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The post mortem exam is important in diagnosing and investigating wildlife diseases. It is even more important to monitor the population of species that are not easily observed in the wild, such as otters. Of the 13 otter species, 11 are endangered due to many factors, such as climate change, pollution, or urbanisation. The authors present a review of the patterns of mortality of free-ranging otters worldwide, aiming to improve the knowledge of otter mortality and the role of mortality studies in their conservation. The main cause of death in aquatic otters is vehicle collision; hence, sea otter deaths are associated with shark attacks and imprisonment in fishing gear. It is possible to conclude that humans and human activity play a significant role in the mortality of these animals. In the future, a more standardised analysis of otter carcasses is necessary to understand their threats and diseases and design significant measures to protect these species.

The post mortem exam is important in diagnosing and investigating wildlife diseases. It is even more important to monitor the population of species that are not easily observed in the wild, such as otters. Of the 13 otter species, 11 are endangered due to many factors, such as climate change, pollution, or urbanisation. The authors present a review of the patterns of mortality of free-ranging otters worldwide, aiming to improve the knowledge of otter mortality and the role of mortality studies in their conservation. The main cause of death in aquatic otters is vehicle collision; hence, sea otter deaths are associated with shark attacks and imprisonment in fishing gear. It is possible to conclude that humans and human activity play a significant role in the mortality of these animals. In the future, a more standardised analysis of otter carcasses is necessary to understand their threats and diseases and design significant measures to protect these species. [ABSTRACT FROM AUTHOR]

Nocturnal activity of tropical otters is rarely reported. To date no studies have documented den use by sympatric giant (Pteronura brasiliensis) and neotropical otters (Lontra longicaudis). We used camera-traps to monitor den use by sympatric otters along an equatorial Amazonian river. Camera-traps provided evidence that giant otters were more nocturnal around dens than sympatric neotropical otters. Nocturnal activity was recorded in 11% of giant otter photos (n = 14 of 125 photos), but was recorded only once for neotropical otters. Den use by giant and neotropical otters overlapped spatially and temporally but not concurrently. We hypothesize that previously reported nocturnal activity in neotropical otters is facilitated by the absence or low density of giant otters. Our results also underscore the need to use complementary techniques together with den counts for monitoring otters as sympatric species can use the same dens. [ABSTRACT FROM AUTHOR]

Some taxa of mammals live in water, all of which evolved from land-dwelling ancestors. In the family Mustelidae (Mammalia: Carnivora), most species live on land, while otters, comprising the subfamily Lutrinae, inhabit aquatic environments, which include the almost exclusively aquatic sea otters (Enhydra lutris). Thus, the transition from a terrestrial to an aquatic lifestyle has occurred within this family. Despite potentially different selection pressures on body size in aquatic and terrestrial habitats, no divergence in the evolutionary pattern of body size between otters and other mustelids has previously been shown using models of trait evolution on a phylogeny. We applied models that explicitly incorporated lineage-specific directional selection to the evolution of body mass in living mustelids. Using a simulation-based likelihood and approximate Bayesian computation approach, we demonstrated lineage-specific directional selection for larger body mass in otters, which is distinct from other mustelids. There was no evidence of a difference between sea otters and other otters in the strength of directional selection for larger body mass. Additionally, our analyses supported no difference in the rate at which body mass evolves in both directions between otters and other mustelids. These findings suggest that the evolution of body mass in otters is associated with selective advantages of larger size rather than the relaxation of constraints on body size in aquatic habitats, like other aquatic mammals such as sirenians, cetaceans, and pinnipeds. [ABSTRACT FROM AUTHOR]

Mustelids are an ecologically diverse group of mammals that span several dietary niches. Compared to other mammalian clades, however, less is known about how the morphology of the dentition reflects these dietary differences. The following examines dental form in the beech marten (Martes foina), the river otter (Lontra canadensis), the wolverine (Gulo gulo), and the sea otter (Enhydra lutris). Lower carnassial molar morphology is examined using methods for dental topographic analysis, enamel thickness measurement, and pulp volume measurement to assess this form-function relationship. It is predicted that mustelids will covary in their dental form with their diet, where dental topography will reflect the reliance on tough or soft foods, enamel thickness will vary as a product of hard-object feeding, and pulp volume will vary as a product of dietary abrasiveness/hard-object feeding. Results suggest that mustelid dental form reflects the dietary ecology of each species; however, pulp volume does not covary with diet as it does in anthropoid primates, for example. These animals represent a morphocline of increasing specialization in carnassial form leading from the plesiomorphic marten to the highly specialized sea otter. These results provide further evidence of convergence among mammals where molar form is largely driven by diet. These results also provide insight into how taxa such as the sea otter and wolverine are adapted to dealing with diets that include bivalves and bones, respectively, through decreased dental topography and thickened enamel. [ABSTRACT FROM AUTHOR]

Abstract Background The huillín (Lontra provocax, Thomas 1908) is an otter, endemic to southern Argentina and Chile. It is in danger of extinction. In the Nahuel Huapi National Park and surroundings is the only freshwater, known and stable population of huillín in Argentina. In this park, several urban and rural centers coexist with this species. The main objective of our work was to answer: How does the local zoological knowledge (LZK) vary about the huillín, particularly its identification and sighting, among people from different social groups, with different ages and gender, who live in the rural or urban environment and with different periods of permanence in the place? Methods Ninety-six written interviews were conducted using visual stimuli to ensure that interviewees refer to the huillín. In addition, we also inquire about the LZK of other species with which it can be confused. Additional open interviews were conducted with participants who observed the huillín to determine the georeferencing of the reported sites and include them on a final map. Results 95% of people identified the huillín and this was confused with the coipo in 3% and with the american mink, in 5%. The results show that, in general, the LZK did not vary significantly with the sociocultural characteristics of the participants, showing a remarkable homogeneity. However, people in rural areas are more likely to observe the species than people in urban areas. Moreover, people between 20 and 40 years of age are more likely to observe the huillín. The LZK mapping has identified areas that are consistent with and/or adjacent to official source records. Other areas have also been identified that may provide new information. Conclusion With this participatory work, we realize that the species is recognized by urban and rural inhabitants and very few confused it. The homogeneity in the LZK found constitutes a kick for the realization of other participatory studies that promote lines of research, action and management that improve the quality of the environments where the only freshwater, known and stable population of the huillín in Argentina lives.

