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Using information from two recently published atlases of threatened invertebrate species in peninsular Spain, we examined the climatic, land use and geographic characteristics of the 100 km UTM cells with most likelihood of suffering extinctions (extinction cells), as well as the attributes of the species prone to population extinctions. Extinction cells have had significantly (1) lower precipitation values, (2) higher temperatures, (3) higher percentages of anthropic land uses or (4) higher rates of anthropization during the last 20 years than the remaining cells. Nevertheless, probable extinctions may occur under a wide range of climatic and anthropization change rates and these variables can only explain a low proportion (~5 %) of variability in the occurrence or number of extinction cells. Aquatic species seem to suffer higher local extinction rates than terrestrial species. Interestingly, many invertebrate species with approximately 25 or less occurrence cells are on a clear trajectory towards extinction. These results outline the difficulties and uncertainties in relating probable population extinctions with climatic and land use changes in the case of invertebrate data. However, they also suggest that a third of the considered Spanish threatened species could have lost some of their populations, and that current conservation efforts are insufficient to reverse this tendency. [ABSTRACT FROM AUTHOR]

Local autocorrelation statistics offer new opportunities for the discrimination of important conservation areas since the spatial dependence of local values upon neighbouring ones may assist conservation decisions. We exemplify the use of local autocorrelation statistics for conservation purposes using data on Spanish threatened invertebrates to identify areas composed of similarly species-rich localities ( hot spots), species-rich 'islands', cold spots and species-poor 'islands'. In order to assess the probable causes of the detected patterns differences in environmental, land use and protected area variables were examined between the different regions. Distributional data for threatened invertebrate species in Spain at 100 km UTM cell resolution were used. After defining a neighbouring area, statistically significant local autocorrelation values (both positive and negative) were estimated. Kruskal-Wallis ANOVA by rank test was used to compare the environmental, land use and protected area percentages between the cells of the different regions. Around 11 and 2 % of total cells can be considered hot spots and rich 'islands', respectively. Hot spots are characterized by a lower percentage of anthropic land uses and a higher percentage of current protected area. However, approximately a third part of these cells possess at least 98 % of their area unprotected. Rich 'island' cells are not environmentally different from those considered as cold spots, though experiencing a lower rate of anthropization and higher proportion of protected area. Unfortunately, almost 70 % of these rich 'island' cells have <2 % of their areas currently protected. The use of local autocorrelation statistics on species richness values may complement conservation decisions by discriminating interconnected sites facilitating local persistence ( hot spots) as well as isolated and vulnerable sites (rich 'islands'). The study of different variables associated with these regions allows us to suggest determinant causal factors. Our results suggest that land use changes due to human activities are the main cause of threats. [ABSTRACT FROM AUTHOR]

The thermoregulation strategies of Scarabaeus sacer L. and Scarabaeus cicatricosus Lucas were studied in the Doñana National Park, Spain. In this area, both species coexist, showing the same habitat and food preferences. However, S. cicatricosus is active during warmer parts of the day compared to S. sacer. Both species thermoregulate their thoracic temperature but, whereas the abdomen of S. sacer is a passive thermal window, S. cicatricosus actively thermoregulates abdominal temperature by increasing heat transfer from the thorax to the abdomen at high Ta values. In the case of S. sacer, their endothermy indicates an adaptive capacity to thorax heat retention, as occurs mainly in winter-flying insects. This mechanism, possibly related to the aerodynamic flight posture in Scarabaeinae, could be an effective barrier to retard the rate of abdominal heat loss during flight. This endothermic strategy makes flight difficult at higher temperatures, although it allows flight during cooler periods of the day. On the other hand, S. cicatricosus showed a different adaptive behaviour to S. sacer. In this case, a significant decrease in abdominal heat loss at higher ambient temperatures would indicate a decrease in heat transfer from the thorax to the abdomen, as occurs in some desert and semiarid insects. This 'heat exchanger' mechanism observed in S. cicatricosus could be due to the irregular posture adopted during flight, with the posterior legs clearly extended and separate from the body. This behaviour increases turbulence and convective cooling, favouring exposure of the soft abdominal tergal cuticle and, subsequently, water loss. Thus, for S. cicatricosus, the well-adapted 'heat exchanger' permits flight during periods of the day when temperatures would possibly be lethal for those species with high endothermy. From an adaptive viewpoint, these mechanisms of thermoregulation may explain how both closely-related sympatric species respond in different ways to environmental temperature, favouring their coexistence. [ABSTRACT FROM AUTHOR]

Saproxylic beetles depend on diverse microhabitats that are exploited by different species assemblages. We focused on anlyse the functional trait patterns and functional diversity components of two main assemblages that were collected with window traps (WTs) and hollow emergence traps (HETs) respectively, between three protected areas of the Iberian Peninsula. For that we measured phenological, physiological, morphological, and ecological traits. Results showed that the main microhabitats exploited by each assemblage (WT and HET) constrain most of the morphological traits and trophic guilds. In addition, relative elytra length and predator guild, together with adult activity period, responded to differences at the habitat level (among study areas). HET assemblages were less taxonomically diverse but more functionally diverse than those of WTs, enhancing the functional relevance of tree hollows. Additionally, niche filtering dominated WT assemblages, which were characterised by a narrower functional space and a higher redundancy. In contrast, in the HET assemblages the coexistence of functionally dissimilar species is driven by the niche heterogeneity. HET and WT assemblages differed in the functional space occupied by each within areas, but both assemblages reflected coincident patterns among areas that pointed to a reduction of functional space with management.