THE ANIMAL FILES

Common bottlenose dolphin

Tursiops truncatus

An echo helps find an object; a whistle helps keep contact.

Common bottlenose dolphins use sound for more than one task. Echolocation helps investigate surroundings and prey, while whistles and body contact participate in social communication. Mothers and calves provide a particularly clear setting in which to study changes in calling.[1]

Follow the evidence ↓
Common bottlenose dolphin
Image: NASA · Commons · Public domain
Prey detection
Uses echolocation[1]
Social signals
Whistles, pulses and body movements[1]
Diet
Fish, squid and other marine animals[1]

Listen for the returning signal

During echolocation, emitted sound returns after reflecting from objects. The returning information helps the dolphin locate things around it, including potential prey. This differs from simply producing a loud sound: the useful result depends on the relationship between the outgoing signal and what comes back.[1]

Calls change in a mother–calf setting

Recordings compared mothers with and without dependent calves. Their signature whistles shifted toward higher or broader frequencies when calves were present. That observation documents a context-linked change; the exact benefit to calves requires more evidence than a resemblance to human child-directed speech.[1]

A hunting group is not the only option

Bottlenose dolphins hunt individually and can also cooperate around fish schools. Diet varies by location because local prey differ. Teeth hold prey that is generally swallowed rather than chewed into small mouthfuls, so capture, group coordination and swallowing are separate parts of the feeding sequence.[1]

A COMMON MIX-UP

Is every dolphin sound an echolocation click?

No. Whistles and other sounds also occur in social communication. A sound must be interpreted by its structure and context rather than assuming that all acoustic activity serves the same task.[1]

TRY A LITTLE REASONING

Why record the same mother with and without her calf?

Reveal the explanation

It helps separate context-linked changes from differences between individuals. Comparing unrelated callers alone could confuse a mother–calf effect with each animal’s own characteristic whistle.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Common bottlenose dolphin (fixed revision; adapted and translated)
  2. NCBI Taxonomy — Tursiops truncatus (identity and classification)

Last fact check:

One discovery leads to another

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