Review and quantitative meta-analysis of diet suggests the Eurasian otter (Lutra lutra) is likely to be a poor bioindicator

The Eurasian otter (Lutra lutra L.) is a top predator in aquatic systems and plays an important role in ecosystem functioning. However, it has undergone dramatic declines throughout Europe as a result of environmental degradation. We examine the putative role of the otter as a bioindicator in Ireland which remains a stronghold for the species and affords a unique opportunity to examine variation in its ecological niche. We describe diet, using spraint contents, along rivers during 2010 and conduct a review and quantitative meta-analysis of the results of a further 21 studies. We aimed to assess variation in otter diet in relation to river productivity, a proxy for natural nutrification and anthropogenic eutrophication, and availability of salmonid prey (Salmo trutta and Salmo salar), to test the hypothesis that otter diet is related to environmental quality. Otter diet did not vary with levels of productivity or availability of salmonids whilst Compositional Analysis suggested there was no selection of salmonid over non-salmonid fish. There was a distinct niche separation between riverine and lacustrine systems, the latter being dominated by Atlantic eel (Anguilla anguilla). Otters are opportunistic and may take insects, freshwater mussels, birds, mammals and even fruit. Otters living along coasts have a greatest niche breath than those in freshwater systems which encompasses a wide variety of intertidal prey though pelagic fish are rarely taken. It is concluded that the ability of the otter to feed on a wide diversity of prey taxa and the strong influence of habitat type, renders it a poor bioindicator of environmental water quality. It seems likely that the plasticity of the habitat and dietary niche of otters, and the extent of suitable habitat, may have sustained populations in Ireland despite intensification of agriculture during the 20th century.

Covering over the cracks in conservation assessments at EU interfaces: A cross-jurisdictional ecoregion scale approach using the Eurasian otter (Lutra lutra)

Throughout the European Union, the EC Habitats Directive requires that member states undertake national surveillance of designated species. Despite biological connections between-populations across-borders, national assessments need not be co-ordinated in any way. We conducted a trans-boundary assessment of the status of Eurasian otters (Lutra lutra) aimed at providing consistency across a single biogeographical unit, i.e. the island of Ireland, comprising two states, i.e. the Republic of Ireland and the United Kingdom (Northern Ireland). Our aim was to ensure consistency with previous assessments conducted separately in each state, and permit each Government to fulfil their separate statutory reporting commitments. The species range increased by 23% from 1996–2006 and 2007–11. The population estimate of 9400 [95%CI 8700–12,200] breeding females during 2010/11 was not significantly different from 8300 [95%CI 7600–9800] breeding females established as a baseline during 1981–82. Modelling of species-habitat associations suggested that available habitat was not limiting and no putative pressures recorded at sites surveyed negatively affected species occurrence. Thus, under the statutory parameters for assessing a species’ conservation status, i.e. range, population, habitat and future prospects, the otter was judged to be in ‘Favourable’ status throughout Ireland and in both discrete political jurisdictions. Thus, we provide a trans-boundary test case for EU member states that share habitats and species across ecoregions, ensuring conservation assessment data are standardised, synchronised, spatially consistent and, therefore, biologically relevant without compromising legal and administrative autonomy within separate jurisdictions.

Reintroduction of the Eurasian otter (Lutra lutra) in Muga and Fluvià basins (north-eastern Spain): viability, development, monitoring and trends of the new population

