[MARMAM] New paper on scale-dependent foraging ecology of bottlenose dolphins
pirotts at libero.it
Mon Aug 5 01:23:19 PDT 2013
Dear MARMAM colleagues,
We are pleased to announce that the following paper has been published
Pirotta, E., Thompson, P. M., Miller, P. I., Brookes, K. L., Cheney, B.,
Barton, T. R., Graham, I. M., Lusseau, D. (2013), Scale-dependent foraging
ecology of a marine top predator modelled using passive acoustic data.
Functional Ecology. doi: 10.1111/1365-2435.12146
1. Understanding which environmental factors drive foraging preferences is
critical for the development of effective management measures, but resource use
patterns may emerge from processes that occur at different spatial and temporal
scales. Direct observations of foraging are also especially challenging in
marine predators, but passive acoustic techniques provide opportunities to
study the behaviour of echolocating species over a range of scales.
2. We used an extensive passive acoustic data set to investigate the
distribution and temporal dynamics of foraging in bottlenose dolphins using the
Moray Firth (Scotland, UK). Echolocation buzzes were identified with a mixture
model of detected echolocation inter-click intervals and used as a proxy of
foraging activity. A robust modelling approach accounting for autocorrelation
in the data was then used to evaluate which environmental factors were
associated with the observed dynamics at two different spatial and temporal
3. At a broad scale, foraging varied seasonally and was also affected by
seabed slope and shelf-sea fronts. At a finer scale, we identified variation in
seasonal use and local interactions with tidal processes. Foraging was best
predicted at a daily scale, accounting for site specificity in the shape of the
4. This study demonstrates how passive acoustic data can be used to understand
foraging ecology in echolocating species and provides a robust analytical
procedure for describing spatio-temporal patterns. Associations between
foraging and environmental characteristics varied according to spatial and
temporal scale, highlighting the need for a multi-scale approach. Our results
indicate that dolphins respond to coarser scale temporal dynamics, but have a
detailed understanding of finer-scale spatial distribution of resources.
KEY WORDS: echolocation; feeding buzz; GEEs; habitat preference; modelling;
multi-scale; PODs; Tursiops
A PDF copy of the work can be downloaded from: http://onlinelibrary.wiley.
Please do not hesitate to contact me for any question regarding our work.
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