Background. Previous studies suggest coexistence between sympatric neotropical (Lontra longicaudis) and giant otters (Pteronura brasiliensis) maybe facilitated by temporal and spatial differences in activity. Yet, to date there has been no systematic evaluation of activity of these species in sympatry. Here we use extensive multi-year field data to compare temporal and spatial patterns in the diurnal activity of sympatric giant and neotropical otters to answer three questions: Do temporal patterns in daytime river use change in relation to seasonal river levels (low, rising, high and declining river levels), do they change due to human disturbances (boats and fishing nets) and do patterns in neotropical otter activity change due to the presence of the larger sized giant otter? Methods. Direct observations of both species were recorded using standardized boat surveys along 218 km of rivers over 53 months during nine years (2011-2013 and 2015-2020). Complementary techniques (Generalized Additive Models, Kernel density estimates and non-parametric tests,) were used to compare diurnal activity patterns along rivers subdivided into 41 river reaches. Results. The presence of giant otters decreased threefold from 67% of the least disturbed reaches (few boats no fishing nets) to 18% of the most disturbed reaches with many boats and fishing nets. In contrast neotropical otter presence nearly doubled from 44% of the least disturbed to 73% of the most disturbed reaches with fewest giant otter detections. Both species were observed across all daytime hours but were observed rarely on the same day. There was no evidence to suggest simultaneous use of the same reach. When species were detected on the same day, they were separated spatially (median distance between species 12.5 km) and temporally (median time difference 3.0 hours). There was little change in activity of either species among seasons. Giant otters were less active in river reaches with fishing nets and boat use, whereas neotropical otter activity did not appear to be strongly affected by these activities. Conclusions. Our findings support evidence that diurnal activity in both otter species is flexible, with daytime activity changing due to human disturbances in the case of giant otters. [ABSTRACT FROM AUTHOR]

Background Previous studies suggest coexistence between sympatric neotropical (Lontra longicaudis) and giant otters (Pteronura brasiliensis) maybe facilitated by temporal and spatial differences in activity. Yet, to date there has been no systematic evaluation of activity of these species in sympatry. Here we use extensive multi-year field data to compare temporal and spatial patterns in the diurnal activity of sympatric giant and neotropical otters to answer three questions: Do temporal patterns in daytime river use change in relation to seasonal river levels (low, rising, high and declining river levels), do they change due to human disturbances (boats and fishing nets) and do patterns in neotropical otter activity change due to the presence of the larger sized giant otter? Methods Direct observations of both species were recorded using standardized boat surveys along 218 km of rivers over 53 months during nine years (2011–2013 and 2015–2020). Complementary techniques (Generalized Additive Models, Kernel density estimates and non-parametric tests,) were used to compare diurnal activity patterns along rivers subdivided into 41 river reaches. Results The presence of giant otters decreased threefold from 67% of the least disturbed reaches (few boats no fishing nets) to 18% of the most disturbed reaches with many boats and fishing nets. In contrast neotropical otter presence nearly doubled from 44% of the least disturbed to 73% of the most disturbed reaches with fewest giant otter detections. Both species were observed across all daytime hours but were observed rarely on the same day. There was no evidence to suggest simultaneous use of the same reach. When species were detected on the same day, they were separated spatially (median distance between species 12.5 km) and temporally (median time difference 3.0 hours). There was little change in activity of either species among seasons. Giant otters were less active in river reaches with fishing nets and boat use, whereas neotropical otter activity did not appear to be strongly affected by these activities. Conclusions Our findings support evidence that diurnal activity in both otter species is flexible, with daytime activity changing due to human disturbances in the case of giant otters.

Background: The huillín (Lontra provocax, Thomas 1908) is an otter, endemic to southern Argentina and Chile. It is in danger of extinction. In the Nahuel Huapi National Park and surroundings is the only freshwater, known and stable population of huillín in Argentina. In this park, several urban and rural centers coexist with this species. The main objective of our work was to answer: How does the local zoological knowledge (LZK) vary about the huillín, particularly its identification and sighting, among people from different social groups, with different ages and gender, who live in the rural or urban environment and with different periods of permanence in the place? Methods: Ninety-six written interviews were conducted using visual stimuli to ensure that interviewees refer to the huillín. In addition, we also inquire about the LZK of other species with which it can be confused. Additional open interviews were conducted with participants who observed the huillín to determine the georeferencing of the reported sites and include them on a final map. Results: 95% of people identified the huillín and this was confused with the coipo in 3% and with the american mink, in 5%. The results show that, in general, the LZK did not vary significantly with the sociocultural characteristics of the participants, showing a remarkable homogeneity. However, people in rural areas are more likely to observe the species than people in urban areas. Moreover, people between 20 and 40 years of age are more likely to observe the huillín. The LZK mapping has identified areas that are consistent with and/or adjacent to official source records. Other areas have also been identified that may provide new information. Conclusion: With this participatory work, we realize that the species is recognized by urban and rural inhabitants and very few confused it. The homogeneity in the LZK found constitutes a kick for the realization of other participatory studies that promote lines of research, action and management that improve the quality of the environments where the only freshwater, known and stable population of the huillín in Argentina lives. [ABSTRACT FROM AUTHOR]

