Otters

Sea otters are carnivorous, amphibious mammals that are active both above and under water. Accordingly, it might be expected that their eyes are adapted for both aerial and aqueous vision. We examined the anatomy and physiological optics of the sea otter eye with a view towards describing and explaining its amphibious visual characteristics. We employed photokeratoscopy to measure the refractive power of the sea otter cornea, which we found to be 59 D. Using video dynamic photorefraction, we found that sea otters can focus targets clearly both in air and water, relying on accommodation to compensate for the refractive loss of their corneas upon immersion in water. Our anatomical investigations revealed that the anterior epithelium of the cornea is extensively developed, as is the iris musculature, meridional ciliary muscle, and the corneoscleral venous plexus. The first feature is most likely an adaptation to the salinity of the marine environment. We believe the latter features are part of a novel, well-developed lenticular accommodative mechanism.

CONTENTS
Asian Otter Conservation Network Report
African Otter Report
Conservation of threatened otters and their habitats in Guyana: workshop report
New sighting of the near threatened Eurasian otter (Lutra lutra) in Tunisia
A study of the diet and distribution of the Eurasian otter in the Water of Leith, Edinburgh, Scotland
Using artwork as a tool to raise public awareness for the conservation of Iraq’s smooth-coated otter (Lutrogale perspicillata maxwelli)
Distribution modelling of the Eurasian otter (Lutra lutra) on the Isle of Anglesey, Wales
The potential role of social media in support of otter conservation in the Indian Himalayan Biodiversity Hotspot
First record of Eurasian otter (Lutra lutra) from Chilika Lagoon – A Ramsar site situated on the East coast of India
Participatory monitoring committees: an opportunity for neotropical otter conservation in Mexico
Bridging the gap: preliminary otter (Lutra lutra) survey on the links between the rivers Dee, Don and Spey catchments, Scotland
A preliminary population estimate of the vulnerable smooth-coated otter Lutrogale perspicillata maxwelli (Hayman 1956) in the Hawizeh Marsh in Southeastern Iraq with confirmed occurrence in the Hoor Ol-Azim wetland in Southwestern Iran
Existence of smooth-coated otters (Lutrogale perspicillata) in the Ganges-Padma River basin area of Rajshahi, Bangladesh
Public perception of otters in South Korea
Obituary: Motokazu Ando

The smooth-coated otter Lutrogale perspicillata is an IUCN-Vulnerable species as a result of habitat loss and poaching. The objective of this study was to estimate the population status and activity pattern of smooth-coated otter in Bhitarkanika National Park. To achieve this, 15 camera trap stations were established in the study area between 16th June and 5th August 2019. We recorded notionally 30 independent capture events of smooth-coated otter, over a total of 725 camera trap days. The encounter rate of smooth-coated otter was 2.06/photo-captures/100 trap days, with a diurnal activity pattern. Further research and monitoring, and awareness campaigns for local stakeholders is required in order to design effective conservation strategies of the species.

CONTENTS
Asian Otter Conservation Network Report
African Otter Network (AON) and the Power Of One initiative
First photographic documentation of smooth-coated otter in Mahi River, Gujarat, India
Preliminary study on the occurrence, distribution and traditional knowledge of otters in the Lake Victoria Basin, Kenya
Towards a cooperation between the Eurasian otter and local people of Hima Anjar/Kfarzabad, Lebanon: A case study
Preliminary results of first-ever otter survey in Chornobyl Exclusion Zone, Northern Ukraine
A survey of the Eurasian otter on the River Don, Aberdeenshire, Scotland, 2017-18
The Eurasian otter – A review of the current world status
The frequency and size of main prey items taken by the Eurasian otter on the Isle of Harris, Scotland
Recent records of the Eurasian otter in the Mercure-Lao River Valley, South Italy

