Maintenance or Variation in Core Temperature in Diving Penguins

1. Maintenance or Variation in Core Temperature in Diving Penguins A closer look at blood flow and internal body temperatures

4. Future Directions Should utilize Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) Non-invasive techniques Reduce �snapshot� measurements and instead provide �real time� continuous measurements

5. Diving Physiology of Penguins Core temperature conservation vs. variability in King Penguins and Emperor Penguins The two studies had different results

6. Review of Previous Findings Core temperatures dropped during dive times Was attributed to ingestion of cold food

7. Temperature Regulation in Diving Mammals Endotherms subject to extreme temperatures conserve energy and water by allowing their body temperatures to vary Diving mammals must face both air and water conditions. Water has 25 times the thermal conductivity of air Temperature regulation is thus quite challenging Flexibility should confer an advantage

8. The question: Does internal body temperature remain the same or change during dives in penguins? How does this relate to fitness?

9. Methodology Laboratory-based experiment Recent trends towards field studies Advantages of lab studies: Ability to control environmental variables, such as temperature Ability to control temperature of food, which has been shown to influence stomach temperature Environmental Manipulation Adjust temperature of water Watch response in blood perfusion, core vs. peripheral temperature, and diving performance as a function of dive times Do penguins exhibit phenotypic plasticity?

10. Methodology 5 males, 5 females in each group 2 groups per year Randomly chosen sample Expose each group to each temperature for one month Maintain constant ambient temperature Regulate diet and provide food at constant temperature (upon insertion into tank) Record all measurements Analyze with repeated measures ANOVA

11. Study Design Temps: -5 C 0 C 5 C 10 C 15 C

12. Methodology Measurement Temperature Measurements Blood Perfusion Dive Times Aerobic Dive Limit Method Temperature loggers MRI Video surveillance Measure lactate levels in blood

13. By exposing the penguins to different water temperatures, we will be able to assess their responses to temperature while keeping other variables constant Diet, temperature of food Do we see regional heterogeneity in body temperature? What are the patterns of blood perfusion? Are penguins exceeding their ADL? Are their dives longer in warmer or colder environments? Do they exhibit any phenotypic plasticity?

14. Implications Phenotypic plasticity can be seen as an alternative to evolution, or as an adaptive trait itself What do the penguins do in warmer waters? Could this suggest their response to predicted climate change? Phenotypic plasticity could confer an advantage should the environment change

15. Thank you!