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BACKGROUND: A major impact of invasive Myocastor coypus in their introduction range is the collapse of riverbanks and nearby infrastructure, such as railway lines, due to the species' burrowing activities. Because widespread implementation of preventive measures along watercourses is unfeasible, identifying susceptible areas is key to guide targeted management actions. This study used species–habitat models to: (i) identify local environmental features of the railway line/watercourse intersections (RLWIs) that make them particularly susceptible to coypu damage, and (ii) predict species occurrence probability over a wide lowland–hilly area of northern Italy (Lombardy) to identify priority areas for monitoring. RESULTS: Local‐scale models identified that the RLWIs most susceptible to burrowing were those surrounded by arable land with interspersed hedgerows locally characterized by high herbaceous vegetation and clay soil. In urbanized areas and areas of intensive agriculture, coypu dens were generally located significantly closer to the railway, increasing the risk of collapse. A landscape‐scale species distribution model showed that lowland areas along major rivers and lake shores, and also agricultural areas with a dense minor hydrographic network, particularly in the southeast of the study area, are more likely to be occupied by coypu. CONCLUSION: Local‐scale models showed that specific environmental characteristics increase the risk of burrowing near RLWIs. The landscape‐scale model allowed us to predict which areas require thorough monitoring of RLWIs to search for such local characteristics to implement preventive management measures. The proposed model‐based framework can be applied to any geographical context to predict and prevent coypu damage. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures. [ABSTRACT FROM AUTHOR]

This study evaluated the chemical, physical and sensory properties of canned beaver and nutria. These animals are currently hunted not for their meat, but to reduce their numbers in the wild. The situation is complicated by the fact that both species are on the relevant lists. However, while the beaver is a protected animal, the nutria is an invasive species. This leads to complications in the application of the relevant legislation. Hunters are therefore limited in what they can do with the meat of these species. The chemical composition of the products did not differ (p > 0.05). Canned beaver was the darkest (p < 0.05) product and canned nutria the softest (p < 0.05). Both meat products were sensory acceptable and no off-odour or off-flavour was perceived. Canning meat is something that hunters can easily do at home, and the resulting product meets all the requirements for food safety. [ABSTRACT FROM AUTHOR]

Nutria, or coypu (Myocastor coypus), are invasive semi‐aquatic rodents present across the United States, Europe, and Asia. Despite successful eradication efforts in certain areas, nutria have resurged in the mid‐Atlantic USA, underscoring the need for advanced monitoring tools. Environmental DNA (eDNA) has emerged as a promising technique for species detection and monitoring. Here, an eDNA assay for nutria using qPCR was field‐validated in Virginia, USA, showcasing its potential as a tool for post‐eradication monitoring. The findings reveal an association between water levels and detection of nutria eDNA, highlighting the importance of water levels in nutria behavior. A painted turtle assay was introduced to confirm nutria absence and demonstrate the potential of passive sampling. The study showcases the sensitivity and efficiency of eDNA assays, emphasizing their value for monitoring and verifying invasive species eradication. [ABSTRACT FROM AUTHOR]

Strongyloides myopotami is an intestinal nematode parasite of nutrias. Identification of S. myopotami is conducted based on the morphological characteristics of adult worms or cultured larvae. To widely and effectively understand the infection in nutrias, it would be preferable to develop the molecular identification using a few grams of the feces. Here, we attempted to identify S. myopotami using DNA extracted from eggs obtained from fecal samples. Among previously reported primer pairs targeting the 18S rRNA gene of Strongyloides spp., most could not be successful. We newly designed primers that successfully amplified the partial sequences in S. myopotami, resulting in being sequenced. Our simple protocol can be useful in nationwide surveys for clarifying the risk of human infection. [ABSTRACT FROM AUTHOR]

Simple Summary: Nutria (Myocastor coypus) is a pest animal present in Africa, Europe, North America and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. A health survey on a population of coypu of Northwest Italy has been carried out to evaluate its zoonotic risks. None of the animals were positive for Hepatitis E virus, Encephalomyocarditis virus, Francisella or Neospora caninum, whereas two animals tested positive for Toxoplasma gondii. Moreover, a high prevalence of histological lesions has been found. Coypu can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary to fully understand the biological role and the importance of coypu as a disease reservoir in our country. Myocastor coypus is a pest animal present in Africa, Europe, North America and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. Forty-four coypus from the "Parco Naturale La Mandria" (Piedmont region, Northwest Italy) have been analysed. A complete necropsy and a whole histological evaluation of the liver, kidney and lung have been carried out on all the animals. Moreover, the positivity to Hepatitis E Virus (HEV), Encephalomyocarditis virus (EMCV), Francisella spp., Toxoplasma gondii and Neospora caninum have been investigated. None of the animal were positive for HEV, EMCV, Francisella spp. or Neospora caninum. Two animals tested positive for Toxoplasma gondii. A high presence of histological lesions has been identified in different organs, suggesting that lesions could be induced by different pathogens. As previously reported, coypu can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary to fully understand the biological role and the importance of coypu as a disease reservoir in our country. [ABSTRACT FROM AUTHOR]

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Abstract Nutria, or coypu (Myocastor coypus), are invasive semi‐aquatic rodents present across the United States, Europe, and Asia. Despite successful eradication efforts in certain areas, nutria have resurged in the mid‐Atlantic USA, underscoring the need for advanced monitoring tools. Environmental DNA (eDNA) has emerged as a promising technique for species detection and monitoring. Here, an eDNA assay for nutria using qPCR was field‐validated in Virginia, USA, showcasing its potential as a tool for post‐eradication monitoring. The findings reveal an association between water levels and detection of nutria eDNA, highlighting the importance of water levels in nutria behavior. A painted turtle assay was introduced to confirm nutria absence and demonstrate the potential of passive sampling. The study showcases the sensitivity and efficiency of eDNA assays, emphasizing their value for monitoring and verifying invasive species eradication.

