Hello everyone - I am so very pleased to finally announce the
publication of my modelling work on North Pacific right whale
distributions. The article provides (I hope!) insights into right
whale habitat use in the NP, and shows how models at different
scales can help elucidate ecological processes. Technically, the
work combines historic data with contemporary oceanographic model
output using the MaxEnt presence-only modelling framework. I hope
some of you find this of interest.
Abstract below, full text available at:
http://www.int-res.com/articles/esr_oa/n015p223.pdf
Best regards,
ed.
Gregr, Edward J. 2011. Insights into North Pacific right whale Eubalaena
japonica habitat from historic whaling records. Endangered
Species Research, 15:223-239.
Whaling records from the mid-1800s provide the largest set of
observations with which to conduct a basin-scale analysis of
potential North Pacific right whale Eubalaena japonica
habitat. Since these data lack the concurrent oceanographic data
necessary to investigate the species’ habitat characteristics I
used ocean climate from a 20th century circulation model to create
a suitable set of habitat predictors. My goals were to (1)
identify regions of suitable habitat and (2) investigate the
processes underlying the species–habitat relationship by (3)
examining model performance at different spatial and temporal
scales. The results show 2 non-overlapping habitat regions in the
subarctic North Pacific, supporting the notion of 2 distinct
subpopulations. The analysis also implicates surface temperature
and temperature variability as strong indicators of potential
right whale habitat. Tests of model performance at different
scales strongly suggest that at the basin-scale, right whales use
regions of cold water with low inter-annual variability and high
within-season variability (i.e. areas where high frontal activity
occurs predictably from year to year). The significance of these
indicators decreased at the regional scale emphasising the
coupling of scale and process, and thus the need for different
predictors at different scales. Comparisons of models built using
different subsets of the dependent data showed how hypotheses can
be tested and potential biases in observational data can be
explored. Analyses of rare species’ habitat such as this can
provide guidance for more directed survey efforts and help
identify areas and processes of potential biological importance.