[MARMAM] New paper:Local abundance, apparent survival and site fidelity of Bryde’s whales in the Hauraki Gulf (New Zealand) inferred from long-term photo-identification

Gaby de Tezanos Pinto gaby at pachamama.co.nz
Sun Jul 23 15:27:26 PDT 2017

Dear MARMAM community,

On behalf of all co-authors, I will like to bring to your attention a new
article entitled:
Local abundance, apparent survival and site fidelity of Bryde’s whales in
the Hauraki Gulf (New Zealand) inferred from long-term photo-identificationESR
34:61-73 (2017)  -  DOI: https://doi.org/10.3354/esr00839

Bryde’s whales *Balaenoptera edeni* in New Zealand are classified as
‘nationally critical’ according to the New Zealand Threat Classification
System. In the Hauraki Gulf, Bryde’s whales occur year-round and are
subject to ship-strike mortality events. Photo-identification surveys were
conducted to estimate local abundance, apparent survival and site fidelity
during 2 periods from 2004 to 2006 (261 daily surveys) and from 2011 to
2013 (382 daily surveys). The photo-identification database contained a
total of 364 sighting records of 72 Bryde’s whales. Overall, 20 whales were
sighted across the 2 survey periods, indicating long-term site fidelity.
Local abundance was estimated using the robust design (RD) and POPAN
mark-recapture approaches for each period, including upward adjustment for
the proportion of unmarked whales. RD seasonal abundance estimates varied
from 17 to 43 whales between 2004 and 2006, and from 13 to 31 whales
between 2011 and 2013. Temporary emigration followed a random pattern (γ’ =
γ’’) and was estimated at 0.557 between 2004 and 2006, and 0.610 between
2011 and 2013. POPAN seasonal abundance ranged from 38 to 74 whales for the
2004 to 2006 period and from 42 to 68 whales for 2011 to 2013. Apparent
survival was estimated across periods at 0.878 (95% CI = 0.811-0.923). From
the ‘super population’ estimate of the 2011 to 2013 survey period (*N*super =
135 whales, CI = 100-183), we calculated a potential biological removal
(PBR) of 1 whale yr-1. Given the impact of ship strikes on this local unit,
it is important to continue long-term photo-identification of Bryde’s
whales. This technique provides valuable demographic information for a
poorly known species.

Authors:  G.Tezanos-Pinto, K. Hupman, N. Wiseman, S. L. Dwyer, C. S. Baker,
L. Brooks, B. Outhwaite, C. Lea, K. A. Stockin.

Thank you
Gaby (on behalf of all co-authors)

Gabriela Tezanos-Pinto
Massey University, Albany
New Zealand
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