Gender determination in Swainson´s hawk (buteo swainsoni) using molecular procedures and discriminant function analysis

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The bare head of the Northern bald ibis (Geronticus eremita) fulfills a thermoregulatory function

[Background] Dark pigments provide animals with several adaptive benefits such as protection against ultraviolet (UV) radiation and mechanical abrasion, but may also impose several constraints like a high absorbance of solar radiation. Endotherms, with relatively constant and high body temperatures, may be especially prone to thermoregulatory limitations if dark coloured and inhabiting hot environments. It is therefore expected that adaptations have specifically evolved because of these limitations. Bare, highly vascularised head skin may have evolved in birds with dark plumage from hot geographical regions because of favouring heat dissipation. Using the Northern bald ibis (Geronticus eremita) as a model species, we measured the surface temperature (Tsurf) of the head, the bill and the black feathered body of 11 birds along ambient temperatures (Ta) ranging from 21 to 42.5 °C employing thermal imaging.[Results] While Tsurf of the bill and the feathered body was only slightly above Ta, head Tsurf was considerably higher, by up to 12 °C. Estimated values of heat loss followed similar variations. We also found that the red colour intensity of the head of ibises increased with head Tsurf, suggesting that birds are capable of controlling blood flow and the thermoregulatory function of the head.[Conclusions] These findings are consistent with the hypothesis that bare skin has evolved in dark pigmented birds inhabiting hot environments because of their ability to dissipate heat.IG was supported by a Ramón y Cajal Fellowship (RYC-2012-10237) from the Spanish Ministry of Economy and Competitiveness (MINECO).Peer reviewe

Personal reflections on Gary Bortolotti's links with Spain

Letter.Peer reviewe

Genetic studies facilitated management decisions on the invasion of the ruddy duck in Europe

The ruddy duck (Oxyura jamaicensis), a stifftail native to the Americas, was introduced to the UK in the 1950s and has since been recorded in 22 western Palearctic countries. By 2000, the UK popu- lation peaked at nearly 6,000 individuals. In 1991, hybridisation with the native and globally threatened (IUCN Endangered) white-headed duck (Oxyura leu- cocephala), a stifftail restricted to the Mediterranean and Asia, was recorded in Spain and culling of hybrids and ruddy ducks began. Here we report on a series of genetic studies that have enabled and supported management decisions to the benefit of the white- headed duck. First, genetic data confirmed that these are two distinct species, each of which is more closely related to other stifftail species. Second, molecular studies indicated that ruddy ducks in Spain, Iceland and elsewhere in Europe were of captive origin and not descendants from vagrants from their native North America. Third, genetic methods were used to distin- guish among different hybrid generations in Spain and detected no ruddy duck introgression in birds identi- fied morphologically as white-headed ducks. Collec- tively, these results supported management decisions to eradicate ruddy ducks from Europe. Subsequently, a control programme reduced the UK population by over 95 % by 2010, and the arrival of ruddy ducks to Spain decreased from 21 birds in 2003 to two sightings in 2010–2011. However, increased efforts to control small ruddy duck populations elsewhere in Europe and Morocco are still required to ensure conservation of the white-headed duck. This case of invasion by hybridization demonstrates that successful control is feasible given early detection followed by a rapid response plan; it also shows the contribution of research to management and that to guarantee the conservation of an endangered native species action may be required in countries outside its distribution range.Peer reviewe

Efectos de radio-emisores de cola en cernícalos primilla adultos

[ENG]The behavior,b reeding successa nd survivalo f radio-taggeda nd non-radio-tagged (control) Lesser Kestrels (Falco naumanni) in southern Spain in 1989-1990 were compared. The copulation period, copulation rates and prey delivery rates to both mates and nestlings did not differ significantlyb etween radio-taggeda nd control individuals.I n addition, there were no differences in annual survival rates or breeding success between radio-tagged and control birds.[ESP]-Sec ompararon aspectosd e comportamiento,6 xito reproductor y supervivencia entre cernlcalosp rimillas (Falco naumanni) portadores de radiotransmisorese n la cola y otros marcados finicamente con anillas (controles) en el sur de Espafia en 1989-1990. E1 periodo de c6pulas, la frecuencia de las mismas, asi como las tasas de cebas de pareja y a los pollos no se diferenci6 significativamentee ntre los individuosp ortadoresd e radiotransmisoresy los controles.T ampoco se detectaron diferenciase n las tasasd e supervivenciaa nual y 6xito reproductivo entre los dos grupos comparados.Peer reviewe

Porphyrins produce uniquely ephemeral animal colouration: a possible signal of virginity

