RAINFALL PATTERN AND PRODUCTIVITY
OF ARCTIC NESTING GEESE
Bylot Island
Ba
ffi
n
N
Isl
an
d
Nicolas Lecomte 1, Gilles Gauthier 1 & Jean-François Giroux 2
[email protected] ;
150 km
1
Département de Biologie and Centre d’Études Nordiques, Université Laval, Qc;
2 Université du Québec à Montréal, Qc
Water availability is a key factor affecting nesting success and the arctic trophic interactions
Experimental results
Observational results
Precipitations in a changing arctic
Over the last 17 years, the mean monthly precipitation
have a slight but positive impact on the success of nests
in both habitats (R2=0.04).
great as change in air temperature but its impact on
ecosystems has received less attention than the latter.
Fig 5.
40
To test the causal link
between water availability
and
productivity,
we
supplemented 40 nests
with water boxes in both
nesting habitats
R2=0.07
20
Fig 3. Goose eggs are a prime source of food for Arctic
Foxes (Alopex lagopus) and avian predators. Eggs are
exposed to predation when incubating females
periodically leave their nest to drink
-20
-40
Departure from the 1989-2005 average
5 year running mean
1989
1992
1995
1998
2001
2004
Years
Fig 1. Rainfall anomaly on Bylot Island during the nesting
season (June-July) of Greater Snow Geese (Chen
caerulescens atlantica) indicating an increase of 30 mm
of total precipitation from 1989 to 2005
Greater snow goose and wetlands
Wetlands are the preferred nesting habitats of geese and
offer abundant water for incubating females. However,
geese nest also in dry tundra where water is scarce
because wetlands are restricted to only small patches.
Fig 2. Wetlands offer key habitats for arctic species and
could be greatly affected by change in rainfall abundance
Our behavioral observations suggested that geese
nesting in dry tundra expose their nest to greater degree
than those in wetland habitat because they had to travel
a greater distance to find water.
1.0
Nesting success
0
Experimental nests
wetland
mesic
0.9
0.8
0.7
0.6
c
Control nests
b
a
146
114
20
20
0.0
Nesting success difference
between wet vs dry tundra
Total rainfall (mm)
Most global climatic models foresee that climate change
will be the strongest in the Arctic. Change in rainfall
abundance resulting from global warming could be as
Nest habitats
0.16
Fig 6. Effect of the water boxes and the habitat on the
mean nesting success (± SE). Numbers in bars indicate
R2 = 0.67
sample size. Different letters indicate significant t-test
between groups (P<0.001).
0.12
0.08
Conclusion
0.04
0.00
20
30
40 50 60 70 80
Total rainfall (mm)
90
Fig 4. The annual correlation between the summer total
rainfall (1995-2005) and the difference of nesting
success between habitats indicates a positive impact of
water availability on nest success in dry tundra
Funding, assistance, and logistical support provided by:
ACKNOWLEDGEMENTS
Environnement
Canada
Environment
Canada
1. Rainfall abundance has a direct positive impact on
the productivity of geese mediated through the
behavioral process of incubation recesses.
2. Wetlands provide key habitats for nesting geese by
their high availability of water, even during dry
summers.
3. Further studies need to quantify the long-term
effects of rainfall changes on the dynamic of arctic-bird
populations.
Thanks to fieldwork helpers, especially V. Careau, M. A. Giroux, A. Hargreaves & M. Morissette
Arctic Goose
Joint Venture