Global warming, anthropological activities, water pollution, integration of nonindigenous species, these factors profoundly influence the biodiversity of Lake Jorf Toba in southwestern Algeria. The environment is becoming more arid, with long heat waves and less precipitation. The conservation of endangered arid zone species is a big challenge, especially if we are talking about a semi-aquatic animal like the Eurasian otter (Lutra lutra). The study aims to evaluate the situation of otters in arid environments such as Lake Jorf Torba. Our data showed the existence of Lutra lutra in the lake, which is an index of food and shelter availability. The major otter forage was Barbus antinorii, Hypophthalmichthys molitrix, Cyprinus carpio, and some arthropods. The otter preferred a rocky shelter to protect itself from the wind, cold and high temperatures. Our observation confirms that the Lutra lutra has always existed in the lake, but during our tracking, we noticed the mortality of two otters. Otters in lake Jorf Torba are a small population, which needs to be protected, and a serious conservation approach should be adopted. [ABSTRACT FROM AUTHOR]

This study seeks to determine the role and cultural significance of otariids and mustelids in the historical and cultural evolution of the Strait of Magellan, at the southern tip of South America. The geographical location of this inter-oceanic corridor not only allowed the passage of European navigators with geopolitical and commercial ambitions from the beginning of the 16th century, but also made possible the exchange, transmission and transformation of knowledge about the sea.Our research focuses on the hunting of pinnipeds and otters with a broad temporal approach, taking into account archaeozoological evidence from occupation sites dating from around 7,500 years ago to recent times. Historical data on the activity of foreign seal-skinners in the late 18th and early 19th centuries in the waters of the Strait of Magellan were also taken into account, at a time when the overexploitation of sea lions was having an impact on the demography of pinnipeds and, consequently, on marine ecosystems. The archaeological study shows that, despite the fact that this type of hunting was an important economic resource from the earliest occupations of canoeing or marine nomadic Indians, there are cultural periods in which it played a less prominent role than seabird hunting or fishing (ca. 3200 to 2300 BP). This suggests that its importance for the subsistence of these human groups is not constant, perhaps due to factors that we do not know today related to environmental changes and/or cultural phenomena.Finally, we have been able to observe the evolution of the role played by pinnipeds and otters in the indigenous socio-cultural context, which from being a vital resource, necessary for food, shelter and habitation, became, over the course of the 18th and 19th centuries, a commodity destined for inter-ethnic trade and commerce. This development will have major repercussions for these societies.

The Neotropical otter Lontra longicaudis is a top predator in aquatic ecosystems from North, Central, and South America and is subjected to substantial environmental distress due to historic and contemporary anthropogenic disturbance. Currently, L. longicaudis is considered 'near threatened' by the International Union for Conservation of Nature Red List of Threatened Species. This study renders the first genomic resource for L. longicaudis; its mitochondrial genome was assembled and characterised in detail. The AT-rich mitochondrial genome of L. longicaudis was 16,436 bp in length and encoded 13 protein coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and a 994 bp long putative control region (CR). The heavy use of CTA (Leu), ATA (Met), and ATC (Ile) codons in PCGs contributes to the AT-rich nature of this genome. Out of 22 tRNAs, tRNA-Ser (AGY) (trnS1) lacked a typical 'cloverleaf' secondary structure. In the CR, numerous microsatellites and two tandem repeats were detected as well as multiple 'hairpin' structures. Ka/Ks values estimated for all but one PCG were < 1, indicating purifying selection in most PCGs. atp8 experienced neutral selection. A phylogenomic analysis based on PCGs confirms the monophyly of the family Mustelidae and also supports the monophyletic status of the subfamilies Guloinae, Helictidinae, Melinae, Mustelinae and Lutrinae; Ictonychinae was found to be polyphyletic. In the Lutrinae, L. longicaudis had an early branching position. The characterisation of a complete mitochondrial genome in the Neotropical otter L. longicaudis constitutes the first step towards supporting conservation efforts using genomic tools in this and other mustelids inhabiting aquatic neotropical environments under considerable contemporary anthropogenic disturbance. [ABSTRACT FROM AUTHOR]

In the fourth national otter survey in Spain, 8,024 sampling points were carried out covering the entire Spanish mainland. Sampling unit used was the UTM grid (10x10 km). A total of 4,019 cells were prospected, representing 77.3% of the mainland Spain grids. Inside every grid, we made transects of 600 m distance (n=4,822; 60.1%) and spot-check (n=3,202; 39.9%). An overall value of 5,199 locations sampled with a positive presence of otter was obtained, representing 64.8%. Regarding UTM grids, 2,920 were otter positive, where at least one sampling point was found with valid otter traces or signals, representing 76.4% of the cells sampled. Percentage of the territory of mainland Spain with otter was 59.9%. Overall, the results were more positive in the Spain western half than in the eastern one, and more positive in the Spain northern half than in the southern one. By regions, the maximum percentage of positive sampling points and grids was reached in Galicia (northwestern Spain), with 95.4% and 96.8% respectively. On the contrary, the minimum values of positive sampling points and grids were obtained in Valencia (eastern Spain), with 15.0% and 20.7% respectively. In relation to the third survey (2004-2006), otter has continued its spread, more slowly than a decade before, and mainly on Mediterranean basins. The numbers and percentages indicate a similar otter distribution in the 2000s and 2010s decades. In several territories, some cells with otter presence in the third survey were not sampled in the current survey; This fact has reduced the percentages obtained for the presence of otters in Spain. [ABSTRACT FROM AUTHOR]

In the 20th century, wild otter populations declined across the world. This decline was associated with several factors, such as habitat destruction and hunting. Other underlying causes were anthropogenic contaminant loads in their food and water sources. Aquatic mammals such as otters are very susceptible to chemical contamination and, as top predators, can be considered sentinel species for the health of the ecosystem. This brief review aims to show the presence of environmental contaminants in different otter species and how they may have contributed to the population decline of these species. Although many studies have been carried out on the presence of these compounds in otters, in the future, it is important to continue monitoring these populations to understand their impacts under the One Heath concept. [ABSTRACT FROM AUTHOR]

