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Terence P. Dawson - One of the best experts on this subject based on the ideXlab platform.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity & Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats ( Melaleuca forests, marécage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity and Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats (Melaleuca forests, marecage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
David H Wahl - One of the best experts on this subject based on the ideXlab platform.
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phenotypic variation and vulnerability to predation in juvenile bluegill sunfish lepomis macrochirus
Oecologia, 2004Co-Authors: Steven R Chipps, Jessica A Dunbar, David H WahlAbstract:Bluegill sunfish (Lepomis macrochirus) are known to diversify into two forms specialized for foraging on either limnetic or Littoral prey. Because juvenile bluegills seek vegetative cover in the presence of largemouth bass (Micropterus salmoides) predators, natural selection should favor the Littoral body design at size ranges most vulnerable to predation. Yet within bluegill populations, both limnetic and Littoral forms occur where vegetation and predators are present. While adaptive for foraging in different environments, does habitat-linked phenotypic variation also influence predator evasiveness for juvenile bluegills? We evaluate this question by quantifying susceptibility to predation for two groups of morphologically distinct bluegills; a limnetic form characteristic of bluegills inhabiting open water areas (limnetic bluegill) and a Littoral form characteristic of bluegills inhabiting dense vegetation (Littoral bluegill). In a series of predation trials, we found that bluegill behaviors differed in open water habitat but not in simulated vegetation. In open water habitat, limnetic bluegills formed more dense shoaling aggregations, maintained a larger distance from the predator, and required longer amounts of time to capture than Littoral bluegill. When provided with simulated vegetation, largemouth bass spent longer amounts of time pursuing Littoral bluegill and captured significantly fewer Littoral bluegills than limnetic fish. Hence, morphological and behavioral variation in bluegills was linked to differential susceptibility to predation in open water and vegetated environments. Combined with previous studies, these findings show that morphological and behavioral adaptations enhance both foraging performance and predator evasiveness in different lake habitats.
James E.m. Watson - One of the best experts on this subject based on the ideXlab platform.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity & Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats ( Melaleuca forests, marécage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity and Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats (Melaleuca forests, marecage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
Nathalie Lécrivain - One of the best experts on this subject based on the ideXlab platform.
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Étude de la contamination et de l'écotoxicité associée des sédiments de surface en zone Littorale lacustre
2019Co-Authors: Nathalie LécrivainAbstract:La zone Littorale, de grande importance pour le fonctionnement écologique du lac, est souvent la première zone réceptrice de la contamination provenant du bassin versant. Cette pollution est majoritairement piégée dans les sédiments de surface. Pour autant, les conditions environnementales variables qui règnent en zone Littorale sont susceptibles de favoriser la biodisponibilité des contaminants par le jeu des réactions physico-chimiques et biologiques. Cette thèse s’appuie sur l’étude de deux grands lacs péri-alpins, le Lac du Bourget et le Lac d’Annecy, pour mieux comprendre le comportement des polluants sédimentaires (ETM, HAP et PCB) en zone Littorale lacustre. Nos travaux visent notamment (1) à caractériser la contamination Littorale et l’influence des sources locales dans cette contamination, (2) à évaluer l’écotoxicité des sédiments littoraux et les changements de mobilité et de biodisponibilité des polluants sédimentaires sous l’influence de changements abiotiques de la zone Littorale tels que ceux induits par le marnage lacustre. Nos résultats montrent que la contamination des sédiments et organismes autochtones présente une hétérogénéité spatiale significative sur le Littoral des deux lacs, tant en intensité qu’en composition (i.e. profil de contamination). L’implication de sources locales (e.g. eaux pluviales drainées sur le bassin-versant) dans cette hétérogénéité spatiale a été mise en évidence. L’écotoxicité des sédiments de la zone Littorale, évaluée via la réponse de biomarqueurs enzymatiques (AChE, GST), physiologiques (e.g. taux d’ingestion chez D. magna) et des traits de vie (e.g. taux de croissance, reproduction et survie) présente également une hétérogénéité spatiale significative. La biodisponibilité des ETM sédimentaires a été plus spécifiquement étudiée aux interfaces sédiment-eau-biote. Elle varie selon l’élément, le biote exposé (benthique ou pélagique) et sous l’effet du marnage. L’assèchement et remise en eau du sédiment Littoral s’accompagnent d’une réduction de la fraction biodisponible des ETM. L’abaissement de la hauteur d’eau, en revanche, entraîne une accentuation de la remise en suspension de particules sédimentaires susceptibles d’exercer un risque écotoxicologique sur le biote Littoral. Nos résultats soulignent la complexité de la contamination Littorale et de son transfert dans les grands lacs péri-alpins et encouragent les approches écotoxicologiques dans l’évaluation de l’état écologique.
Robert J. Whittaker - One of the best experts on this subject based on the ideXlab platform.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity & Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats ( Melaleuca forests, marécage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
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The importance of Littoral forest remnants for indigenous bird conservation in southeastern Madagascar
Biodiversity and Conservation, 2005Co-Authors: James E.m. Watson, Robert J. Whittaker, Terence P. DawsonAbstract:The Littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the Littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 Littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats (Melaleuca forests, marecage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the Littoral forests were depauperate of bird species and contained few species that were found within the Littoral forests. The geographic location of Littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in Littoral forest remnants. These results suggest that these Littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the Littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.
