Isolation and characterization of polymorphic microsatellite markers in the migratory freshwater fish Prochilodus costatus

We isolated six polymorphic microsatellite loci in the migratory freshwater fish Prochilodus costatus, which is an endemic species and important fisheries resource from São Francisco river basin, Brazil. We have evaluated the applicability of these loci to study genetic variation in wild population of this fish. Thus, based on the genotypes of 32–48 individuals, we detected two to 21 alleles per locus, observed and expected heterozygosities ranging from 0.19 to 0.89 and from 0.17 to 0.92, respectively. These polymorphic markers should provide efficient tools to study population genetic structure of this fish.     

Vocalizations and relationships of Brown Creepers Certhia americana: a taxonomic mystery

Two taxa of creepers ( Certhia spp.) occur in Europe, C. familiaris and its sibling species C. brachydactyla. The North American Brown Creeper was considered a close relative of C. brachydactyla by one author, a close relative of or conspecific with C familiaris by others, and more recently as a distinct species, C. americana, by the American Ornithologists' Union. Songs of these three creepers are comprised mostly of social calls which are derived from begging calls. Sequence of syllables (syntax) is very conservative in songs of European population of C. familiaris and C. brachydactyla. In contrast, syntax in songs of western North American C. americana is highly variable; however, syllable morphology and syntax in some populations or individuals within populations is remarkably similar to songs of C. brachydactyla, notably from France and Spain. Two social calls and sleeping behaviour of C. americana are also similar to those of C. brachydactyla. Either C. americana and C. brachydactyla are close relatives or they have characters retained from the ancestor common to all three species whereas those in extant C familiaris have diverged.     

Recovery of Germination from Different Osmotic Conditions by Four Halophytes from Southeastern Spain

Seeds of four halophytes from southeastern Spain (the perennialsHalocnemum strobilaceum,Arthrocnemum macrostachyum and Sarcocorniafruticosa, and the annual Salicornia ramosissima) were exposedto iso-osmotic stress with NaCl, MgCl₂, MgSO₄and Na₂SO₄. Theosmotic potential that enforced dormancy in the majority ofseeds was determined. The percentage of ungerminated seeds thatrecovered when they were transferred to distilled water didnot differ significantly from the percentage germination ofseeds in distilled water controls, irrespective of the saltused to impose the stress. Therefore, the factor responsiblefor the dormancy of seeds seems to be the decrease in osmoticpotential. Such osmotic pretreatments promoted an increase inthe rate of recovery germination which, inArthrocnemum macrostachyumand Sarcocornia fruticosa, doubled their rates of germinationcompared to distilled water controls. The osmotic potentialsof the soils where the four species occur naturally were morenegative than those allowing seeds to germinate after osmoticstress. Copyright 2000 Annals of Botany Company Arthrocnemum macrostachyum, Halocnemum strobilaceum, halophytes, osmotic stimulation, recovery of seed germination, Salicornia ramosissima, Sarcocornia fruticosa.     

The structure of the outer shell layer in radiolitid rudists, a morphoconstructional approach

Radiolitids (Bivalvia, Radiolitidae) built the calcite outer layer of their shell with compact structure as many other bivalves, or with repetitively layered non-compact structure following different patterns: continuous radial ridges, discontinuous radial ridges, normal cellular, cellular with radially elongate cells, discontinuous cellular, and discontinuous cellular with elongate cells. Some special structures may develop in localized parts: radial structures and inner-marginal or radial grooves. All these structures are currently used in the diagnosis of the family and for the characterization of subfamilies. Constructional morphology analyses and re-evaluation of all these structures reveal that they were misunderstood in some important aspects in the bivalve Treatise and that, consequently, the diagnosis of the family has to be emended and their subfamilies reconsidered. All outer shell layer structure related characters are described, illustrated, and interpreted under a constructional approach, some characters are proposed to emend the diagnosis of the family, and two possible clades are preliminarily distinguished.     

Plankton response to weakening of the Iberian coastal upwelling

Coastal upwelling regions, which are affected by equatorward‐wind variability, are among the most productive areas of the oceans. It has been suggested that global warming will lead to a general strengthening of coastal upwelling, with important ecological implications and an impact on fisheries. However, in the case of the Iberian upwelling, the long‐term analysis of climatological variables described here reveals a weakening in coastal upwelling. This is linked to a decrease of zonal sea level pressure gradient, and correlated with an observed increase of sea surface temperature and North Atlantic Oscillation. Weakening of coastal upwelling has led to quantifiable modifications of the ecosystem. In outer shelf waters a drop in new production over the last 40 years is likely related to the reduction of sardine landings at local harbors. On the other hand, in inner shelf and Ria waters, the observed weakening of upwelling has slowed down the residual circulation that introduces nutrients to the euphotic layer, and has increased the stability of the water column. The drop in nutrient levels has been compensated by an increase of organic matter remineralization. The phytoplankton community has responded to those environmental trends with an increase in the percentage of dinoflagellates and Pseudonitzschia spp. and a reduction in total diatoms. The former favors the proliferation of harmful algal blooms and reduces the permitted harvesting period for the mussel aquaculture industry. The demise of the sardine fishery and the potential threat to the mussel culture could have serious socio‐economic consequences for the region.     

