Padrões de muda de penas e reprodução em aves florestais no parque estadual Carlos Botelho, estado de São Paulo
Medolago, Cesar Augusto Bronzatto
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This study aims to describe the pattern of moulting and reproduction, evaluating their temporal overlap in an assembly of birds in the Atlantic Forest. These events tend to have little or no overlap due to high energy costs involved, but some authors argue that in tropical regions, they may present a significant overlap, since the period of resource abundance would be longer in this region. We also noticed the amount of fat deposition, because this phenomenon is important in thermo-isolation, energy reserves and development of egg-yolk. It is possible that environmental variables act directly on the breeding period of birds, which in turn influences the moult, it is expected that this starts right after the breeding season, when the young leave their nests. There taking into account that ecological groups, such as trophic guilds, may show different patterns for the periods, since the supply of food resources varies temporally in a different way for each group. It were determined five areas in Carlos Botelho State Park , state of São Paulo ( 24 ° 06 ' 55'' , 24 º 14' 41'' S , 47 º 47 ' 18'' and 48 º 07' 17'' W), which were sampled from June 2012 to May 2013, once a month, during the daytime, using lines with ten mist nets (3x12m , mesh 36mm ). Each bird was received a numbered metal band provided by CEMAVE. With a total of 4650 mistnet-hours were held 700 catches and 130 were recaptures, totaling 54 species, all residents. The period of moult of flight concentrated from November to April, with its peak in February. Incubation began in August, with the highest percentage of individuals presenting brood patch occurred in the months of November and December, declining from February, when the percentage of young individuals in the assemblage began to increase. The highest percentage of individuals with fat deposition occurred in the months comprising the coldest period of the year. The incubation period began at the end of the dry season, increasing with the photoperiod, reaching its peak in November. Thus, the young individuals leave their nests in the beginning of the hot season, when the supply of food resources would be higher, which would support the new individuals in the community as well as the start of moult period. There was little difference in the incubation period and fat deposition between trophic guilds and no difference in their moult period. The overlap between the events found in this study was 7 %, which confirms the tendency to avoid the overlap of these cycles, even in tropical regions, such as the Atlantic Forest, due to high energy costs involved.