Seasonality, biology and threats to Sicalis luteola (Sparrman, 1789) (Aves, Thraupidae) in northeastern Brazil / Sazonalidade, biologia e ameaças ao canário-tipio Sicalis luteola (Sparrman, 1789) (Aves, Thraupidae) no Nordeste do Brasil

Abstract Sicalis luteola occurs from Mexico to South America. In the Northeastern Brazilian region its biology, population dynamics and threats are poorly known. The subspecies S. luteola luteiventris apparently migrates northward during austral winter. The specific aims of this work were: 1) to verify the seasonality of the species; 2) to analyze information on molting and breeding, and 3) to check the main threats to this bird in northeastern Brazil. The highest number of records were in March, April, and May (51.12%) and the lowest in November and December (3%).We found a greater population peak in April in the states of Rio Grande do Norte and Ceará, and in April and May in Pernambuco. In Paraíba there was not an apparent seasonal variation in frequency. We captured 66 individuals, all adults, being 38 males and 28 females. 30% of the captured birds showed contour feathers molt, mainly on the head. A total of 23 individuals had brood patch, all being females. Six nests were found and four contained two to three eggs. We found that the main threat is the illegal trade. Our findings may support conservation plans for this bird in the region.

Resumo Sicalis luteola ocorre do México a América do Sul. No Nordeste do Brasil sua biologia, dinâmica populacional e ameaças são pouco conhecidas. A subespécie S. luteola luteiventris aparentemente migra em direção ao norte durante o inverno austral. Os objetivos específicos deste trabalho foram: 1) verificar a sazonalidade da espécie, 2) obter informações referentes a muda e reprodução, e 3) verificar quais as principais ameaças. Os meses com os maiores números de registros foram março, abril e maio (51,12%), enquanto os meses de novembro e dezembro foram os menos representativos (3%). Foi encontrado um grande pico populacional no mês de abril nos estados do Rio Grande do Norte e Ceará, e em abril e maio em Pernambuco. Na Paraíba não houve uma variação sazonal marcante. Foram capturados 66 indivíduos, todos adultos, sendo 38 machos e 28 fêmeas. 30% das aves capturadas apresentaram muda nas penas de contorno, principalmente na cabeça. Um total de 23 indivíduos apresentou placa de incubação, sendo todas fêmeas. Seis ninhos foram encontrados, quatro deles continham dois ou três ovos. A principal ameaça a espécie no Nordeste é o comércio ilegal de aves silvestres. Este trabalho fornece importantes ferramentas para subsidiar planos de conservação para essa ave na região.

Seasonality, biology and threats to Sicalis luteola (Sparrman, 1789) (Aves, Thraupidae) in northeastern Brazil.

Sicalis luteola occurs from Mexico to South America. In the Northeastern Brazilian region its biology, population dynamics and threats are poorly known. The subspecies S. luteola luteiventris apparently migrates northward during austral winter. The specific aims of this work were: 1) to verify the seasonality of the species; 2) to analyze information on molting and breeding, and 3) to check the main threats to this bird in northeastern Brazil. The highest number of records were in March, April, and May (51.12%) and the lowest in November and December (3%).We found a greater population peak in April in the states of Rio Grande do Norte and Ceará, and in April and May in Pernambuco. In Paraíba there was not an apparent seasonal variation in frequency. We captured 66 individuals, all adults, being 38 males and 28 females. 30% of the captured birds showed contour feathers molt, mainly on the head. A total of 23 individuals had brood patch, all being females. Six nests were found and four contained two to three eggs. We found that the main threat is the illegal trade. Our findings may support conservation plans for this bird in the region.

Effects of barium and cadmium on the population development of the marine nematode Rhabditis (Pellioditis) marina.

Offshore oil and gas drilling often involves the use of fluids containing barium and traces of other heavy metals. These may affect the environment, but information on their toxicity to benthic biota remains scant. Here, we present results of a 10-day bioassay with the marine nematode Rhabditis (Pellioditis) marina at different loads of barium (0-10 ,000 ppm nominal concentrations) and cadmium (0-12 ppm) in the range of concentrations reported from drilling-impacted sediments. Barium did not affect the fitness and population development of R. (P.) marina at concentrations up to 300 ppm, but did cause a decrease in population abundance and an increase in development time from concentrations of 400-2000 ppm onwards. Increased mortality occurred at 4800 ppm Ba. For cadmium, LOEC and EC50 values for total population abundance were 2.95 and 8.82 ppm, respectively. Cd concentrations as low as 2.40 to 2.68 caused a decrease in the abundance of adult nematodes, indicating that assays covering more generations would likely demonstrate yet more pronounced population-level effects. Our results indicate that oil and gas drilling activities may potentially have important implications for the meiobenthos through the toxicity of barium and associated metals like cadmium.