Angiostrongrylus cantonensis as a cause of cerebrospinal disease in a yellow-tailed black cockatoo (Calyptorhynchus funereus) and two tawny frogmouths (Podargus strigoides)

A captive yellow-tailed black cockatoo (Calyptorhynchus funereus) and 2 free-living tawny frogmouths (Podargus strigoides), both native Australian species, were presented with neurologic signs including depression and pelvic limb paresis and paralysis. Despite supportive treatment, all 3 birds died or were euthanatized. On histologic examination, sections of metastrongyloid nematode larvae were found in the central nervous system of all 3 birds, whereas intact larvae, identified as Angiostrongylus cantonensis, were recovered from the brain and spinal cord of 2 birds. Angiostrongylus cantonensis, the rat lungworm. has an obligatory migratory phase through the host's central nervous system, which can cause severe pathologic lesions. Natural infections in accidental hosts have been documented only in mammals, and to our knowledge, angiostrongyliasis in avian hosts has not been previously reported.

Sex- and melanism-specific variations in the oxidative status of adult tawny owls in response to manipulated reproductive effort.

Oxidative stress, determined by the balance between the production of damaging reactive oxygen species (ROS) and antioxidant defences, is hypothesized to play an important role in shaping the cost of reproduction and life history trade-offs. To test this hypothesis, we manipulated reproductive effort in 94 breeding pairs of tawny owls (Strix aluco) to investigate the sex- and melanism-specific effects on markers of oxidative stress in red blood cells (RBCs). This colour polymorphic bird species shows sex-specific division of labour and melanism-specific history strategies. Brood sizes at hatching were experimentally enlarged or reduced to increase or decrease reproductive effort, respectively. We obtained an integrative measure of the oxidative balance by measuring ROS production by RBCs, intracellular antioxidant glutathione levels and membrane resistance to ROS. We found that light melanic males (the sex undertaking offspring food provisioning) produced more ROS than darker conspecifics, but only when rearing an enlarged brood. In both sexes, light melanic individuals had also a larger pool of intracellular antioxidant glutathione than darker owls under relaxed reproductive conditions (i.e. reduced brood), but not when investing substantial effort in current reproduction (enlarged brood). Finally, resistance to oxidative stress was differently affected by the brood size manipulation experiment in males and females independently of their plumage coloration. Altogether, our results support the hypothesis that reproductive effort can alter the oxidative balance in a sex- and colour-specific way. This further emphasizes the close link between melanin-based coloration and life history strategies.

Analysis of genetic parentage in the tawny owl (Strix aluco) reveals extra-pair paternity is low

We have investigated genetic parentage in a Swiss population of tawny owls (Strix aluco). To this end, we performed genetic analysis for six polymorphic loci of 49 avian microsatellite loci tested for cross-species amplification. We found one extra-pair young out of 137 (0.7%) nestlings in 37 families (2.7%). There was no intra-specific brood parasitism. Our results are in accordance with previous findings for other raptors and owls that genetic monogamy is the rule. Female tawny owls cannot raise offspring without a substantial contribution by their mates. Hence one favoured hypothesis is that high paternal investment in reproduction selects for behaviour that prevents cuckoldry.

Sex- and melanism-specific variations in the oxidative status of adult tawny owls in response to manipulated reproductive effort

Funding: This work was supported by the Swiss National Science Foundation [grants PPOA-102913 and 3100AO_120517 to AR and 31003A_124988 to PB). © 2015. Published by The Company of Biologists Ltd.

Disponibilidad de micromamíferos en el área de campeo del cárabo común en los bosques de Burceña (Valle de Mena): Primeros resultados del estudio

