polar bear status update, moscow, 2013 - norsk...
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Polar Bear Status Update, Moscow, 2013
Conservation Status, and Potential Threats
IUCN/SSC Polar Bear Specialist Group
Because all risks to polar bear conservation must be
placed in the context of human caused global warming
the time frame is critical to any discussion.
Think of 3 major time frames:
Long View Certainty-Mid Century+
Near Term Uncertainty
Where we are now
Polar Bear
Distribution:
Circumpolar in
19
subpopulations
5
Four major ecoregions
6
Regardless of
Ecoregion--
Polar bears depend on
the sea-ice surface for
catching their prey
7
Polar bears feed
almost exclusively on
ringed and bearded
8
This marine dependence has allowed them to become the
largest of the bears.
And, polar bears can reliably catch seals only from the
sea ice surface
10
And a warmer world means less sea ice
But the world is warming
Global Mean Annual Temp Anomaly
Diff
eren
ce fr
om 1
951
-19
80 M
ean
(D
eg
C)
1870 1890 1910 1930 1950 1970 1990 2010
-0.4
-0.2
00
.10
.30.
50
.7
12,000 years of Global mean temperatures
(Marcott et al. 2013)
0 5 10 15 20 25
-10
12
34
5
Time
Tem
pera
ture
0 5 10 15 20 25
-10
12
34
5
Time
Tem
pera
ture
0 5 10 15 20 25
-10
12
34
5
Time
Tem
pera
ture
17
GHGs Increasing
GHGs Stable
Warming must continue as long as GHG levels rise
This is the
uncertainty This is
the
certainty
Note: no overall recovery in 2013
So, if we don’t stop the rise
in GHGs, polar bear
numbers utimately can only
decline.
In the near term, however, there is much uncertainty, and
need for aggressive and cooperative management
We do not expect all populations to suffer from
warming at the same time or in the same ways
Some subpopulations will be able to maintain
a traditional harvest for many years
And, bears in some areas could experience transient benefits
before they ultimately decline.
So, where are we now?
2009 2013
2013: 1 increasing, 5 stable, 4 declining, 9 data deficient
2009: 1 increasing, 3 stable, 8 declining, 7 data deficient
Let’s look at the subpopulations that changed status
FoxeBasin
BaffinBay
DavisStrait
M'ClintockChannel
WesternHudson Bay
Gulf ofBoothia
SouthernHudson Bay
LancasterSound
250km 80°W 70°
70°
60°N
Data Deficient to Stable
Recent aerial survey estimated 2580 (95% CI: 2093 – 3180) polar bears
(Stapleton et al. 2012)-not statistically different from an earlier estimate
of 1994 indicating a stable population. But estimates of vital rates are
unavailable, and vital rates observed from adjacent populations vary
considerably.
DavisStrait
FoxeBasin
EastGreenland
BaffinBay
SouthernHudson Bay
250km 50°60°W
50°N
60°
Declining to Stable
Recent inventory completed in 2007 estimated the subpopulation as
2,158 (95% CI: 1,833–2,542) (Peacock et al. 2013), much higher than
early estimates. But low recent estimates of reproductive and recruitment rates may reflect negative effects of greater densities or worsening ice condition.
LancasterSound
BaffinBay
M'ClintockChannel Foxe
Basin
KaneBasin
ArcticBasin
ViscountMelville
Gulf ofBoothia
NorthernBeaufort
NorwegianBay
250 km 100°W 90°
80°
70°N
Declining to Data Deficient
Estimate of 2,541 ± 391 based on an analysis of mark-recapture data up
to 1997 (Taylor et al. 2008)-larger than a previous estimate of 1,675 that
included Norwegian Bay (Stirling et al. 1984). Age of the estimate and
limited vital rates data suggesting low renewal rate require a DD status.
ArcticBasin
LancasterSound
BaffinBay
KaneBasin
ViscountMelville
NorthernBeaufort
NorwegianBay
M'ClintockChannel250 km 80°90°W
80°N
Declining to Data Deficient
The most current (1993 – 97) estimate is 203 ± 44 (SE; Taylor et al.
2008). Survival rate estimates for the NW subpopulation were derived
from pooled Lancaster Sound and NW data because the subpopulations
are adjacent and the number of bears captured in NW was too small to
generate reliable survival estimates.
ChukchiSea
ArcticBasin
LaptevSea Southern
Beaufort
250km 180° 170°W
60°N
70°
Declining to Data Deficient
Stable or improved body condition and reproduction between 1986-1994
and 2008-2011,among bears captured in the spring in the U.S. portion of
the population’s range (Rode et al. 2013) suggests capacity for positive
natural population growth despite recent sea ice declines. But, autumn-
based observations on Wrangel Island, 2004-2010, suggest low cub
production and reduced maternity denning (Ovsyanikov 2012). This and
absence of a population estimate suggested status of data deficient.
AB
DS
KS
LP
BS
CS
FB
BB
SH
EG
NB
SB
LS
MC
WH
KB
VM
GB NW
Hunting
Contaminants
Oil and Gas
Other
Concerns
With 9 subpopulations data deficient on trend and
12 on status, we obviously have work to do:
Next: Circumpolar monitoring strategy
Then: Suggested research priorities.
Discussion?