To
predict the potential breeding hotspots of southern right whales in
southern Brazil, we used a Maxent model with a “presence-only” dataset.
The dataset was obtained from a systematic aerial survey and public
records of the Programa de Monitoramento de Cetáceos da Bacia de Santos
and Sistema de Apoio ao Monitoramento de Mamíferos Marinhos. Because of
spatial autocorrelation, 528 records out of 3028 were used in the
modelling process. The explanatory variables used in the models were
coastal distance, linearity, slope and substrate type. The models were
created separately for unaccompanied adults (Ad) and mother-calf pairs
(Fe). Both models showed good accuracy according to their area under the
curve values (Ad=0.974; Fe=0.958). Coastal distance was the most
relevant explanatory variable for the unaccompanied adult model (54%),
whereas coastal linearity was more relevant for the mother-calf pair
model (82%). The estimated area for mother-calf pairs was more
restricted to coastal areas than that for unaccompanied adults, possibly
owing to the high number of shelter areas for calves near the coast.
This is the first study to predict the potential breeding hotspots of
southern right whales in Brazil and its results will allow for a more
directed management of these whales and provide further research
opportunities. |