2 results
Validation of the Basic Psychological Needs in Exercise Scale in a Portuguese Sample
- João Miguel Raimundo Peres Moutão, Luis Filipe Cid Serra, José Augusto Marinho Alves, José Carlos Leitão, Symeon P. Vlachopoulos
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- Journal:
- The Spanish Journal of Psychology / Volume 15 / Issue 1 / March 2012
- Published online by Cambridge University Press:
- 10 January 2013, pp. 399-409
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In line with self-determination theory (SDT: Deci & Ryan, 1985, 2002) the satisfaction of the basic psychological needs for autonomy, competence, and relatedness has been identified as an important predictor of behavior and optimal functioning in various contexts including exercise. The lack of a valid and reliable instrument to assess the extent to which these needs are fulfilled among Portuguese exercise participants limits the evaluation of causal links proposed by SDT in the Portuguese exercise context. The aim of the present study was to translate into Portuguese and validate the Basic Psychological Needs in Exercise Scale (BPNES: Vlachopoulos & Michailidou, 2006). Using data from 522 exercise participants the findings provided evidence of strong internal consistency of the translated BPNES subscales while confirmatory factor analysis supported a good fit of the correlated 3-factor model to the data. The present findings support the use of the translated into Portuguese BPNES to assess the extent of basic psychological need fulfilment among Portuguese exercise participants.
Resource seasonality and the structure of mixed species bird flocks in a coastal Atlantic forest of southeastern Brazil
- Pedro Ferreira Develey, Carlos Augusto Peres
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- Journal:
- Journal of Tropical Ecology / Volume 16 / Issue 1 / January 2000
- Published online by Cambridge University Press:
- 01 January 2000, pp. 33-53
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ABSTRACT. Multi-species bird flocks in tropical forests are maintained throughout the annual cycle despite seasonal differences in resource availability, and the reproductive schedules and ecological requirements of individual species. This study examines the relationship between seasonal variation in flock structure and the availability of fruits and arthropods over a 12-mo period at a coastal Atlantic forest within the Juréia–Itatins Ecological Station, São Paulo, Brazil. Fruit abundance was estimated by a phenological survey of both canopy and understory trees, whereas arthropod abundance was quantified monthly on the basis of a nocturnal visual census technique. The seasonal variation in flock structure and composition was affected by both the breeding seasons of different core and attendant species, and the availability of food resources. The number of bird species attending flocks was greater during the dry season, declining thereafter during the breeding season. Understorey fruit availability exhibited a marked seasonal fluctuation with the lowest levels between the late dry and early wet season. Seasonal variation in canopy fruit availability, on the other hand, was far less demarcated than that of understorey plants. Arthropod abundance was greatest during the wettest months of the year, which apparently determined the timing of the main breeding season. Bird species richness attending flocks was, therefore, significantly correlated with the availability of understorey arthropods, but not with that of either understorey and canopy fruits. Arthropod abundance thus appears to affect profoundly the reproductive schedules of the understorey avifauna, which in turn influences the seasonal variation of flock size and composition.
RESUMO. Nas florestas tropicais a formação de bandos mistos de aves ocorre ao longo de todo o ano, porém existem variações sazonais na composição e estrutura destes bandos. Tais variações estão ligadas ao período reprodutivo das aves, à disponibilidade de recursos alimentares e a requisitos ecológicos inerentes a cada espécie. Este trabalho analisou a dinâmica sazonal destes bandos durante um ano, relacionando estes dados com a disponibilidade de recursos alimentares em uma área de Mata Atlântica na Estação Ecológica Juréia–Itatins. A disponibilidade de frutos foi estimada através de acompanhamento fenológico de espécies de dossel e de sub-bosque, enquanto a abundância de artrópodos foi feita através de censos noturnos mensais. A variação sazonal na estrutura e composição dos bandos foi afetada pela atividade reprodutiva das espécies mais freqüentes e pela disponibilidade de recursos alimentares. Nos meses mais secos ocorreu um aumento do número de espécies nos bandos, ocorrendo um declínio durante o período de reprodução das aves. A quantidade de frutos de sub-bosque apresentou maior escassez entre o final do período seco e o início do período chuvoso, variando de maneira muito mais drástica quando comparada aos frutos de dossel. A abundância de artrópodos foi maior durante os meses mais chuvosos do ano, coincidindo com a época reprodutiva das aves. A riqueza das espécies de aves associadas a bandos mistos foi significativamente correlacionada com a abundância de artrópodos, mas não com a disponibilidade de frutos de dossel e sub-bosque. A abundância de artrópodos deve ter influenciado o início das atividades reprodutivas das aves, que por sua vez, causou as variações sazonais na composição e tamanho dos bandos.