Hi MARMAM,
My co-authors and I are pleased to announce the publication of the
following paper in Marine Mammal Science:
Labadie, G., Tixier, P., Barbraud, C., Fay, R., Gasco, N., Duhamel,
G. and Guinet, C. 2018. First demographic insights on historically
harvested and poorly known male sperm whale populations off the
Crozet and Kerguelen Islands (Southern Ocean). Marine Mammal Science
1–21.
ABSTRACT
Age and sex dependent spatial segregation has resulted in limited
knowledge of the ecology and demography of sperm whale adult males
feeding seasonally in high latitudes. This study focused on adult
males interacting with the Patagonian toothfish (Dissostichus
eleginoides) fishery operating off the Kerguelen and Crozet
Archipelagos. Demographic parameters were estimated using a
10-yr-long photo-identification data set paired with multistate
closed robust design capture-mark-recapture models. The examination
of a set of 29,078 photographs taken from fishing vessels during
sperm whale depredation events resulted in identification of 295
individuals with nine visiting both study areas. Dispersal between
both study regions was estimated to be 1% per year. The mean annual
number of interacting sperm whales was estimated to n = 82 (95% CI
58–141) in Crozet and n = 106 (95% CI 76–174) in Kerguelen.
Transient proportions were 13% in Crozet and 26% in Kerguelen.
Corrected for transience, apparent survival estimates were 0.953
(95% CI 0.890–0.993) in Crozet, and 0.911 (95% CI 0.804–0.986) in
Kerguelen. These survival and population size estimates are the
first for depredating adult males in high latitudes, and can be used
in evaluating the current conservation status of this historically
harvested stock and to investigate depredation trends in both Crozet
and Kerguelen Islands.
The paper is available online at onlinelibrary.wiley.com
Feel free to contact me directly for a PDF copy.
Cheers,
Guillemette Labadie
PhD Student in Biology
Université Laval, Qc, Canada
guillemette.labadie@gmail.com