The chemical industry is the leading sector in the EU in terms of added value. However, contaminants pose a major threat and significant costs to the environment and human health. While EU legislation and international conventions aim to reduce this threat, regulators struggle to assess and manage chemical risks, given the vast number of substances involved and the lack of data on exposure and hazards. The European Green Deal sets a 'zero pollution ambition for a toxic free environment' by 2050 and the EU Chemicals Strategy calls for increased monitoring of chemicals in the environment. Monitoring of contaminants in biota can, inter alia: provide regulators with early warning of bioaccumulation problems with chemicals of emerging concern; trigger risk assessment of persistent, bioaccumulative and toxic substances; enable risk assessment of chemical mixtures in biota; enable risk assessment of mixtures; and enable assessment of the effectiveness of risk management measures and of chemicals regulations overall. A number of these purposes are to be addressed under the recently launched European Partnership for Risk Assessment of Chemicals (PARC). Apex predators are of particular value to biomonitoring. Securing sufficient data at European scale implies large-scale, long-term monitoring and a steady supply of large numbers of fresh apex predator tissue samples from across Europe. Natural science collections are very well-placed to supply these. Pan-European monitoring requires effective coordination among field organisations, collections and analytical laboratories for the flow of required specimens, processing and storage of specimens and tissue samples, contaminant analyses delivering pan-European data sets, and provision of specimen and population contextual data. Collections are well-placed to coordinate this. The COST Action European Raptor Biomonitoring Facility provides a well-developed model showing how this can work, integrating a European Raptor Biomonitoring Scheme, Specimen Bank and Sampling Programme. Simultaneously, the EU-funded LIFE APEX has demonstrated a range of regulatory applications using cutting-edge analytical techniques. PARC plans to make best use of such sampling and biomonitoring programmes. Collections are poised to play a critical role in supporting PARC objectives and thereby contribute to delivery of the EU's zero-pollution ambition. [ABSTRACT FROM AUTHOR]

This report describes the distribution of Smooth-coated otters in Ratnagiri, Maharashtra, and investigates the utility of scat counts for quantifying otter occurrence. The study duration was from February to June 2020. Surveys were conducted along the Jog River in Anjarle and Aade River in Aadekond using camera traps. The results subjected to principal component analysis indicated that the occurrence of Smooth-coated Otters at Anjarle is 76% and at Aadekond 48%. We also mapped the distribution and threats associated with Smooth-coated Otters. This study serves as a baseline for efforts to support long-term otter research and conservation. [ABSTRACT FROM AUTHOR]

Conservation of freshwater biodiversity and management of human-wildlife conflicts are major conservation challenges globally. Human-wildlife conflict occurs due to attacks on people, depredation of fisheries, damage to fishing equipment and entanglement in nets. Here we review the current literature on conflicts with tropical and subtropical crocodilians, cetaceans and otters in freshwater and brackish habitats. We also present a new multispecies case study of conflicts with four freshwater predators in the Western Amazon: black caiman (Melanosuchus niger), giant otter (Pteronura brasiliensis), boto (Inia geoffrensis) and tucuxi (Sotalia fluviatilis). Documented conflicts occur with 34 crocodilian, cetacean and otter species. Of the species reviewed in this study, 37.5% had conflicts frequently documented in the literature, with the saltwater crocodile (Crocodylus porosus) the most studied species. We found conflict severity had a positive relationship with species body mass, and a negative relationship with IUCN Red List status. In the Amazonian case study, we found that the black caiman was ranked as the greatest 'problem' followed by the boto, giant otter and tucuxi. There was a significant difference between the responses of local fishers when each of the four species were found entangled in nets. We make recommendations for future research, based on the findings of the review and Amazon case study, including the need to standardise data collection. [ABSTRACT FROM AUTHOR]

Studies of otters on Rubondo Island National Park were ongoing for several years. Ad hoc observations recorded between 2017 and 2021 are reported on here and it is suggested this location be considered as an otter refuge. [ABSTRACT FROM AUTHOR]

The Eurasian Otter Lutra lutra is an elusive, solitary animal that has one of the widest distributions of all palearctic mammals. Once widely distributed in Asia, the Eurasian Otter population is now vulnerable to urbanization, pollution, poaching, and dam construction. Eurasian Otter distribution in the Indian Himalayan rivers is little explored, and information from this high-altitude riverine ecosystem is sparse. This publication reports a rare photographic record of the Eurasian Otter which confirms its presence in the high-altitude temperate forest of the Upper Bhagirathi Basin, western Himalayan region. The otter was recorded during investigations of terrestrial and aquatic fauna in the Bhagirathi Basin (7,586 km², 500–5,000 m) of Uttarakhand State, India from October 2015 to May 2019. Among aquatic fauna, Brown Trout were found to be abundant in high altitude river stretches, with a catch per unit effort of 1.02 kg h–1. Additionally, 26 families of freshwater macroinvertebrates underscored a rich diet available for the Brown Trout, which in turn is a potential food source for the otters. The riverine ecosystem is undergoing dramatic changes because of the increasing demand for hydropower plants in the Bhagirathi Basin. Although mitigation measures are currently in place for fish, the presence of otters further necessitates the need for targeted management for high-altitude Himalayan rivers. There is an imperative need for intensive otter surveys using methods such as camera traps in riparian habitats along the Bhagirathi River and its tributaries. [ABSTRACT FROM AUTHOR]