The geographic distribution of the populations
of a species are influenced by the spatial structure of the
ecosystems, the environmental factors and the presence
of geographic barriers. The Neotropical otter, Lontra longicaudis,
is widely distributed throughout the Americas,
where a wide range of environmental conditions and geographical
features could promote genetic and morphological
variation on the three currently recognized subspecies. In
this study, we combined phylogeographic, morphometric
and environmental niche modelling analyses to examine
whether: (1) genetic variation is associated with the presence
of barriers to gene flow and/or hydrography; (2) genetic and
morphologic variation are associated with environmental
variation; and (3) the observed variation in L. longicaudis
populations corresponds to the previously defined subspecies.
We found strong phylogeographic structure between
the northern (L. l. annectens) and the two-southern subspecies
(L. l. longicaudis and L. l. enudris), and although shallower,
we also detected genetic differentiation between the two South American subspecies. Such genetic differentiation
corresponds to the hydrography and to the geographical barriers
characteristic of the distributional area of the species.
We found a correlation between the shape of the skull and
mandible with the environmental variation through the distribution
of the species, and we rejected the hypothesis of
niche equivalency and similarity between the three identified
genetic lineages, suggesting adaptations to different environmental
conditions. Our results support that the variation in
environmental conditions, in concert with geographical barriers
to gene flow and hydrography, have led to population
divergence of L. longicaudis along the Neotropics. These
results have important taxonomic implications for the species
and its conservation.

Eurasian otters Lutra lutra (Linnaeus, 1758) are known to occur in Portugal since historical times but only in 1995 a national survey confirmed the species' broad distribution. Since then, studies and projects conducted in different aquatic environments indicate the existence of a healthy population, the availability of vegetation cover, water and prey being the major factors explaining otter presence. Spraint analyses showed that fish, amphibians and American crayfish form the bulk of otter diet. Due to increasing knowledge about the species ecology and distribution , in 2005, otter status was changed, from " Insufficiently Known " to " Least Concern ". Recent main lines of investigation have become increasingly threat specific and include: otter use of reservoirs, man-otter conflicts (fish farming), otters and non-native species interactions (prevalence in otter diet; competition with American mink) and otters and antimicrobial resistant bacteria. Destruction of the riparian vegetation commonly associated with dam construction, river regulation, agricultural expansion, gravel and sand extraction, as well as the development of tourism in, costal and wetland areas are still potential threats to otter populations. Overall, in the near future otters seem safe from major disrupting settings but otter conservation and effective management are still an important issues. This is especially relevant in the Iberian Peninsula , as climate changes are expected to reduce suitable otter habitats. Knowledge gaps and future research needs are also addressed in this chapter. RESUMEN La presencia de la nutria euroasiática Lutra lutra (Linnaeus, 1758) en Portugal se conoce desde tiempos históricos, pero no fue hasta 1995 cuando gracias a un sondeo nacional se confirmó la amplia distribución de la especie. Desde entonces, se han realizado múltiples estudios y proyectos en diferentes ambientes acuáticos que indican la existencia de una población sana, siendo la disponibilidad de cobertura vegetal, el agua y las presas los principales factores que explican la presencia de la nutria. Los análisis de excrementos mostraron que los peces, los anfibios y el cangrejo de río americano forman el grueso de la dieta de la nutria. Debido al aumento de los conocimientos sobre la ecología y distribución de la especie, en 2005, el estado de la nutria pasó de "Insuficientemente Conocida" a "Preocupación Menor". Recientes líneas de investigación se han dado a conocer un aumento de amenazas específicas que incluyen: el uso de los embalses por parte de las nutrias, los conflictos hombre-nutria (acuicultura), y las interacciones entre las nutrias y las especies no nativas (prevalencia en la dieta de la nutria , la competencia con el visón americano) y las nutrias y bacterias resistentes a los antimicrobianos. La destrucción de la vegetación de ribera aso-ciada comúnmente con la construcción de presas, la regulación de caudales, la expansión agrícola, la extracción de grava y arena, así como el desarrollo del turismo en zonas costeras y humedales son potenciales amenazas a las poblaciones de nutria. En general, a corto plazo las nutrias parecen a salvo de las principales afecciones pero su conservación y su correcta gestión siguen siendo un problema importante. Esto es especialmente relevante en la Península Ibérica, pues se espera que los cambios climáticos reduzcan los hábitats adecuados para la nu-tria. En esta capítulo se abordan también temas como la falta de datos existentes y las necesidades de investigación futuras. LABURPENA Lutra lutra (Linnaeus, 1758) igaraba eurasiarraren presentzia antzinatik ezagutzen dugu, baina 1995. urtean egindako Estatu mailako zun-daketari esker baieztatu zuten espeziea toki zabalean banatuta dagoela. Ordutik uretako hainbat ingurunetan egin izan diren ikerketa eta proiektu ugariek agerian utzi dute populazio osasuntsua dagoela bertan eta igarabaren presentzia ahalbidetzen duten faktore nagusiak ho-nako hauek dira: estaldura begetala, ura eta harrapakinak izatea. Gorotzen azterketek bistaratu zutenez, igarabaren dietako elementu nagu-siak honako hauek dira: arrainak, anfibioak eta ibai-karramarro amerikarra. Espeziearen banaketari eta ekologiari buruzko ezagutzak ugaritu izanaren ondorioz, 2005ean, igarabaren egoera "ez da behar adina ezaguna" izatetik, "kezka txikiagoa" egoerara aldatu zen. Azken ikerketa-ildoen arabera, ordea, mehatxu espezifikoak ugaritu egin dira eta horien artean daude hauek: igarabek urtegiak erabiltzea, gizakia-igaraba-ren arteko gatazkak (akuikultura), igaraben eta bertakoak ez diren espezieen arteko interakzioak (igarabaren dietan nagusi dira, bisoi amerikarrarekin lehia), igarabak eta mikrobianoen aurkakoekiko erresistenteak diren bakterioak. Ibaiertzeko landaredia suntsitzea da igarabaren populazioetarako mehatxu nagusietako bat eta hori, gehienetan, honako hauekin lotuta dago: urtegiak eraikitzea, emariak erregulatzea, ne-kazaritzaren hedapena, legarra eta hondarra ateratzea eta hezeguneetako eta kostaldeko turismoa garatu izana. Oro har, epe laburrera be-gira, igarabak asaldura nagusietatik salbu daudela ematen du, baina haien behar bezalako kudeaketa eta kontserbazioa oraindik ere arazo handia da. Hori bereziki esanguratsua da iberiar penintsulan; izan ere, klima-aldaketek igarabarako egokiak diren habitatak gutxituko dituz-tela aurrez ikusi dute. Kapitulu honetan, gainera, beste gai batzuk ere landuko ditugu: eskuragarri dauden datuak falta direla eta etorkizune-rako ikerketen beharrak, esate baterako.

