52-Hertz whale
... that the 52-Hertz whale is known only by its unique sound (listen, speeded up ten times to 520 hertz), the only one of its kind ever recorded, and has been called the loneliest whale in the world?
... that the <b id="mwUg"><a class="mw-redirect" href="./52-Hertz_whale" id="mwUw" rel="mw:WikiLink" title="52-Hertz whale">52-Hertz whale</a></b> is known only by its unique <a class="mw-redirect" href="./Whale_sound" id="mwVA" rel="mw:WikiLink" title="Whale sound">sound</a> <i id="mwVQ">(listen, speeded up ten times to 520 hertz)</i>, the only one of its kind ever recorded, and has been called the loneliest <a href="./Whale" id="mwVg" rel="mw:WikiLink" title="Whale">whale</a> in the world?