Presentation at WIU\'s Biology Day 2006 to middle school students

2. How Does theHow Does the
Walrus Hear?Walrus Hear?
What Does theWhat Does the
Walrus Say?Walrus Say?

3. Walrus HearingWalrus Hearing
 Little knownLittle known
 Only one study andOnly one study and
probably not entirelyprobably not entirely
accurate.accurate.
 AmphibiousAmphibious
 AerialAerial
 UnderwaterUnderwater

4. Outer and Middle EarOuter and Middle Ear
 Sound vibrations travel to the pinna.Sound vibrations travel to the pinna.
 Sound is channeled to the ear drumSound is channeled to the ear drum
(tympanic membrane)(tympanic membrane)
 Sound is amplified and travels across 3Sound is amplified and travels across 3
bonesbones
 Malleus, Incus, StapesMalleus, Incus, Stapes

6. The Inner EarThe Inner Ear
 CochleaCochlea
 Oval windowOval window
 Doorway to CochleaDoorway to Cochlea
 Basilar MembraneBasilar Membrane
 Vibrations lead to pitch and tone detectionVibrations lead to pitch and tone detection
 Hair CellsHair Cells
 Bend as the basilar membrane rubs togetherBend as the basilar membrane rubs together
 Auditory NerveAuditory Nerve
 Hair cells that bend release CaHair cells that bend release Ca++
that relays thethat relays the
message to the brain.message to the brain.

8. Cochlea-straightenedCochlea-straightened

10. Adaptations in WaterAdaptations in Water
 Bone ConductanceBone Conductance
 Reduced PinnaReduced Pinna

11. Questions On HearingQuestions On Hearing

12. Do they Talk?Do they Talk?
 NO!NO!
 Walruses communicateWalruses communicate
 SoundsSounds
 TouchTouch
 SmellSmell
 BehaviorBehavior

13. ActivityActivity
 Break into groupsBreak into groups
 Come up with sounds that you think aCome up with sounds that you think a
walrus would makewalrus would make
 Must give a demo of the soundMust give a demo of the sound
 Why does this sound matter?Why does this sound matter?

14. My ResearchMy Research
 Study PinnipedsStudy Pinnipeds
 Pacific WalrusPacific Walrus
 Pacific Harbor SealPacific Harbor Seal
 California Sea LionCalifornia Sea Lion
 Record Underwater SoundsRecord Underwater Sounds
 Look for Ultrasonic frequenciesLook for Ultrasonic frequencies
 Catalog the Repertoire at HigherCatalog the Repertoire at Higher
FrequenciesFrequencies

15. BackgroundBackground
 Males are typicallyMales are typically
vocal to attractvocal to attract
females duringfemales during
breeding seasonbreeding season
 Pick up linePick up line
 No studies onNo studies on
femalesfemales
 Very vocal animalsVery vocal animals

16. GoalsGoals
 To record underwaterTo record underwater
sounds to look forsounds to look for
ultrasonicultrasonic
components andcomponents and
potential use towardspotential use towards
echolocation.echolocation.
 To observe behaviorsTo observe behaviors
in attempt toin attempt to
understand functionunderstand function
of sounds produced.of sounds produced.

17. MaterialsMaterials
 Ithaco 605 Hydrophone-Ithaco 605 Hydrophone-
Ultrasonic frequencyUltrasonic frequency
response.response.
 DELL XPS M140 Laptop.DELL XPS M140 Laptop.
 Goldwave sound analysisGoldwave sound analysis
program and recordingprogram and recording
software.software.
 Spectrogram soundSpectrogram sound
analysis program.analysis program.

18. MethodsMethods
 Recordings takenRecordings taken
during Spring andduring Spring and
Summer months ofSummer months of
2006 at Brookfield2006 at Brookfield
Zoo between 6-10AM.Zoo between 6-10AM.
 Behavioral notesBehavioral notes
taken as needed astaken as needed as
well as video.well as video.

19. What do I do with theWhat do I do with the
datadata
 Listen to sound filesListen to sound files
 Identify SoundsIdentify Sounds
 Analyze withAnalyze with
SoftwareSoftware
 Identify certainIdentify certain
featuresfeatures
 Run statistical testsRun statistical tests
 Similar and differentSimilar and different

20. Glugs by JoanGlugs by Joan

21. Unclassified SoundUnclassified Sound

22. ConclusionsConclusions
 Walruses makeWalruses make
really cool soundsreally cool sounds
 Still not sure whyStill not sure why
 Much of it isn’tMuch of it isn’t
ultrasonicultrasonic

23. Just for funJust for fun

24. QUESTIONS?QUESTIONS?
Mehgan Clark: MM-NOOK@WIU.EDU