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Book Population Dynamics of the Natterjack Toad Bufo Calamita in a Fragmented Pond Complex South West Ireland

Download or read book Population Dynamics of the Natterjack Toad Bufo Calamita in a Fragmented Pond Complex South West Ireland written by Aurélie Emily Aubry and published by . This book was released on 2009 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis documented and explored empirical data on populations of natterjack toads (Bufo calamita Laurenti), a pond-breeding amphibian particularly vulnerable to climate change, habitat degradation and fragmentation. The research used data collected in the field (census and environmental data, mark-recapture study) to assess the spatiotemporal dynamics of toad populations at local (2-5km) and regional (>10km) scales, to identify the local environmental determinants of toad breeding activity and success and to assess the movement patterns of juvenile and adult toads within and between breeding sites. There was no synchrony in the toad breeding activity and success at the local level, suggesting that populations function as individual clusters independent of each other, with little or irregular dispersal among populations. Regional synchrony in both rainfall and temperature probably explain the observed regional synchrony in the number of egg strings (used as a surrogate for adult breeding female population size). Using a model selection approach, results indicated that the abundance and diversity of predators of tadpoles were the most influential factors on toad reproductive success. A 46-day mesocosm experiment indicated that the presence of B. calamita tadpoles and their predators (here the dragonfly Sympetrum striolatum larvae) could enhance the functioning of pond ecosystems through both direct and indirect effects, in particular through increases in decomposition rates and enhanced secondary production. Several aspects of the research suggested that some of the toad populations were structured as source-sink populations, where the viability of local populations in sink habitats relies on immigration from source areas. The maintenance of a network of ponds within the dispersal range of species is therefore essential to ensure the long-term viability of amphibian populations, especially for those species (e.g. B. calamita) breeding in temporary ponds.

Book The Natterjack Toad

Download or read book The Natterjack Toad written by Trevor John Clark Beebee and published by . This book was released on 1983 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Dispersal in the Natterjack Toad a Species with a Fragmented Distribution

Download or read book Dispersal in the Natterjack Toad a Species with a Fragmented Distribution written by Virginie Stevens and published by . This book was released on 2006 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Natterjack Toad

Download or read book The Natterjack Toad written by and published by . This book was released on 1978 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Investigation Into the Effects of Batrachochytrium Dendrobatidis Bd on Natterjack Toad Bufo Calamita Populations in the UK

Download or read book An Investigation Into the Effects of Batrachochytrium Dendrobatidis Bd on Natterjack Toad Bufo Calamita Populations in the UK written by Peter Minting and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The chytridiomycete Batrachochytrium dendrobatidis (Bd) is a parasite which has been blamed for amphibian declines across the world. This study was designed to investigate the effects of Bd on natterjack toads (Bufo calamita), following the discovery of Bd populations of this species in the UK. The effect of Bd on natterjack toads was assessed by fieldwork and experiments. Wild adult natterjacks were tagged and repeatedly tested for Bd during 2009-2011. Captive adults and juveniles from infected populations were also tested in response to changes in environmental conditions. Swabs were used to collect Bd DNA from the skin of study animals. Swabbing did not reliably diagnose infection but the quantity of Bd DNA in swabs (Bd score) provided an indication of infection activity. Immersion in water appeared to trigger Bd zoospore emergence from the skin, resulting in an increase in the likelihood of Bd detection and increases in Bd score. Bd dynamics in natterjack populations were also influenced by salinity. Natterjacks in the UK are found mainly in coastal habitat, where ponds are often inundated by high tides. Adults captured in brackish water were less likely to test positive than those caught in fresh water. Bd isolated from coastal natterjacks was killed in vitro by a salinity equivalent to 50% seawater. The isolate grew fastest at low salinities, suggesting that it may have become adapted to brackish conditions. Despite this adaptation, tidal inundation may be sufficient to disinfect ponds and limit Bd transmission. Capture-mark-recapture (CMR) data from adult natterjacks revealed a weak negative correlation between Bd score and survival in the wild. Males had higher Bd scores than females but survival did not differ between sexes and there was no correlation between Bd score and growth. An experiment showed BD could kill natterjacks if infection activity was boosted by wet conditions. However only 6% of wild adults recorded Bd scores in excess of a mortality threshold derived from this experiment. Many adults and juvenile natterjacks can tolerate Bd infection and act as reservoirs of this pathogen. Despite detection of Bd in at least 14 UK natterjack populations by 2011, no mass mortalities of adult natterjacks have been reported and spawning has continued at all sites. Bd does not appear to have a major effect on natterjacks but this situation may not persist and vigilance should be maintained. Bd isolated from natterjack toads in this study belomgs to a global panzootic lineage (GPL) of Bd which Farrer et al (2011) claim has achieved a global distribution as a result of human activities.

Book Density related features of natterjack toad Bufo calamita populations in Britain

Download or read book Density related features of natterjack toad Bufo calamita populations in Britain written by J. S. Denton and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Conservation of an Endangered Amphibian

Download or read book Conservation of an Endangered Amphibian written by Marina Reyne and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book A study of the factors determining the suitability of artificially constructed breeding sites for the natterjack toad Bufo calamita at the Ainsdale National Nature Reserve

Download or read book A study of the factors determining the suitability of artificially constructed breeding sites for the natterjack toad Bufo calamita at the Ainsdale National Nature Reserve written by K M. AITCHISON and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Natterjack Toad

Download or read book Natterjack Toad written by J. S. Denton and published by . This book was released on 1995 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Adaptation to a Variable Environment

Download or read book Adaptation to a Variable Environment written by Lee Damien Brady and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Natterjack Toad Bufo Calamita

Download or read book Natterjack Toad Bufo Calamita written by Scottish Natural Heritage (Agency) and published by . This book was released on 1996* with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: