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Some publications pertinent to this talk:

Some publications pertinent to this talk:

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Some publications pertinent to this talk:

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  1. Seeing the world through the nose of a bird: exploring the sensory ecology of Procellariiform seabirds Dr. Gabrielle Nevitt, Associate ProfessorUniversity of California, Davis Logistical support and funding provided by: CNRS / IPEV (France); BAS (UK)NSF Polar Programs and NSF Sensory Biology (USA)

  2. Some publications pertinent to this talk: • Nevitt, GA, Veit RR, and Kareiva P. 1995. Dimethyl sulfide as a foraging cue for Antarctic procellariiform seabirds. Nature 376, 680-682. • Nevitt, GA. 2000. Olfactory Foraging by Antarctic Procellariiform Seabirds: Life at High Reynolds Numbers. Biological Bulletin, 198, 245-253 • Nevitt GA, Reid K and Trathan P. 2004. Testing olfactory foraging strategies in an Antarctic seabird assemblage. Journal of Experimental Biology, 207, 3537-3544 • Silverman ED, Veit RR and Nevitt GA. 2004. Nearest neighbors as foraging cues: information transfer in a patchy environment. Marine Ecology Progress Series, 277, 25-35 • Bonadonna F and Nevitt GA. 2004. Partner-specific odor recognition in an Antarctic Seabird. Science, 306, 835 http://www.npb.ucdavis.edu/npbdirectory/nevitt.html

  3. Some Antarctic procellariiform seabirds

  4. The procellariiforms:(petrels, albatrosses and shearwaters) • Olfactory systems are well developed. • Species are highly pelagic. • Food resources are patchily distributed over vast areas so… • Many species commonly forage and navigate over extreme distances.

  5. Nearly all procellariiforms have highly developed olfactory system Cross section through the peripheral olfactory system (Bang 1966)

  6. krill fish squid

  7. Procellariiform seabirds routinely travel extreme distances over featureless ocean Wilson’s storm petrel

  8. Wandering albatross South Georgia Kergeulen

  9. Movement Patterns of Wandering Albatrosses South Africa South East (Shaffer et al. 2001, 2003)

  10. Different large-scale foraging strategies Commuting Scavenging

  11. Procellariiforms have different life history characteristics

  12. Can birds detect odors emitted from their prey? This turns out to be the wrong question.

  13. Several false assumptions have gotten in the way of thinking of odors as potential foraging and navigation cues: • Odor cues translate into concentration gradients over large distances. • Odors are ephemeral. • Transport is mediated by diffusion.

  14. Several false assumptions have gotten in the way of thinking of odors as potential foraging and navigation cues: • Odor cues translate into concentration gradients over large distances. • Odors are ephemeral. • Transport is mediated by diffusion.

  15. New concept: Navigation by Olfactory Landscapes Scented compounds are predictably elevated where productivity is high • shelf breaks • frontal zones • sea mounts (Nevitt, et al. Nature 1995)

  16. Olfactory Landscapes navigation large scale small scale (Nevitt, 2000)

  17. Dimethyl sulphide (DMS) is an important signal molecule in the marine environment DMS Oceanic Concentrations (nmol L-1) 10.0 1.0 0.1 Latitude Longitude (Data from Kettle, et al. 1999)

  18. Chlorophyll concentrations around Kerguelen Like DMS, chlorophyll occurs in predictable Locations and is associated with productive areas of ocean 25oS, 40o-75oE Kerguelen 54oS, 40o-75oE (Courtesy of SeaWiFS Project data base)

  19. Atmospheric DMS Oceanic DMS Metabolism and senescence Metabolism and excretion ZOO PLANKTON (DMSP) PHYTO PLANKTON (DMSP) DMSP DMS + Acrylic acid (adapted from Dacey and Wakham, 1986)

  20. DMS hotspots Oceanic DMS Metabolism and senescence Digestion and excretion ZOO PLANKTON (DMSP) PHYTO PLANKTON (DMSP) Ingestion DMSP DMS + Acrylic acid

  21. Variation in DMS seawater concentrations around a frontal zone (Sciare et al. 1999)

  22. The study system Africa Kerguelen Antarctic prion (Pachipitila desolata)

  23. The lab

  24. Establishing physiological sensitivity to the odor cue: Cardiac monitoring • Hypothesis: Birds respond to an odor presentation with a change in resting heart rate • Methods: • Establish resting heart rate • Present test subject with either odor (DMS) or control (water) stimulus using a vapor dilution olfactometer • Record heart rate. (e.g., Benvenuti, et al. 1992)

  25. Cardiac monitoring bird

  26. p<0.01 50 40 30 Mean change in heart rate (bpm) 20 10 0 DMS Control Antarctic prions respond to DMS at 3-4 nM concentrations Cardiac Monitoring N=10 (Nevitt and Bonadonna, submitted)

  27. Behavioral orientation to the odor cue: Y maze testing TEST ODOR: DMS in ethylene glycol CONTROL ODOR: ethylene glycol (e.g., Bonadonna and Nevitt, 2004)

  28. Behavioral orientation to the odor cue: Y maze testing TEST ODOR: DMS in ethylene glycol CONTROL ODOR: ethylene glycol (e.g., Bonadonna and Nevitt, 2004)

  29. 100 p<0.01 80 60 % Choice 40 20 N=24 0 DMS Control No choice Antarctic prions respond to DMS at biogenic (< pM) concentrations Y-Maze Testing (Nevitt and Bonadonna, submitted)

  30. Can procellariiform seabirds detect DMS? Conclusions: Antarctic prion adults can detect DMS at biologically relevant levels.

  31. What about at sea?

  32. Behavioral experiments at sea A good day

  33. Attraction to Scented Slicks Experimental Design control slick ship wind 100 meters odor slick

  34. Basic Behavior Assumptions: odor olfactory visual wind

  35. SAMPLE DATA Wilson’s storm-petrel ODOR CONTROL

  36. (Nevitt, Reid and Trathan, 2004) (0 = no response; X= positive response; ND = no data)

  37. Some key observations (South Georgia) Some species respond to visual cues and macerated krill Other species track DMS and…

  38. Feeding frenzy! (Photo by G. Robertson)

  39. At small scales, Procellariiforms use different olfactory foraging strategies to find prey

  40. DMS DMSP

  41. DMS DMSP

  42. DMS DMSP

  43. PYR DMS DMSP

  44. PYR DMS DMSP