No abstract

The Bl ue-winged Ma caw (Primolius maracana) i s currently cl assified as near threatened, and studies have shown a decrease in its population size in the southern and northeastern limits of its distribution over the last 50 years . In this study we assess the current s ta tus of a l ocal population in Northeastern Brazil and propose a conservation action plan. We vi sited 56 l ocalities i n the Serra de Sa ntana mountain range to search for direct a nd indirect evidence of the species' presence or a bsence. We recorded P. maracana a t 27 l oca tions, restricted to two ma in a reas (Pi menteira-Rio Fundo and Serra da Arara-Serra de São João). There was a positive correl ation between the a ge of reported s ightings a nd flock s ize (rs = 0.3; p = 0.02), s uggesting a decreasing population size over the l ast several decades. P. maracana breeds during the rainy s eason (December-May) i n this region, and nests were recorded in mul ungus, cumarus and craibeiras trees. Based on soil use cri teria, plant cover, fauna use, and i ndicator s pecies, hillside habitats ha ve been l ess i mpacted than flat a reas i n the upper highlands (mean conservation for high flat a rea = 5.8 ± 2.0 a nd for hill side a reas = 8.0 ± 2.1; t53 = 3.96, p < 0.01). The da ta indicate that Pi menteira-Rio Fundo a nd Serra da Ara ra-Serra de São João are pri ori ty areas for local conservation actions and that P. maracana i s adapted to the hyper-xerophilous caatinga, and not restricted to the peri pheral formations of this environment, a s previ ously s uggested. We propose measures to control the population decl ine, establish conserva tion units, i mplement tourism programs, a dopt responsible environmental pra ctices, a nd increase public a wareness and mobilization. Such a ctions must be i mplemented by l ocal government a nd ci vil s ociety entities, university res ea rchers , a nd l a ndowners i n order to be effecti ve.Keywords : Ps i tta ci da e, ca a ti nga , nes t poa chi ng, Serra de Sa nta na . ResumoA ma ra canã-verdadeira (Primolius maracana) é a tua lmente considerada quase a meaçada e es tudos i ndicam di minuição no ta ma nho populacional a o l ongo dos últimos 50 a nos nos l imites s ul e nordeste da s ua distribuição. Neste tra balho, avaliamos o es tado a tual de uma população no Nordeste do Bra sil e propomos um plano de a ção para a s ua conserva ção. Visitamos 56 l oca lidades na Serra de Santana em busca de evidências diretas e i ndiretas da presença ou a usência da espécie. Registramos P. maracana em 27 l ocalidades, restritas a duas á reas principais (Pimenteira-Rio Fundo e Serra da Ara ra-Serra de São João). Houve uma correlação positiva entre a idade das observações relatadas e o tamanho do bando (rs = 0,3; p = 0,02), o que sugere uma di minuição populacional a o l ongo das últimas décadas. Observamos a ocorrência de reprodução durante a estação chuvosa com ni nhos s endo construídos em mulungus, cumarus e craibeiras. Com ba se em cri térios de uso do s olo, cobertura vegetal, uso da fa una e espécies ind...

Understanding latitudinal variation in avian life-history traits has been a focus of many demographic studies around the world. However, we still know little about annual or intra-annual demographic variation within tropical regions or about how factors such as breeding season and precipitation influence demographic rates. In this study, we estimated intra-annual apparent survival of the White-lined Tanager (Tachyphonus rufus) using capture-mark-recapture data from northeastern Brazil. We tested whether survival varied seasonally (breeding vs. non-breeding), with rainfall, by age and residence status in our study area. Intra-annual apparent survival was correlated with the reproductive cycle, being lower during the breeding (0.65 ± 0.16 SE) vs. the non-breeding season (0.97 ± 0.05 SE). The annual apparent survival (~0.6) was relatively low for a tropical species. In both years, we observed highest abundance in spring (November, 3.1–3.7 birds/ha) and lowest abundance in autumn-winter periods (May-August, 1.1–1.4 bird/ha). The low survival during the breeding season probably reflects the trade-off between survival and reproduction and the cost of reproduction. Our findings represent an advance in the understanding of the demography of tropical birds because we did not find a predicted high annual apparent survival, and we elucidated some aspects of intra-annual variation in survival. Further exploration of latitudinal variation in demographic traits, especially in diverse, but poorly known habitats is needed to fully vet and develop life history theories.

No abstract

No abstract