Aquesta tesi es basa en el programa de reintroducció de la llúdriga eurasiàtica (Lutra lutra) a les conques dels rius Muga i Fluvià (Catalunya) durant la segona meitat dels 1990s. Els objectius de la tesi foren demostrar la viabilitat de la reintroducció, demostrar l'èxit de la mateixa, estudiar aspectes ecològics i etològics de l'espècie, aprofitant l'oportunitat única de gaudir d'una població "de disseny" i determinar les probabilitats de supervivència de la població a llarg termini. La reintroducció de la llúdriga a les conques dels rius Muga i Fluvià va reeixir, doncs l'àrea geogràfica ocupada efectivament es va incrementar fins a un 64% d'estacions positives a l'hivern 2001-02. La troballa de tres exemplars adults nascuts a l'àrea de reintroducció és una altra prova que valida l'èxit del programa. La densitat d'exemplars calculada a través dels censos visuals ha resultat baixa (0.04-0.11 llúdrigues/km), però s'aproxima al que hom pot esperar en els primers estadis d'una població reintroduïda, encara poc nombrosa però distribuïda en una gran àrea. La mortalitat post-alliberament va ser del 22% un any després de l'alliberament, similar o inferior a la d'altres programes de reintroducció de llúdrigues reeixits. La mortalitat va ser deguda principalment a atropellaments (56%). El patró d'activitat de les llúdrigues reintroduïdes va esdevenir principalment nocturn i crepuscular, amb una escassa activitat diürna. Les seves àrees vitals van ser del mateix ordre (34,2 km) que les calculades en d'altres estudis realitzats a Europa. La longitud mitjana de riu recorreguda per una llúdriga durant 24 hores va ser de 4,2 km per les femelles i 7,6 km pels mascles. Durant el període de radioseguiment dues femelles van criar i els seus moviments van poder ser estudiats amb deteniment. La resposta de la nova població de llúdrigues a les fluctuacions estacionals en la disponibilitat d'aigua, habitual a les regions mediterrànies, va consistir en la concentració en una àrea menor durant el període de sequera estival, a causa de l'increment de trams secs, inhabitables per la llúdriga per la manca d'aliment, fet que va provocar expansions i contraccions periòdiques en l'àrea de distribució. La persistència a llarg termini de la població reintroduïda va ser estudiada mitjançant una Anàlisi de Viabilitat Poblacional (PVA). El resultat va ser un baix risc d'extinció de la població en els propers 100 anys i la majoria dels escenaris simulats (65%) van assolir el criteri d'un mínim de 90% de probabilitat de supervivència. Del model poblacional construït es dedueix que un punt clau per assegurar la viabilitat de la població reintroduïda és la reducció de la mortalitat accidental. A l'àrea d'estudi, els atropellaments causen més del 50% de la mortalitat i aquesta pot ser reduïda mitjançant la construcció de passos de fauna, el tancament lateral d'alguns trams de carretera perillosos i el control de la velocitat en algunes vies. El projecte de reintroducció ha posat a punt un protocol per a la captura, maneig i alliberament de llúdrigues salvatges, que pot contenir informació útil per a programes similars. També ha suposat una oportunitat única d'estudiar una població dissenyada artificialment i poder comparar diversos mètodes per estimar la distribució i la densitat de poblacions de llúdrigues. Per últim, la reintroducció portada a terme a les conques dels rius Muga i Fluvià ha aconseguit crear una nova població de llúdrigues, que persisteix en el temps, que es reprodueix regularment i que es dispersa progressivament, fins i tot a noves conques fluvials.

How well can models predict changes in species distributions? A 13-year-old otter model revisited

Species distribution and ecological niche models are increasingly used in biodiversity management and conservation. However, one thing that is important but rarely done is to follow up on the predictive performance of these models over time, to check if their predictions are fulfilled and maintain accuracy, or if they apply only to the set in which they were produced. In 2003, a distribution model of the Eurasian otter (Lutra lutra) in Spain was published, based on the results of a country-wide otter survey published in 1998. This model was built with logistic regression of otter presence-absence in UTM 10 km2 cells on a diverse set of environmental, human and spatial variables, selected according to statistical criteria. Here we evaluate this model against the results of the most recent otter survey, carried out a decade later and after a significant expansion of the otter distribution area in this country. Despite the time elapsed and the evident changes in this species’ distribution, the model maintained a good predictive capacity, considering both discrimination and calibration measures. Otter distribution did not expand randomly or simply towards vicinity areas,m but specifically towards the areas predicted as most favourable by the model based on data from 10 years before. This corroborates the utility of predictive distribution models, at least in the medium term and when they are made with robust methods and relevant predictor variables.

Viral metagenomic analysis of feces of wild small carnivores

Background: Recent studies have clearly demonstrated the enormous virus diversity that exists among wild animals. This exemplifies the required expansion of our knowledge of the virus diversity present in wildlife, as well as the potential transmission of these viruses to domestic animals or humans. Methods: In the present study we evaluated the viral diversity of fecal samples (n = 42) collected from 10 different species of wild small carnivores inhabiting the northern part of Spain using random PCR in combination with next-generation sequencing. Samples were collected from American mink (Neovison vison), European mink (Mustela lutreola), European polecat (Mustela putorius), European pine marten (Martes martes), stone marten (Martes foina), Eurasian otter (Lutra lutra) and Eurasian badger (Meles meles) of the family of Mustelidae; common genet (Genetta genetta) of the family of Viverridae; red fox (Vulpes vulpes) of the family of Canidae and European wild cat (Felis silvestris) of the family of Felidae. Results: A number of sequences of possible novel viruses or virus variants were detected, including a theilovirus, phleboviruses, an amdovirus, a kobuvirus and picobirnaviruses. Conclusions: Using random PCR in combination with next generation sequencing, sequences of various novel viruses or virus variants were detected in fecal samples collected from Spanish carnivores. Detected novel viruses highlight the viral diversity that is present in fecal material of wild carnivores.

