The sea cows have good hearing but may be less aware of sounds when they're sleeping.
- Manatees have sensitive hearing, research shows.
- Still, the animals are often struck by fast-moving watercraft.
Manatees have sensitive hearing, but that doesn't necessarily keep them safe from passing boat propellers, a new study finds.
These docile sea cows have no natural predators in their coastal U.S. habitat, but fast-moving speedboats and other watercraft are a danger. Collisions with boat hulls or propellers can severely wound or kill a manatee.
Researchers have long questioned why manatees can't seem to effectively avoid boats. The animals' vision is bad, so researchers from Mote Marine Laboratory and Aquarium turned to the question of how well manatees hear.
Mote researcher Joe Gaspard and colleagues tested the auditory abilities of two aquarium manatees, Buffett and Hugh, both of which are trained to participate in behavioral research. The researchers had the manatees swim to a "listening station" underwater and then had them touch a yellow paddle when they heard a sound. A correct response earned the manatees a reward of fruit or veggies.