The Experts below are selected from a list of 24105 Experts worldwide ranked by ideXlab platform
Philip S. Hammond - One of the best experts on this subject based on the ideXlab platform.
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Habitat Preferences and distribution of the harbour porpoise Phocoena phocoena west of Scotland
Marine Ecology Progress Series, 2013Co-Authors: Cormac G. Booth, Clare B. Embling, Jonathan Gordon, S. V. Calderan, Philip S. HammondAbstract:The west coast of Scotland is comprised of complex coastlines and topography, and a range of physical processes influence its coastal marine environment. The region is host to one of the highest densities of harbour porpoise Phocoena phocoena in Europe. The aim of this study was to identify Habitat Preferences driving the distribution of harbour porpoise, to gain a better understanding of the spatial distribution of the species in the region, as well as to assess the consistency of such patterns across time and space. Visual and acoustic line-transect surveys were conducted between 2003 and 2010. Generalised Additive Models (GAMs) with Generalised Estimating Equations (GEEs) were used to robustly determine relationships between the relative density of harbour porpoises and temporally and spatially variable oceanographic covariates. Predictive models showed that depth, slope, spring tidal range and distance to land were consistently important in explaining porpoise distribution. Consistent Preferences for water depths between 50 and 150 m and highly sloped regions were observed across the temporal models. Predicted distributions revealed a consistent inshore presence for the species throughout the west coast of Scotland and confirmed that predictable oceanographic features could help inform the establishment of Special Areas of Conservation (SACs) for the species.
Graham J. Pierce - One of the best experts on this subject based on the ideXlab platform.
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Habitat Preferences and interannual variability in occurrence of the harbour porpoise phocoena phocoena off northwest scotland
Marine Ecology Progress Series, 2009Co-Authors: Francesca Marubini, Alessandro Gimona, Peter G H Evans, Peter J Wright, Graham J. PierceAbstract:The harbour porpoise Phocoena phocoena is the most common cetacean around the British Isles, but knowledge of its ecology, Habitat Preferences and inter-annual variability is still inadequate. Here, sightings collected by the Sea Watch Foundation during vessel surveys in West Scotland (August during the years 1993, 1994, 1996 and 1997) were critically analysed and used to construct a predictive Habitat model for harbour porpoises in the Greater Minch. Generalised additive models were used to analyse relative abundance in relation to environmental variables; a preference for waters within 15 km from the shore and between 50 and 150 m depth was clearly identified. A relationship between tidal variables and porpoise distribution was also recognised with more sightings predicted for high tidal stream speed areas as well as during times of high tide. Maps constructed from the model were used to identify potential ‘hotspots’and compare between years. Four areas with high relative abundance were identified in (1) the region between Ardnamurchan, Coll and the Small Isles, (2) southeast of Barra, (3) northeast of Skye to Gairloch, and (4) west of Pairc Peninsula (Isle of Lewis) to Shiant Islands. Number of sightings fluctuated up to 4-fold between consecutive years; such extreme variability in relative abundance is offered as a bench-mark for comparing trends in the future as well as evidence that the Greater Minch represents only a small part of the effective range of this population.
Cormac G. Booth - One of the best experts on this subject based on the ideXlab platform.
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Habitat Preferences and distribution of the harbour porpoise Phocoena phocoena west of Scotland
Marine Ecology Progress Series, 2013Co-Authors: Cormac G. Booth, Clare B. Embling, Jonathan Gordon, S. V. Calderan, Philip S. HammondAbstract:The west coast of Scotland is comprised of complex coastlines and topography, and a range of physical processes influence its coastal marine environment. The region is host to one of the highest densities of harbour porpoise Phocoena phocoena in Europe. The aim of this study was to identify Habitat Preferences driving the distribution of harbour porpoise, to gain a better understanding of the spatial distribution of the species in the region, as well as to assess the consistency of such patterns across time and space. Visual and acoustic line-transect surveys were conducted between 2003 and 2010. Generalised Additive Models (GAMs) with Generalised Estimating Equations (GEEs) were used to robustly determine relationships between the relative density of harbour porpoises and temporally and spatially variable oceanographic covariates. Predictive models showed that depth, slope, spring tidal range and distance to land were consistently important in explaining porpoise distribution. Consistent Preferences for water depths between 50 and 150 m and highly sloped regions were observed across the temporal models. Predicted distributions revealed a consistent inshore presence for the species throughout the west coast of Scotland and confirmed that predictable oceanographic features could help inform the establishment of Special Areas of Conservation (SACs) for the species.
