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At-sea distribution and trophic ecology of small seabird species (i.e.<100 g) is far less known when compared to their larger relatives. We studied the habitat use (spatial ecology) and isotopic niches (trophic ecology) of the endangered Monteiro's storm-petrel Hydrobates monteiroi during the incubation and chick-rearing periods of 2013. There was a sexual foraging segregation of Monteiro's storm-petrels during the breeding period (tracking data) but also during the non-breeding stage (stable isotope analysis). Females took advantage of their longer wings to forage over the shallower Mid-Atlantic ridge (MAR) north of Azores, under colder and windier regimes when compared to males, who mostly exploited northern deep waters comparatively closer to the breeding colony. Between-sex differences in the spatial distribution were more obvious during the incubation period, with the overlap in their distribution increasing during the chick-rearing phase. There was also an isotopic segregation between sexes both during the previous breeding and the non-breeding stages, with females exhibiting a narrower, lower level isotopic niche when compared to males. Though the distribution patterns reported here should be useful for the at-sea conservation of this endangered species, future research should focus on (1) performing year-round tracking to map the species' distribution during the non-breeding period and (2) gathering multi-year tracking information to understand the effect of inter-annual environmental stochasticity on the foraging choices and trophic habits of the species., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande. Oceanographic characteristics differed between years. On a regional scale, the North Atlantic Oscillation (NAO) index was low and negative in 2011, and on a local scale, birds used areas with significantly lower values of chlorophyll a concentration and significantly higher values of sea surface temperature anomalies. Hatching success was higher in 2012 than in 2011. At both colonies, egg cracking was the main cause of hatching failure, but in 2011 several eggs on Selvagem Grande were deserted. In 2012 birds laid earlier and chicks had longer wings and were heavier. At both colonies, nests that were deeper, were sheltered from prevailing winds and had small chambers and a soil substrate had a higher probability of being used successfully by the birds. Nests occupied solely by Macaronesian shearwaters were much deeper and had less volume than nests shared with other species. Our study suggests that the breeding success of Macaronesian shearwaters is strongly related to nest site characteristics and that at-sea environmental conditions exert a strong influence on reproductive parameters, with birds breeding in a poor year (evaluated in terms of lower marine productivity) laying much later and their chicks growing at a slower rate than in a good year. The influence of nest site characteristics and environmental conditions may be very important for understanding the breeding ecology of Procellariiformes and may help explain the negative population trend of Macaronesian shearwaters., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The arrival and breeding dates of small migrant birds have advanced throughout Europe. This study evaluates the hypothesis of a faster migration along the migratory route, which should lead to a decrease in stopover duration in staging areas over the last decades. Several climatic predictors were analysed as proxies to understand the stopover ecology of reed warbler Acrocephalus scirpaceus migrating through Central Portugal. The minimum stopover duration of migratory reed warblers decreased significantly over the last decade during both the spring and autumn migrations. Warmer conditions en route should increase food availability, increasing the body condition of departing birds and the quality of departing sites en route to Portugal, such that migrants will reduce the stopover duration at Portuguese reedbeds., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Flight dynamics theories are influenced by two major topics: how birds adapt their flight to cope with heterogeneous habitats, and whether birds plan to use the wind field or simply experience it. The aim of this study was to understand the flight dynamics of free-flying Cory's shearwaters in relation to the wind characteristics on the coastal upwelling region of continental Portugal. We deployed recently miniaturised devices-global positioning system loggers to collect precise and detailed information on birds' positions and motions. Prevalent winds were blowing from the north-east and adults used those winds by adjusting their flight directions mainly towards north-west and south-west, flying with cross and tail winds, respectively, and avoiding head winds. This is confirmation that Cory's shearwaters use a shear soaring flying strategy while exploiting the environment for food: adults foraged mainly with cross winds and their ground speed was not constant during all foraging trips as it changed dynamically as a result of the ocean surface shear winds. During travelling phases, ground speed was strongly influenced by the position of the bird with regard to the wind direction, as ground speed increased significantly with increasing tail wind component (TWC) values. Adults appear to choose foraging directions to exploit ambient wind, in order to improve shear soaring efficiency (cross winding) and exploit diurnal changes in tail wind strength to maximise commuting efficiency. We report, for the first time, precise ground speed values (GPS-derived data) and computed actual flight speed values (using TWC analysis) for Cory's shearwater.