Influence of the nycthemeral cycle on the roosting behaviour of the Orange-winged Amazon

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Environmental stimuli exert important effects on the expression of the endogenous rhythms. Daily movements of groups of parrots in response to the light/dark cycle have been studied by several researchers. However, the factors modifying the intrinsic rhythmicity of this behaviour remain little known. This study describes how the nychthemeral/circadian periodicity of roost daily movements of the Orange-winged Amazon Amazona amazonica is modified by weather factors. Numbers of parrots arriving or leaving the roosting site llha dos Papagaios were determined on a minute by minute basis. More parrots have significantly arrived at the roost after sunset than before, while more parrots have significantly left the roost before sunrise than after. The peak exodus of parrots occurred at 23 +/- 5.24 minutes before sunrise, when the average light intensity was 1 lux. The peak influx of parrots occurred at 6 +/- 6.1 minutes after sunset, when the average light intensity was 50 lux. By altering ambient light intensity, weather conditions have significantly influenced the arrival and departure times, with parrots leaving later and arriving earlier when conditions were overcast at the roost site.842509515PARATURCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Using Shannon entropy on measuring the individual variability in the Rufous-bellied thrush Turdus rufiventris vocal communication

We applied the information theory concepts to notes repertoire characteristics combined with temporal parameters of the Rufous-bellied thrush Turdus rufiventris song, using this particular case to test a new method of analysing quantitatively complex animal communication systems. Like most Turdus thrushes, Rufous-bellied thrushes are remarkable for their long, varied and melodious songs. For the analysis of the species repertoire, we used recordings of 44 individuals from 24 localities covering its full geographical range. We measured the repertoire size, note duration and rhythm (frequency of note utterance), and combined these parameters with the Shannon entropy values calculated for each individual. Although individuals maintain species-specific recognition capacity, we find a large variation between their song parameters and show that the information theory can be useful to analyse large and varied animal vocal repertoires. We are introducing two new parameters, temporal average entropy (E-t) and utterance frequency average entropy (E-f), for measuring such communication systems. (C) 2000 Academic Press.2071576

Vocal Repertoire of the Yellow-Faced Parrot (Alipiopsitta xanthops)

We describe the vocal repertoire of the Yellow-faced Parrot (Alipiopsitta xanthops) from recorded vocalizations and also flock sizes in Brasilia (Brazil) during 2006. Vocal communication signals are both long-range and short-range sounds. We describe seven call types: flight call (long-range), long-range alarm call, congregation call (long-range), two agonistic calls (long-range/short-range), sentinel call (shortrange), and a short-range alarm call. The flight call is equivalent to the functional song and contains the species-specific recognition code. Flight calls may also be uttered when perched and, when in quick series, function as long-range alarm calls. Long-range alarm calls become a high intensity congregation signal when several individuals overlap and, despite degradation and attenuation, may contain the species-specific code over distances of 800 m. The average (+/- SD) feeding flock size was 7.7 +/- 8.2 individuals (n = 116) while the roosting flock size was 79.1 +/- 10.5 individuals (n = 7). Short-range calls maintain communication while minimizing detection. High intensity vocalizations allow long-range communication, improving feeding efficiency through use of large areas and stimulating late afternoon roost congregations. Low intensity vocalizations maintain communications without providing the position of the parrot. Received 22 June 2010. Accepted 9 February 2011.1233603608Faepex (Unicamp)Katherine McLennan Brown Charitable Foundatio

Species richness and relative abundance of birds in natural and anthropogenic fragments of Brazilian Atlantic forest

Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants), the other consisted of a set of naturally occurring forest fragments (forest patches). Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment). However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.<br>Comunidades de aves foram estudadas em duas regiões fragmentadas de floresta Atlântica no Estado do Paraná, sul do Brasil; uma região é constituída de fragmentos florestais que foram criados como resultado de atividades humanas (remanescentes florestais) e a outra de um conjunto de fragmentos florestais naturais (manchas de floresta). Usando dados quantitativos (o método de contagens pontuais) previamente obtidos em 3 manchas de floresta e em 3 remanescentes florestais durante um ano, a riqueza e a abundância relativa de aves foram comparadas naqueles habitats considerando as espécies pelos seus hábitos alimentares. Insetívoros, omnívoros e frugívoros apresentaram tendências gerais similares em ambos os habitats, diminuindo o número de espécies com o tamanho menor e o isolamento maior do fragmento florestal. Entretanto essas tendências foram diferentes considerando dados da abundância relativa: os insetívoros de tronco mostraram o maior valor na menor mancha enquanto que a menor abundância relativa foi obtida no menor remanescente. Na paisagem naturalmente fragmentada, o tempo permitiu que a perda de algumas espécies de insetívoros de tronco fosse compensada pelo aumento na abundância das outras. Em contraste, os remanescentes representam essencialmente ilhas recém formadas que ainda não atingiram o equilíbrio e onde futuras perdas de espécies as fariam similares às manchas