Acoustic Signal Production in Animals (Tendon Plucking, Tremulation, Pulsation, Fanning, Fluid Compression, Streaming)

Flashcards covering tendon plucking, tremulation, pulsation, fanning, fluid compression, and streaming with examples and purposes from the lecture notes.

What is tendon plucking in animal sound production?

A method of producing sound by putting tension on a tendon and plucking it over a bony protuberance, which sounds like a thud rather than a guitar resonating.

Which organism is given as an example of tendon plucking, and how many tendons do they have to produce sounds?

Croaking gouramis; they have two tendons that can produce plucking sounds.

Why might having two sound-producing mechanisms be advantageous?

It allows doubling the rate (frequency) of sound and expands the range of sound varieties to encode more information.

What is tremulation?

A sound-production method in which the entire body rocks to transmit vibrations into another object, typically at very low frequencies.

In red-eyed tree frogs, why is tremulation used at night instead of vocalization?

To signal dominance while avoiding predators—the vocalization would attract nighttime predators, so tremulation is quieter and cheaper energy-wise.

How does body size relate to tremulation strength in frogs?

Larger frogs can generate stronger tremulations.

How can monarch butterfly larvae respond to tremulation in a plant during a human-caused frequency event?

They tremulate when a frequency matches the leaves’ resonant frequency, causing the plant to vibrate and prompting larval tremulation.

What is pulsation in the context of sound production?

The contraction and expansion of a closed flexible object within a fluid, generating sound.

What is a classic example of pulsation sounds in animals?

Sounds produced by swim bladders in fish.

What are sonic muscles and what is their role with swim bladders?

Muscles that attach to or surround the swim bladder; rapid contraction produces pulsation sounds; these muscles hypertrophy during reproductive seasons and atrophy outside them.

Which fish have the fastest sonic muscles and what is their contraction rate?

Toadfish and midshipman; about 300 contractions per second, yielding a fundamental frequency around 300 Hz.

What is fanning in acoustic production?

Moving a flat solid object cyclically through air to produce sound; common in very small organisms like mosquitoes and fruit flies, with little far-field sound.

How do male fruit flies use wing fanning in courtship?

The male’s wingbeat sound attracts females and increases mating likelihood.

What is the wingbeat-frequency signaling observed in elephant mosquitoes?

Opposite-sexed individuals converge on the same wingbeat frequency indicating compatibility; same-sex individuals diverge indicating incompatibility.

What is fluid compression as a sound production mechanism?

Sound produced by rapid pressure changes in a fluid, causing phenomena like cavitation bubbles or sonic booms from rapid wing or propeller action.

How do snapping shrimp produce sound?

By snapping their claws so quickly that cavitation bubbles form and collapse, creating a sharp sound.

How do manakins produce pops via fluid compression?

Rapid wing flicks cause fluid compression, generating a popping sound similar to a sonic boom.

What is streaming in acoustic signaling?

Sound produced by moving through a fluid quickly enough for the flow over the body to generate sound, often via feather edges vibrating in birds.

How do nighthawks use streaming as a courtship signal?

During a high-speed dive, they flare their primary feathers, causing the edges to vibrate and produce a race-car-like sound that attracts females.