Environmental pollution caused by antimicrobial resistance is a global public health concern. To investigate the contribution of nutrias (Myocastor coypus) to the presence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales in the Ijira River, prevalence of ESBL-producing Enterobacterales in their feces was examined using deoxycholate-hydrogen sulfide-lactose agar containing cefotaxime. Additionally, the composition of the fecal microbiota of nutria was examined using DNA metabarcoding analysis of the 16S ribosomal RNA gene and compared with that of Amami rabbit, deer, fox, and raccoon dog. The absence of ESBL-producing Enterobacterales and substantially lower abundance of Enterobacterales was observed in the feces of nutrias than in those of other wild mammals. Our results suggest the low potential of antimicrobialresistant Enterobacterales persistence and dissemination by nutria. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aims to investigate the behavior and ecology of nutria (Myocastor coypus), a semi-aquatic rodent that was introduced to South Korea for commercial farming and subsequently damaged aquatic ecosystems after its release. How the behavioral ecology of introduced nutria changes over time and across seasons remains unclear. Twenty-four adult nutria (twelve males and twelve females) were radio tracked in 2015–2016 to identify their home range size and activity patterns in the Macdo wetland, South Korea. This study found that the nutria home range size varied seasonally, with males having larger home ranges than females. Additionally, nutria showed crepuscular and nocturnal activity patterns throughout the year, with no significant difference between sexes. The findings of this study provide crucial information on the home range and activity patterns of introduced nutria in the Macdo wetland, which can guide management efforts to mitigate their impacts on the ecosystem. It is the first quantitative analysis of the home range and activity patterns of introduced nutria based on radio tracking data in the Macdo wetland. Nutria (Myocastor coypus) are semi-aquatic rodents that were introduced in South Korea for commercial farming but significantly damaged aquatic ecosystems. Understanding nutria ecological behavior is essential for developing effective control and eradication strategies to mitigate their impacts. Thus, this study aimed to investigate the home range and activity patterns of 24 nutria (12 males and 12 females) in the Macdo wetland in South Korea from 2015–2016 through radio tracking. The average minimum convex polygon home range of the nutria was 0.29 ± 0.55 km2, with a 95% kernel density estimation (KDE) home range of 0.43 ± 0.85 km2 and a 50% KDE home range of 0.05 ± 1.1 km2. The home range of males was larger than that of females; however, the winter home range of females was as large as that of males. The home range also varied seasonally, with the smallest observed in winter. The nutria showed crepuscular and nocturnal activity patterns throughout the year, with no significant difference between sexes. The activities in spring, summer, and autumn showed no significant differences, but the activity in winter was significantly different from that in the other seasons. This study may serve as a basis for developing appropriately timed and scaled management strategies to mitigate the impacts of nutria on ecosystems. In conclusion, several environmental and biological factors contribute to the behavior of nutria in South Korea. [ABSTRACT FROM AUTHOR]

Myocastor coypus is a pest animal present in Africa, Europe, North America and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. Forty-four coypus from the “Parco Naturale La Mandria” (Piedmont region, Northwest Italy) have been analysed. A complete necropsy and a whole histological evaluation of the liver, kidney and lung have been carried out on all the animals. Moreover, the positivity to Hepatitis E Virus (HEV), Encephalomyocarditis virus (EMCV), Francisella spp., Toxoplasma gondii and Neospora caninum have been investigated. None of the animal were positive for HEV, EMCV, Francisella spp. or Neospora caninum. Two animals tested positive for Toxoplasma gondii. A high presence of histological lesions has been identified in different organs, suggesting that lesions could be induced by different pathogens. As previously reported, coypu can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary to fully understand the biological role and the importance of coypu as a disease reservoir in our country.

The present report describes a case of Echinococcus multilocularis infection in nutria (Myocastor coypus) culled in the central area of Slovenia. Post-mortem exam showed multiple cystic lesions in the liver. Gross examination, as well as parasitological and histopathological examinations, revealed numerous cysts of various sizes, filled with yellow clear fluid and displacing most of the liver parenchyma. The cyst lumina contained numerous protoscolices approximately 100 μm in diameter and calcareous corpuscles. The protoscolices had two visible suckers and a rostellum with birefringent hooks. The lesions were consistent with an E. multilocularis cyst. Molecular analysis confirmed that the nutria was infected with E. multilocularis. To our knowledge, this is the first report of echinococcosis in nutria in Slovenia that presents gross, parasitological, and histological lesions and the result of molecular analysis. Nutrias in Slovenia are dangerous invaders but can also be a relevant bioindicator of the presence of the parasite in the environment.