Colours that underlie animal pigmentation can either be permanent or renewable in the short term. Here we describe the discovery of a conspicuous salmon-pink colouration in the base of bustard feathers and down that has never been reported because of its extraordinarily brief expression. HPLC analyses indicated that its constituent pigments are coproporphyrin III and protoporphyrin IX, which are prone to photodegradation. Accordingly, an experimental exposure of feathers of three bustard species to sunlight produced a rapid disappearance of the salmon-pink colouration, together with a marked decrease in reflectance around 670 nm coinciding with the absorption of porphyrin photoproducts. The disappearance of the salmon-pink colouration can occur in a period as short as 12 min, likely making it the most ephemeral colour phenotype in any extant bird. The presence of this colour trait in males performing sexual displays may thus indicate to females a high probability that the males were performing their first displays and would engage in their first copulations in the breeding season. In dominant males, sperm quality decreases over successive copulations, thus porphyrin-based colouration may evolve as a signal of virginity that allows females to maximize their fitness in lek mating systemsPeer reviewe

– Point or transect counts as alternatives to censusing steppe birds in Patagonia

[ENG]– Point or transect counts as alternatives to censusing steppe birds in Patagonia. – Success- ful evaluation of bird populations in Patagonia depends on the appropriate choice and use of survey meth- ods. Our objective was to evaluate three bird survey methodologies: point counts, foot transects, and road transects, for bird distribution evaluation (particularly birds of prey) in shrub-steppe landscapes of south- ern Patagonia. Field work was undertaken during the spring of 1998 and 1999 in Santa Cruz province, southern Argentine Patagonia. We performed 15-min point counts, 30-min foot transects and vehicle road transects at 40–60 km/h. During the 1998 spring, we contacted 65 raptors representing 8 species during 125 point counts. We also contacted 252 raptors (10 species) during 3537 km of road transects. Road transects produced 22 times more contacts per unit effort than did point counts. During spring 1999, we contacted 2065 individuals, representing 54 species of birds. Foot and road transects provided significantly more contacts than point counts, both for raptors and all species of birds. Although more raptors were contacted by road census, foot transects performed well for all other species of birds. The detection and identification of birds by foot transects were less affected by prevailing wind conditions, and contact rate was higher than that of point counts on a time effort basis.[ESP]– La detección y recuento de aves en Patagonia, como en cualquier otra región del mundo, será óptima dependiendo del ajuste entre las condiciones físicas y ambientales del lugar con el método de recuento elegido. Nuestro objetivo fue valorar tres alternativas metodológicas de recuento de aves: puntos fijos, transectos a pié y en coche, para obtener información sobre la distribución de aves (presencia-ausen- cia), en particular rapaces, en la estepa patagónica. El estudio se llevó a cabo en la provincia de Santa Cruz (Argentina), durante las primaveras de 1998 y 1999. Se realizaron censos en puntos fijos de 15 min de duración, transectos a pie de 30 min de duración, y recorridos en coche a velocidades nunca superiores a 60 km/h. Durante la primavera de 1998, se contactaron 65 individuos de aves rapaces (8 especies) en 125 puntos fijos y 252 rapaces (10 especies) en 3537 km de transecto en vehículo. Los censos en carretera pro- dujeron hasta 22 veces mas contactos por unidad de esfuerzo que los censos en puntos fijos. Durante 1999 se contactaron 2065 aves, pertenecientes a 54 especies. Se contactaron significativamente mas aves en general, y rapaces en particular, durante los transectos a pie y en coche que durante los puntos fijos. Los recorridos en coche resultaron con mas contactos de rapaces por unidad de esfuerzo. Sin embargo, si se tiene interés por incluir en los recuentos a otras aves menos conspicuas, los recorridos a pié resultaríanPeer reviewe

Generation of raptor diversity in Europe: Linking speciation with climate changes and the ability to migrate

Europe holds a rich community of diurnal birds of prey, and the highest proportion of transcontinental migratory raptorial species of any landmass. This study will test the hypotheses that the high diversification of the raptor assemblage in Europe is a recent event, that closely related species sharing the same trophic niches can only coexist in sympatry during the breeding period, when food availability is higher, and finally that migration is a function of size, with the smaller species in every trophic group moving further. A consensus molecular phylogeny for the 38 regular breeding species of raptors in Europe was obtained from BirdTree (www.birdtree.org). For the same species, a trophic niche cluster dendrogram was constructed. Size and migratory strategy were introduced in the resulting phylogeny, where trophic groups were also identified. Multispecific trophic groups tended to be composed of reciprocal sister species of different sizes, while monospecific groups (n = 3) were composed of highly specialized species. Many speciation events took place recently, during the glacial cycles of the Quaternary, and size divergence among competing species may be due to character displacement. Nowadays, the smaller species in every trophic group migrate to sub-Saharan Africa. This investigation illustrates how the rich assemblage of diurnal birds of prey in Europe, more diverse and more migratory than, for instance, the North American assemblage at equivalent latitudes, has emerged recently due to the multiplication of look-alike species with similar trophic ecologies, possibly in climate refugia during cold period

Breeding density and brood size of rough-legged hawks in Northh-western Quebec

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