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Rodriguez B.,Canary Islands Ornithology and Natural History Group GOHNIC
Wader Study Group Bulletin | Year: 2014

We present the results of monthly censuses of waterbirds in a rocky coastal sector of the city of Arrecife, Lanzarote (Canary Islands). Spatial and temporal changes both in species abundance and composition were studied during two annual cycles. An aggregate total of 8,927 individuals were counted, representing 7 families, 14 genera and 24 species. The most diverse family was Scolopacidae (11 species), and the most abundant was Laridae. All species recorded in this study are considered to be regular migrants through the Canary Islands, except the vagrant Ring-billed Gull Larus delawarensis. Three species also breed regularly in the archipelago: Yellow-legged Gull Larus michahellis, Lesser Black-backed Gull L. fuscus and Kentish Plover Charadrius alexandrinus. Most waterbirds were found at the end of the summer, in winter or in late spring. For some species, spatial differences in occurrence were also observed between the different sectors of the study area. An average of 577 ±176 individuals, belonging to 18 species, spent the winter at this site; this represents 24.9% of the total Canarian wintering population of Ringed Plover Charadrius hiaticula, 21.7% of Grey Plover Pluvialis squatarola, 13.0% of Whimbrel Numenius phaeopus and 12.5% of Bar-tailed Godwit Limosa lapponica. More than 1% of the Spanish wintering population of Ringed Plover and Whimbrel can be found in this area. Due to its proximity to the city, there is high human pressure, so several management measures should be implemented to guarantee the conservation of the ornithological value of this site. © 2014, International Wader Study Group. All rights reserved.

Shafaeipour A.,Yasouj University | Siverio M.,Canary Islands Ornithology and Natural History Group GOHNIC | Siverio F.,Canary Islands Ornithology and Natural History Group GOHNIC
Acta Zoologica Bulgarica | Year: 2016

Both ecology and biology of the peregrine falcon are well known throughout its range. However, excepting the data from the Canary Islands, knowledge on the Barbary falcon natural history is scarce. We studied four Barbary falcon nesting sites in South-western Iran between 2011 and 2014. All eyries were located in cavities of cliffs whose average height was 80 m, on average just over 1 km away from roads and villages. Although sample size was small (n = 7 clutches), the mean clutch size (four eggs) and productivity (3.43 fledglings) per eyrie reached the highest values recorded for peregrine falcons.

Rodriguez B.,Canary Islands Ornithology and Natural History Group GOHNIC | Rodriguez A.,Canary Islands Ornithology and Natural History Group GOHNIC | Rodriguez A.,CSIC - Doñana Biological Station | Siverio M.,Canary Islands Ornithology and Natural History Group GOHNIC | Siverio F.,Canary Islands Ornithology and Natural History Group GOHNIC
Ibis | Year: 2013

We studied nesting habitat selection of the endangered non-migratory Osprey Pandion haliaetus population of the Canary Islands and evaluated the effect of human expansion in recent decades. Compared with randomly selected potential nest-sites, Osprey nests were more frequently found on taller, southwest-facing cliffs, characterized by lower human pressure and closer to Yellow-legged Gull Larus michahellis colonies and Barbary Falcon Falco pelegrinoides breeding sites. Furthermore, changes in some breeding habitat features have been detected in recent decades. According to our predictive models, large areas of suitable habitat are available but unoccupied in the Canaries, and human activities are probably limiting the settlement and dispersion of new pairs. © 2013 British Ornithologists' Union.

Rodriguez B.,Canary Islands Ornithology and Natural History Group GOHNIC | Siverio F.,Canary Islands Ornithology and Natural History Group GOHNIC | Siverio M.,Canary Islands Ornithology and Natural History Group GOHNIC | Barone R.,Canary Islands Ornithology and Natural History Group GOHNIC | And 2 more authors.
Bird Study | Year: 2015

Capsule: Flowers of an invasive plant species are more visited by native birds than flowers of ornithophilous endemic plants. Aims: To describe the bird guild and its behaviour visiting the century plant Agave americana in an insular environment and to determine which factors are affecting visitation rates. Methods: We noted number and species of birds visiting inflorescences on Tenerife, Canary Islands. We used multimodel inference of generalized linear models to analyse the factors affecting the number of visits and the visitor species richness. Results: Eighty-one per cent of inflorescences were visited by eight native bird species. All species fed on nectar and only the Atlantic Canary fed also on pollen. Foraging behaviour varied among species. Visitation rate increased with density and diversity of birds and flower characteristics and decreased through the day. The number of species visiting the inflorescences increased with diversity and density of birds in the surroundings and decreased through the day. Conclusion: The native bird community uses the invasive century plant as a feeding resource at a higher rate than it uses endemic ornithophilous plants. This could have negative effects for the pollination of endemic plants, but positive effects for birds. © 2015 British Trust for Ornithology.