Animal grouping, groups restructure, changing the docks and various technological operations causes disorders to the nutria manifested by aggressive behaviour. Tranquilizers prevent the stress and lower the catecholamine’s levels. In a number of 300 individuals grouped into four groups (one control group and three experimental groups) was surveyed the effect of Promazine (20 mg/kg, experimental group I), Diazepam (15 mg/kg, experimental group II) and Nitrazepam (15 mg/kg, experimental group III) administration for preventing stress and aggression resulted from various technological operations. Grouping animals and groups restructure generates behaviour disorders manifested by acute aggression, maximum within 4-6 hours and maintained for 24-36 hours. In the three experimental groups the intensity and frequency of aggressive acts decreased near zero, with greater efficacy in experimental group II and III. Duration of cataleptic effect was 3-7 hours (experimental group I), and 8-12 hours in the other two experimental groups, covering the period in which aggression is greatest. Waking up is done in 2-3 hours, moment at which the behaviour is almost that of an old group. The negative consequences of groups restructure, transport and other technological disturbing measures can be prevented by animal’s tranquilization, and the three substances investigated had an efficient preventive effect.

Nutria, a semi-aquatic, South American rodent, was introduced to Maryland during the early 1940s. Originally brought to the area for fur farms, the market never established and animals were released or escaped. Nutria thrived, destroying coastal wetlands which resulted in negative environmental and economic impacts to the Chesapeake Bay region. To preserve and protect valuable wetland resources, the Chesapeake Bay Nutria Eradication Project (CBNEP) was established in 2002 through a partnership between the United States Fish and Wildlife Service, the United States Department of Agriculture’s Wildlife Services, Maryland Department of Natural Resources, and many state agencies and non-governmental organizations. Since inception, the CBNEP has removed and reduced nutria populations to near zero across ¼ million acres of wetlands throughout the Delmarva Peninsula (Maryland, Delaware, and Virginia). The CBNEP has aided in the protection of critical natural resources and provided assistance to over 400 private landowners. Throughout its history, the CBNEP has developed new detection techniques and modified existing methods as the nature of the eradication effort changed. We provide a project overview and detail several observer-based and device-based methods that were developed and used for detection of nutria including: shoreline and ground surveys, monitoring platforms, detector dogs, lure development and remote triggered cameras.

Nutria (Myocastor coypus) were introduced to the eastern shore of Chesapeake Bay, USA in the 1940s. They reached peak densities in the late 1990s, causing massive wetland loss. Beginning in 2002, a systematic plan to eradicate nutria from the 1.7M ha Delmarva Peninsula was implemented. Since that time the nutria population has been effectively reduced, and no nutria have been detected since May 2015. A lack of detection does not equate with complete absence. We address the following three questions. (1) What is the expected probability of nutria eradication from the Delmarva Peninsula as of the end of 2020? (2) If the probability of eradication is below the management target of 0.95, how much more surveillance is required? (3) How sensitive is the estimated probability of eradication to varying levels of public surveillance and modelled population growth rates? These questions were addressed by employing a stochastic spatially-explicit surveillance model that uses data in which no nutria were detected to quantify the probability of complete absence (PoA) over the entire Delmarva Peninsula. We applied an analytical framework that decomposes the spatial risk of survivors and data into management zones, and took advantage of low-cost public reporting of nutria sightings. Active surveillance by the eradication program included detector dog and tracker surveys, shoreline surveys, detection with ground and water platforms (with hair snares), and camera traps. Results showed that the PoA increased with time and surveillance from a beginning PoA in May 2015 of 0.01 to a mean of 0.75 at the end of 2020. This indicates that the PoA on the Delmarva was well below the target threshold of 0.95 for declaring eradication success. However, given continued surveillance without detection, a PoA of 0.95 would be achieved by June 2022. This analysis provides an objective mechanism to align the expectations of policy makers, managers and the public on when eradication of nutria from the entire Delmarva Peninsula should be declared successful. [ABSTRACT FROM AUTHOR]

Este estudio presenta el primer registro de Myocastor coypus en el estado de Mato Grosso do Sul, además de señalar su distribución al sur de América del Sur, destacando dónde se considera nativo y exótico en Brasil. El 23 de abril de 2018, aproximadamente a las 6:00 pm, se registró, con un LC (longitud corporal) de 40 cm, un espécimen adulto atropellado en un camino lateral cerca de humedales y una represa, en un área rural en el municipio de Bataguassu, al este del estado de Mato Grosso do Sul. No es posible determinar el origen de M. coypus reportado en el presente estudio; tampoco es posible establecer si fue introducido o dispersado de forma natural por las zonas pantanosas del río Paraná, ya que la especie tiene registros en la frontera de los estados de Mato Grosso do Sul y Paraná.

