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Selected AbstractsSeasonal differences in population-, ensemble- and community-level responses of bats to landscape structure in AmazoniaOIKOS, Issue 10 2010Brian T. Klingbeil The amount (composition) and spatial arrangement (configuration) of forest patches in fragmented landscapes influence the accessibility, as well as the abundance and diversity of resources available to bats. Moreover, tropical fruit and insect abundance differ seasonally in response to changes in precipitation, and many bats in the family Phyllostomidae employ seasonal reproductive strategies. Because reproductive activities involve constraints on time and energy as well as increased nutritional demands, foraging behavior and home range size may differ between wet and dry seasons. Nonetheless, seasonal variation in response to landscape structure by bats has not been examined previously. Consequently, population-, ensemble- and assemblage-level responses of phyllostomids to landscape composition and configuration were quantified separately during the wet and dry season at three circular focal scales (1, 3 and 5 km radii) for 14 sites in fragmented lowland Amazon forest. Responses to landscape characteristics were scale-dependent, species-specific, and seasonal. Abundances of frugivores responded to landscape composition in the dry season and to landscape configuration in the wet season. Conversely, abundances of animalivores responded to landscape configuration in the dry season and to landscape composition in the wet season. Divergent responses to landscape structure between seasons suggest that variation in resource abundance and diversity play a significant role in structuring population-, ensemble- and assemblage-level patterns. As such, considerations of the effects of dietary flexibility and reproductive constraints on foraging strategies and habitat use may be important when designing management plans that successfully promote long-term persistence of biodiversity in fragmented landscapes. [source] FC02.4 Meteorological factors and standard series patch test reactionsCONTACT DERMATITIS, Issue 3 2004Janice Hegewald The existence of seasonal patterns to patch test reactions has been described, but with conflicting causal interpretations. The potential seasonality of patch tests may be due to irritation, changes to skin barrier or changes to immunological functions caused by meteorological fluctuations. For example, increased skin irritability due to cold winter weather and low humidity may cause an increase in irritative/doubtful and weak positive (false positive) reactions. To investigate the extent of the association between weather and patch test results, consecutive patients (N = 73691) patch tested with the standard series of the German Contact Dermatitis Research Group (DKG) at German or Austrian IVDK (http://www.ivdk.de) centres were matched with weather data collected at a nearby (30 km radius) weather station. Temperature and absolute humidity (AH) on the day of patch test application and the two preceding days were averaged to represent the environment most likely to have influenced the skin condition at the time of testing. The results of 24 standard series substances were analyzed with multivariate logistic regression. Half of the standard series substances examined, including fragrance mix, nickel sulphate, and formaldehyde, exhibited evidence of a relationship with meteorological conditions. Fragrance mix and p-Phenylene diamine exhibited the strongest evidence of an association to weather, with the odds of the reactions in all three reaction categories (ir/?, +, ++/+++) increasing during winter conditions. Due to the association between weather and patch test reactivity, the potential effect of meteorological conditions should be considered in the interpretation of patch test reactions. [source] Alcohol in Mayan Guatemala: consumption, distribution, production and composition of cuxaADDICTION, Issue 5 2009Fotis Kanteres ABSTRACT Aims To describe the consumption, distribution, production and chemical composition of alcohol, including cuxa (pronounced ,coo sha'), in Nahualá, a highland Mayan municipality in Guatemala. Cuxa is a sugarcane-derived spirit, in part produced clandestinely, that has been distributed in the community for several decades. Methods Key informant interviews with alcohol distributors and consumers, cuxa producers and health professionals, as well as analyses of questionnaires from a sample of 47 spouses who came to the local health centre for problems related to their husband's drinking. Sampling and chemical analysis of cuxa from 12 of 13 identified sales points in the head-town of Nahualá and its nearby settlements (10 km radius). Fieldwork was conducted between November 2007 and March 2008. Results Alcohol consumption was found to be integrated culturally in this community. The overall drinking culture was marked by irregular heavy drinking occasions, especially around market days, with substantial inebriation and health problems, especially among street inhabiting drinkers. Cuxa contributed to these problems, and cuxa drinking was socially stigmatized. Cuxa was produced both clandestinely and industrially, and sold legally by taverns and illegally by clandestine distributors. The alcoholic strength of the samples was typically between 17 and 19% vol.; clandestinely produced cuxa samples showed acetaldehyde contamination. Conclusions Measures should be taken to reduce the harm associated with alcohol in this community, including efforts to reduce acetaldehyde levels in cuxa. [source] Contrasting responses of arable spiders to the landscape matrix at different spatial scalesJOURNAL OF BIOGEOGRAPHY, Issue 1 2008Martin H. Schmidt Abstract Aim, Animal communities can be influenced by the composition of the surrounding landscape through immigration. Depending on habitat preferences, however, the effect of the landscape matrix can be positive or negative and can vary with scale. We tested this idea with arable spiders and tried to infer dispersal distances from relationships between local density and landscape composition at different spatial scales. Location, Thirty-eight landscapes around the cities of Göttingen and Giessen, Germany. Methods, Spiders were captured with pitfall traps in one field of winter wheat in each landscape. Landscape composition around the fields was characterized at 11 scales from 95 m to 3 km radius by land-use mapping and subsequent GIS analysis. Correlation tests were performed between landscape composition and local densities or species richness. Results, In both study regions, local species richness was enhanced by non-crop habitats on a landscape scale. The overall densities of wolf spiders (Lycosidae), long-jawed spiders (Tetragnathidae), crab spiders (Thomisidae), and dwarf sheet spiders (Hahniidae) increased significantly in landscapes with high percentages of non-crop