This paper looks at the care of otters taken into rescue and rehabilitation centres. It stresses the need for keeping human contact to a minimum in order to prevent imprinting. The method used to rear " orphaned " cubs is described as well as the problems facing juveniles and adults. This is rehabilitation and therefore not a veterinary paper and so details of medication, etc are not included.

Investigations into the feeding habits of the Neotropical otter (Lontra longicaudis annectens in the Bavispe-Yaqui river basin were conducted based on 73 scats collected from 1995, 1999, 2001 and 2002. Neotropical otters feed mainly on various species of fishes (58%), insects (30%), mammals (3.7%), amphibians (0.7%), reptiles (0.7%), birds (5.8%) and mollusks (1.5%). Fish prey was mainly composed by Oreochromis sp. and unidentified insects from Order Choleoptera, follow by crickets Melanoplus differentialis which were the most consumed insects. This paper shows differences in feeding habits compared to other feeding preferences of the species in different areas of the country. To date, this is one of a few studies to report a large percentage of insect consumption by otters and the first study to report the presence of carrion from this same species in their diets.

The Eurasian otter (Lutra lutra) has the widest distribution of all 13 otter species but the actual worldwide status is very uncertain. It disappeared in many parts of Europe largely due to pollution but with considerable effort to improve environmental conditions they are starting to return in some areas. However, the rate of this return is largely exaggerated which creates problems with fisheries. In vast parts of its range in Asia and North Africa there is very little data and few modern records. It is therefore important to continue conservation efforts, increase public awareness and research to obtain up-to-date information on the true status.

