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Massive Mortalities (massive + mortality)
Selected AbstractsWhere do Swainson's hawks winter?DIVERSITY AND DISTRIBUTIONS, Issue 5 2008Satellite images used to identify potential habitat ABSTRACT During recent years, predictive modelling techniques have been increasingly used to identify regional patterns of species spatial occurrence, to explore species,habitat relationships and to aid in biodiversity conservation. In the case of birds, predictive modelling has been mainly applied to the study of species with little variable interannual patterns of spatial occurrence (e.g. year-round resident species or migratory species in their breeding grounds showing territorial behaviour). We used predictive models to analyse the factors that determine broad-scale patterns of occurrence and abundance of wintering Swainson's hawks (Buteo swainsoni). This species has been the focus of field monitoring in its wintering ground in Argentina due to massive pesticide poisoning of thousands of individuals during the 1990s, but its unpredictable pattern of spatial distribution and the uncertainty about the current wintering area occupied by hawks led to discontinuing such field monitoring. Data on the presence and abundance of hawks were recorded in 30 × 30 km squares (n = 115) surveyed during three austral summers (2001,03). Sixteen land-use/land-cover, topography, and Normalized Difference Vegetation Index (NDVI) variables were used as predictors to build generalized additive models (GAMs). Both occurrence and abundance models showed a good predictive ability. Land use, altitude, and NDVI during spring previous to the arrival of hawks to wintering areas were good predictors of the distribution of Swainson's hawks in the Argentine pampas, but only land use and NDVI were entered into the model of abundance of the species in the region. The predictive cartography developed from the models allowed us to identify the current wintering area of Swainson's hawks in the Argentine pampas. The highest occurrence probability and relative abundances for the species were predicted for a broad area of south-eastern pampas that has been overlooked so far and where neither field research nor conservation efforts aiming to prevent massive mortalities has been established. [source] Influence of climate and reproductive timing on demography of little brown myotis Myotis lucifugusJOURNAL OF ANIMAL ECOLOGY, Issue 1 2010Winifred F. Frick Summary 1. Estimating variation in demographic rates, such as survival and fecundity, is important for testing life-history theory and identifying conservation and management goals. 2. We used 16 years (1993,2008) of mark,recapture data to estimate age-specific survival and breeding probabilities of the little brown myotis Myotis lucifugus LeConte in southern New Hampshire, USA. Using Kendall & Nichols' (1995) full-likelihood approach of the robust design to account for temporary emigration, we tested whether survival and breeding propensity is influenced by regional weather patterns and timing of reproduction. 3. Our results demonstrate that adult female survival of M. lucifugus ranged from 0ˇ63 (95% CL = 0ˇ56, 0ˇ68) to 0ˇ90 (95% CL = 0ˇ77, 0ˇ94), and was highest in wet years with high cumulative summer precipitation. First-year survival [range: 0ˇ23 (95% CL = 0ˇ14, 0ˇ35) to 0ˇ46 (95% CL = 0ˇ34, 0ˇ57)] was considerably lower than adult survival and depended on pup date of birth, such that young born earlier in the summer (c. late May) had a significantly higher probability of surviving their first year than young born later in the summer (c. mid-July). Similarly, the probability of young females returning to the maternity colony to breed in the summer following their birth year was higher for individuals born earlier in the summer [range: 0ˇ23 (95% CL = 0ˇ08, 0ˇ50) to 0ˇ53 (95% CL = 0ˇ30, 0ˇ75)]. 4. The positive influence of early parturition on 1st-year survival and breeding propensity demonstrates significant fitness benefits to reproductive timing in this temperate insectivorous bat. 5. Climatic factors can have important consequences for population dynamics of temperate bats, which may be negatively affected by summer drying patterns associated with global climate change. 6. Understanding long-term demographic trends will be important in the face of a novel disease phenomenon (White-Nose Syndrome) that is associated with massive mortalities in hibernating bat species, including M. lucifugus, in the northeastern United States. [source] Transcriptome response of the Pacific oyster (Crassostrea gigas) to infection with Vibrio tubiashii using cDNA AFLP differential displayANIMAL GENETICS, Issue 5 2009N. Taris Summary We used qualitative complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) differential display analysis and real-time, quantitative PCR (RT-qPCR) to identify genes in the Pacific oyster Crassostrea gigas, whose transcription either changes in response to exposure to a pathogenic bacterium (Vibrio tubiashii) or varies between families known to differ in sensitivity to heat stress, before and at 12 and 36 h after bacterial exposure at a temperature of 25 °C. These conditions simulate those associated with summer mortality syndrome, a poorly understood cause of massive mortalities in cultured Pacific oysters in North America, Asia and Europe. Using 32 AFLP primer pairs, we identified 92 transcript-derived fragments