The present report describes a case of Echinococcus multilocularis infection in nutria (Myocastor coypus) culled in the central area of Slovenia. Post-mortem exam showed multiple cystic lesions in the liver. Gross examination, as well as parasitological and histopathological examinations, revealed numerous cysts of various sizes, filled with yellow clear fluid and displacing most of the liver parenchyma. The cyst lumina contained numerous protoscolices approximately 100 μm in diameter and calcareous corpuscles. The protoscolices had two visible suckers and a rostellum with birefringent hooks. The lesions were consistent with an E. multilocularis cyst. Molecular analysis confirmed that the nutria was infected with E. multilocularis. To our knowledge, this is the first report of echinococcosis in nutria in Slovenia that presents gross, parasitological, and histological lesions and the result of molecular analysis. Nutrias in Slovenia are dangerous invaders but can also be a relevant bioindicator of the presence of the parasite in the environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Nutria (Myocastor coypus) are semi-aquatic rodents that were introduced in South Korea for commercial farming but significantly damaged aquatic ecosystems. Understanding nutria ecological behavior is essential for developing effective control and eradication strategies to mitigate their impacts. Thus, this study aimed to investigate the home range and activity patterns of 24 nutria (12 males and 12 females) in the Macdo wetland in South Korea from 2015–2016 through radio tracking. The average minimum convex polygon home range of the nutria was 0.29 ± 0.55 km2, with a 95% kernel density estimation (KDE) home range of 0.43 ± 0.85 km2 and a 50% KDE home range of 0.05 ± 1.1 km2. The home range of males was larger than that of females; however, the winter home range of females was as large as that of males. The home range also varied seasonally, with the smallest observed in winter. The nutria showed crepuscular and nocturnal activity patterns throughout the year, with no significant difference between sexes. The activities in spring, summer, and autumn showed no significant differences, but the activity in winter was significantly different from that in the other seasons. This study may serve as a basis for developing appropriately timed and scaled management strategies to mitigate the impacts of nutria on ecosystems. In conclusion, several environmental and biological factors contribute to the behavior of nutria in South Korea.

The coypu is a semiaquatic rodent, native to South America and introduced to many parts of the world, mainly due to fur farming and as zoo animal. Nowadays, it is widely distributed in Europe, forming many invasive populations; thus, the species is listed as being of European Union concern according to the EU invasive alien species regulation. Here, we provide an update on the known status and distribution of the coypu in Austria since Spitzenberger (2001), presenting known occurrence records and additionally hunting bag data from the federal state of Styria. We derived 197 spatially explicit records, ranging from 1930 to 2021 and covering all nine federal states of Austria. Currently, the coypu is established in at least three federal states (Burgenland, Lower Austria, Styria) and probably also in Vorarlberg, with its main distribution in the lowlands of eastern to south-eastern Austria. We show a significant relationship between annual fluctuations in hunting bag data and the preceding winter temperatures suggesting that harsh winters might have a regulatory effect on Austrian coypu populations. Further, we emphasize the importance of monitoring and field surveys, not only for a detailed assessment of its distribution, but also to clarify potential metapopulation dynamics with occurrences in neighbouring countries. This is essential for future management, especially in the light of its declaration as invasive alien species of European Union concern. [ABSTRACT FROM AUTHOR]

The coypu, Myocastor coypus, has been introduced worldwide for fur farming and is widely recognized as one of the most invasive alien mammals of the world, affecting natural ecosystems, crops and possibly human health. Here we present a comprehensive up-to-date review of its distribution and status in Asia and Africa. Using a multi-source approach, we collected occurrences from published literature as well as from online biodiversity platforms (e.g. GBIF, iNaturalist), video sharing platforms, and local experts. Additionally, we used an ensemble modelling approach to predict the climatic suitability across Africa and Asia. We present an updated distribution map, including a total of 1506 spatially explicit records from 1973 to 2021, covering 1 African and 16 Asian countries. We find evidence for current populations in Kenya and five new countries since the last review of (Carter and Leonard, Wildl Soc Bull 30:162–175, 2002): Iran, Jordan, Lebanon, Uzbekistan, and Vietnam, and identify main clusters of coypu occurrence in Western (including Transcaucasia) and East Asia. We show that warm temperate and Mediterranean areas on both continents are predicted to be climatically suitable for the coypu and highlight not only areas of possible spread, but also potential data gaps, i.e. with high suitability and low availability of concrete information (e.g. China, Southern Russia). We emphasize the importance of citizen involvement and the urgency for coypu-targeted studies in data-poor regions to obtain a clear picture of the geographical distribution and to better address management strategies. [ABSTRACT FROM AUTHOR]

This study presents the first record of Myocastor coypus in the state of Mato Grosso do Sul, in addition to detailing its distribution within southern South America, highlighting where it is considered native or exotic in Brazil. On April 23, 2018, at approximately 18:00, an adult specimen with a 40 cm BL (body length) was registered after being run over on a side road near wetlands and a dam in a rural area in the municipality of Bataguassu, eastern state of Mato Grosso do Sul. It is not possible to state the origin of the M. coypus reported in the present study; whether it was introduced or dispersed naturally through the flooded areas of the Paraná River, since the species has records on the border of the states of Mato Grosso do Sul and Paraná. [ABSTRACT FROM AUTHOR]

ABSTRACT: The nutria (Myocastor coypus) is a medium-sized, semi-aquatic rodent valued by the skin and meat industry. This study aimed to describe and systematize the caudal cerebral artery on the brain surface in nutria, establishing a standard model and its main variations in this species. The thirty animals used were euthanized according to animal welfare rules. The vessels were filled with latex stained with red pigment and the samples were fixed in formaldehyde. In nutria, the brain was vascularized by the vertebral basilar system. The terminal branches of the basilar artery originated the rostral cerebellar, caudal cerebral, rostral choroidal and middle cerebral arteries, and its terminal branch, the rostral cerebral artery. The terminal branch of the basilar artery projected the caudal cerebral artery, which is usually a single medium-caliber vessel, into the transverse fissure of the brain. The caudal cerebral artery was presented as a single (66.7% of the cases to the right and 76.7% to the left) and double vessel (33.3% of the cases to the right and 23.3% to the left). It originated the rostral mesencephalic artery, the proximal component, and the caudal inter-hemispheric artery. The terminal branches of the rostral and caudal tectal mesencephalic arteries formed a typical anastomotic network. The caudal inter-hemispheric artery emitted central branches, the caudal choroidal artery, hemispherical occipital arteries, rostral tectal mesencephalic branches and distal components, and anastomosed “in osculum” with the terminal branches of the rostral inter-hemispheric artery. The caudal choroidal artery anastomosed with the rostral choroidal artery, where it branched out on the thalamic mass, vascularizing all diencephalic structures and the hippocampus. The caudal cerebral artery and its terminal branches anastomosed with the terminal branches of the rostral and middle cerebral arteries in a restricted region of the caudal pole of the cerebral hemisphere. The vascularization area of the caudal cerebral artery and its central branches in the paleopallial of the piriform lobe is extremely restricted, caudomedially.

