With inspiration from Phil Karlton’s wise saying “There are only two hard things in Computer Science: cache invalidation and naming things," let's try to reach wiki-consensus on orca bioacoustic nomenclature!

Orca signals

The three types of vocalizations produced by killer whales:

• call (aka "pulsed call" or "pulsed signal")
  • signal consists of pulses generated at repetition rates of ~250-2000 pulses/s (Ford, 1987)
  • characterized by a fundamental frequency and harmonics (therefore more complex than a whistle)
  • typical duration and bandwidth: most ~0.5-1.5s, but range of 5 milliseconds to 10s (Ford, 1987); 200-20,000 Hz (Ford, 1987 says: "primary energy 1-6kHz, with some high-frequency components up to 30kHz)
  • discrete calls = calls in "distinctive structural categories," "highly repetitive", "different categories distinguishable by ear", "variability in structure occurred within all discrete call categories, but certain categories tended to be more variable than others", (Ford, 1987)
  • stereotyped calls = repeated and recognizable
  • variable calls = not stereotyped
  • biphonic call = a call with two simultaneous, independently-modulated fundamental frequencies
  • repertoire = stereotyped calls of a group
• whistle
  • a single sinusoid with varying frequency ("for the most part" say Brown and Miller, 2007)
  • "non-pulsed or continuous waveform... a single, narrowband tone with little or no harmonic or sideband structure" ... and "extreme structural variability" (Ford, 1987)
  • typical duration and bandwidth: ~1-10 s; 1000-20,000 Hz
• click (aka "echolocation" or "echolocation signal" or "biosonar")
  • a short, broadband pulse
  • typical duration and bandwidth: 0.1-25 milliseconds (Ford, 1987); 100-100,000 Hz
  • impulse train = a series of broadband pulses
    • slow clicks = impulse train with inter-click interval (ICI) > 1 second
    • fast clicks = impulse train with ICI < 1 second
    • buzz = impulse train with ICI < 0.1 second

Other sounds that indicate the presence of killer whales:

• percussive
  • impact of pectoral fin or tail on sea surface
  • impact of body on sea surface (e.g. upon breaching or porpoising)
• cavitation
  • caused by fluke during rapid acceleration (e.g. during Bigg's predation events)
  • caused by tail strike (used by Icelandic or Norwegian KWs to stun herring)
• predation
  • caused by the jaw closing rapidly (e.g. a SRKW capturing a salmon)

With consideration of at least:

• Brown and Miller (2007)

Orcas

Groups

• matriline (aka "matrilineal line") = group from the same mother
• pod = group of several matrilines
• clan = group of pods that share calls

Ecotypes of the Northeast Pacific

• SRKWs = Southern Resident Killer Whales
  • J, K, and L pods
• NRKWs = Northern Resident Killer Whales
  • Many pods...
• Bigg's = West Coast Transient Killer Whales
• Offshores