259890 research outputs found
Sort by
Seabird Migration at Cabo Carvoeiro (Peniche, Portugal) in Autumn 2015
No full textLand-based counts at Cabo Carvoeiro (Peniche, Portugal), made between 15 August and 15 November 2015 (effort 90 d, 517 h), tallied 302469 birds, most of which (99.98%) were southbound. Although 65 species were observed, four species contributed to 91% of the total: 207608 Northern Gannet Morus bassanus, 32281 Cory’s Shearwater Calonectris borealis, 16086 Manx Shearwater Puffinus puffinus, and 15222 Balearic Shearwater Puffinus mauretanicus. Passage as a whole increased throughout the period, mainly due to a gradual intensification of Northern Gannet migration. More than 67 000 southbound procellariforms of 12 species were recorded, as were 6183 Stercorariidae of four species. Daily passage rates of species recorded on more than 68 d were positively correlated in 22 of 36 cases. For Northern Gannet and Mediterranean Gull Ichthyaetus melanocephalus, the proportion of adult birds increased steadily, outnumbering younger birds. Extrapolation based on counted versus uncounted daylight hours suggests that at least 415000 Northern Gannets, 65000 Cory’s Shearwaters, and 30000 Balearic Shearwaters passed south at Cabo Carvoeiro in autumn 2015. Clearly, a very large share of the global population of the endangered Balearic Shearwater can be monitored at Cabo Carvoeiro. Based on generally unidirectional passage patterns, high species diversity, as well as high season totals and daily passage rates of several species, Cabo Carvoeiro is one of the most promising mainland sites in the eastern North Atlantic to monitor a wide range of seabirds
Reviews: Journal of a voyage: Federico Craveri and the Gulf of California in 1856 (Craveri, F.; T. Bowen [Ed.], B. D\u27Arpa and B. Cavatorta [Translators]); How to be an Antiracist (Kendi, I.X.); The Skin We\u27re In: A Year of Black Resistance and Power (Cole, D.); Hawai\u27i\u27s White Tern: Manu-o-ku, an Urban Seabird (Scott, S.)
No full text
Reproductive Ecology of the Black-necked Swan \u3ci\u3eCygnus melancoryphus\u3c/i\u3e in a Marine Wetland of Southern Chile
No full textThe Black-necked Swan Cygnus melancoryphus is an endangered species in Chile. After the Río Cruces ecological disaster in Valdivia in 2004 (due to installation of a new pulp mill), the Black-necked Swans that survived were mostly dispersed to marine wetlands of the large island of Chiloé, passing from continental wetlands to the marine environment. The objectives of this study were to provide the first observations of nesting Black-necked Swans in the marine wetland of Chiloé Island, and to identify factors that may affect the survival of their cygnets. Our study was carried out in Caulín Bay (41°49ʹS; 073°38ʹW), Chiloé Island, during austral winter and spring of 2011 and 2014. During both years, the Black-necked Swan nested in different sectors of Caulín Bay. The construction of nests began in mid-July, and the first hatchings were recorded in September. In 2011, 23 nests were found in the stone promontories sector and 39 nests were found at Lacaos Island. In 2014, the Black-necked Swan, nesting only in Lacaos Island, occupied 47 nests. We discuss the need to evaluate potential factors that affect the survival of this species’ cygnets in the marine wetland of Caulín Ba
Field Separation of Cory\u27s Calonectris borealis and Scopoli\u27s C. diomedea Shearwaters by Underwing Pattern
No full textField separation of Cory’s Calonectris borealis and Scopoli’s C. diomedea shearwaters is notoriously difficult. Past, provisional research found that the most reliable method of separation is by underwing pattern. Here, we present a comprehensive study of the underwing patterns of both species from colonies and other locations in the eastern North Atlantic Ocean (Cory’s Shearwater) and Mediterranean Sea (Scopoli’s Shearwater). Data were derived from museum specimens, typed bycatch victims, and photographs of birds at colony, inshore by colony, and offshore in the Mediterranean. Results demonstrate that the large majority of Cory’s/Scopoli’s shearwaters are separable in the field, though overlapping features of the remainder are problematic. Improvements to the criteria for field separation will enhance studies of breeding limits, regional migration, and limits and variation in range, which, in turn, will highlight conservation needs of the two species
Winter Colony Attendance by Adult Southern Giant Petrels \u3ci\u3eMacronectes giganteus\u3c/i\u3e: Implications for Rodent Eradications
No full textSouthern Giant Petrels Macronectes giganteus are partial migrants, but the proportion of adult males and females that visit the colony on Gough Island during winter is poorly defined. A better understanding of winter colony attendance is important to predict the possible impact of non-target mortality during restoration efforts involving poison baiting to eradicate introduced mammals. We repeatedly checked the individual identity of all giant petrels attending the largest breeding colony on Gough Island for rings during April–May 2021. Although the maximum number of individually identifiable ringed adults in a single check was 202, overall, 353 ringed adults were recorded, including almost 90% of the individuals that bred in 2020. Males were more likely to be present than females, but the ratio of males to females decreased from the end of April (3.24:1) to the latter half of May (1.25:1). Many birds were paired with their previous breeding partners by the end of May, despite egg laying not starting until late August. Our observations indicate that most adult Southern Giant Petrels are present at their breeding colonies on Gough Island three to four months before breeding, and are thus potentially susceptible to non-target poisoning during mammal eradication operations
The Potential of Ecologists to Enhance our Understanding of Seabird Health
No full textEcologists play a pivotal role in the detection and investigation of population changes in seabirds and by doing so have significant potential to contribute to enhancing knowledge of seabird health. This review highlights key examples in the literature where ecologists have employed diligent passive health surveillance and/or undertaken targeted investigations of seabirds, strategies that have augmented our knowledge of seabird health at individual and population levels. Within the context of One Health, an integrated approach to perceiving and managing health, this review amalgamates veterinarian and ecology disciplines by summarising auxiliary metrics of clinical health that may be considered for incorporation into ongoing fieldwork. A focus on effective surveillance will advance understanding of disease processes impacting seabird health
Breeding Microhabitat Patterns among Sympatric Tropical Larids
No full textThe selection of breeding microhabitat (nesting sites) affects successful reproduction in seabirds, yet the process of nesting-site selection in sympatric tropical species remains poorly known. During the 2021 breeding season, we assessed nesting-site selection among five larid species at three cays of Cuba and quantified explanatory variables. Random forest classification models were used to assess which landscape features among eight variables best explained site selection by each species. Patterns were clear for most species, especially the highly gregarious Roseate Tern Sterna dougallii, Royal Tern Thalasseus maximus, and Sandwich Tern T. sandvicensis. Patterns were consistent among the study cays. Dominant plant species, minimal distance to cay edge, vegetation cover, and substratum at nesting sites were among the more important explanatory variables. Interspecific differences in nesting-site selection may be important for the assemblage of multispecific colonies by reducing aggressive interactions, competition, and breeding failures
Flight Altitudes of Chick-rearing Rhinoceros Auklets \u3ci\u3eCerorhinca monocerata\u3c/i\u3e Measured by GPS Logger
No full textAlcids generally fly at low altitudes (below 5 m) over the sea but may occasionally fly higher in certain areas, which may put them at risk of collision with turbine blades in offshore wind farms. We used GPS loggers to investigate the location and altitude of flying Rhinoceros Auklets Cerorhinca monocerata. They typically flew at low altitudes averaging \u3c 1 m but flew higher (\u3e 20 m) when returning the last 5–10 km to their colony, which was located at an elevation of 120–130 m above sea level. Thus, the region over which Rhinoceros Auklets fly highest may vary, depending on the location and elevation of their breeding sites. Therefore, it is important to consider spatio-temporal flight altitude patterns when assessing their collision risks with offshore wind turbines