The nutria (Myocastor coypus), a rodent native to South America, has been introduced and has established feral populations at numerous locations in North America, Europe, and Asia. As such, the nutria is subject to research and management programs, including investigation of surgical fertility-control techniques. We evaluated the efficacy of a mixture of ketamine and medetomidine, with additional use of isoflurane and reversal with atipamezole, to provide safe, reliable anesthesia for surgical procedures under field conditions. We anesthetized 40 free-ranging nutrias between December 2018 and March 2019, in Turin, Italy, to perform surgical reproduction control techniques. We administered a ketamine and medetomidine mixture (6 mg/kg and 140 µg/kg, respectively) after trapping the animals and weighing them in the cage traps. After induction, we reweighed the rodents and performed a brief clinical examination. The times of loss of palpebral and pedal reflexes were noted. After induction of anesthesia, heart rate, respiratory rate, and percentage of oxygen saturation were monitored and recorded. Isoflurane was delivered through a face mask to 27 nutrias (70%) to maintain an adequate depth of anesthesia. Upon completion of surgery and other procedures, atipamezole was administered to the animals at doses 2.5 higher than those of medetomidine (actual dose: 366±31 µg/kg). Induction times were short (3±2 min), with the animals completely immobilized. The heart rate and respiratory rate both decreased. After administration of atipamezole, recoveries were smooth and complete. There were two deaths after higher doses of atipamezole and longer surgeries. Carprofen (4 mg/kg) was administered subcutaneously for its analgesic effects. The animals were released at the end of all the procedures. Overall, the medetomidine and ketamine mixture, with supplemental isoflurane in most instances, provided a reliable anesthesia in free-ranging nutrias, adequate for performing surgical procedures under field conditions. [ABSTRACT FROM AUTHOR]

Feral nutria were established near Blackwater National Wildlife Refuge (BNWR) in Dorchester County Maryland in 1943 after a failed attempt to create a fur industry. As the population expanded in number and distribution, natural resource managers began to notice an accelerating trend in wetland loss in the areas most heavily infested by nutria. By the late 1980s, an estimated 35,000 nutria occupied BNWR, which had seen approximately 5,000 acres of emergent marsh converted to shallow open water habitats and mudflats. Exclusion studies in the 1990s demonstrated a direct link between nutria and marsh loss, and by 2000 officials had procured funding to initiate an eradication feasibility study. This paper provides a historical overview of the eradication campaign that has been underway since 2002. The Chesapeake Bay Nutria Eradication Project (CBNEP) is a cooperative partnership between the U.S. Fish and Wildlife Service, USDA Wildlife Services program, and numerous state and non-governmental organizations. The CBNEP employs an adaptive management strategy utilizing systematic trapping carried out by salaried wildlife specialists to eliminate nutria from infested watersheds. We present a phased approach that allows us to continually expand the eradication zone and maintain nutria-free areas with a relatively small staff. Through an active research and development program, we have innovated new tools and techniques for trapping and detecting nutria including: floating trap sets, attractants, decoys, remote triggered cameras, detection platforms, hair snares, and Judas nutria. To date, we have reduced nutria populations to near-zero densities across 250,000 acres of emergent marsh. Based on extensive surveys, remaining populations should be removed by the end of 2014. Following a 2-year verification/biosecurity protocol, we hope to have nutria eradicated from the Delmarva Peninsula by 2017.

Sex differences in growth, blood indicators, carcass values and meat quality in nutrias were evaluated. In the fattening experiment, 136 nutrias of both sexes (1 : 1 ratio) were fattened until 8 months of age. At the end of the experiment, 18 males and 18 females with average weights were selected for the determination of biochemical indicators, carcass value and meat quality. The growth of males was significantly higher than in females; the differences were 12% at three months of age and increased to 24% at eight months of age. The effect of sex on the biochemical indicators of blood was observed in total protein (P ≤ 0.029), albumin (P ≤ 0.012), urea (P ≤ 0.019) and cholesterol (P ≤ 0.026), with higher values in males. In the case of haematology examination, the significantly higher values in males were in the number of erythrocytes (5.10 × 1012/l) and in the haematocrit value (55.8%). Dressing out percentage was higher in males (P ≤ 0.039), and other parameters of carcass value were not affected by sex. For the meat physical properties, only lightness (P ≤ 0.019) was higher in males. In the case of the chemical composition of meat, ether extract (P ≤ 0.033) and energetic value (P ≤ 0.024) were lower in females. The results of this study show high differences in the growth of male and female nutrias, whereas carcass composition, physical meat quality and meat chemical composition are less affected by nutria sex.

This article provides information about a promising alternative field of animal husbandry -- nutria breeding. This involves the production of fur and high-quality meat products, which contain a large amount of nitrogenous extractives and muscle hemoglobin. This study examined the sexual system of female nutria, and the dynamics, duration and features of each stage of the female nutria's sexual cycle, including estrus, sexual arousal, hunting, braking and phase balancing. The methods of observation, clinical examination, research of smears and fingerprints, and analysis of the cytogram of the vaginal epithelium at different stages of sexual and physiological maturity of female nutria were used. When analyzing the cytogram of the vaginal epithelium, the structure, color, and percentage of basal, parabasal, superficial, and keratinized cells were indicated. Information about the timing of sexual and physiological maturity, their features, processes and signs of manifestation, and different timing of sexual and physiological maturity in summer and winter is provided. [ABSTRACT FROM AUTHOR]

Beach nesting waterbirds are among the most vulnerable groups of birds that are threatened by climate change, habitat loss, predation, and human disturbance. To improve conservation management strategies, causes of nest failure for ground-nesting waterbirds and effectiveness of mammalian predator control were investigated. Changes in breeding population size and hatching success of Royal (Thalasseus maximus) and Sandwich (T. sandvicensis) terns were evaluated based on pre-mammalian removal (2012-2014) vs. post-mammalian removal (2015-2016) breeding data. Video systems were used at colonies in 2015 and 2016 to determine causes of nest failure. No differences in breeding parameters were found between removal periods, however video data confirmed nest predation as the primary cause of nest failure. Laughing Gull (Leucophaeus atricilla) was the top predator and accounted for 63% of all detected predation events. In 2015, video monitoring identified a novel predator, exotic and invasive nutria (Myocastor coypus), that were responsible for 43% of predation events. In 2016, following a 280% increase in nutria removal from 2015, no nutria predation was recorded. [ABSTRACT FROM AUTHOR]

Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common, effective practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target pest species of interest. Our objective was to evaluate the efficacy of 2 nonlethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCTs and 3 SCTs at each of 7 sites on a 10,500-ha mixed-use island located 15 km northwest of Portland, Oregon, USA. We pre-baited using carrots, apples, and sweet potatoes for ≥3 consecutive days before trapping. We checked traps daily, and an infrared motion camera was established near each MCT to document activity. We captured 26 nutria over 724 trap nights, and all captures occurred at 4 sites. Nutria captured by MCTs were larger (6.38 ± 1.68 [SD] kg, n = 10) than nutria captured by SCTs (4.21 ± 2.48 [SD] kg, n = 16; F1,25 = 5.51,P = 0.02). Camera surveillance showed multiple nutria present in an MCT on ≥2 occasions, although individuals

is a large semi-aquatic rodent ranked as one of the 100 most invasive species in the world. In Brazil, few ecological studies have been proposed to understand the relationship of this species with the environment. To date, drivers that facilitate its establishment in new areas remain unknown. However, it is generally accepted that the natural distribution of this species is limited to far southern Brazil. The present study aimed to understand the geographic distribution of M. coypus and indicate areas of greater risk of establishment based on bioclimatic predictors and a surveillance map. We observed that M. coypus suitability and risk assessment areas are restricted to the southeastern and southern regions of Brazil and that anthropogenic landscape modifications are an adequate variable to explain the occurrence of the species. Due to the environmental impacts caused by this species, monitoring in environments where it has been introduced is required. The model used herein presented efficient applicability and fit for Brazil. Preventive actions and the management of M. coypus in predicted regions prior to its establishment are recommended. [ABSTRACT FROM AUTHOR]

L'articolo affronta il caso dell'emergente gastronomia della nutria interrogando il rapporto che questa crea nella relazione tra uomo e ambiente ed analizzando come questa ci informi su come la nostra società affronti la globalizzazione del bioscape tra reazione ed adattamento al cambiamento. [ABSTRACT FROM AUTHOR]

Tumor incidence in wild mammals is reportedly very low. Wild nutria, a large rodent, is known to carry many infectious diseases, but rarely exhibits neoplastic diseases. We necropsied a male wild nutria and found a large nodular mass in the left inguinal region, adjacent to the penis. Histopathologically, the mass was diagnosed as preputial gland adenoma. Spontaneous preputial gland adenomas are extremely rare in all animals. Moreover, reports of tumors in nutrias have been limited to adenocarcinomas of the lungs and uterus, as well as subcutaneous fibromas. Here, we describe preputial gland adenoma in a wild nutria. [ABSTRACT FROM AUTHOR]

Nutria are large semi-aquatic, herbivorous rodents native to South America, but were brought to the United States in the early 1900s for the fur farming industry. At high densities, nutria damage marsh vegetation. To more effectively manage nutria, we identified effective attractants and designed a multiple capture trap (MCT). Four lures (nutria urine, nutria fur extract, synthetic anal gland secretion, and a commercially available apple-based lure) were examined under field conditions, using leg-hold traps. A total of 285 nutria were captured during a 10-day trial with 1,000 trap-nights. All lures tested increased trapping success from 42% to 120% over untreated traps, with nutria fur extract being the most effective. Additionally, the lures did not attract nontarget animals. Next, we tested the MCT: 6 were baited with foods (carrots, corn, and sweet potatoes), and another 6 used trays of fertilized marsh plants as the lure. During the 10-day trial, with 122 trap-nights, 10 nutria were caught in the food-baited traps and 12 in the marsh plant-baited traps. As many as 3 nutria were captured overnight in one trap. On two occasions, individual nutria escaped the traps when approached by a person. No non-target animals were captured, however, it was suspected that swamp rabbits were entering the MCTs to feed and then were able to go back out the “one-way door”.