[ES] Este trabajo forma parte de un proyecto en el que se estudian dos poblaciones de cárabo común (Strix aluco); una en Durango (Bizkaia) y otra en Burceña (Burgos). Este trabajo se ha llevado a cabo en Burceña y en él se muestran los primeros resultados del uso del espacio de estas rapaces nocturnas y su disponibilidad de alimento en los bosques de esta zona. Para ello hemos obtenido localizaciones de diez cárabos durante un año para conocer los territorios de cada uno y hemos capturado en vivo la dieta principal de esta ave, micromamíferos. Estos resultados los hemos relacionado entre sí para saber si influye el uso del espacio en las capturas de micromamíferos. Estas dos variables también las hemos relacionado con el tipo y la edad de los bosques muestreados. Según los resultados obtenidos podemos afirmar que sí existe una influencia del uso en las capturas, demostrando una relación negativa; es decir, donde se han capturado más micromamíferos es en los bosques que menos frecuentan los cárabos, que a su vez, son los bosques menos accesibles para estas rapaces. ABSTRACT This investigation is part of a work project whereby two Tawny owl (Strix aluco) populations are studied. One of them lives in Durango, Biscay and the other one in Burceña, Burgos. This specific work took place in Burceña and lasted one year. It shows the first results of the study on the use of the space of the Tawny owls and the food availability in their woodland range area. We spotted and traced the home range of ten different tawny owls, and also trapped small mammals which are the staple diet of these owls. We compared both the results obtained in order to know if the use of the area is related to the capture of small mammals. These two variables (space-capture) were also related to the type and age of the sampled forests. The results obtained show that it is true there is an influence of the use of space upon the captures proving to be a negative relation, that is, the largest numbers of micromammals were captured in the woodlands where there are fewer owls, because they are the least accessible forests for these birds of prey.

Range extensions and conservation of some threatened or little known Brazilian grassland birds

Populations of grassland birds are declining in Brazil due to profound alterations to grassland habitats. In this paper, we present recent records and range extensions for 12 threatened or little known Brazilian grassland species: Ocellated Crake Micropygia schomburgkii, Sickle-winged Nightjar Eleothreptus anomalus, Campo Miner Geositta poeciloptera, Rufous-sided Pygmytyrant Euscarthmus rufomarginatus, Sharp-tailed Grass-tyrant Culicivora caudacuta, Cocktailed Tyrant Alectrurus tricolor, Cinereous Warbling-finch Poospiza cinerea, Black-masked Finch Coryphaspiza melanotis, Tawny-bellied Seedeater Sporophila hypoxantha, Marsh Seedeater S. palustris, Chestnut Seedeater S. cinnamomea and Black-bellied Seedeater S. melanogaster. We also comment on the biogeography and conservation of these species.

Food availability and predation risk, rather than intrinsic attributes are the main factors shaping the reproductive decisions of a long-lived predator

Funded by Natural Research Limited Natural Environment Research Council studentship. Grant Numbers: NE/J500148/1, NE/F021402/1

As rodovias e as aves de rapina nocturnas relação entre a densidade, o habitat e a mortalidade