The diel activity pattern of small carnivores was studied using the camera trap technique at Nelliampathy Reserve Forest, Kerala, India. Six species of small carnivores were recorded during the study. These include Brown Palm Civet Paradoxurus jerdoni, Small Indian Civet Viverricula indica, Stripe-necked Mongoose Herpestes vitticollis, Brown Mongoose Herpestes fuscus, Nilgiri Marten Martes gwatkinsii, and Leopard Cat Prionailurus bengalensis. The maximum diel activity overlap was detected between the Brown Palm Civet and Small Indian Civet, while the activity overlap was minimal between the Stripe-necked Mongoose and Small Indian Civet. [ABSTRACT FROM AUTHOR]

We determined the occupancy of otter species and assessed several habitat features influencing their occurrence in four different land-use types: continuous logged forests (CF), heavily degraded forest (DF), riparian reserves within oil palm plantation (RR), and oil palm plantations without riparian reserves (OP). Our aim was to ascertain the usefulness of retaining riparian reserve in oil palm dominated landscape for otter conservation. This study was conducted in the Malaysian state of Sabah, northern part of Borneo. We surveyed 36 stream sub-transects across all of the different land-use types and detected otter presence based on their tracks and spraints. Overall, two out of the four otter species found in Sabah were detected within the surveyed areas, i.e., the Asian Small-clawed Otter, A. cinereus and Smooth-coated Otter, L. perspicillata. Streams in agricultural sites were found to have significantly higher otter occupancy compared to forested areas: RR (psi = 0.97), OP (0.83), DF (0.44), and CF (0.37). Using Generalised Linear Modelling (GLM), we identified that otter occupancy in oil palm landscapes was positively influenced by the availability of large trees and other vegetation along the banks. Deeper streams were also more preferred by otters. Interestingly, streams in oil palm plantations located nearer to human settlements recorded higher detection of otter signs. In general, this study suggests that streams in oil palm plantation with riparian vegetation are useful habitat for otter species. Hence, retaining riparian reserves within oil palm plantations is a useful management strategy to improve biodiversity conservation in an agricultural landscape. [ABSTRACT FROM AUTHOR]

A total of 18 transects near rivers and streams of different sizes in the area of "Strandzha" Nature Park were studied. The otter was found out in 92% of the studied transects of optimal habitats. It can be assumed that the total number of otters in "Strandzha" Nature Park is 60-70 individuals. [ABSTRACT FROM AUTHOR]

Opportunistic records of animal occurrence may be problematic for inferring species distribution and habitat requirements because of unknown and uncontrolled sources of sampling variance. In this study, we used occurrence records for river otters (Lontra canadensis) derived from sign surveys, road kills, trapper bycatch, and opportunistic sightings (n = 185 records collected 2001–2012) to assess the potential distribution and habitat relationships of otters across central and western New York, USA. To mitigate for obvious observation biases, we standardized observation intensity across regions a priori and restricted inference to readily accessible areas (i.e., ≤700 m from the nearest road). Model selection, and the direction of covariate effects, proved robust to these sampling biases although effect sizes varied −7.1% to +48.0% after bias correction, with the coefficient for the proportion of available shoreline being the most unstable. Ultimately, the top bias‐corrected model proved a reliable index for otter probability of occurrence given a strong, positive, and linear relationship with a withheld set of standardized survey records for otters collected in winter 2016–2017 (n = 57; R2 = 0.90). This model indicated that approximately 20% of the study area represented high probability of otter occurrence. We demonstrated that reliable inference on wildlife habitat requirements can be obtained from disparate records of animal occurrence provided that data biases are known and effectively mitigated. © 2020 The Wildlife Society. Opportunistic data can be successfully integrated into species distribution models following ad hoc corrections to control for sampling bias. We demonstrate that such data can be successfully used to model otter occurrence across central and western New York, USA. [ABSTRACT FROM AUTHOR]

Understanding the factors affecting presence and habitat requirements of threatened species is fundamental to their conservation. Patterns of occurrence and resource use by the vulnerable Smooth-coated otter were examined by sampling Moyar River in the Western Ghats biodiversity hotspot of India between 2015 and 2017 for otter spraints, tracks, dens and grooming sites. An occurrence-based framework was used to determine the influence of environmental covariates on otter detectability. Information on environmental parameters was recorded every 400 meters along the riverbanks in postmonsoon, winter, and summer seasons. Smooth-coated otter occurrence was high before the summer but waned drastically after monsoon when increased water levels reduce detectability of otters by washing away signs of their presence. Otter occurrence and resource use patterns were influenced by river substrate, habitat characteristics, riverbank traits and forest types. Otters prefer wider rivers, but avoided rocky areas with shallow water. Resource use patterns were determined by habitat traits and disturbance in all three seasons. Various forms of disturbances adversely affected the otter occurrence. Restoration of degraded habitats is necessary to improve the long-term conservation prospects of otters. Regional otter conservation plans need to be species-specific to help maintain the ecological balance of Moyar River ecosystem. [ABSTRACT FROM AUTHOR]

The domestic rabbit (Oryctolagus cuniculus) has a huge variability in terms of color patterns and fur color. One of the sources of variability is the A locus. The present paper aims at describing the color patterns that result from the recombination of alleles located at A locus. The color patterns of rabbit fur are determined by allelic and non-allelic interactions. Locus A is one that includes, in order of dominance, the alleles A, at and a. Recombining these alleles in different genomic contexts results in a large number of possible color patterns. [ABSTRACT FROM AUTHOR]

Perceived as an indicator of the balance in wildlife and clean nature, the Eurasian otter (Lutra lutra L.) is near-threatened due to the fact that its fur is valuable, the increase in environmental pollution, the decrease in wetlands, the rivers in their habitats are turned into channels. There are 86 rainbow trout (Oncorhynchus mykiss) farms legally licensed by the Provincial Ministry of Agriculture and Forestry Muğla - Turkey. Since otter meets 70% of its nutrient need from fish, it is seen as a predatory species by aquaculture producers. For this reason, it is necessary to work on establishing otter habitats and breeding farms jointly with rainbow trout farmers in order to eliminate the negative effects of both rainbow trout farms and Eurasian otters. In this way, Eurasian otters that are near-threatened, will be saved and also a different contribution will be made to our economy. [ABSTRACT FROM AUTHOR]

