; recovery of native flora and fauna is usually rapid and remarkable

Brodifacoum Levels and Biomarkers in Coastal Fish Species following a Rodent Eradication in an Italian Marine Protected Area: Preliminary Results

Brodifacoum is the most common rodenticide used for the eradication of invasive rodents from islands. It blocks the vitamin K cycle, resulting in hemorrhages in target mammals. Non-target species may be incidentally exposed to brodifacoum, including marine species. A case study conducted on the Italian Marine Protected Area of Tavolara Island was reported after a rodent eradication using the aerial broadcast of a brodifacoum pellet. Brodifacoum presence and effects on non-target marine organisms were investigated. Different fish species were sampled, and a set of analyses was conducted to determine vitamin K and vitamin K epoxide reductase concentrations, prothrombin time, and erythrocytic nuclear abnormalities (ENA) assay. In all the examined organisms, brodifacoum was not detected. The results obtained showed differences in vitamin K and vitamin K epoxide concentrations among the samples studied, with a positive correlation for three species between vitamin K, vitamin K epoxide, and fish weight. The prothrombin time assay showed a good blood clotting capacity in the fish. Higher abnormality values were recorded for four species. The results of this study suggest that it is possible to hypothesize that the sampled fish were not likely to have been exposed to brodifacoum and that consequently there are no negative issues concerning human consumption

Relative palatability and efficacy of brodifacoum-25D conservation rodenticide pellets for mouse eradication on Midway Atoll

Invasive mice (Mus spp.) can negatively impact island species and ecosystems. Because fewer island rodent eradications have been attempted for mice compared to rats (Rattus spp.), less is known about efficacy and palatability of rodenticide baits for mouse eradications. We performed a series of bait acceptance and efficacy cage trials using a standard formulation of brodifacoum-based rodenticide on wild-caught mice from Sand Island, Midway Atoll, to help inform a proposed eradication there. Mice were offered ad libitum brodifacoum pellets along with various alternative food sources, and a “no choice” treatment group received only bait pellets. Mortality in the no choice trial was 100%; however, when offered alternative foods, mice preferred the alternative diets to the bait, leading to low mortality (40%). Because there was concern that the bittering agent Bitrex® in the formulation may have reduced palatability, we conducted a subsequent trial comparing brodifacoum bait with and without Bitrex. Mortality in the with-Bitrex treatment group was slightly higher, indicating that the bittering agent was not likely responsible for low efficacy. Laboratory trials cannot account for the numerous environmental and behavioral factors that influence bait acceptance nor replicate the true availability of alternative food sources in the environment, so low efficacy results from these trials should be interpreted cautiously and not necessarily as a measure of the likelihood of success or failure of a proposed eradication

Non-target species mortality and the measurement of brodifacoum rodenticide residues after a rat (Rattus rattus) eradication on Palmyra Atoll, tropical

a b s t r a c t The use of rodenticides to control or eradicate invasive rats (Rattus spp.) for conservation purposes has rapidly grown in the past decades, especially on islands. The non-target consequences and the fate of toxicant residue from such rodent eradication operations have not been well explored. In a cooperative effort, we monitored the application of a rodenticide, 'Brodifacoum 25W: Conservation', during an attempt to eradicate Rattus rattus from Palmyra Atoll. In 2011, Brodifacoum 25W: Conservation was aerially broadcasted twice over the entire atoll (2.5 km 2 ) at rates of 80 kg/ha and 75 kg/ha and a supplemental hand broadcast application (71.6 kg/ha) occurred three weeks after the second aerial application over a 10 ha area. We documented brodifacoum residues in soil, water, and biota, and documented mortality of non-target organisms. Some bait (14-19% of the target application rate) entered the marine environment to distances 7 m from the shore. After the application commenced, carcasses of 84 animals representing 15 species of birds, fish, reptiles and invertebrates were collected opportunistically as potential non-target mortalities. In addition, fish, reptiles, and invertebrates were systematically collected for residue analysis. Brodifacoum residues were detected in most (84.3%) of the animal samples analyzed. Although detection of residues in samples was anticipated, the extent and concentrations in many parts of the food web were greater than expected. Risk assessments should carefully consider application rates and entire food webs prior to operations using rodenticides. Published by Elsevier Ltd

Intended Consequences Statement in Conservation Science and Practice

As the biodiversity crisis accelerates, the stakes are higher for threatened plants and animals. Rebuilding the health of our planet will require addressing underlying threats at many scales, including habitat loss and climate change. Conservation interventions such as habitat protection, management, restoration, predator control, trans location, genetic rescue, and biological control have the potential to help threatened or endangered species avert extinction. These existing, well-tested methods can be complemented and augmented by more frequent and faster adoption of new technologies, such as powerful new genetic tools. In addition, synthetic biology might offer solutions to currently intractable conservation problems. We believe that conservation needs to be bold and clear-eyed in this moment of great urgency

