A total of 249 serum samples from 13 wild animal species namely fallow deer (Dama dama, n = 1), roe deer (Capreolus capreolus, n = 80), red deer (Cervus elaphus, n = 22), chamois (Rupicapra ...rupicapra, n = 21), mouflon (Ovis musimon, n = 4), brown hare (Lepus europaeus, n = 2), nutria (Myocastor coypus, n = 1), red fox (Vulpes vulpes, n = 97), stone marten (Martes foina, n = 12), European badger (Meles meles, n = 2), golden jackal (Canis aureus, n = 2) Eurasian lynx (Lynx lynx, n = 2) and grey wolf (Canis lupus, n = 3) were analysed for the presence of antibodies against Leptospira interrogans sensu stricto. Serum samples were examined via the microscopic agglutination test for the presence of specific antibodies against Leptospira serovars Icterohaemorrhagiae, Bratislava, Pomona, Grippotyphosa, Hardjo, Sejroe, Australis, Autumnalis, Canicola, Saxkoebing and Tarassovi. Antibodies to at least one of the pathogenic serovars were detected in 77 (30.9%; CI = 25–37%) sera. The proportion of positive samples varied intraspecifically and was the biggest in large carnivores (lynx, wolf and jackal; 86%), followed by mezzo predators: stone marten (67%) and red fox (34%), and large herbivores: red deer (32%), roe deer (25%), alpine chamois (10%) and mouflon (0%). Out of the 77 positive samples, 42 samples (53.8%) had positive titres against a single serovar, while 35 (45.4%) samples had positive titres against two or more serovars. The most frequently detected antibodies were those against the serovar Icterohaemorrhagiae. The present study confirmed the presence of multiple pathogenic serovars in wildlife throughout Slovenia. It can be concluded that wild animals are reservoirs for at least some of the leptospiral serovars and are a potential source of leptospirosis for other wild and domestic animals, as well as for humans.
Several eradication programs have been developed and executed to curb alien invasive species that tend to damage the ecological environments they colonize; however, only few studies have evaluated ...the utilization of carcasses of these species after eradication. Nutria (Myocastor coypus) is an invasive rodent species targeted by eradication programs in many countries. We noted that nutria produce large amounts of ursodeoxycholic acid (UDCA) in their bile. UDCA is a unique component responsible for the anti-inflammatory and hepatoprotective effects exerted by bear bile. Therefore, we sought to examine the medicinal utility of nutria carcasses by investigating the hepatoprotective effect of their bile in mice. C57BL/6 mice were injected with thioacetamide (TAA), which induced liver damage by increasing Kupffer cell infiltration. Administration of nutria bile reduced hepatic inflammation, improved hepatic function, and increased the levels of senescence marker protein 30 (an indicator of hepatocyte viability). Our results show that nutria bile exerts protective effects against TAA-induced liver injury in mice, suggesting that nutria carcasses may be used for the treatment of liver injuries.
This work improves our knowledge about the relationship between diet and environment among Northern Patagonian caviomorph rodents. In order to characterize long-term individual diets, we present δ13C ...and δ15N data from osteological remains of the caviomorph rodents Dolichotis patagonum, Myocastor coypus, Lagostomus maximus, Lagidium viscacia, Microcavia australis, Galea leucoblephara and Ctenomys sp., recovered from archaeological and recent contexts. These data are analyzed by temporal and geographic context and compared with the previous dietary studies based on macrorremains and microhistological analysis. Significative differences were found between rodents from Monte and Patagonian phytogeographic provinces, as well as between archaeological and modern members of the genus Ctenomys, indicating diet changes between Late Holocene and recent times individuals, that could confirm the climatic variations and/or the recent overgrazing effect. The results indicate trends in rodent diets of 20th and 21st centuries were different to those of the Late Holocene, suggesting a decrease in precipitation and/or an increase of the summer pattern of the same, and/or an increase of mean annual temperature. In addition, this work confirms the generalist strategy of several taxa, although mainly in Ctenomys, which its diet co-varies with these environments.
•Isotopic diets of rodents from archaeological and recent contexts of North Patagonia were studied.•Agreement between isotopic and histological values of many caviomorph rodents.•Geographic differences in diets of rodents inhabiting Monte and Patagonian regions.•Temporal changes in isotope values and inferred diet among the genus Ctenomys.•The latter appear related to vegetation changes, recent warming, and overgrazing.