Keywords: otter; PIT tag; predation; radio tag; white sturgeon EN otter PIT tag predation radio tag white sturgeon 780 784 5 12/21/20 20201201 NES 201201 INTRODUCTION White sturgeon ( I Acipenser transmontanus i ) in the Nechako River, British Columbia, Canada have experienced recruitment failure since 1967 (McAdam et al., 2005) and this population was listed as endangered under the Species at Risk Act (SARA) in 2006 (Fisheries & Oceans Canada, 2014). Sturgeon radio tags were collected in suspected otter feeding sites and sturgeon PIT tags were collected from otter latrine sites. It is difficult to be confident that all radio-tagged sturgeon mortalities are a result of river otter predation, however there is evidence that at least a proportion of radio-tag mortalities were caused by otters. [Extracted from the article]

The North American river otter (Lontra canadensis) is the largest mustelid in North Carolina, US, and was once extirpated from the central and western portions of the state. Over time and after a successful reintroduction project, otters are now abundant and occur throughout North Carolina. However, there is a concern that diseases may have an impact on the otter population, as well as on other aquatic mammals, either through exposure to emerging diseases, contact with domestic animals such as domestic cats (Felis catus), or less robust condition of individuals through declines in water quality. We tested brain and kidney tissue from harvested otters for the pathogens that cause leptospirosis, parvovirus, and toxoplasmosis. Leptospirosis and toxoplasmosis are priority zoonoses and are maintained by domestic and wild mammals. Although parvovirus is not zoonotic, it does affect pets, causing mild to fatal symptoms. Across the 2014–15 and 2015–16 trapping seasons, we tested 220 otters (76 females, 144 males) using real-time PCR for Leptospira interrogans, parvovirus, and Toxoplasma gondii. Of the otters tested, 1% (3/220) were positive for L. interrogans, 19% (41/220) were positive for parvovirus, and 24% (53/220) were positive for T. gondii. Although the pathogens for parvovirus and toxoplasmosis are relatively common in North Carolina otters, the otter harvest has remained steady and the population appears to be abundant and self-sustaining. Therefore, parvovirus and toxoplasmosis do not currently appear to be negatively impacting the population. However, subsequent research should examine transmission parameters between domestic and wild species and the sublethal effects of infection. [ABSTRACT FROM AUTHOR]

This study investigated the current distribution of otters (Lutrinae) in all states of Peninsular Malaysia. Four species of otters have been recorded in Peninsular Malaysia in the past based on field survey methodology, namely the Asian small-clawed otter (Aonyx cinereus), smooth-coated otter (Lutrogale perspicillata), hairy-nosed otter (Lutra sumatrana), and Eurasian otter (Lutra lutra). This study aims to determine the current number of otter species and their distribution in Peninsular Malaysia through molecular approaches using D-loop and Cyt b loci of mitochondrial DNA sequences. Our findings indicate that 337 samples were identified as three species of otter that are currently distributed in Peninsular Malaysia: A. cinereus (112 samples), L. perspicillata (218 samples), and L. sumatrana (7 samples). All three species can be found in Perak, Kelantan, Pahang, Selangor, and Johor while other states only contained two species (A. cinereus and L. perspicillata). Seven sympatric locations were recorded between two or three species: Tumpat and Kg. Padang Salim (Kelantan), Penarik and Sg. Kemaman (Terengganu), Taman Negara (Pahang), Tg. Piai (Johor), and Kuala Gula (Perak). The discovery of L. sumatrana in this study has confirmed that this species is still present in Peninsular Malaysia. However, L. lutra was not observed in this study. Our findings successfully highlight the diversity and distribution of Peninsular Malaysian otters that suggest the importance of continuous assessment and population status of otters to ensure their ongoing survival in Peninsular Malaysia. [ABSTRACT FROM AUTHOR]

Background The Eurasian otter (Lutra lutra) underwent a strong decline in large areas of the Central-Western part of its distribution range, during the second half of the twentieth century. In Italy, only residual fragmented nuclei survive in the Central-Southern part of the peninsula. Nowadays, the otter is one of the most endangered mammals in Italy, and increasing the knowledge about the ecology of this species is a key step in defining fitting management strategies. Here we provide information about the diet of otter on the Agri river system, one of the most important presence sites in Italy, to understand both the species’ food requirements and the impact on fish communities. Methods DNA metabarcoding and High Throughput Sequencing were used on DNA extracted from spraints. We amplified DNA with a primer set for vertebrates, focusing efforts on the bulk of the otter’s diet (fishes and amphibians). Results Our findings showed that the diet of the otter was dominated by cyprinids (97.77%, and 99.14% of fishes), while amphibians represented 0.85% of the sequences analyzed. Results are in general accordance with previous studies based on morphological characterization; however, molecular analyses allow the resolving of some morphological uncertainties. Although the study area offers a very wide range of available prey, the diet of the otters shows marked selectivity. We highlighted a variation in prey consumed, in accordance with the typology of water system (i.e., river, lake, tributary). Some of the preys found in the diet were alien species introduced by man for sport fishing. Our findings could help define strategies useful for the conservation of the otter population in Southern Italy, suggesting management actions directed at avoiding fish community alterations through illegal stockings without severe controls on their taxonomic status. These introductions could result in a general reduction in the diversity of the otter’s preys, affecting its predatory behavior.

