Density-dependent changes in the distribution of Southern Right Whales (Eubalaena australis) in the breeding ground Peninsula Valdés.
PeerJ
; 6: e5957, 2018.
Article
em En
| MEDLINE
| ID: mdl-30564513
ABSTRACT
BACKGROUND:
The Southern Right Whale (Eubalaena australis) population of the South-western Atlantic Ocean is recovering. In the breeding ground of Peninsula Valdés, as a consequence of the population growth, expansion to new areas by some types of groups and a change in the habitat use patterns at the coastal area were recorded.METHODS:
We analysed information gathered from aerial surveys conducted along the coast of Peninsula Valdés in 15 years of effective sampling in a 19-year span. These surveys were divided into four periods (1999-2000; 2004-2007; 2008-2012 and 2013-2016) and estimated the density of whales in a 620 km of coast divided into segments of five km.RESULTS:
The density of the whales increased to near three whales per km2 (averaged over each period) in the high-density areas. When this mean number was reached, the significant changes in density in the adjacent areas were detected in the following period. These changes were a decrease in density in the high-density areas and an increase of density in the low-density areas.DISCUSSION:
We propose that a threshold in density elicits a response in habitat use, with the Mother-calf pairs remaining in the area, while the other groups are displaced to new areas.
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Base de dados:
MEDLINE
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En
Ano de publicação:
2018
Tipo de documento:
Article