Nutria were introduced from South America to the United States in the 1930s for fur farms and, due to releases and escapees, are currently established in 15 states. Nutria are important to the Louisiana fur industry, but they also cause extensive damage to coastal marsh ecosystems when populations are high. Louisiana uses an incentive program for hunters and trappers during trapping season (winter), which helps to control the fast-growing nutria populations. While this approach is effective, additional management tools are needed to control nutria year-round and over large areas. Other tools for nutria control include toxicants, baits and lures, and multiple-capture traps. In this study, we evaluated nutria responses to olfactory cues in a Y-maze that potentially could be used as lures in traps or bait stations. Three olfactory cues were selected more frequently than others: Nutria #1 (apple-based commercial lure), nutria gland secretion, and female nutria fur extract. We also evaluated attention by nutria to two species of fertilized and non-fertilized marsh plants that potentially could be used as lures in multiple-capture traps on coastal marsh. Nutria did not show a strong preference for either plant species, but they gave significantly more attention to fertilized plants than non-fertilized plants or soil treatments. Results with nutria urine were equivocal. The materials identified in this study show potential for the development of additional tools to manage nutria populations and their impacts on coastal marsh ecosystems.

Nutria have been present in the Pacific Northwest for more than 70 years, and though their dramatic impacts on wetlands in the southeastern U.S. is well documented, the northwestern populations have been little studied. Using paired exclosure plots, nutria herbivory pressure on the native vegetation is shown to be considerable but dependent on species type and disturbance history. In coastal wetland habitats, nutria selectively feed on forbs compared to grasses, lowering their aboveground biomass. This study also shows opposing responses to nutria herbivory for disturbed and undisturbed plots, with nutria lowering total biomass in areas that have not experienced a biomass-clearing disturbance event and thus have diminished competition intensity.

Nutria are large semi-aquatic rodents native to South America. Nutria were first introduced to the United States because of their fur, and some populations remain economically important to the fur industry. Accidental and intentional releases have permitted them to establish in wetlands across the United States. Burrowing and foraging by nutria often inflict severe damage and can be devastating to native vegetation. Nutria are recognized as at least a contributing factor to the decline of native Louisiana coastal marsh. Management plans to reduce impacts require reducing nutria populations, or where possible, eliminating them from target sites. At present, public hunting and trapping encouraged by an incentive payment program are primary approaches to reduce unwanted populations. However, alternative tools, including toxins, need to be assessed for possible use. Previous studies assessing zinc phosphide baiting have addressed nutria control on open waterways. Considerable data can be extrapolated from these prior studies and applied to baiting on coastal marshes. However, animals may respond differently to baits and baiting strategies applied to coastal marsh. We conducted a series of studies to assess the potential for developing a feasible strategy to suppress nutria populations with zinc phosphide bait on Louisiana coastal marsh. Tetracycline and metallic flakes show promise as tools for studying nutria foraging behavior. Nutria activity on rafts was marginal, probably because of their access to native vegetation. Simple audio, olfactory, and ocular cues tested as attractants to entice nutria to bait station showed marginal efficacy. Olfactory stimuli demonstrated the most potential for developing future attractants.

The nutria (Myocastor coypus) is a large semi-aquatic rodent that was introduced throughout much of the world as a means of increasing the fur market in the first half of the 20th Century. Although not considered a pest in their native range of South America, nutria presence elsewhere has often met with greater detriment than benefit. Nutria have damaged crops, marsh vegetation, and water control structures. Nutria damage has been described for decades, yet science is now better defining values provided by marshes that are prime habitat for many mammalian, avian, reptilian, and amphibian species as well as flora. The uniqueness of the marsh and coastal habitats is in jeopardy of being so damaged as to make the cost of repair astronomical. Nutria foraging often causes current re-vegetation projects to fail unless exclosures are constructed. We review potential methods to control nutria damage in Louisiana. Techniques discussed include: incentive (bounty) payment, chemical control (toxicants), incentive-bonus, induced infertility, trapping, controlled hunting, and chemical repellents. We rank these by feasibility of implementation and their probability of success.

The Presidential Executive Order 13112 for control of invasive species signed by President Clinton illustrates the national concern over the negative impact that nutria (Myocastor coypus) and other non-native, invasive species have on the nation’s natural resources. Nutria are established in 15 states nationwide and cause damage to agricultural crops and natural ecosystems. Despite efforts to control their populations, nutria are found in Maryland throughout the Eastern Shore and in the Potomac and Patuxent Rivers on the Western Shore. Twenty-three federal, state, and private organizations have combined their efforts to develop a three-year pilot plan for nutria control entitled "Marsh Restoration: Nutria Control in Maryland." In 1999 and 2000, funding became available to begin the first year of the three-year pilot effort. The objectives of the pilot program are to develop accurate population estimates, determine effective trapping strategies to maximize nutria harvest and minimize impacts to non-target species, evaluate the effects of population control on nutria home range and movement patterns, determine how population control affects nutria reproductive behavior, determine if the health of nutria populations is influenced by intense harvest pressure, and monitor the effects of intense nutria harvest on vegetative response. Implementation of the control plan will begin during summer 2000.

Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common, effective practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target pest species of interest. Our objective was to evaluate the efficacy of 2 nonlethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCTs and 3 SCTs at each of 7 sites on a 10,500-ha mixed-use island located 15 km northwest of Portland, Oregon, USA. We prebaited using carrots, apples, and sweet potatoes for ≥3 consecutive days before trapping. We checked traps daily, and an infrared motion camera was established near each MCT to document activity. We captured 26 nutria over 724 trap nights, and all captures occurred at 4 sites. Nutria captured by MCTs were larger (6.38 ± 1.68 [SD] kg, n = 10) than nutria captured by SCTs (4.21 ± 2.48 [SD] kg, n = 16; F1,25 = 5.51, P = 0.02). Camera surveillance showed multiple nutria present in an MCT on≥2 occasions, although individuals <3.7 kg were able to escape. The MCTs were more expensive, larger, heavier, and more difficult to transport and deploy. However, MCTs were less likely to capture nontargets. Improvements to MCT door design would likely increase multiple catch opportunities and decrease escapes. [ABSTRACT FROM AUTHOR]

Nutria (Myocastor coypus) are an introduced invasive species expanding their range in North America and may have detrimental effects on wetlands. Little is known about habitat covariates that may limit or enhance range expansion of nutria, especially when combined with predicted changes in climate. We used a hierarchical modeling approach to develop broad‐ and local‐scale maximum entropy (MaxEnt) models based on nutria harvest records in the eastern United States from 2006–2015. We developed models for current conditions and for climate change projections in 2050. At a broad scale, nutria habitat was located in areas with ≤80 annual freezing days. At local scales, nutria were found in areas with high proportions of freshwater forested‐shrub wetlands close to other wetlands. Managers who are concerned about possible nutria range expansion can use this hierarchical modeling framework to identify areas for surveillance and prioritize control efforts. © 2019 The Wildlife Society. At a broad scale, nutria habitat was located in areas with ≤80 annual freezing days, whereas at local scales, they were associated with areas having high proportions of freshwater forested‐shrub wetlands close to other wetlands. Managers who are concerned about possible nutria range expansion can use this hierarchical modeling framework to identify areas for surveillance and prioritize control efforts. [ABSTRACT FROM AUTHOR]

Sex differences in growth, blood indicators, carcass values and meat quality in nutrias were evaluated. In the fattening experiment, 136 nutrias of both sexes (1 : 1 ratio) were fattened until 8 months of age. At the end of the experiment, 18 males and 18 females with average weights were selected for the determination of biochemical indicators, carcass value and meat quality. The growth of males was significantly higher than in females; the differences were 12% at three months of age and increased to 24% at eight months of age. The effect of sex on the biochemical indicators of blood was observed in total protein (P ≤ 0.029), albumin (P ≤ 0.012), urea (P ≤ 0.019) and cholesterol (P ≤ 0.026), with higher values in males. In the case of haematology examination, the significantly higher values in males were in the number of erythrocytes (5.10 × 1012/l) and in the haematocrit value (55.8%). Dressing out percentage was higher in males (P ≤ 0.039), and other parameters of carcass value were not affected by sex. For the meat physical properties, only lightness (P ≤ 0.019) was higher in males. In the case of the chemical composition of meat, ether extract (P ≤ 0.033) and energetic value (P ≤ 0.024) were lower in females. The results of this study show high differences in the growth of male and female nutrias, whereas carcass composition, physical meat quality and meat chemical composition are less affected by nutria sex. [ABSTRACT FROM AUTHOR]

The study determined the muscle fibre characteristics and sensory properties of the longissimus lumborum muscle (LL) of eight-month-old nutrias of three colour types and the correlations between meat histochemical measurements and eating quality. The following nutria colour types were used in the experiment: Standard (ST), Moravian Silver (MS), and Prestice Multicolour (PM). The nutria colour type significantly (P < 0.001) affected the number of type IIB fibres with the lowest number in ST (108 per mm2). The proportion of type I fibres varied between 10.6 and 14.2%; type IIA fibres varied between 6.1 and 7.8%; and type IIB fibres varied between 78.2 and 83.4% and it was not affected by colour type. The cross-sectional area (CSA) was 2.565-2.841 µm2 in type I, 2.867-3.010 µm2 in type IIA, and 4.698-5.517 µm2 in type IIB fibres. The CSA of type IIB fibres (P < 0.001) was the largest in ST. The sensory trait of tenderness (P < 0.05) was the lowest in MS. Correlations between the proportion of fibres and sensory traits were not observed. The CSA of type I fibres correlated with flavour (0.19) and the CSA of type IIB fibres with tenderness (0.10).

Abstract The occurrence of ectoparasites in wild nutria is poorly understood. Fifty-five livetrapped wild nutria (Myocastor coypus) from its indigenous region were examined for ectoparasites after capture from December 2013 to December 2014. The captures came from the Buenos Aires Province, by far the area of the country most densely populated by nutria, characterized as a temperate grassland, which are prime areas for sustained agriculture. Only one species of chewing lice (Pitrufquenia coypus, Marelli, 1932), one flea (Nosopsyllus fasciatus, Bosc, 1800) and one tick (Rhipicephalus sanguineus, Latreille, 1806) were collected. Fourteen percent of the animals were infested and P.coypus, an obligate parasite of the nutria, which was the most prevalent ectoparasite. N. fasciatus and R. sanguineus occurrence remains controversial as they may or may not be some accidental host species. To our knowledge, this is the first comprehensive and systematic survey of ectoparasites in wild nutria from the southern hemisphere, the indigenous region of this species.