Nutrias (Myocastor coypus) were imported to South Korea for farming in 1985; individuals escaped captivity and established wild populations in natural ecosystems in the late 1990s. Numerous studies ...have focused on their monitoring and management; however, information on the continuous movement of individuals is not available. In this study, telemetry data from field conditions were used to identify the nearest-neighbor distances of individuals in association with environmental factors, including plant type, land cover, and biological parameters. The minimum nearest-neighbor distances for the different sexes were, overall, according to the minimum distances for the same sex. Local co-occurrences of individuals, either of the same or different sex, were seasonal. Tall grasslands, followed by herbaceous vegetation, were associated with the co-occurrence of different sexes. Conversely, floating-leaved hydrophytes, followed by xeric herbaceous vegetation, were correlated with the co-occurrence of the same sex. Local female–male co-occurrences were negatively associated with male–male co-occurrences but not with female–female co-occurrences, suggesting male dominance in group formations. Movement and co-occurrence information extracted using Geo-self-organizing maps furthers our understanding of population dispersal and helps formulate management strategies for nutria populations.
Here we review an extensive series of studies of Barataria Basin, an economically and ecologically important coastal basin of the Mississippi Delta. Human activity has greatly altered the hydrology ...of the basin by decreasing riverine inflows from leveeing of the river and its distributaries, increasing runoff with high nutrient concentrations from agricultural fields, and channelization of wetlands of the basin interior that has altered flow paths to often bypass wetlands. This has resulted in degraded water quality in the upper basin and wetland loss in the lower basin. Trophic state analysis found the upper basin to be eutrophic and the lower basin to be mesotrophic. Gross aquatic primary production (GAPP) was highest in the upper basin, lowest in the mid basin, and intermediate in the lower basin. Forested wetlands in the upper basin have degraded over the past several decades due to increased periods of flooding, while there has been massive loss of emergent wetlands in the lower basin due to increasing water levels and pervasive alteration of hydrology. Restoration will entail reconnection of waterways with surrounding wetlands in the upper basin, and implementation of river sediment diversions, marsh creation using dredged sediments and barrier island restoration. Findings from this review are discussed in terms of the functioning of deltas globally.
Nutria (
Myocaster coypus
), invasive, semi-aquatic rodents native to South America, were introduced into Maryland near Blackwater National Wildlife Refuge (BNWR) in 1943. Irruptive population ...growth, expansion, and destructive feeding habits resulted in the destruction of thousands of acres of emergent marshes at and surrounding BNWR. In 2002, a partnership of federal, state and private entities initiated an eradication campaign to protect remaining wetlands from further damage and facilitate the restoration of coastal wetlands throughout the Chesapeake Bay region. Program staff removed nearly 14,000 nutria from five infested watersheds in a systematic trapping and hunting program between 2002 and 2014. As part of ongoing surveillance activities, the Chesapeake Bay Nutria Eradication Project uses a variety of tools to detect and remove nutria. Project staff developed a floating raft, or monitoring platform, to determine site occupancy. These platforms are placed along waterways and checked periodically for evidence of nutria visitation. We evaluated the effectiveness of monitoring platforms and three associated detection methods: hair snares, presence of scat, and trail cameras. Our objectives were to (1) determine if platform placement on land or water influenced nutria visitation rates, (2) determine if the presence of hair snares influenced visitation rates, and (3) determine method-specific detection probabilities. Our analyses indicated that platforms placed on land were 1.5–3.0 times more likely to be visited than those placed in water and that platforms without snares were an estimated 1.7–3.7 times more likely to be visited than those with snares. Although the presence of snares appears to have discouraged visitation, seasonal variation may confound interpretation of these results. Scat was the least effective method of determining nutria visitation, while hair snares were as effective as cameras. Estimated detection probabilities provided by occupancy modeling were 0.73 for hair snares, 0.71 for cameras and 0.40 for scat. We recommend the use of hair snares on monitoring platforms as they are the most cost-effective and reliable detection method available at this time. Future research should focus on determining the cause for the observed decrease in nutria visits after snares were applied.
We used a real-time PCR (rtPCR) targeting a 150-bp amplicon of the mitochondrial small subunit of ribosomal RNA (mtSSU rRNA) to screen for Pneumocystis DNA in lungs of wild squirrels (Callosciurus ...finlaysonii, n = 85) and river rats (Myocastor coypus, n = 43) in Italy. The rtPCR revealed Pneumocystis DNA in 20 of 85 (24%) squirrels and in 35 of 43 (81%) river rats, and was more sensitive than a nested PCR that targets a portion of the mtSSU rRNA and the mitochondrial large subunit of rRNA (mtLSU rRNA). Phylogenetic analysis based on mtSSU rRNA and mtLSU rRNA sequences showed distinct Pneumocystis sequence types in these rodents. The rtPCR assay should be reliable for screening large populations for this potential pathogen, thereby allowing cost-effective monitoring of the disease in wild animals.
