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2010-01-01T00:00:00 |
Satellite transmitters were attached to the body of North Pacific right whales using
a pneumatic delivery system. Whales were tagged with the implantable configuration
of the SPOT 5 transmitters produced by Wildlife Computers (Redmond, WA). Transmitters
were duty-cycled to optimize data collection in the feeding grounds and for maximizing
tag longevity. Tags were programmed to transmit every day for 6 hours (14-21hs UTC)
during daytime and 6 hours (2-9hs UTC) during night time for the months of August
and September. Beginning in October, when migration likely begins, transmitters were
programmed to transmit every other day, following the same alternate 6hr on/off periods.
Satellite tags were monitored by Argos Data Collection and Location Service receivers
on NOAA TIROS-N weather satellites in sun-synchronous polar orbits. Locations were
calculated by Argos from Doppler-shift data when multiple messages were received during
a satellites passage overhead. Argos codes locations in quality classes (LQ) labeled
B, A, 0, 1, 2, 3, in order of increasing accuracy. Argos locations were processed
using the software R. The SDA Argos filter (Freitas et al., 2008) was applied to all
location qualities in software R in order to remove locations that implied unlikely
deviations from the tracks path as well as unrealistic travel rates. This filter requires
two main parameters: turning angles and maximum speed of travel. The default value
of turning angles (Freitas et al., 2008) was used and the maximum speed was assumed
to be 15km/h (e.g. Mate et al., 1997). Exploratory analysis showed that the use of
different maximum speed limits (12 and 18km/h) did not influence the results.
Distances between filtered locations were calculated assuming a great circle route.
Methods are described in the published manuscript: A. N. Zerbini, Baumgartner, M.
F., Kennedy, A. S., Rone, B. K., Wade, P. R., and Clapham, P. J.
Space use patterns of the Endangered North Pacific right whale Eubalaena japonica
in the Bering Sea. Marine Ecology Progress Series. doi: 10.3354/meps11366
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