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Topic:
small man-made pinewood islands only capture widespread
and habitat generalist avian species with increasing population trends, not
contributing to enhance truly woodland species.
* We
evaluate the effect of three categories of factors as predictors of the
interspecific variation in bird habitat occupancy of fragmented
afforestations funded by the Common Agrarian Policy within a landscape
dominated by Mediterranean agricultural habitats.
* Many species
with marked habitat preferences for woodland habitats were very scarce or
were never recorded in this novel habitat. Interspecific variability in
occurrence was mainly explained by regional distribution patterns: occurrence
was significantly and positively associated with the proportion of occupied
10x10 UTM km squares around the study area, regional habitat breadth, and
population trend of species in the period 1998-2011. Read more.
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Topic:
thermoregulation benefits of foraging patch
selection are discernible in small endotherms.
* In
winter, foraging activity is intended to optimize food search while
minimizing both thermoregulation costs and predation risk.
* Our
results support the influence of both thermoregulation benefits and predation
costs on feeding patch choice. The influence of distance to refuge (negative
relationship) was nearly three times higher than that of temperature
(positive relationship) in determining total foraging time spent at a patch.
Light intensity had a negligible and no significant effect.
* This
pattern was generalizable among species and individuals within species, and
highlights the preponderance of latent predation risk over thermoregulation
benefits on foraging decisions of birds wintering in temperate Mediterranean
forests Read more […
y más]
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Topic: species richness can decrease with altitude, but not with
habitat diversity.
* We
provide an alternative explanation for the suggestion made by Allouche et al.
(2012) that species richness decreases at high levels of habitat
diversity because the area available per habitat decreases.
*
Reanalyzing their data for Catalonian birds, the unimodal relationship
between altitudinal range and richness merely reflects the well-known
hump-shaped relationship between species richness and altitude. Bird-species
richness shows a hump-shaped relationship with mean elevation, a negative
linear relationship with altitudinal range, and a positive, monotonic
relationship with habitat diversity, as predicted from classical ecological
theory. Read more.
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