Factors Affecting Adlie Penguin Foraging Energetics and Chick Growth off the Western Antarctic Penin

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Factors Affecting Adélie Penguin Foraging
Energetics and Chick Growth off the Western
Antarctic Peninsula A Modeling Study

• Erik W Chapman
• Eileen E Hofmann
• William R Fraser
• Christine A Ribic

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Research Questions

• How does variability in the marine and
  terrestrial environment influence Adélie penguin
  chick growth?
• How does variability in environmental and
  physiological constraints influence adult Adélie
  penguin foraging energetics and chick growth?

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Climate influence onAdélie Populationsand Scope
of Model
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Research Focus 1

• Objectives What are the effects of variability
  in.
• Timing of Spawning and Lipid Accumulation
• on Antarctic krill energy density and Adélie
  penguin chick growth

• E W Chapman, W R Fraser, E E Hofmann, D L
  Patterson (In Press) Variability in sex/maturity
  stage and demography among Antarctic krill
  (Euphausia superba) on Adélie penguin (Pygoscelis
  adeliae) chick growth A modeling study, Deep-Sea
  Research II

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Results
Timing of Spawning
Simulated fledging mass (kg)
Mass of recruits
Reference mass
Mass of non-recruits
Date of peak spawning
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Results
Timing of Spawning
- 20 days
Simulated fledging mass (kg)
Mass of recruits
Reference mass
Mass of non-recruits
Date of peak spawning
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Results
Timing of Spawning
Simulated fledging mass (kg)
Mass of recruits
Reference mass
Mass of non-recruits
20 days
Date of peak spawning
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Climate Alteration of Phenology Affects Chick
Growth?
Summary
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Research Focus 2

• Objectives What are the effects of variability
  in
• Prey Composition
• Addition of Antarctic silverfish to diet.
• Addition of Electrona antarcticum
• Wetting Effect
• Resulting from increased snowfall
• (melt) in colonies.
• on Antarctic krill energy density
• and Adélie penguin chick growth

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Results - Diet Complexity
Electrona antarcticum
Antarctic silverfish
Mass of Chicks that recruit
Mass of Chicks that do not recruit
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Results - Wetting Effect and Antarctic Silverfish
Added to Diet
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Research Focus 3

• Objectives What are the effects of variability
  in.
• Prey Density and Distribution
• Variability in Ingestion rate and distance
  traveled to prey.
• Diet Composition
• All-female krill diet
• Addition of Antarctic silverfish
• on adult Adélie
  penguin foraging energetics and chick growth

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Results - 100 vs 50 Female Krill
Simulated Fledging Mass (kg)
50 females
100 females
14
18
22
26
30
14
18
22
26
30
10
10
Distance of prey from colony (km)
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Results - Addition of Antarctic Silverfish to
Diet (60)
Simulated Fledging Mass (kg)
All-krill
Krill and Fish
14
18
22
26
30
10
10
14
18
22
26
30
Distance of prey from colony (km)
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Implications

• Adélie penguins at Anvers Island may be
  experiencing several climate-related
  environmental alterations influencing adult
  foraging and chick growth
• Reduced populations of Antarctic krill and
  Antarctic silverfish
• Increased wetting effect
• Altered krill spawning schedule