查看更多>>摘要：Fledgling production has often been used as an estimator of avian reproductive success, and it is conditioned by factors affecting offspring development and/or survival during the nesting period. We aimed to determine which predictors influenced fledgling output among a set of basic breeding parameters and local temperature data collected over 25 years in a Mediterranean great tit, Parus major, population, using an information-theoretic approach for model selection. Of the studied variables, the number of hatchlings per nest was the single-most important predictor influencing fledgling production, with larger broods eventually yielding more fledglings, although mass prior to fledging may have been compromised. This result suggests an overall good adjustment between brood size and resource availability in the studied population.
Gonzalez-Desales, G. A.Monroy-Vilchis, O.Charruau, P.Zarco-Gonzalez, M. M....
6页
查看更多>>摘要：Studies on caiman, Caiman crocodilus chiapasius, in Mexico are scarce. The present study was conducted to evaluate the key characteristics regarding the reproductive ecology of caiman in Mexico. We conducted nest searches from April to September 2014. We observed that nests were built in June and that hatching occurred in September and October. The phase of the moon had an effect on nesting events. The height of the nest, the distance to the nearest tree, and the distance from the top of the nest to the first egg were related to hatching success and incubation temperature.
查看更多>>摘要：We analysed dung beetle communities on ten volcanic islands located around Sicily (Italy) to identify the most probable dispersal routes in the colonization of these islands. Assuming two scenarios, we analysed the dung beetle communities through the coefficient of dispersal direction DD2. Our results suggest that dispersal fluxes do not strictly follow the 'stepping stone' dynamic. Lipari and Vulcano are the likely core source areas for the north-of-Sicily area. In the Sicily Channel, Linosa appears to have been the main target area with three equivalent fluxes from Tunisia, Sicily, and Malta, while the fauna of Pantelleria resulted from their interchange and proximity to Tunisian fauna. In light of the congruence of our results with the known history of human movements and colonization, we propose a likely human contribution to the genesis of the dung beetle fauna of the circum-Sicilian volcanic islands.
查看更多>>摘要：Seed traits are considered an essential factor influencing rodents' foraging preferences. We evaluated the mouse's preferences for seeds of four pine species, Pinus patula, P. pseudostrobus, P. teocote and P. montezumae, that differ in length, width, nutritional content, and concentrated tannins. In 'cafeteria experiments' in the laboratory, we tested six of the nine mice species commonly found in the temperate forest of Southern Mexico. Longer and wider seeds were those of P. teocote and P. montezumae. P. teocote seeds had the highest protein content, P. patula were highest in lipids, and P. montezumae seeds were highest in carbohydrates. In concentrated tannins, gallic acid content was highest in P. patula seeds and tannic acid content was highest in P. teocote seeds. Mice preferred small pine seeds with a high lipid and gallic acid content, a low tannic acid content, and an intermediate protein and carbohydrate content. The foraging behavior of rodents, their energy optimization, and the likely effects on seed fate and plant composition would thus be mediated by combinations of seed traits rather than by single seed traits such as size or tannin contents.
Cornejo-Ortega, J. L.Chavez-Dagostino, R. M.Cupul-Magana, F. G.
9页
查看更多>>摘要：We studied the breeding success of two seabird species, the blue-footed booby, Sula nebouxii, and the brown booby, Sula leucogaster, in relation to touristic disturbance in order to focus conservation management strategies in the protected area of the Marietas Islands in Bahia de Banderas, Mexico. Data were collected throughout the breeding season of 2013 at Isla Larga. We considered three sites under different conditions of simulated disturbance within the colonies: 'medium', visits constrained to a single path; 'high', visits without spatial restrictions, and 'low', no visits. The total numbers of nests, eggs and chicks for each species were recorded weekly at the three sites. On the basis of these data, we determined the viability of eggs (hatching success) and chicks. A generalized linear mixed model (GLIMMIX) showed that breeding success (eggs-to-fledglings rate) had no relationship to the conditions of the area and but was significantly lower in the blue-footed booby. The presence of tourists, as measured in this study, was not the cause of nesting failure. Other, non-evaluated factors likely play a role in limiting the breeding success of the two species of booby studied here.
Rubio, C. J.Macias, D.Caminas, J. A.Fernandez, I. L....