habitats. Out of the 40 species tested, 19 responded positively to the percentage of non-crop habitats in the surrounding landscape, and five responded negatively. Depending on the species, the spatial scales with the highest explanatory power ranged from 95 m to 3 km radius around the study fields, potentially reflecting dispersal distances. Main conclusions, Arable spider species showed contrasting responses to the landscape context with respect both to the direction and to the spatial scale of the relationship. The variation in landscape requirements among species ensures high spider densities in a wide range of situations, which contributes to ecosystem resilience. However, species richness of arable spiders depends on heterogeneous landscapes with high percentages of non-crop habitats. [source] Modelling species distribution at multiple spatial scales: gibbon habitat preferences in a fragmented landscapeANIMAL CONSERVATION, Issue 3 2010T. N. E. Gray Abstract Conservation of Indochinese primates is hampered by a lack of knowledge of species ecology, habitat preferences and, locally, distribution. Predictive distribution and habitat suitability models, using predictors known to affect the distribution of similar species elsewhere, may, therefore be of great benefit to conservationists within the region. Yellow-cheeked crested gibbon Nomascus gabriellae is an IUCN-listed endangered primate distributed east of the Mekong River in Cambodia, southern Vietnam, and possibly southern Lao PDR. Within Cambodia, yellow-cheeked crested gibbon are naturally restricted to evergreen forest fragments within a landscape matrix of deciduous dipterocarp and semi-evergreen forests. During the 2008 dry season, auditory surveys for yellow-cheeked crested gibbon were conducted within Phnom Prich Wildlife Sanctuary, Mondulkiri province, Cambodia. Predictive distribution models, in which variables were included at the scale at which they best explained gibbon occurrence (multi-grain models), were constructed to examine the species' habitat associations and tolerance of habitat fragmentation within the wildlife sanctuary. Gibbon occupancy (,) was higher in evergreen (0.43±0.26,0.62) than in semi-evergreen forest (0.21±0.09,0.4), with gibbon presence constrained by a critical amount of evergreen forest within 5 km radius of listening posts. Three patches of optimal habitat within Phnom Prich Wildlife Sanctuary were identified. These, and connecting habitats, should be the target of increased enforcement effort to limit hunting and habitat conversion. Similar multi-grain models are likely to be valuable for conservationists within mosaic habitats as they can facilitate identification of the minimum suitable fragment size for species of conservation concern. [source] Dispersal kernels of the invasive alien western corn rootworm and the effectiveness of buffer zones in eradication programmes in EuropeANNALS OF APPLIED BIOLOGY, Issue 1 2010L.R. Carrasco Europe is attempting to contain or, in some regions, to eradicate the invading and maize destroying western corn rootworm (WCR). Eradication and containment measures include crop rotation and insecticide treatments within different types of buffer zones surrounding new introduction points. However, quantitative estimates of the relationship between the probability of adult dispersal and distance from an introduction point have not been used to determine the width of buffer zones. We address this by fitting dispersal models of the negative exponential and negative power law families in logarithmic and non-logarithmic form to recapture data from nine mark-release-recapture experiments of marked WCR adults from habitats as typically found in the vicinity of airports in southern Hungary in 2003 and 2004. After each release of 4000,6300 marked WCR, recaptures were recorded three times using non-baited yellow sticky traps at 30,305 m from the release point and sex pheromone-baited transparent sticky traps placed at 500,3500 m. Both the negative exponential and negative power law models in non-log form presented the best overall fit to the numbers of recaptured adults (1% recapture rate). The negative exponential model in log form presented the best fit to the data in the tail. The models suggested that half of the dispersing WCR adults travelling along a given bearing will have travelled between 117 and 425 m and 1% of the adults between 775 and 8250 m after 1 day. An individual-based model of dispersal and mortality over a generation of WCR adults indicated that 9.7,45.3% of the adults would escape a focus zone (where maize is only grown once in 3 consecutive years) of 1 km radius and 0.6,21% a safety zone (where maize is only grown once in 2 consecutive years) of 5 km radius and consequently current European Commission (EC) measures are inadequate for the eradication of WCR in Europe. Although buffer zones large enough to allow eradication would be economically unpalatable, an increase of the minimum width of the focus zone from 1 to 5 km and the safety zone from 5 to 50 km would improve the management of local dispersal. [source] Factors affecting Grey-headed Flying-fox (Pteropus poliocephalus: Pteropodidae) foraging in the Melbourne metropolitan area, AustraliaAUSTRAL ECOLOGY, Issue 5 2005E. MCDONALD-MADDEN Abstract Factors affecting the foraging of mobile native fauna in highly fragmented urban landscapes have seldom been quantified at large spatial scales. We investigated factors affecting foraging by Grey-headed Flying-foxes (Pteropus poliocephalus; ,flying-foxes') in the greater Melbourne metropolitan area. Flying-foxes established a continuously occupied colony site in the Royal Botanic Gardens Melbourne in 1986, and the size of the colony has subsequently increased greatly. We used a stratified-random sampling design to examine the importance of six variables on the detection of foraging flying-foxes: (i) distance from the colony site (0,10, 10,20 and 20,30 km); (ii) distance from the Yarra River (0,5 and 5,20 km); (iii) the relative tree density of the municipality; (iv) whether the site was a park or street; (v) whether there was a relatively high or low density of trees at the site; and (vi) whether food was or was not detected at the site. We surveyed 240 sites within a 30-km radius of the colony site for foraging flying-foxes in both May and October 2002. The probability of detecting a foraging flying-fox declined with increasing distance from the colony site, but increased with increasing tree cover, and was higher for parks compared with streets and when food was present. Flying-foxes were observed foraging in a number of plant genera that have no species that naturally occur in the Melbourne area. Flying-foxes in Melbourne thus forage on planted resources that are widely distributed within a fragmented landscape, and are an example of a positive response by a native species to the process of urbanization. [source] | |||||||||||||