|
|
|
|
|
| Almeida,Paulo J. A. L.; Vieira,Marcus V.; Kajin,Maja; Forero-Medina,German; Cerqueira,Rui. |
| A fundamental step in the emerging Movement Theory is the description of movement paths, and the identification of its proximate and ultimate drivers. The most common characteristic used to describe and analyze movement paths is its tortuosity, and a variety of tortuosity indices have been proposed in different theoretical or empirical contexts. Here we review conceptual differences between five movement indices and their bias due to locations errors, sample sizes and scale-dependency: Intensity of Habitat use (IU), Fractal D, MSD (Mean Squared Distance), Straightness (ST), and Sinuosity (SI). Intensity of Habitat use and ST are straightforward to compute, but ST is actually an unbiased estimator of oriented search and ballistic movements. Fractal D is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diffusion; Fractal dimension; Oriented search; Random walk; Search behaviour. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000500002 |
| |
|
|
| Forero-Medina,German; Vieira,Marcus Vinícius; Grelle,Carlos Eduardo de Viveiros; Almeida,Paulo Jose. |
| Because extinctions are not random across taxa, it is important for conservation biologists to identify the traits that make some species more vulnerable. Factors associated with vulnerability include small geographical ranges, low densities, high trophic level, "slow" life histories, body size, and tolerance to altered habitats. In this study we examined the relationship of body size, reproductive output, longevity, and extinction risk for carnivores occurring in Brazil. We used generalized linear models analyses on phylogenetically independent contrasts to test the effect of body size alone, and the combined effect of body size, litter size and longevity on extinction risk. Body size appeared in the two best models according to the selection criteria... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carnivores; Independent contrasts; Longevity; Reproductive output; South America; Vulnerability to extinction. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032009000200004 |
| |
|
|
|