Nest-site selection by Great Bustards Otis tarda suggests a trade-off between concealment and visibility

Great Bustards Otis tarda have expanded their habitat range from historical occupancy of natural steppes to arable farmland, where the species initially benefited from favourable feeding conditions. More recently, the species has suffered severe declines due partly to agricultural intensification. Nest losses and juvenile mortality are amongst the factors most seriously affecting survival probabilities of many populations of this endangered species, suggesting that management of nesting habitats would bring conservation benefits. We studied nest-site selection in a Great Bustard population of central Spain by radiotracking 42 females for periods of between 1 and 4 years. Females selected nest-sites in fallows or cereal fields, in areas of low patch-type diversity, far from human infrastructure, and with good horizontal visibility. These results suggest that females look for shelter, but also need to have good visibility while incubating, and they support the hypothesis that nest selection is a trade-off between concealment and visibility. We interpret both preferences as adaptations to reduce predation pressure, one of the main causes of nest failure in this species. Nests were placed on slopes significantly orientated to the southeast, which suggests that females also seek sites protected from the cold north-westerly winds that are prevalent in the study area. To reduce nest destruction, harvesting should be delayed as long as possible and habitat conservation measures should not be restricted to lek sites but also include nesting areas, which are frequently located far from leks.     

Traditional and New Cable Restraint Systems to Capture Fox in Central Spain

ABSTRACT Capturing animals is an essential tool of wildlife management, but the use of capture devices is being affected by public pressures on an international scale. In Europe, and particularly Spain, foxes (Vulpes vulpes) are often captured using traditional methods such as nonlocking Spanish Snares (SS) set in an ad hoc fence line known as an alar, but these traditional European methods are rarely compared to modernly described restraints such as the Wisconsin Cable Restraint (WR). We evaluated rates of efficiency, selectivity, injury, and impacts to foxes and nontarget species when using SS (as traditionally set in an alar) or WR within alars or on trails in Castilla-La Mancha, Spain. During 40,372 trap-nights from summer to winter of 2007, we captured 64 foxes, and 8 of 23 potential nontarget species. Our results indicated that WR set in trails were more efficient (0.28 capture rate) for capturing red foxes than SS set in an alar (0.11 capture rate). Relative to injury, foxes captured with the WR in the alar (95.4%), and WR in trails (90.5%), and the SS (90.9%) showed no indicators of poor welfare, and injury score analysis indicated that injuries were of similar magnitude for all capture devices. Overall, the WR set in trails may have performed the best, but all 3 methods are likely sufficient for capturing foxes with minimal injury, acceptable efficiency, and acceptable impact to foxes and sympatric nontarget species. Thus, wildlife managers in Spain and elsewhere can apply our findings to optimize capture and management of foxes.     

Trophic level modulates carabid beetle responses to habitat and landscape structure: a pan‐European study

1. Anthropogenic pressures have produced heterogeneous landscapes expected to influence diversity differently across trophic levels and spatial scales. 2. We tested how activity density and species richness of carabid trophic groups responded to local habitat and landscape structure (forest percentage cover and habitat richness) in 48 landscape parcels (1 km²) across eight European countries. 3. Local habitat affected activity density, but not species richness, of both trophic groups. Activity densities were greater in rotational cropping compared with other habitats; phytophage densities were also greater in grassland than forest habitats. 4. Controlling for country and habitat effects, we found general trophic group responses to landscape structure. Activity densities of phytophages were positively correlated, and zoophages uncorrelated, with increasing habitat richness. This differential functional group response to landscape structure was consistent across Europe, indicated by a lack of a country × habitat richness interaction. Species richness was unaffected by landscape structure. 5. Phytophage sensitivity to landscape structure may arise from relative dependency on seed from ruderal plants. This trophic adaptation, rare in Carabidae, leads to lower phytophage numbers, increasing vulnerability to demographic and stochastic processes that the greater abundance, species richness, and broader diet of the zoophage group may insure against.