CONTENTS
Asian Otter Conservation Network Report
African Otter Network Yearly Report, March 2018
Conservation of endangered otters and their habitats in Laos through education and reducing illegal trade - Workshop Report
Too cute! The rise of otter cafes in Japan
Are Eurasian otters “flooding back”?
Some preliminary observations and conservation measures on otter in Montenegro
Otter sighting at Vil Uyana, Sigiriya, Sri Lanka
Current status and conservation threats to otters in Nepal: A review
Mortality causes and body dimensions of otters determined by means of post mortem analysis in Hungary
An otter survey of the upper reaches and headwaters of the River Dee, Aberdeenshire, Scotland, 2017
A review of the distribution of records of albino otters.

ABSTRACT: Three species of otters, the Eurasian otter (Lutra lutra), the Smooth-coated otter (Lutrogale perspicillata) and the Asian small-clawed otter (Aonyx cinerea) have been recorded in Nepal. Baseline information on otters is not available for the majority of wetland sites within the country. Freshwater ecosystems, the preferred habitat for otters, are adversely affected by both human and natural causes. This paper provides an overview of research on otters in Nepal to date, the key findings and the ways forward.

Volume 3 (2017). Contents:
Developing the Nepal Otter Network
2016, The Year of the Otter
Report on raising awareness of otters with fishermen and fish farmers in Tanzania
African Otter Network
Report on the Asian otters and wetlands training workshop in China
First photographic evidence of smooth-coated otter and Eurasian otter in Iraq since 1950s
A review of China’s otter conservation from the national wetland inventory
Status of smooth-coated otters in the Khauraha River of Bardia National Park, Nepal
The otter as an umbrella species in China
An otter survey of the River Dee, Aberdeenshire, Scotland 2016
Illegal trade in otters in Asia.

This article is part of a Road Ecology topical collection published in the European Journal of Wildlife Research. Abstract: In conservation, there is a high demand for methods to predict how animals respond to human infrastructure, such as estimating the location of road mortalities and evaluating the effectiveness of mitigation measures. Computer-based simulation models have emerged as an important tool in understanding wildlife-infrastructure interactions. Such models, however, often assume animal omniscience of the landscape yielding unrealistic movements, focus more on genetic connectivity than actual movement paths, or are case-specific and mathematically/computationally challenging to apply. Here, we illustrate the potential of SiMRiv, a novel R package for simulating spatially explicit, individual multistate (Markovian) movements incorporating landscape heterogeneity, in the subject of road ecology. In particular, we used SiMRiv to reproduce wildlife movement patterns and predict high-risk areas for road-kill, using Eurasian otters (Lutra lutra) as a model species. We compared the number of road crossings in real otter movements and null models (simulated, multistate Markovian movements) incorporating the effect of the landscape structure (here, water dependence). The number of road crossings in real and simulated movements was remarkably similar, and available limited real road-kill data supported SiMRiv's road-kill risk predictions. Further, other emergent movement properties were also very similar in real and simulated movements. Overall, results show that SiMRiv has potential for reconstructing real wildlife movement patterns, as well as for predicting road-kill risk areas. SiMRiv constitutes a flexible, powerful, and intuitive tool to help biologists and managers to test mechanistic hypotheses on wildlife movement ecology, including those related to wildlife-vehicle interactions.

Background
Despite the increasing worldwide use of global positioning system (GPS) telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects.

Methodology/Principal Findings
We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra). The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD = 8.55). GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%).

Conclusions/Significance
Our results suggest that GPS telemetry is reliably applicable to riparian and even diving freshwater animals. They also highlight the need, in GPS wildlife studies, for performing site-specific pilot studies on GPS functioning as well as for taking into account eventual spatial and temporal correlation of location estimates. The limited price, small dimensions, and high performance of the device presented here make it a useful and cost-effective tool for studies on otters and other aquatic or terrestrial medium-to-large-sized animals.