[MARMAM] New publication on calving areas and critical habitat for Risso's dolphins

marc fernandez marc.fern at gmail.com
Thu May 1 07:30:31 PDT 2014


Dear MARMAM colleagues,

We are pleased to announce that the following paper has been made available
online:

Hartman K, Fernandez M, Azevedo JN (2014) Spatial segregation of calving
and nursing Risso’s dolphins (Grampus griseus) in the Azores, and its
conservation implications. Marine Biology: 1-10 doi
10.1007/s00227-014-2430-x

ABSTRACT

Calving can be a critical period for cetaceans. Areas providing security
for vulnerable calves, and high food availability for lactating females can
be critical habitats requiring specific conservation measures. Here, we
test the hypothesis that calving and nursing habitat could be defined for
Risso’s dolphins (*Grampus griseus*). We investigated the spatial and
temporal preferences of this species around Pico Island, Azores, using data
gathered from land-based surveys and dedicated at-sea observations between
2004 and 2007. We divided observed pods into three groups: (1) those with
newborn and young calves, (2) those with older calves or juveniles and (3)
those consisting only of adults or sub-adults. We analysed eco-geographical
variables and incorporated them into a presence-only spatial distribution
model to evaluate differences in habitat suitability among the groups. We
identified 694 pods of Risso’s dolphins overall. On the 267 pods observed
in the first and second groups, 136 calves or juveniles were identified, of
which 22 were newborns. The peak of the calving season was between June and
August. The pods with newborn calves were larger and closer to shore,
whereas the other groups were more widely dispersed offshore. Our results
support the definition of critical habitat areas for this species, but we
suggest widening the geographical coverage for better mapping around the
island and throughout the archipelago generally. Conservation measures can,
nevertheless, be implemented immediately, in order to reduce human impacts
on a vulnerable component of the Risso’s dolphin population.


The paper can be checked at:

http://link.springer.com/article/10.1007/s00227-014-2430-x?no-access=true

Please do not hesitate to contact us for any question regarding our work.


All the best,

Marc Fernandez
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