National Geographic : 1992 Sep
Zeroing in on a bottlenose dolphin's signature whistles, a suction cup microphone (above) relays data to a boat near Florida's Sarasota Bay. Researchers hold the wild dolphin to prevent cables from tangling. No wires are needed for self-contained data recorders (right), color-coded to match zinc oxide markings on the dorsal fin. Wired for sound (below), dolphins are briefly corralled for observation as they communicate.