Inferring Population Genetic Structure in Widely and Continuously Distributed Carnivores: The Stone Marten (Martes foina) as a Case Study

The stone marten is a widely distributed mustelid in the Palaearctic region that exhibits variable habitat preferences in different parts of its range. The species is a Holocene immigrant from southwest Asia which, according to fossil remains, followed the expansion of the Neolithic farming cultures into Europe and possibly colonized the Iberian Peninsula during the Early Neolithic (ca. 7,000 years BP). However, the population genetic structure and historical biogeography of this generalist carnivore remains essentially unknown. In this study we have combined mitochondrial DNA (mtDNA) sequencing (621 bp) and microsatellite genotyping (23 polymorphic markers) to infer the population genetic structure of the stone marten within the Iberian Peninsula. The mtDNA data revealed low haplotype and nucleotide diversities and a lack of phylogeographic structure, most likely due to a recent colonization of the Iberian Peninsula by a few mtDNA lineages during the Early Neolithic. The microsatellite data set was analysed with a) spatial and non-spatial Bayesian individual-based clustering (IBC) approaches (STRUCTURE, TESS, BAPS and GENELAND), and b) multivariate methods [discriminant analysis of principal components (DAPC) and spatial principal component analysis (sPCA)]. Additionally, because isolation by distance (IBD) is a common spatial genetic pattern in mobile and continuously distributed species and it may represent a challenge to the performance of the above methods, the microsatellite data set was tested for its presence. Overall, the genetic structure of the stone marten in the Iberian Peninsula was characterized by a NE-SW spatial pattern of IBD, and this may explain the observed disagreement between clustering solutions obtained by the different IBC methods. However, there was significant indication for contemporary genetic structuring, albeit weak, into at least three different subpopulations. The detected subdivision could be attributed to the influence of the rivers Ebro, Tagus and Guadiana, suggesting that main watercourses in the Iberian Peninsula may act as semi-permeable barriers to gene flow in stone martens. To our knowledge, this is the first phylogeographic and population genetic study of the species at a broad regional scale. We also wanted to make the case for the importance and benefits of using and comparing multiple different clustering and multivariate methods in spatial genetic analyses of mobile and continuously distributed species.

Evolução da distribuição da lontra (lutra lutra L.) na península ibérica: modelos a diferentes escalas e a sua projeção no espaço e no tempo

A Lontra Euroasiática foi alvo de quatro prospeções na Península Ibérica (1990-2008). Em 2003, foi publicado um modelo de distribuição da lontra, com base nos dados de presença/ausência das prospeções publicadas em 1998. Dadas as suas características, este tipo de modelos pode tornar-se um elemento chave nas estratégias de recuperação da lontra como também, de outras espécies, se comprovada a sua fiabilidade e capacidade de antecipar tendências na distribuição das mesmas. Assim, esta dissertação confrontou as previsões do modelo com os dados de distribuição de 2008, a fim de identificar potências áreas de discordância. Os resultados revelam que, o modelo de distribuição de lontra proposto, apesar de ter por base dados de 1998 e de não considerar explicitamente processos biológicos, conseguiu captar o essencial da relação espécie-ambiente, resultando num bom desempenho preditivo para a distribuição da mesma em Espanha, uma década depois da sua construção; Evolution of otter (Lutra lutra L.) distribution in the Iberian Peninsula: Models at different scales and their projection through space and time Abstract: The Eurasian otter was already surveyed four times in the Iberian Peninsula (1990-2008). In 2003, a distribution model for the otter based on presence/absence data from the survey published in 1998, was published. This type of models has advantages that can make it in a key element for otter conservation strategies and also, for other species, but only, if their reliability and capability to predict species distribution tendencies are validated. The present thesis compares the model predictions with 2008 data, in order to find potential mismatch areas. Results suggest that, although the distribution model for the otter was based on data from 1998 and, doesn’t include explicitly biological mechanisms, it managed to correctly identify the essence of the species-environment relationship, what was translated in a good predictive performance for its actual distribution in Spain, after a decade of its construction.

Use of Coarse-resolution models of species' distributions to guide local conservation inferences

Distribution models are used increasingly for species conservation assessments over extensive areas, but the spatial resolution of the modeled data and, consequently, of the predictions generated directly from these models are usually too coarse for local conservation applications. Comprehensive distribution data at finer spatial resolution, however, require a level of sampling that is impractical for most species and regions. Models can be downscaled to predict distribution at finer resolutions, but this increases uncertainty because the predictive ability of models is not necessarily consistent beyond their original scale. We analyzed the performance of downscaled, previously published models of environmental favorability (a generalized linear modeling technique) for a restricted endemic insectivore, the Iberian desman (Galemys pyrenaicus), and a more widespread carnivore, the Eurasian otter ( Lutra lutra), in the Iberian Peninsula. The models, built from presence–absence data at 10 × 10 km resolution, were extrapolated to a resolution 100 times finer (1 × 1 km). We compared downscaled predictions of environmental quality for the two species with published data on local observations and on important conservation sites proposed by experts. Predictions were significantly related to observed presence or absence of species and to expert selection of sampling sites and important conservation sites. Our results suggest the potential usefulness of downscaled projections of environmental quality as a proxy for expensive and time-consuming field studies when the field studies are not feasible. This method may be valid for other similar species if coarse-resolution distribution data are available to define high-quality areas at a scale that is practical for the application of concrete conservation measures

Access to East European and Eurasian culture : publishing, acquisitions, digitization, metadata

Review of the book 'Access to East European and Eurasian culture: publishing, acquisitions, digitization, metadata', edited by Miranda Remnek, published by Haworth Information Press, 2009.

Ecological risk assessment of the East Coast Otter Trawl Fishery in the Great Barrier Reef Marine Park: Data report

An ecological risk assessment of the East Coast Otter Trawl Fishery in the Great Barrier Reef Region was undertaken in 2010 and 2011. It assessed the risks posed by this fishery to achieving fishery-related and broader ecological objectives of both the Queensland and Australian governments, including risks to the values and integrity of the Great Barrier Reef World Heritage Area. The risks assessed included direct and indirect effects on the species caught in the fishery as well as on the structure and functioning of the ecosystem. This ecosystem-based approach included an assessment of the impacts on harvested species, by-catch, species of conservation concern, marine habitats, species assemblages and ecosystem processes. The assessment took into account current management arrangements and fishing practices at the time of the assessment. The main findings of the assessment were: Current risk levels from trawling activities are generally low. Some risks from trawling remain. Risks from trawling have reduced in the Great Barrier Reef Region. Trawl fishing effort is a key driver of ecological risk. Zoning has been important in reducing risks. Reducing identified unacceptable risks requires a range of management responses. The commercial fishing industry is supportive and being proactive. Further reductions in trawl by-catch, high compliance with rules and accurate information from ongoing risk monitoring are important. Trawl fishing is just one of the sources of risk to the Great Barrier Reef.

Eurasian Neogene large herbivorous mammals and climate

The development and changes in the distribution of herbivorous mammal communities during the Neogene is complex. The Eurasian scale environmental patterns reflect the large scale geographical and climatic patterns. The reorganization of these affect the biome distribution throughout the continent. The distribution of mammal taxa was closely associated with the distribution of biomes. In Eurasia the Neogene development of environments was twofold. The early and middle Miocene that seemed to have been advantageous for mammals was followed by drying of environments during the late Neogene. The mid-latitude drying was the main trend, and it is the combined result of the retreat of Paratethys, the uplift of Tibetan Plateau and changes in the ocean currents and temperatures. The common mammals were "driving" the evolution of mammalian communities. During the late Miocene we see the drying affecting more and more regions, and we see changes in the composition of mammalian communities.

Eurasian large mammal dynamics in response to changing environments during the Late Neogene

Nisäkkäiden levinneisyyteen, niiden morfologisiin ja ekologisiin piirteisiin vaikuttavat ympäristön sekä lyhyet että pitkäkestoiset muutokset, etenkin ilmaston ja kasvillisuuden vaihtelut. Työssä tutkittiin nisäkkäiden sopeutumista ilmastonmuutoksiin Euraasiassa viimeisen 24 miljoonan vuoden aikana. Tutkimuksessa keskityttiin varsinkin viimeiseen kahteen miljoonaan vuoteen, jonka aikana ilmasto muuttui voimakkaasti ja ihmisen toiminta alkoi tulla merkittäväksi. Tämän takia on usein vaikea erottaa, kummasta em. seikasta jonkin nisäkäslajin sukupuutto tai häviäminen alueelta johtui. Aineistona käytettiin laajaa venäjänkielistä kirjallisuutta, josta löytyvät tiedot ovat kääntämättöminä jääneet aiemmin länsimaisen tutkimuksen ulkopuolelle. Työssä käytettiin myös NOW-tietokantaa, jossa on fossiilisten nisäkkäiden löytöpaikat sekä niiden iät.

Comments on the Friends of the Sea Otter critique of the State of California sea otter proposal

Written in response to "A proposal for sea otter protection and research and request for the return of management to the State of California" report published by the California Department of Fish and Game in 1976. (52 page document)