The coypu (
Myocastor coypus
) is a semi-aquatic herbivorous rodent that has been suspected to prey on freshwater unionid mussels in Japan. Fecal DNA metabarcoding that targeted bivalves and ...terrestrial plants was performed to examine the diet of exotic coypu in the Kiso River, central Japan. Thirty-two fecal samples from four floodplain waterbodies were collected seasonally. In one of the waterbodies, live and dead mussels were investigated to examine the possible effects of coypu predation on mussel population structures. Common coypu predation on unionid mussels was confirmed in two waterbodies. Midden surveys showed that medium- to large-sized mussels tended to be consumed by coypu; possibly resulting in population structures with few large-sized individuals. Seasonal diet selection of terrestrial plants was also detected: two perennial plants were consumed throughout the year, whereas some perennial plants were consumed seasonally. The number of terrestrial plant species/taxa as primary food was higher in summer than in winter, which was attributed to the high consumption of annual plants in the summer. Future studies need to examine the exhaustive diet of coypu including other animals and plants, as well as its effects on freshwater ecosystems in invaded regions.
Le ragondin (
Myocastor coypus
) est un rongeur herbivore semi-aquatique que l'on soupçonne être la proie des moules unionidées d'eau douce au Japon. Un métabarcodage de l'ADN fécal ciblant les bivalves et les plantes terrestres a été effectué pour examiner le régime alimentaire du ragondin exotique de la rivière Kiso, au centre du Japon. Trente-deux échantillons de matières fécales provenant de quatre plans d'eau de plaine d'inondation ont été prélevés de façon saisonnière. Dans l'un de ces plans d'eau, des moules vivantes et mortes ont été étudiées afin d'examiner les effets possibles de la prédation du ragondin sur les structures des populations de moules. La prédation courante du ragondin sur les moules unionidées a été confirmée dans deux plans d'eau. Les études des buttes dépotoir ont montré que les moules de taille moyenne à grande ont tendance à être consommées par le ragondin, ce qui peut entraîner des structures de population comportant peu d'individus de grande taille. La sélection saisonnière du régime alimentaire des plantes terrestres a également été détectée : deux plantes pérennes ont été consommées tout au long de l'année, tandis que certaines plantes pérennes ont été consommées de façon saisonnière. Le nombre d'espèces/taxa végétales terrestres comme aliment principal était plus élevé en été qu'en hiver, ce qui a été attribué à la forte consommation de plantes annuelles en été. Les études futures doivent examiner le régime alimentaire exhaustif du ragondin, y compris d'autres animaux et plantes, ainsi que ses effets sur les écosystèmes d'eau douce dans les régions envahies.
Climate change and invasive species are often treated as important, but independent, issues. Nevertheless, they have strong connections: changes in climate and societal responses to climate change ...may exacerbate the impacts of invasive species, whereas invasive species may affect the magnitude, rate, and impact of climate change. We argue that the design and implementation of climate-change policy in the United States should specifically consider the implications for invasive species; conversely, invasive-species policy should address consequences for climate change. The development of such policies should be based on (1) characterization of interactions between invasive species and climate change, (2) identification of areas where climate-change policies could negatively affect invasive-species management, and (3) identification of areas where policies could benefit from synergies between climate change and invasive-species management.
Alien species management can be improved by understanding the population genetic structure of alien species that affect native ecosystems. In this study, we analyzed the spatial genetic structure of ...nutria (
Myocastor coypus
), an invasive rodent species in the Yodo River system in Japan, to improve efficiency of management strategies. We performed genetic analyses of mitochondrial DNA (mtDNA) sequences and 13 microsatellite DNA loci from nutria captured at two locations: the Katsura River and Shirokita Cove, in the upper and lower reaches of the Yodo River system, respectively. Three mtDNA haplotypes (N1, N2, and N3) were identified within the Yodo River system, and the same haplotype (N1) was dominant in both the Katsura River and Shirokita Cove populations. Microsatellite variation was low in both populations. The upstream Katsura River population consisted of a single genetic population, whereas the downstream Shirokita Cove population showed a genetic subdivision likely caused by genetic drift. These results suggest that the Yodo River system populations may have originated from the single ancestral populations. Habitat disruptions, such as severe flood events, may have caused the genetic drift observed in these populations and result in the genetic subdivision within a single river system. Additionally, microsatellite DNA analysis showed that in Shirokita Cove, there was significant isolation-by-distance in female nutria and dispersal occurred over relatively short distances. Therefore, when influence of flooding and migration on population dynamics are considered, a combination of localized intensive trapping and extensive monitoring may be necessary to control nutria density.
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