What's the role of birds
in aquatic ecosystems
and how may birds be
affected by climate
change?
What's the role of birds
in aquatic ecosystems
and how may birds be
affected by climate
change?
The esthetic factor
Out of more than
200 pages, less
than ¼ page on
birds
WATERBIRDS
Beautiful
Go for large prey
Aquatic Ecology
...it’s all about
N and P
Birds are hot.......and energetically expensive
Bird 40ºC
Mammal 37ºC
Reptile 37ºC
Reptile 30ºC
Reptile 20ºC
Basal M etabolism (W att)
100
10
1
0,1
0,01
0,1
1
10
Mass (kg)
100
Bewick’s Swans and Fennel Pondweed
Bewick’s swans as gourmants
Kirkwood’s
MEImax± 95% CI
gr assGrass
OP 941
Grass
gr as s B &M
K 942
sugar beet
WM3
Beets
sugar
beet4
Beets
t uber sTubers
WS96
White Sea
‘96
Dvina
Bay
t uber sTubers
LM 95
Lauwersmeer ‘95
Lauwersmeer
t uber sTubers
LM 96
Lauwersmeer
Lauwersmeer ‘96
Korovinskaya ‘98 Bay
Korovinskaya
t uber
s PD
Tubers
0
50
100
150
200
dai l y met abol i sabl e ener gy i nt ake (Wat t )
daily metabolisable energy intake (Watt)
Klaassen et al. Oikos 2010
The impact of waterbirds?
• Cormorants
– 20.000 breeding pairs in NL
– consuming 10.000 tons of fish annually
– diet selection + ideal free distribution
– > local effects of most interest
Number of Mute Swans
Veluwemeer
10000
1000
Sep
100
Jul
May
10
1985
1990
1995
2000
Year
2005
2010
Hot birds......and diet quality
burning off carbon
increasing protein
density !!
Hot birds......and diet quality
MNR:BMR
gross N:C
(mgN kJ-1)
foliage
10
10
0.35
1
1
0.035
N:C terrestrial
plants (5-95%)
0.1
0.001
0.01
0.1
1
10
body mass (kg)
0.1
0.0035
100
Hot birds......and diet quality
MNR:BMR
gross N:C
(mgN kJ-1)
WATERBIRDS
10
foliage
10
0.35
Beautiful
Go for large prey
1
Need a lot (endothermy)
1
0.035
N:C terrestrial
May doplants
with
“low quality”
(5-95%)
0.1
0.001
0.01
0.1
1
10
body mass (kg)
Birds fly
From: ‘the travelling birds’
0.1
0.0035
100
WATERBIRDS
Beautiful
Go for large prey
Need a lot (endothermy)
May do with “low quality”
Have wings
- dispersal
Wetland eutrofication by waterbirds
“Inputs of Nitrogen from guano of migratory
waterfowl…can represent a major input of N and P
to certain lakes…”
“Vertebrates excreta, particularly of birds,
are well known to import large quantities of
nutrient, especially N and P to inland waters….”
Wetzel (2001) Limnology
Do waterfowl play a significant role as nutrient vectors?
· How much is it (>local scale)?
· Who are the main contributors?
Background: Allochthonous nutrient input
Hahn, Bauer, Klaassen
Carnivores
Herbivores
Freshwater Biology 08/2007
Excretion in lakes/rivers
Hahn, Bauer & Klaassen
Freshwater Biology 10/2007
Model applications – The Netherlands
Year
N (tons)
2001/02
243.4 - 458.1
2002/03
278.2 - 527.7
2003/04
272.3 - 517.2
Freshwater NL: 357 440ha
N: 0.74-1.40 kg*ha-1
Year
N (tons)
Internal
External
2001/02
47-124
36-87
2002/03
55-144
37-89
2003/04
58-152
41-98
N: 0.26-0.65 kg*ha-1
M5
Effects of foraging and bioturbation
nutrient cycling increases
> net increase in nutrient availability
>algae profit over macrophytes
increased turbidity
>macrophytes suffer
Dia 21
M5
The nitrogen surplus is the difference
between the input by mineral fertilisers,
livestock manure, atmospheric deposition,
biological nitrogen fixation and other inputs
such as sewage sludge, and the output in the
form of harvested crops. The nitrogen
surplus indicates the nitrogen which
potentially can be lost to groundwater and
surface waters and cause eutrophication
problems.
MarcelK; 9-3-2007
WATERBIRDS
Beautiful
Go for large prey
Need a lot (endothermy)
May do with “low quality”
Have wings
- dispersal
- redistribute nutrients
Foraging & Bioturbation
What's the role of birds
in aquatic ecosystems
and how may birds be
affected by climate
change?
Waterbirds and
Climate Change
Problems with making predictions
• Waterbirds at high trophic level
• not all organisms, communities and
ecosystems respond in synchrony
Waterbirds and
Climate Change
Problems with making predictions
• Waterbirds at high trophic level
• Complex behaviour including adaptations
Waterbirds and
Climate Change
Problems with making predictions
• Waterbirds at high trophic level
• Complex behaviour including
adaptations
• Living in a big world
• suitable habitats are not uniformly
distributed
Waterbirds and
Climate Change
Problems with making predictions
• Waterbirds at high trophic level
• Complex behaviour including
adaptations
• Living in a big world
• suitable habitats are not uniformly
distributed
• changes not identical or correlated across
the globe
Differential changes along flyway
Changes in onset
of spring
1982-1999
Based on NDVI data
by Høgda (1999)
Denmark : leave two weeks earlier
140
135
Departure Denmark
130
125
120
115
110
105
100
1990
1992
1994
1996
1998
2000
2002
Year
Trøndelag: increasing importance
16
Staging time Trondelag
14
12
10
8
6
4
2
0
1990
1992
1994
1996
Year
1998
2000
2002
Waterbirds and
Climate Change
Problems with making predictions
•
•
•
•
Waterbirds at high trophic level
Complex behaviour including adaptations
Living in a big world
Other Global change processes
National Environmental Research Institute – Aarhus University
Predictions of breeding habitat suitability
Present
1oC temp. increase
scenario
National Environmental Research Institute – Aarhus University
2oC temp. increase
scenario
Source: Jensen et al. (2008)
Predictions of winter habitat suitability
Present
Change from 2000 - 2050
National Environmental Research Institute – Aarhus University
Source: Wisz et al. (2008a)
Waterbirds and
Climate Change
Problems with making predictions
•
•
•
•
Waterbirds at high trophic level
Complex behaviour including adaptations
Living in a big world
Other Global change processes