The status of Asian populations of the Eurasian otter Lutra lutra is largely unknown. Since its designation as a Natural Monument (in 1983) and as Endangered (in 1997) in South Korea the authorities there have been trying to conserve and recover the species. We conducted a national otter survey by standard methods in 2017 and compared the current otter distribution to those recorded in a previous survey (2010). We found otter signs in 84.5% of 1,105 10 × 10 km grid cells, with the highest sprainting intensity in the south-west in the Yeongsan River Basin and on the south coast, where we recorded 7.05 and 6.26 spraints/site, respectively. Despite relatively low spraint densities, the otter has expanded its range since 2010 by colonizing urban areas. This trend suggests that South Korea could be a source area for the recovery of the Eurasian otter in East Asia. [ABSTRACT FROM AUTHOR]

Background. The Eurasian otter (Lutra lutra) underwent a strong decline in large areas of the Central-Western part of its distribution range, during the second half of the twentieth century. In Italy, only residual fragmented nuclei survive in the Central- Southern part of the peninsula. Nowadays, the otter is one of the most endangered mammals in Italy, and increasing the knowledge about the ecology of this species is a key step in defining fitting management strategies. Here we provide information about the diet of otter on the Agri river system, one of the most important presence sites in Italy, to understand both the species' food requirements and the impact on fish communities. Methods. DNA metabarcoding and High Throughput Sequencing were used on DNA extracted from spraints. We amplified DNA with a primer set for vertebrates, focusing efforts on the bulk of the otter's diet (fishes and amphibians). Results. Our findings showed that the diet of the otter was dominated by cyprinids (97.77%, and 99.14% of fishes), while amphibians represented 0.85% of the sequences analyzed. Results are in general accordance with previous studies based on morphological characterization; however, molecular analyses allow the resolving of some morphological uncertainties. Although the study area offers a very wide range of available prey, the diet of the otters shows marked selectivity. We highlighted a variation in prey consumed, in accordance with the typology of water system (i.e., river, lake, tributary). Some of the preys found in the diet were alien species introduced by man for sport fishing. Our findings could help define strategies useful for the conservation of the otter population in Southern Italy, suggesting management actions directed at avoiding fish community alterations through illegal stockings without severe controls on their taxonomic status. These introductions could result in a general reduction in the diversity of the otter's preys, affecting its predatory behavior. [ABSTRACT FROM AUTHOR]

The Eurasian otter (Lutra lutra) has been reported to be widely distributed in mountain wetlands of Nepal, though recent records have been scarce. The species is categorized as Near Threatened in the National Red List Assessment estimating its population as 1,000-4,000 individuals which is not based on a comprehensive status survey. Here, we review the past reports of the status and distribution of Eurasian otters in Nepal, and provide an update on the basis of literature review and a limited test surveys of some wetlands. We conclude that there has not been a single verifiable and conclusive record of the Eurasian otter in Nepal in recent years. Recent verifiable reports of otters have been entirely of smooth-coated otters. We suggest that there may have been a dramatic countrywide decline of Eurasian otter from their former ranges. Anthropogenic threats, illegal trade and habitat degradation threaten otter species throughout Asia, and reliable scientific and genetic studies are needed to get clear understanding of Eurasian otter status in Nepal. [ABSTRACT FROM AUTHOR]

Ecologists traditionally investigate the feeding ecology of vertebrates by visual identification of prey in their scats using a microscope. This analysis, however, presents some pitfalls, such as poor prey identification at genus/species level. DNA barcoding is an alternative to the traditional diet analysis, recently applied to investigate the diet of several vertebrates. It allows the identification of cryptic or not-recognizable prey portions basing their identification on the analysis of conserved DNA fragments. Here, we combined microscope analysis with DNA barcoding to investigate the diet of the Eurasian otter (Lutra lutra) in an area recently recolonized by the species, in the surroundings of Tarvisio, NE Italy. We collected 102 spraints and analysed all of them at microscope. A random subsample (N=50) was then analysed through DNA barcoding, via amplification of the V9 region of the SSU 18S-rDNA 18S gene. Furthermore, we assessed seasonal variation in otter diet and whether otters select certain salmonids size classes, to identify potential conflict with anglers. According to the microscope analysis, otters ate primarily fish (salmonids and European bullhead), secondarily amphibians and, more rarely, crayfish, both annually and seasonally. DNA barcoding analysis confirmed the microscope results, attributing some salmonids sequences to the brown trout (Salmo trutta). The lack of potential prey species reference sequences in the GenBank database hampered us in identifying the other taxa found in the spraints at more informative levels. Consumed salmonids and bullheads were of small size. In particular, otters selected salmonids size class of 100 mm, which is much smaller than the minimum catchable size for angling. Overall, our study confirms DNA barcoding potential for otter diet analyses, highlighting the need of additional markers to improve molecular prey identification and suggesting that otters do not constitute a significant threat to anglers in the area. [ABSTRACT FROM AUTHOR]

The game fund surface of Vâlcea County is of 529.265ha, distributed in 47 funds with a climate that ranges from moderately continental in Sub-Carpathian hills up to a mountain climate in high areas. Eight species were selected from the county's main game and fish species, namely: fallow deer (Damadama L), bear (Ursusarctos L), fox (Vulpes vulpes L), badger (Meles meles L), marten (Martes martes L), otter (Lutra lutra L), huchon (Hucho hucho) and carp (Cyprinus carpio). These species were classified based on their ordering after 19 criteria (harvesting period, harvesting cost, harvesting knowledge, tools necessary for harvesting, the harvesting's process complexity, harvesting development, knowledge about the species, distribution domain, market potential, market request, market "celebrity", raw product's price, the price of the derived product, derived products portfolio). Grades from 1 to 8 were given for each analysed species, resulting that the most important species are fallow deer and huchon, while the least important ones are otter and badger. The county presents a high potential for harvesting and trading game species as the forest and fish areas are very well represented. As such, the game and fish species have the proper space and environment to reproduce and develop. [ABSTRACT FROM AUTHOR]

Abstract Background Infectious skin disorders are not uncommon in mink. Such disorders are important as they have a negative impact on animal health and welfare as well as on the quality and value of the fur. This study presents the isolation of Arcanobacterium phocae from mink with severe skin lesions and other pathological conditions, and from wild seals and otters. Results In 2015, A. phocae was isolated for the first time in Denmark from outbreaks of dermatitis in mink farms. The outbreaks affected at least 12 farms. Originating from these 12 farms, 23 animals cultured positive for A. phocae. The main clinical findings were necrotizing pododermatitis or dermatitis located to other body sites, such as the lumbar and cervical regions. A. phocae could be isolated from skin lesions and in nine animals also from liver, spleen and lung, indicating a systemic spread. The bacterium was also, for the first time in Denmark, detected in dead seals (n = 9) (lungs, throat or wounds) and otters (n = 2) (throat and foot). Conclusions An infectious skin disorder in mink associated with A. phocae has started to occur in Danish farmed mink. The origin of the infection has not been identified and it is still not clear what the pathogenesis or the port of entry for A. phocae infections are.

