Summary 1.We studied seasonal changes in the thermoregulatory behaviour of the lacertid lizard Psammodroums algirus in a Mediterranean evergreen forest. Body temperatures ( T b ), environmental operative temperatures ( T e ) and upper and lower limits of the selected thermal range ( T sel ) were lower in May than in July. 2. On average, mean deviations of T b from T sel (0·7 ° C in both seasons) were much smaller than those of T e (8·3 ° C in both seasons). Thus both the accuracy (average difference between T b and T sel ) and effectiveness (the extent to which T b are closer than T e to T sel ) of thermoregulation were high, and similar in both seasons. 3. However the thermoregulatory contribution of two distinct behavioural mechanisms varied markedly between seasons. Daily activity contributed significantly to the regulation of T b in May (when a population of T e thermometers matching lizard activity patterns would be, on average, 1·0 ° C closer to T sel than were randomly available T e ), but not in July (when such a population would be only 0·2 ° C closer to T sel than were randomly available T e ). The selection of sun-shade patches, the contribution of which was larger than that of daily activity in both seasons, was more important in July (when it produced a distribution of T e that would be, on average, 3·1 ° C closer to T sel than were randomly distributed T e ) than in May (when a population of thermometers matching the lizards' pattern of exposure to sunlight would be 1·3 ° C closer to T sel than were randomly available T e ). 4. These changes are discussed in the light of seasonal differences in the daily patterns of among-patch variation in T e . In spring, lizard activity was low in the early morning because even the selection of sunlit patches was of limited utility to attain T b within T sel ; in summer, lizards could remain active at midday, despite low overall thermal suitability, by selecting shaded patches. Thus the contribution of patch selection to thermoregulation was important in the early basking period of both seasons, and at summer midday hours. 5. Our data suggest that shuttling between sun and shade, rather than selecting sun or shade, may be an additional mechanism of behavioural thermoregulation, the importance of which would be greatest at times of day when lizards use patches at random (e.g. spring midday hours), and that their mean T b is closer to the grand mean of full sun and full shade T e than to the mean equilibrium T e within any type of patch.

Parasite community ecology has recently focused on understanding the forces structuring these communities. There are few surveys, however, designed to study the spatial repeatability and predictability of parasite communities at the local scale in one host. The purpose of our study was to address the relationship between infracommunity and component community richness, and to describe spatial variations on the local scale, of helminth parasite communities in an avian host, the red-legged partridge (Alectoris rufta). We sampled 235 wild partridges from 8 separate localities, with different partridge population densities, in the Ciudad Real and Toledo provinces of central Spain, and we determined their overall and intestinal helminth species. We found that habitat variables (mean temperature and land use) were not significantly associated with any component community. The partridge population abundance index was directly correlated with the prevalence and mean intensity of infection but not with component community species richness. There was a curvilinear relationship between infracommunity and component community species richness, as well as negative interspecific associations, for the helminth species assemblage parasitizing the intestine. A nestedness/anti-nestedness pattern, considered as part of a continuum, was associated with prevalence, mean intensity and partridge population abundance index, but not with component community richness. Increases in the partridge population abundance index and the prevalence and mean intensity of infection were associated with increases in helminth community nestedness. Although negative interactions between helminth species could not be ruled out as forces structuring helminth communities, our results suggest that parasite community structure in the red-legged partridge was primarily determined by the extrinsic influence of parasite habitat heterogeneity and its amplification of the differing probabilities of colonization of parasite species.

Carnivores are umbrella species with a key role in ecosystems. In the Mediterranean, they face with several conservation problems, mainly habitat loss or transformation. In this region, scrubland habitats are considered of minor conservation relevance as compared to mature forest formations. Conservation of scrublands in Mediterranean ecosystems is also diYcult because to control Wres, they are removed over large areas. For carnivores, scrublands may be essential to guarantee shelter and food. Here, we analyzed the importance of scrublands and other habitat variables in determining the richness of medium-sized carnivores in a typical Mediterranean area of central Spain (Monfragüe Natural Park). The Park was divided into plots of 2 £ 2 km (n = 30). In each plot, a 2 kmlength survey route was walked searching for carnivore scats. We recorded the number of species of carnivores and we related this value to several habitat variables. Habitat variables were summarized by means of Principal Component Analysis (PCA). Habitat models were developed by, using multiple regression models, including PCA factors and the habitat type as predictors. The only variable included in the Wnal model was the Wrst PCA factor. Carnivore richness was positively associated with large tree, shrub, and rock cover areas, which is the typical habitat structure of scrublands. This habitat oVers the best available area for shelter and may be considered as a key element for carnivore conservation in the Mediterranean region. To reconciliate carnivore conservation and forestry management, we proposed small-scale clearances as a management alternative to typical large scrubland removals.

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