that are qualitatively differentially expressed. We then cloned and sequenced 14 of these fragments, designed fragment-specific primers and quantified their transcription patterns using RT-qPCR. Most of the differences in transcription patterns between stress-tolerant and stress-sensitive families were evident before bacterial exposure, and genes that responded to bacterial exposure did so in parallel between stress-sensitive and stress-tolerant families. blast searches of sequence databases revealed that these fragments represent genes involved in immune response as well as genes related to metabolic processes. Our data support the hypothesis that family level differences in resistance to stress in Pacific oysters are largely attributable to constitutive differences in gene transcription or ,general vigour' that are detectable before and maintained after infection, rather than being due to induced responses at the transcriptome level. [source] Outbreak of betanodavirus infection in tilapia, Oreochromis niloticus (L.), in fresh waterJOURNAL OF FISH DISEASES, Issue 8 2009L Bigarré Abstract A betanodavirus associated with a massive mortality was isolated from larvae of tilapia, Oreochromis niloticus, maintained in fresh water at 30 °C. Histopathology revealed vacuolation of the nervous system, suggesting an infection by a betanodavirus. The virus was identified by indirect fluorescent antibody test in the SSN1 cell line and further characterized by sequencing of a PCR product. Sequencing of the T4 region of the coat protein gene indicated a phylogenetic clustering of this isolate within the red-spotted grouper nervous necrosis virus type. However, the tilapia isolate formed a unique branch distinct from other betanodavirus isolates. The disease was experimentally reproduced by bath infection of young tilapia at 30 °C. The reservoir of virus at the origin of the outbreak remains unidentified. To our knowledge, this is the first report of natural nodavirus infection in tilapia reared in fresh water. [source] Ecology and management of exotic and endemic Asian longhorned beetle Anoplophora glabripennisAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2009Jiafu Hu Abstract 1The Asian longhorned beetle is native to China and Korea, and was found for the first time outside its native habitat in the U.S.A. in 1996, with subsequent detections being made in Canada and several European countries. 2We review the taxonomy, distribution, basic biology, behaviour, ecology and management of endemic and exotic Anoplophora glabripennis, including information that is available in the extensive Chinese literature. 3This species has caused massive mortality of Populus species in China and models have demonstrated that it could become established in many locations worldwide. 4Anoplophora glabripennis is polyphagous but prefers Acer, Salix and Populus, section Aigeiros. 5Although A. glabripennis adults do not disperse far when surrounded by host trees, they have the potential to fly more than 2000 m in a season. 6Volatile organic compounds from preferred host trees are attractive to A. glabripennis and this attraction is heightened by drought stress. Males and females orientate to a volatile released by female A. glabripennis and males attempt to copulate after contacting a sex pheromone on the female cuticle. 7At present, A. glabripennis is being (or has been) eradicated from areas where it has been introduced. After detection, extensive surveys are conducted and, if breeding populations are detected, at the very least, infested trees are removed and destroyed. Close attention is paid to imported solid wood packaging material to prevent new introductions. 8Standard practice to control A. glabripennis in China is to spray insecticides in tree canopies. In North America, largely as a preventative measure, systemic insecticides are injected into trees. Entomopathogenic fungi have been developed for the control of A. glabripennis, and entomopathogenic nematodes, coleopteran and hymenopteran parasitoids and predatory woodpeckers have been investigated as biocontrol agents. 9Ecological control of A. glabripennis in China involves planting mixtures of preferred and nonpreferred tree species, and this practice can successfully prevent outbreaks. [source] Pathogenicity of Phytophthora austrocedrae on Austrocedrus chilensis and its relation with mal del ciprés in PatagoniaPLANT PATHOLOGY, Issue 4 2010A. G. Greslebin Field observations, isolations and pathogenicity tests were performed on Austrocedrus chilensis (Cupressaceae) trees to determine the pathogenicity of Phytophthora austrocedrae and its role in the aetiology of the cypress disease mal del ciprés (MDC) in Argentina. It was found that P. austrocedrae is a primary pathogen of A. chilensis. It was isolated from large necrotic lesions in the inner bark, and superficially in the sapwood, at the root collar and stem, in most of the MDC-affected stands surveyed along the range of A. chilensis in Argentina. The main symptom in naturally infected trees was a necrotic lesion extending from killed roots up to 1 m up the tree bole. Seedlings, saplings and adult trees were all susceptible to inoculation with P. austrocedrae. Under favourable experimental conditions (flooding), inoculated seedlings suffered massive mortality in less than a month. The importance of diseases caused by Phytophthora spp. in South American forests is discussed. [source] | |||||||||||||