An epidemiological study was conducted to determine whether Toxoplasma gondii protozoal brain infection and seropositivity in southern sea otters are associated with specific risk factors, including age, sex, geographic distribution and month of sampling.

This study was conducted in an about 130-km section of Kizilirmak River located between Hirfanli Dam and border of Kalecik district between February 2005 and August 2009. Footprints and feces of otter were identified and direct observations were made in order to determine its activity areas (including 7 localities). As a result of analysis of 233 fecal samples of otter, preys in its diet were divided into 5 categories as invertebrates, fish, bird, mammal, and unidentified pieces. It was determined that 69.91% of the diet were fish, 18.80% were invertebrate, 4.39% were bird, 4.39% were mammal, and 2.51% were unidentified remains. Habitat characteristics were recorded and habitat quality was calculated for Lutra lutra. Behaviors of Eurasian otter individuals determined as a result of the direct observation were recorded and photos were taken. [ABSTRACT FROM AUTHOR]

Central to appropriate wildlife management is an effective monitoring program. Monitoring wildlife in urban environments offers unique challenges in the form of barriers, prohibited access and crime. It also, however, provides a unique opportunity to enlist residential communities in collecting data on distribution of a number of species. Opportunistic sightings data has its flaws, including the lack of data on species absences, and unequal sampling effort. Yet these data may still provide reliable information on the distribution of species and complement localized, hypothesis driven research. Where possible opportunistic sightings data should be validated against traditional methods to determine their value for long term monitoring programmes. We use Maxent to model citizen-reported sightings to determine whether sightings of Cape clawless otters (Aonyx capensis) can complement standardized river occupancy surveys to monitor an elusive, widely distributed species living within a fragmented urban/natural matrix. The drivers of otter presence and the predicted distribution of otters modelled from citizen sightings mirrored that provided by previously published results based on occupancy models in the same system, and highlighted further areas of suitable otter habitat and routes for dispersal. Involving citizens in the monitoring of the urban otter population complemented standardized occupancy surveys and provided additional benefits. In addition to alleviating the pressure on local authorities to allocate resources to routine monitoring, citizen involvement provides an opportunity to gather supplementary data on behaviour and/or threats to the species; shed light on the potential dispersal routes, and promote awareness and encourage coexistence with urban adapted wildlife. [ABSTRACT FROM AUTHOR]

We investigated the ability of North American river otters (Lontra canadensis) to visually discriminate between 2D objects. The otters learned to discriminate between stimuli using multiple visual features and then were tested with stimuli in which one of the features was eliminated (color or shape). Two adult otters were trained in a two-alternative forced choice task to discriminate between a red circle and a blue triangle. Test sessions included probe trials containing novel shapes, colors, or shape-color combinations. Both otters successfully learned to discriminate between stimuli varying in multiple features. One of the otters was able to successfully discriminate between novel test stimuli when either color or shape were eliminated as salient features. This study was the first to explore the ability of L. canadensis to use different visual features to recognize objects and provides some preliminary evidence for color vision in this species. This research adds to the sparse literature on perceptual and cognitive capabilities in otters and can be used to support future conservation efforts for this species. [ABSTRACT FROM AUTHOR]

Abstract In this study, we provide the first description of Cystoisospora infection in Asian small-clawed otters (Aonyx cinereus). In July 2017, three juvenile otters recently imported from the Republic of Indonesia showed severe diarrhea and were diagnosed with coccidial infection; two of them eventually died. Fecal examination revealed the presence of numerous oocysts. Sporulated oocysts showed typical Cystoisospora features, measuring 24.6 ± 1.6 (22.0–27.0) × 21.8 ± 1.4 (19.0–25.0) μm, with an oocyst length/width ratio of 1.1 ± 0.1 (1.0–1.3). Each sporocyst contained four sporozoites in a head-to-tail arrangement. The Stieda body was absent, and the sporocyst residuum was present. These morphological characteristics differentiated this species from the other valid Cystoisospora species described from mustelids. Molecular analysis was conducted at two loci: the nuclear 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes. The 18S sequence showed high similarity with canine Cystoisispora ohioensis (1-bp difference, 1422/1423 [99.9%]). At the cytochrome c oxidase subunit I gene locus, the sequence from otters was identical to that of feline Cystoisospora rivolta (847/847 [100%]). Phylogenetic analyses using concatenated data demonstrated that Cystoisospora sp. from otters and C. rivolta grouped together in the same Cystoisospora clade. Based on these data, we concluded that Cystoisospora sp. detected from otters appeared to be highly similar to C. rivolta. Graphical abstract Image 1 Highlights • We characterized Cystoisospora infection in three Asian small-clawed otters. • Two otters showed anorexia, green diarrhea, and vomiting. • Fecal examination revealed numerous oocysts with typical Cystoisospora features. • Sporulated oocysts were morphologically differentiated from those of other Cystoisospora spp. from mustelids. • Molecular and morphological features were highly similar to feline C. rivolta. [ABSTRACT FROM AUTHOR]