Temporal variation in allele frequency of microsatellites of Spix´s Macaw (Cyanopsitta spixii) in captivity

The Spix´s macaw (Cyanopsitta spixii, Psittaciformes) is endemic to Brazil and is extinct in the wild due to habitat degradation and illegal trade. There are records of the first captures for captive breeding during the 1970s. Currently, there are about 130 individuals in three reproduction centers coordinated by the Brazilian government for future reintroduction. The objective of the present study was to estimate the allelic diversity of the species during this period in captivity. Based on data from twelve polymorphic microsatellites (nine specific) and the studbook (birth and death dates) we observed that allele frequency varied over the decades in captivity. At the beginning, when wild founders were introduced in the captive population, the number of alleles increased. However, in recent decades alleles were lost because some founders died without leaving descendants. These results suggest that deleterious effect of drift may be increasing and this may also be affecting genes of adaptive importance. As all individuals are closely related and there are few effective founders and no wild individuals to improve the genetic diversity of the captive population, it is imperative to maximize the retention of genetic diversity by the reproduction of all individuals, mainly those least genetically represented in the population.