4页
查看更多>>摘要：Tuna are highly migratory pelagic species (HMPS) with great importance in commercial fishing. Several authors have highlighted the effect of climatic oscillations such as the NAO (North Atlantic Oscillation) on HMPS. This paper analyzes the effects of the NAO on two HMPS: albacore, Thunnus alalunga, and yellowfin tuna, Thunnus albacares. Fishing data from the Spanish fleet operating in the North Atlantic area were obtained from the International Commission for the Conservation of Atlantic Tunas (ICCAT) database. The results show a positive correlation between the NAO index and the Catch per Unit Effort (CPUE) for both albacore and yellowfin tuna, depicting a potential effect on their capturability.
查看更多>>摘要：The present paper highlights problems associated with the currently-accepted taxonomy of brown bear, Ursus arctos, and their consequences for conservation at the European level. The enormous morphological variability within Ursus arctos is not acknowledged in current taxonomy and conservation practice. Seven major clades are recognized in Ursus arctos by molecular researchers, and although Western Europe maintains most of the populations belonging to the relict Clade 1 brown bear lineage, no reference to this is made in current conservation policy. Furthermore, the tiny population of Apennine brown bears, characterized by unique skull morphology, is not even recognized as a distinct ESU (evolutionari significant unit) by current European legislation, nor is it included in the IUCN Red List. This may have serious consequences as brown bear conservation in Western Europe has been mainly based on restocking and reintroduction programs.
查看更多>>摘要：Success of vertebrate translocations is crucial to improve efficacy and efficiency of conservation actions but it is often difficult to assess because negative results (failed translocations) are seldom published. We developed surveys and sent them to heads of conservation services in three major Spanish Mediterranean regions. The purpose of our surveys was to determine which methodological factor, that could easily be implemented in practice, was more influential for translocation success. These factors included the origin of translocated individuals (captive or wild) and translocation effort (propagule size and program duration). After analyzing 83 programs, corresponding to 34 different vertebrate species, by means of generalized linear mixed modelling, we found that 'origin' was more relevant for translocation success than 'effort', although we could not rule out some role of translocation effort. Variance in success of translocation programs involving individuals from wild sources was smaller and consequently results more predictable. Origin interacted with taxa so that success was higher when using wild birds and especially wild fish and mammals, but not when releasing reptiles. Hence, we suggest that, for any given effort, translocation results will be better for most vertebrate taxa if individuals from wild sources are used. When this is not feasible, managers should release captive-reared individuals for a long number of years rather than a short number of years.
查看更多>>摘要：Calcareous fens are considered to be among the most threatened ecosystems of Europe. They are also one of the most diverse habitats as they support an incredibly rich and diverse range of plant and animal species. However, in spite of their diversity, calcareous fens are still poorly investigated, especially when referring to fen invertebrates, such as spiders. Because spiders are good bioindicators, knowledge of their ecology in rare and threatened habitats is of interest. The aim of this study was to document the composition and diversity of spider species, families and foraging guilds in the ground-and grass-layers of the Apsuciems calcareous fen, and to evaluate the influence of vegetation structure on spider community organization. In summer 2012, we collected ground-dwelling spiders using pitfall traps and grass-dwelling spiders using sweep-netting. A total of 2,937 spider individuals belonging to 19 families and 80 species was collected in the Apsuciems fen. Our results indicate that spider species and families tend to be stratified across the vertical structure of the habitat; the spider composition in the ground stratum differed from that in the grass stratum. On the contrary, however, the spider foraging guild structure between the ground-layer and the grass-layer was similar. Each of the two studied strata presented similar guilds in similar proportions. Our results also showed that spider composition differed considerably between fen parts and that much of this variability could be explained by the architectural properties of the habitat. More diverse vegetation generally supported a higher number of spider species.
Comas, M.Reguera, S.Zamora-Camacho, F. J.Salvado, H....
4页
查看更多>>摘要：Skeletochronology allows estimation of lizard age with a single capture (from a bone), making long-term monitoring unnecessary. Nevertheless, this method often involves the death of the animal to obtain the bone. We tested the reliability of skeletochronology of phalanges (which may be obtained without killing) by comparing the estimated age from femurs and humeri with the age estimated from phalanges. Our results show skeletochronology of phalanges is a reliable method to estimate age in lizards as cross-section readings from all bones studied presented a high correlation and repeatability regardless of the bone chosen. This approach provides an alternative to the killing of lizards for skeletochronology studies.
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