Aging Hallmarks: the benefits of physical exercise

World population has been continuously increasing and progressively aging. Aging is characterized by a complex and intraindividual process associated with nine major cellular and molecular hallmarks, namely, genomic instability, telomere attrition, epigenetic alterations, a loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. This review exposes the positive antiaging impact of physical exercise at the cellular level, highlighting its specific role in attenuating the aging effects of each hallmark. Exercise should be seen as a polypill, which improves the health-related quality of life and functional capabilities while mitigating physiological changes and comorbidities associated with aging. To achieve a framework of effective physical exercise interventions on aging, further research on its benefits and the most effective strategies is encouraged

Reflections on 25 Years of Global Conservation on Islands as We Enter into the U.N. Decade of Restoration

Since the year 1500, islands have been home to over 75% of known bird, mammal, amphibian, and reptile extinctions. The majority of these have been caused by introduced species, particularly vertebrates such as rats, mice, cats, and ungulates. Arguably, the most damaging vertebrate taxon on island ecosystems is the rodents. Mice and rats have been implicated in around half of all bird and reptile extinctions. Rodents have been introduced now to over 80% of the world’s islands. Over the last 70+ years, conservationists around the world have been working to recover species and island ecosystems from the impacts of invasive species, particularly rodents, developing systematic approaches and techniques that are guided by principles of island invasive species eradication. The eradication of rodents from islands is not only possible, but has been completed on over 600 islands, from small offshore rocks to 400,000-ha South Georgia Island, with hundreds of native species protected from the threat of extinction. Rodent eradication is becoming a mainstream tool used by managers worldwide. However, there are limits to current technologies and approaches, and, globally, we can only reach a relatively small number of islands and threatened island species. To protect and recover threatened species, conservationists must increase the scale, scope, and pace of eradication of invasive species from islands, and focus on innovation of new tools, techniques, and strategies to be allow restoration on larger and more complex islands. One of the biggest challenges to success is ensuring that the public is supportive and allows pest management tools to be used for conservation purposes. New technologies are on the horizon to improve invasive species eradications, including genetic tools and species-specific toxicants

Reflections on 25 Years of Global Conservation on Islands as We Enter into the U.N. Decade of Restoration

Since the year 1500, islands have been home to over 75% of known bird, mammal, amphibian, and reptile extinctions. The majority of these have been caused by introduced species, particularly vertebrates such as rats, mice, cats, and ungulates. Arguably, the most damaging vertebrate taxon on island ecosystems is the rodents. Mice and rats have been implicated in around half of all bird and reptile extinctions. Rodents have been introduced now to over 80% of the world’s islands. Over the last 70+ years, conservationists around the world have been working to recover species and island ecosystems from the impacts of invasive species, particularly rodents, developing systematic approaches and techniques that are guided by principles of island invasive species eradication. The eradication of rodents from islands is not only possible, but has been completed on over 600 islands, from small offshore rocks to 400,000-ha South Georgia Island, with hundreds of native species protected from the threat of extinction. Rodent eradication is becoming a mainstream tool used by managers worldwide. However, there are limits to current technologies and approaches, and, globally, we can only reach a relatively small number of islands and threatened island species. To protect and recover threatened species, conservationists must increase the scale, scope, and pace of eradication of invasive species from islands, and focus on innovation of new tools, techniques, and strategies to be allow restoration on larger and more complex islands. One of the biggest challenges to success is ensuring that the public is supportive and allows pest management tools to be used for conservation purposes. New technologies are on the horizon to improve invasive species eradications, including genetic tools and species-specific toxicants

Invasive Rodent Ecology, Impacts, and Management with an Emphasis on the United States

Many invasive rodent species have become established in the United States and its territories, both on the mainland and on islands. While most were introduced accidently, some were introduced for food or fur. These rodents have caused serious impacts to native flora and fauna, agriculture, and other resources. They have caused the extinction of many species of birds in insular ecosystems. Although many methods are used to control or eradicate introduced rodents, rodenticides and traps are the main tools. Since the early 1990s, agencies have been eradicating rodents from various islands, primarily for conservation purposes. There have been numerous eradication attempts in the United States and most have been successful. We review introduced rodent impacts and eradications, both successful and unsuccessful, which have occurred, with an emphasis on the United States. Finally, we consider some research needs and some remaining challenges in invasive rodent management and eradication in the United States, including the use of toxicants, land access, public attitudes, resource availability, and monitoring difficulties

From Planning to Implementation: Streamlining Compliance for U.S. Rodent Eradications

Implementing rodent eradication projects on federally owned islands in the U.S. can take 10 or more years to plan and often accounts for more than 50% of total project expenses. Consequently, identifying ways to improve planning efficiency by streamlining the compliance process will allow land managers to restore more islands, thereby increasing ecosystem productivity and improving species resilience. The compliance process, defined here as fulfilling National Environmental Policy Act requirements and securing all necessary state and federal permits, creates a valuable and robust framework to examine goals, develop alternatives, assess anticipated impacts, establish partnerships, and engage the public. Additionally, it provides permitting agencies and the public an opportunity to participate in the planning process. One significant challenge to the planning process is that many variables that need to be accounted for early in the process are social, economic, or political in nature and are frequently overlooked, downplayed, or disregarded. We reviewed the planning documents for several rodent eradication projects and identified areas where the process could be streamlined, described lessons learned, and made recommendations for future projects. Streamlining can be achieved by identifying programmatic solutions, understanding social and political constraints, and developing a robust, transparent assessment of a range of alternatives