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Santa Cruz de Tenerife, Spain

Siverio M.,Constitucion 17 3 | Rodriguez B.,La Malecita s n | Rodriguez A.,CSIC - Donana Biological Station | Siverio F.,Los Barros 21
Wildlife Biology | Year: 2011

We studied the diet of the osprey Pandion haliaetus in the Canary Islands during 1997-2008 using prey remains under perches and nests, and direct observations. We collected data both in breeding territories and in non-breeding areas. We counted a minimum of 307 fish individuals as prey remains (both during breeding and non-breeding seasons), and identified another 78 during 433 hours of field observations. According to our results, ospreys consumed at least 15 taxa belonging to 12 families. We found slight differences in the spatial (both intra and inter insular) and temporal diet composition. During the breeding season, the main prey species were flying fishes (belonging to the family Exocoetidae) and needlefishes (belonging to the family Belonidae) according to the two employed methods (i.e. prey remains and direct observations). In the non-breeding period, the diet was composed primarily of non-autochthones freshwater fishes such as common carp Cyprinus carpio and goldfish Carassius auratus. In general, the diet diversity was similar to the diversity reported in other breeding populations of subtropical areas, and being less diverse than those of tropical areas. More precise studies evaluating the effect of fish availability in marine reserves, overfishing areas or fish farms on the demographic parameters are necessary for the management and conservation of threatened Canarian ospreys. © 2011 Wildlife Biology, NKV. Source


Rodriguez B.,La Malecita s n | Rodriguez A.,CSIC - Donana Biological Station | Siverio F.,Los Barros 21 | Siverio M.,Constitucin 19 3
Journal of Raptor Research | Year: 2010

We studied the causes of raptor admissions to the only wildlife rehabilitation center on the largest island of the Canarian Archipelago (Tenerife) over ten years (1998-2007). A total of 2611 birds of prey, belonging to nine falconiform diurnal raptor and four strigiform species, were admitted. The Eurasian Kestrel (Falco tinnunculus) and the Long-eared Owl (Asio otus) were the species most commonly admitted and jointly made up 85.6 of admissions. The most frequent causes of admission to the wildlife rehabilitation center were collisions (with cars, high-voltage electric transmission towers, etc.; 42.2), starvation (5.1) and entanglement in glue traps intended for rodents (4.7). Poisoning and shooting were recorded for 2.4 and 1.5 of the birds admitted, respectively. Only collisions increased during the study period. A total of 1010 birds (44.4 of the total) were released to the wild following rehabilitation. We recommend more financial support for rehabilitation centers to develop detailed analytical diagnoses and rehabilitation services. © 2010 The Raptor Research Foundation, Inc. Source


Siverio M.,Constitution 17 3 | Siverio F.,Los Barros 21 | Rodriguez B.,La Malecita s n | Rodriguez A.,CSIC - Donana Biological Station
Ostrich | Year: 2011

Territory spacing and breeding rates of an insular population (north-western Tenerife, Canary Islands) of Barbary Falcon Falco peregrinus pelegrinoides was studied from 1993 to 2008. The population increased constantly since the outset, from two pairs in 1993 to 12 in 2008. Mean density was 5.48 pairs per 100 km 2 and mean nearest neighbour distance was 3 119 m. The regularity of the spatial distribution pattern of the nests, observed in most years, may be maintained in the future despite the expectation that new pairs may occupy still-vacant territories. Considering the 79 breeding attempts analysed, the mean number of fledged young per territorial pair was 1.92, per laying pair was 2.0 (n = 76), and per successful pair was 2.24 (n = 68). No significant variations were observed between the annual mean number of fledged young per laying pair, nor between the number of fledged young of pairs according to density in a 5 km radius. All fledglings (brood size one to four) left the nest in the month of May. In order to avoid affecting breeding success, sporting activities practised in the breeding areas must be correctly managed by the appropriate authorities. © 2011 Copyright Taylor and Francis Group, LLC. Source


Rodriguez B.,La Malecita s n | Siverio F.,Los Barros 21 | Rodriguez A.,CSIC - Donana Biological Station | Siverio M.,Constitucion 19 3 | And 2 more authors.
Bird Study | Year: 2010

Capsule: Taller and sheltered cliffs located in rugged areas are selected for breeding and only some life history traits fit the predictions of the so-called 'insular' syndrome. Aims: To analyse the density and nesting habitat preferences of Buzzards on the island of Tenerife, and describe the life history traits of this population. Methods: Density was studied by intensive field searching for all established pairs in a well-defined area. Habitat features of breeding territories were compared with randomly selected sites using univariate and multivariate analysis (GLM). Breeding biology was described based upon a total of 57 breeding attempts. Results: Density was positively correlated with estimated surface of forested areas. The best model explaining characteristics of territory used for nesting reflected land ruggedness, nest shelter and distance to the nearest Barbary Falcon breeding site. Mean clutch size was 2.60 ± 0.82, productivity was 1.68 ± 0.97 and the percentage of successful pairs was 84.2%. Conclusions: Buzzards mainly use cliffs to nest, especially taller and sheltered ones, located in rugged areas and in sympatry with Barbary Falcons. Characteristics of breeding territory did not predict productivity. All reproductive rates were similar to those reported for some continental populations except nesting success, which was higher. © 2010 British Trust for Ornithology. Source


Rodriguez B.,La Malecita s n | Siverio F.,Los Barros 21 | Siverio M.,Constitucion 17 3 | Rodriguez A.,CSIC - Donana Biological Station
Bulletin of the British Ornithologists' Club | Year: 2011

The taxonomie status of the Barbary Falcon has been controversial for many years, it being variously considered a subspecies of Peregrine Falcon (Falco peregrinus pelegrinoides) or treated as a full species (F. pelegrinoides). Although morphological and molecular studies are still scarce, they suggest that subspecific status is more appropriate. Other subspecies of Peregrine, such as F. p. brookei, exhibit some plumage characteristics similar to Barbary Falcon. We quantitatively describe coloration patterns of Barbary Falcons breeding in the Canary Islands, based on photographs of wild birds, injured or dead individuals brought to rehabilitation centres, and specimens deposited in museum collections. We tested sexual differences, and compared Canaries falcons with a sample of specimens labelled as F. p. brookei. Males of both taxa are usually paler and possess less barred underparts than females. The majority (>60%) of birds in the Canaries have a Barbary Falcon-like appearance, but there is much overlap with F. p. brookei. This variation in coloration could be natural or relate to escaped falconry birds, meaning that molecular studies are needed to clarify the identity of wild falcons on the Canary Islands. © British Ornithologists' Club 2011. Source

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