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Localizing Vocalizations in fish-eating southern resident killer whales ( Orcinus orca)

Localizing Vocalizations in fish-eating southern resident killer whales ( Orcinus orca). Peggy Foreman Beam Reach 2006 Marine Science and Sustainability School. Social Arrangements. Pod- primary social unit of matrilineal groups Subpods and matrilines (J, K, and L)

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Localizing Vocalizations in fish-eating southern resident killer whales ( Orcinus orca)

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  1. Localizing Vocalizations in fish-eating southern resident killer whales (Orcinus orca) Peggy Foreman Beam Reach 2006 Marine Science and Sustainability School

  2. Social Arrangements • Pod- primary social unit of matrilineal groups • Subpods and matrilines (J, K, and L) • Communities- frequent associations with one or more pods, yet have different distributions with other communities (J + K + L) • Clans- acoustically related; shared vocal tradition (J clan)

  3. Vocal Clans • Complex repertoire of whistles, clicks, and calls • Calls are pulsed signals generated in high repetition rates and most fall into discrete categories • These discrete calls are the most common sound type when individuals are widely spread out (cohesion)

  4. Gender • 86 whales (~14 sexually mature males and ~23 reproductive females) • Sexual dimorphism • Predict lower frequency fundamental for males • May spatially segregate to some degree when foraging • Shorter duration of calls • Changes in harmonic frequency

  5. Questions • Are there any variations in calls in regards to gender? Call Characteristics: Call duration, Fundamental Frequency, and variations in the first harmonic of a call

  6. Materials * Towed linear 4 hydrophone array * National Instruments Board with 4 channels * PC computer: Ishmael software to localize calls Raven software to analyze calls * Clipboard: PDA/data sheets (behavioral data) * Binoculars * Range finder (research assistant) * Camera (research assistant)/ID guides

  7. Methods • Hydrophone array was deployed off the starboard steps • Continuous Acoustic Recording in Ishmael (sampling rate of 22050, DFT rate 512) • Behavior Data ( # focal animal/s, distance, bearing, and predominant group behavior state) • Opportunistic lone individuals or small groups (increase my success in localizing)

  8. Acoustic Analysis: ISHMAEL • Software designed to localize • Phone pair bearing, crossed-pair bearing, hyperbolic location, and beam forming • 0°, 180° can’t get a valid bearing (15°) • Dinghy experiment: accurate with in 17° and closer than 300m to the boat worked best • calculates two bearings

  9. Acoustic Analysis: ISHMAEL

  10. Raven Analysis: Call Characteristics • Duration • Fundamental • 1st Harmonic Analysis (low, high, and change in Frequency)

  11. Results: • Acoustic and surface behavior observations were recorded on 6 out of 19 field days • 19.5 hr of acoustical recordings and 16.95 hr of PDA data (1170 one minute files) • Looked through 115 one minute files • Localized 122 calls • 19 of those localized calls matched my bearing (avg 5.8° difference)

  12. Results: SD= slow directional

  13. Results: ANOVA: F[2,16]=2.4212, p= 0.1206 4 3 12 95% confidence intervals

  14. Results: ANOVA: F[2,16]=1.8183, p= 0.1943 4 3 12

  15. Results: 1st Harmonic ANOVA: F[2,16]=0.4785, p= 0.6283 4 3 12

  16. Results: 1st Harmonic ANOVA: F[2,16]=1.2457, p= 0.3142 4 3 12

  17. Results: 1st Harmonic ANOVA: F[2,16]=3.5752, p= 0.0521 12 4 3 4 3 12

  18. Discussion

  19. Discussion • Real differences between gender and mixed groups? • Analyzed calls: Different call types? • Males and Females could be using different calls • The frequency Modulation changes with mixed gender groups could that be due to group size? • Variations due to more than one pod together?

  20. Why is this important? • Localizing is only one piece of the larger picture • Who is speaking…is it the oldest matriarch • …is it the male on the periphery • scouting out “good” foraging areas • Acoustically recognize individuals • - especially in winter • - detect when additions or loss of individuals • occur in the population

  21. Future Studies • Full summer season to see if changes in calls change with location, behavior, different social organizations • Calling rate • Source level of calls • Call type vs. surface behavior • Do males and females use the same discrete calls (vary with age?)

  22. Acknowledgements • Huge thank you to the instructors of Beam Reach • (Jason Wood, Donna Hauser, Scott Veirs, and Val Veirs) • Beam Reach colleagues (Rena Escobedo, Emily Pierson, Erin Soucy, Colleen Barry, and Juliette Nash) • Todd, Mike, Glenn for the use and safe navigation of the Gato Verde • Puyallup Tribe of Indians for your financial support • Dr. James Ha for creating my specialized PDA program

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