Francesca Marubini - One of the best experts on this subject based on the ideXlab platform.
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Habitat Preferences and interannual variability in occurrence of the harbour porpoise phocoena phocoena off northwest scotland
Marine Ecology Progress Series, 2009Co-Authors: Francesca Marubini, Alessandro Gimona, Peter G H Evans, Peter J Wright, Graham J. PierceAbstract:The harbour porpoise Phocoena phocoena is the most common cetacean around the British Isles, but knowledge of its ecology, Habitat Preferences and inter-annual variability is still inadequate. Here, sightings collected by the Sea Watch Foundation during vessel surveys in West Scotland (August during the years 1993, 1994, 1996 and 1997) were critically analysed and used to construct a predictive Habitat model for harbour porpoises in the Greater Minch. Generalised additive models were used to analyse relative abundance in relation to environmental variables; a preference for waters within 15 km from the shore and between 50 and 150 m depth was clearly identified. A relationship between tidal variables and porpoise distribution was also recognised with more sightings predicted for high tidal stream speed areas as well as during times of high tide. Maps constructed from the model were used to identify potential ‘hotspots’and compare between years. Four areas with high relative abundance were identified in (1) the region between Ardnamurchan, Coll and the Small Isles, (2) southeast of Barra, (3) northeast of Skye to Gairloch, and (4) west of Pairc Peninsula (Isle of Lewis) to Shiant Islands. Number of sightings fluctuated up to 4-fold between consecutive years; such extreme variability in relative abundance is offered as a bench-mark for comparing trends in the future as well as evidence that the Greater Minch represents only a small part of the effective range of this population.
Zuzanna Pestka - One of the best experts on this subject based on the ideXlab platform.
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Habitat Preferences of red backed shrikes lanius collurio and barred warblers sylvia nisoria breeding sympatrically in a wetland farmland mosaic
Bird Study, 2018Co-Authors: Zuzanna Pestka, Dariusz Jakubas, Katarzyna WojczulanisjakubasAbstract:ABSTRACTCapsule: The Red-backed Shrike Lanius collurio and the Barred Warbler Sylvia nisoria had similar Habitat Preferences and their territories often overlapped. However, we found that Red-backed Shrikes were more flexible in Habitat choice whilst Barred Warblers had more specific requirements.Aim: We aimed to analyse and compare distribution and Habitat Preferences of Red-backed Shrikes and Barred Warblers breeding sympatrically in semi-natural landscape in a wetland/farmland mosaic.Methods: We examined Habitat availability and use by the two species within their breeding territories to identify differences in Habitat selection.Results: Territories of both species were similar in Habitat composition and used levees, bushes, fallow areas and single trees. However, the spatial characteristics of the territories differed between species. Red-backed Shrikes used a wider range of sizes and shapes of Habitat patches, whilst Barred Warblers preferred a more complex landscape structure and a higher diversity ...
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Habitat Preferences of Red-backed Shrikes Lanius collurio and Barred Warblers Sylvia nisoria breeding sympatrically in a wetland/farmland mosaic
2018Co-Authors: Zuzanna Pestka, Dariusz Jakubas, Katarzyna Wojczulanis-jakubasAbstract:Capsule: The Red-backed Shrike Lanius collurio and the Barred Warbler Sylvia nisoria had similar Habitat Preferences and their territories often overlapped. However, we found that Red-backed Shrikes were more flexible in Habitat choice whilst Barred Warblers had more specific requirements. Aim: We aimed to analyse and compare distribution and Habitat Preferences of Red-backed Shrikes and Barred Warblers breeding sympatrically in semi-natural landscape in a wetland/farmland mosaic. Methods: We examined Habitat availability and use by the two species within their breeding territories to identify differences in Habitat selection. Results: Territories of both species were similar in Habitat composition and used levees, bushes, fallow areas and single trees. However, the spatial characteristics of the territories differed between species. Red-backed Shrikes used a wider range of sizes and shapes of Habitat patches, whilst Barred Warblers preferred a more complex landscape structure and a higher diversity of Habitat types. We also found that areas of 71% of Barred Warbler and 34% of Red-backed Shrike territories overlapped. Conclusion: Whilst both species showed similar Habitat choices, they appeared to differ significantly in terms of landscape structure: Red-backed Shrikes were more flexible and less selective than Barred Warblers in their Habitat choice.