PubMed | CSIC - Doñana Biological Station and Canary Islands Ornithology and Natural History Group GOHNIC
Type: | Journal: Scientific reports | Year: 2015

Light pollution and its consequences on ecosystems are increasing worldwide. Knowledge on the threshold levels of light pollution at which significant ecological impacts emerge and the size of dark refuges to maintain natural nocturnal processes is crucial to mitigate its negative consequences. Seabird fledglings are attracted by artificial lights when they leave their nest at night, causing high mortality. We used GPS data-loggers to track the flights of Corys shearwater Calonectris diomedea fledglings from nest-burrows to ground, and to evaluate the light pollution levels of overflown areas on Tenerife, Canary Islands, using nocturnal, high-resolution satellite imagery. Birds were grounded at locations closer than 16 km from colonies in their maiden flights, and 50% were rescued within a 3 km radius from the nest-site. Most birds left the nests in the first three hours after sunset. Rescue locations showed radiance values greater than colonies, and flight distance was positively related to light pollution levels. Breeding habitat alteration by light pollution was more severe for inland colonies. We provide scientific-based information to manage dark refuges facilitating that fledglings from inland colonies reach the sea successfully. We also offer methodological approaches useful for other critically threatened petrel species grounded by light pollution.

Siverio M.,Canary Islands Ornithology and Natural History Group GOHNIC | Lopez-Suarez P.,Naturalia Capa Verde Lda | Siverio F.,Canary Islands Ornithology and Natural History Group GOHNIC | Rodriguez B.,Canary Islands Ornithology and Natural History Group GOHNIC | And 2 more authors.
African Journal of Ecology | Year: 2014

Between 2004 and 2007, we studied density, habitat features and breeding parameters of the osprey (Pandion haliaetus) population in Boa Vista Island (Cape Verde). A total of 79 nest structures were identified, 37 of which were occupied for at least 1 year during the study period. The osprey population ranged between 14 and 18 pairs, and the mean density and distance between neighbouring occupied nests were 2.58 pairs per 100 km2 and 3089 m, respectively. Occupied nests were found to be significantly further from the coastline and roads than unoccupied nests, but the distances from villages were similar. The majority (81.1%) of the 37 occupied nests were easily accessible to humans. Mean clutch size was 2.59, average productivity was 0.76 young/active nest, and breeding success was 58.8% [Correction added on 13 May 2013, after first online publication: the average productivity was changed from 0.72 to 0.76]. Density in Boa Vista was higher than that in other sedentary island populations in the Western Palearctic, whereas the productivity was the lowest of this region. Clutch size did not vary among Western Palearctic populations, but the differences observed in productivity were likely influenced by local factors that in Boa Vista are attributed to nest depredation by the brown-necked raven (Corvus ruficollis) and to direct human persecution. © 2013 John Wiley & Sons Ltd.

Rodriguez A.,CSIC - Doñana Biological Station | Rodriguez A.,Canary Islands Ornithology And Natural History Group Gohnic | Garcia D.,Islands Biodiversity Research Initiative IRBI | Cardona E.,Islands Biodiversity Research Initiative IRBI | And 2 more authors.
Journal of Ornithology | Year: 2015

Petrels are among the most threatened group of birds. On top of facing predation by introduced mammals and incidental bycatch, these seabirds have to deal with an emerging threat, light pollution, which is increasing globally. Fledglings are disoriented and attracted to artificial lights in their maiden night flights from their nests to the sea. Once grounded, they are exposed to multiple threats leading to high mortality. We report on numbers of three petrel species (Balearic shearwater Puffinus mauretanicus, Scopoli’s shearwater Calonectris diomedea, and European storm-petrel Hydrobates pelagicus) rescued on the Balearic Islands, Mediterranean Sea, in the period 1999–2013. We assessed the proportion of grounded fledglings in the population and colonies impact based on radiance levels measured from a nocturnal satellite image. We also calculated the radius of light pollution impact. At least 304 fledgling birds were found stranded due to attraction to artificial lights, fatally affecting 8.5 % of them. The proportion of grounded fledglings ranged between 0.13 and 0.56 % of the fledglings produced annually. The body mass of Balearic and Scopoli’s shearwater fledglings decreased with rescue date. Light-induced mortality increased during the fledging period for Scopoli’s shearwaters. Birds were rescued at a mean distance of 4833 m from the nearest colony, and between 30 and 47 % of colonies were exposed to light-polluted areas. Although impact seems to be low for all species, urban development and, consequently, the increase in light pollution in the proximity of the colonies should be taken into account to reduce as much as possible this emerging source of mortality. © Dt. Ornithologen-Gesellschaft e.V. 2015.

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