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Combining Methods to Describe Important Marine Habitats for Top Predators: Application to Identify Biological Hotspots in Tropical Waters.

Thiers L, Louzao M, Ridoux V, Le Corre M, Jaquemet S, Weimerskirch H - PLoS ONE (2014)

Bottom Line: To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds.We found that the distribution of frigatebirds included the distributions of the associated species.The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

View Article: PubMed Central - PubMed

Affiliation: Centre d'Études Biologiques de Chizé, Station d'Ecologie de Chizé-La Rochelle UMR 7372, Centre National de la Recherche Scientifique, 79360, Villiers en Bois, France.

ABSTRACT
In tropical waters resources are usually scarce and patchy, and predatory species generally show specific adaptations for foraging. Tropical seabirds often forage in association with sub-surface predators that create feeding opportunities by bringing prey close to the surface, and the birds often aggregate in large multispecific flocks. Here we hypothesize that frigatebirds, a tropical seabird adapted to foraging with low energetic costs, could be a good predictor of the distribution of their associated predatory species, including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins, tunas). To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds. By developing species distribution models (SDMs), we identified key marine areas for tropical predators in relation to contemporaneous oceanographic features to investigate multi-species spatial overlap areas and identify predator hotspots in the Mozambique Channel. SDMs reasonably matched observed patterns and both static (e.g. bathymetry) and dynamic (e.g. Chlorophyll a concentration and sea surface temperature) factors were important explaining predator distribution patterns. We found that the distribution of frigatebirds included the distributions of the associated species. The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

No MeSH data available.


Related in: MedlinePlus

Associated seabird descriptive spatial analysis in the Mozambique Channel.(a) Tern and (b) boobies density (number of birds.km−2) from vessel-based surveys between September and December (2002–2010) (light green) and from aerial survey in December 2009 (dark green) are represented. White rectangles represent the breeding colony in Europa Island, Juan de Nova and the wintering ground in the Comoros.
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pone-0115057-g003: Associated seabird descriptive spatial analysis in the Mozambique Channel.(a) Tern and (b) boobies density (number of birds.km−2) from vessel-based surveys between September and December (2002–2010) (light green) and from aerial survey in December 2009 (dark green) are represented. White rectangles represent the breeding colony in Europa Island, Juan de Nova and the wintering ground in the Comoros.

Mentions: Based on vessel surveys, terns showed a wide distribution in the MC with their main concentration area in the south-west of the Channel (more than 2000 birds in a single observation) followed by an important concentration area in the north-east sector (Fig. 3a). Aerial observations confirm the wide distribution of sooty terns in the surveyed area, but show larger aggregations around the Comoro archipelago and very low densities on the continental shelf of Madagascar (Fig. 3b).


Combining Methods to Describe Important Marine Habitats for Top Predators: Application to Identify Biological Hotspots in Tropical Waters.

Thiers L, Louzao M, Ridoux V, Le Corre M, Jaquemet S, Weimerskirch H - PLoS ONE (2014)

Associated seabird descriptive spatial analysis in the Mozambique Channel.(a) Tern and (b) boobies density (number of birds.km−2) from vessel-based surveys between September and December (2002–2010) (light green) and from aerial survey in December 2009 (dark green) are represented. White rectangles represent the breeding colony in Europa Island, Juan de Nova and the wintering ground in the Comoros.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262456&req=5

pone-0115057-g003: Associated seabird descriptive spatial analysis in the Mozambique Channel.(a) Tern and (b) boobies density (number of birds.km−2) from vessel-based surveys between September and December (2002–2010) (light green) and from aerial survey in December 2009 (dark green) are represented. White rectangles represent the breeding colony in Europa Island, Juan de Nova and the wintering ground in the Comoros.
Mentions: Based on vessel surveys, terns showed a wide distribution in the MC with their main concentration area in the south-west of the Channel (more than 2000 birds in a single observation) followed by an important concentration area in the north-east sector (Fig. 3a). Aerial observations confirm the wide distribution of sooty terns in the surveyed area, but show larger aggregations around the Comoro archipelago and very low densities on the continental shelf of Madagascar (Fig. 3b).

Bottom Line: To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds.We found that the distribution of frigatebirds included the distributions of the associated species.The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

View Article: PubMed Central - PubMed

Affiliation: Centre d'Études Biologiques de Chizé, Station d'Ecologie de Chizé-La Rochelle UMR 7372, Centre National de la Recherche Scientifique, 79360, Villiers en Bois, France.

ABSTRACT
In tropical waters resources are usually scarce and patchy, and predatory species generally show specific adaptations for foraging. Tropical seabirds often forage in association with sub-surface predators that create feeding opportunities by bringing prey close to the surface, and the birds often aggregate in large multispecific flocks. Here we hypothesize that frigatebirds, a tropical seabird adapted to foraging with low energetic costs, could be a good predictor of the distribution of their associated predatory species, including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins, tunas). To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds. By developing species distribution models (SDMs), we identified key marine areas for tropical predators in relation to contemporaneous oceanographic features to investigate multi-species spatial overlap areas and identify predator hotspots in the Mozambique Channel. SDMs reasonably matched observed patterns and both static (e.g. bathymetry) and dynamic (e.g. Chlorophyll a concentration and sea surface temperature) factors were important explaining predator distribution patterns. We found that the distribution of frigatebirds included the distributions of the associated species. The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

No MeSH data available.


Related in: MedlinePlus