As estradas e tráfego inerente surgem como a criação antrópica mais conspícua e penetrante na paisagem natural, sendo considerados os principais agentes causadores de fragmentação e destruição de habitats, assim como representam um obstáculo físico sem precedentes, limitando as relações directas entre os indivíduos, por diminuição da frequência de dispersão e aumento da mortalidade por atropelamento, impedindo o fluxo natural de genes e suscitando o aumento de fenómenos de inbreeding e perda de heterozigotia. Todos os impactes deletérios associados às rodovias são claramente perceptíveis em vertebrados, onde as aves de rapinas nocturnas não são excepção. Uma vez que estas rapaces beneficiam das suas bermas e orlas, como locais de poiso, nidificação ou como corredores de dispersão através da paisagem, são frequentemente vítimas de mortalidade por atropelamento em estradas, sendo esta problemática considerada actualmente uma das mais recentes e importantes formas de mortalidade não natural em rapinas nocturnas e vinculada como um dos maiores problemas de conservação que afecta este grupo. Não obstante, esse mútuo efeito de atracção/repulsa das estradas a estas rapaces, as rodovias criam uma barreira específica que limita a dinâmica, comportamento e densidade populacional das espécies residentes, reconhecendo-se que o isolamento daí resultante, pode comprometer a viabilidade populacional a longo prazo, podendo mesmo conduzir a altos riscos de extinção das populações locais devido a efeitos estocásticos. Mediante esta problemática, este trabalho debruçou-se sobre um único objectivo principal: a avaliação do impacte das rodovias e do tráfego, na densidade das aves de rapina nocturnas. Este estudo foi efectuado na região Alentejana, abrangendo uma área de cariz tipicamente mediterrânico, delimitada pelas localidades de Montemor-o-Novo, Arraiolos e Évora, sendo seccionada por 143 quilómetros de estradas, divididas em autoestrada, rodovias com elevada e reduzida densidade de tráfego. A monitorização das rapinas nocturnas foi conduzida em dois anos amostrais (2005 e 2007), tendo sido focalizada sobretudo em duas espécies de Strigiformes, a Coruja­ do-mato Strix aluco e o Mocho-galego Athene noctua, recorrendo ao uso de playbacks com reprodução de vocalizações de indivíduos conspecíficos. Foram usadas 32 variáveis explicativas integradas em três grandes grupos: variáveis de estrada, métricas da paisagem, uso do solo, tendo sido analiticamente testadas, recorrendo à aplicação de Modelos Lineares Generalizados. Os principais resultados obtidos demonstram que as variáveis de estrada, aliadas à densidade de tráfego e ruído inerente à sua circulação, são provavelmente, responsáveis por um comportamento de repulsa das espécies de aves de rapina nocturnas em estudo, apresentando estas densidades mais elevadas longe de áreas antropicamente perturbadas e, portanto, de menor qualidade que se encontram adjacentes às rodovias. Todavia a presença de habitat favorável a estas rapaces é provavelmente o descritor com maior poder estatístico no que concerne à sua distribuição e densidade, sendo os montados densos e a presença de zonas agrícolas de sequeiro, positivamente correlacionadas, respectivamente com a densidade de casais reprodutores de Coruja-do-mato e Mocho-galego. Mediante a observação dos resultados será veemente a aplicação de medidas de mitigação específicas, que fundamentalmente considerem o afastamento dos efectivos populacionais longe das estradas e tráfego, conservando e assegurando as características estruturais, requisitos e qualidade dos habitats, de modo a incrementar e garantir a viabilidade e densidade das populações, fidelizando a territorialidade e permanência destas aves nestas áreas. Adicionalmente deverá investir-se na conectividade das manchas de paisagem fragmentada pelas rodovias, criando opções de conservação estratégicas, em zonas ecologicamente mais sensíveis, que não somente minimizem o efeito de repulsa reconhecido nestas aves, mas também os níveis de mortalidade por atropelamento, tornando os ecossistemas mais funcionais para a sobrevivência destes rapaces. ABSTRACT; Roads and traffic are the most conspicuous and pervasive human creation, being the great responsible for fragmentation and habitats destruction, reducing animal movement through landscape, which implies decrease of gene flow and loss of variability that can fragmented populations, thus reducing their sizes and densities. All deleterious impacts associated with roads are clearly visible in vertebrates, where owls aren't exception, being frequent victims of road mortality, since they can use roadside habitats and edges for hunting, nesting or dispersal corridors through the landscape, being nowadays one of the most recent and important causes of non­natural mortality in owls and has been recognized as one of the largest conservation problems affecting this group. However, the attractive and avoidance effect of roads and his edges on owls creates a barrier effect that limits dynamics, behaviour and breeding density of resident species, recognizing that possible isolation, could compromise populations survival, make them more vulnerable to high risks of local extinction due to stochastic effects. Despite that, several authors suggest that owls use roads to hunt, as marginal habitats, or for navigation corridors through the landscape ln this context, the major aims of this study was to verify if there are negative effects of roads on the density of owls, considering traffic as an influencing factor. This study was conducted in Alentejo, covering a typical Mediterranean area, including three main localities Montemor-o-Novo, Évora and Arraiolos, being sectioned by 143 km of roads, including highway, roads with high traffic density, and the remaining with low traffic density. The owl census was conducted in two sampling years (2005 and 2007) and was focused mainly on Little owl Athene noctua and Tawny Owl Strix aluco species, using the playback technique, with conspecific calls. We used 32 explanatory variables, mainly included in three groups: road variables, landscape metrics and land use, having been analytically tested, with application of Generalised Linear Models. The main results show that noisy roads with high traffic density are probably the most responsible for the avoidance behaviour of owls, under the study area, showing density depression near high anthropogenic disturbed areas adjacent to roads. However, the presence of habitat quality to these birds is probably the descriptor with greater statistical power, considering its distribution and density, with the dense oak woodland and croplands and arable lands, positively correlated, respectively with Tawny owl and Little owl density. ln consequence, the great conservation effort should be done in order to keep breeding populations away from roads and traffic, ensuring the structural features, requirements and quality of its habitats in order to enhance and ensure the viability and density of owl's populations in these areas. ln addition, it is important to invest in connectivity between roadside fragmented patches, creating strategic conservation options, in sensitive areas, which minimize the avoidance effect, recognized in owls, but also road-kill levels, making ecosystems more functional to survival of these top predators.