A região onde se localiza o estado do Rio de Janeiro pode ser considerada biogeograficamente importante por abrigar os limites geográficos extremos da Serra do Mar e das florestas dos tabuleiros (ou de baixada), formações bastante significativas para a distribuição de diversas espécies de aves. Nesse estudo, através de extensa consulta bibliográfica, foram encontradas 59 espécies de aves com seu limite sul (40 espécies) ou norte (19 espécies) de distribuição geográfica localizado no estado do Rio de Janeiro. As espécies com limite sul de distribuição no estado têm registros em quase todo o território fluminense, exceto na região do alto vale do rio Paraíba do Sul e na porção mais ocidental da costa fluminense. São espécies predominantemente associadas às florestas de baixada e submontanas e mais da metade está incluída na lista de espécies ameaçadas de extinção do estado. As espécies com limite norte de distribuição no Rio de Janeiro podem ser classificadas em dois grupos básicos quanto ao seu padrão de distribuição em território fluminense. O primeiro grupo é composto por espécies de ambientes florestais montanos e endêmicas da Mata Atlântica, enquanto o segundo grupo é constituído por visitantes ocasionais associados a ambientes aquáticos. A baixa representatividade de espécies ameaçadas entre aquelas com limite norte de distribuição no Rio de Janeiro pode ser explicada pela elevada proporção, entre suas espécies florestais, de representantes de matas serranas, melhor preservadas que as matas de baixada.

The state of Rio de Janeiro is located in a region that can be considered biogeographically important for harboring extreme geographical limits of the Serra do Mar and lowland forests, which are very significant for the distribution of several bird species. In this study, through extensive bibliographic search, 59 bird species were found with their southern (40 species) or northern (19 species) limit of distribution located in the state of Rio de Janeiro. Birds with the southern limit of distribution in Rio de Janeiro have been recorded in almost the entire state, except in the upper valley of the Paraíba do Sul river and the western portion of the coastal zone of the state. This birds species are predominantly associated with lowland and submontane forests and more than half is included in the list of species threatened with extinction in the state. Birds with the northern limit of distribution in the state of Rio de Janeiro can be classified into two basic groups according to their distribution pattern in the region. The first group consists of endemic montane Atlantic forest birds, while the second group consists of occasional visitors associated with aquatic environments. The low proportion of threatened bird species among those with the northern limit of distribution in Rio de Janeiro can be explained by the high proportion of species inhabiting montane forests, which are more protected than the lowland forests.

The replacement and growth of 311 primary feathers of eight captive male rock pigeons, Columba livia Gmelin, 1789 were monitored daily. Feather replacement was recorded in all months, but the primaries 1 to 5 (innermost primaries) were replaced mostly from September to December, whereas the primaries 6 to 10 (outermost primaries) were more frequently replaced from January to August. Each primary was held in plumage from six to fifteen months, but the lifetime of the outer feathers was longer than that of the inner feathers. A new primary emerges two or three days after its predecessor has been dropped, but the primaries replacing the feathers accidentally lost during bird handling emerge only after about eight days. The average growth period of a primary ranged from 21 to 37 days, with the larger and outermost feathers exhibiting a longer growth period. A constant average growth rate of 4 to 5 mm/day was found for all primaries until the last two days of growth, when the growth rate of the feathers became progressively slower. Bilateral symmetry in the primary replacement, when the same feather is replaced simultaneously in both wings, was not significant (22.2%) in the birds monitored in this study.

We studied the altitudinal distribution of 426 bird species in the Serra dos Órgãos, a mountainous region in southeastern Brazil. Thirty-four localities were visited between 1991 and 2009. Our study revealed a decline in bird species richness with elevation, although a smaller number of species was recorded at lower altitudes (below 300 m) possibly due to local extinctions caused by the intense human occupation of the region. A less diverse avifauna was found above 2,000 m, with only one species (Caprimulgus longirostris) recorded exclusively in this altitudinal range. Most endemic species were found between 300 and 1,200 m, but the endemism was more significant at higher altitudes. Nearly half of the birds found above 1,400 m were endemic species. Most of the threatened species from the state of Rio de Janeiro recorded in our study were found below 1,200 m, but no significant difference was found between the proportions of threatened species among different altitudinal ranges. Species of seventeen genera have exhibited some replacement (sometimes with partial overlap) along altitudinal gradients.