Hidden in Paradise: Fascinating, Rare Dolphins and Whales You’ve Never Seen Before
Pantropical Spotted Dolphin
Sightings per 100 hours: 6.59Baird's thousands of observations have produced a somewhat startling result: Species are distributed unevenly between the northernmost islands of Kauai and Nihau, and the southern members of the chain. The most dramatic difference, Baird said, is found among the region's pantropical spotted dolphins.“They’re almost the most abundant species in general, and yet almost absent from Kauai and Nihau,” he said. Four of Baird's nine pantropical spotted dolphin sightings near the northern islands have been of the same individual.Rough-toothed dolphins (right), on the other hand, tend to be relatively rare -- except in the waters around Kauai and Nihau. “We don’t really know what may have caused that kind of difference,” Baird said.He suggests two possibilities. One is that oceanographic differences may be modifying the distribution of prey species. The second, slightly more sinister possibility, is that human activities in the northern region are better tolerated by rough-toothed dolphins. This could include things like burgeoning aquaculture operations, wind farms, and U.S. Navy exercises, which employ mid-frequency sonar.Not coincidentally, much of Baird’s work is funded by the Navy’s Pacific Fleet, which has a keen interest in understanding how cetacean populations are affected by the fleet’s undersea activities. “The work is still ongoing, but my suspicion is that rough-toothed dolphins are probably extremely tolerant to exposure to mid-frequency sonar,” Baird said.Images: Robin BairdRough-Toothed Dolphin
Sightings per 100 Hours: 3.71Now that Baird no longer lives in Hawaii, he travels there multiple times a year. Field trips to the Hawaiian Islands can last for weeks. If it sounds like a great life, it definitely can be, though Baird admits the long days on the water can sometimes creep toward tedium.And yet, “When I’m out in really deep water, there’s just a lot of potential,” he said. “Every day on the water, anything could happen. We could see any one of 18 different species, some of which are so poorly known. There’s one species we’ve only seen once: a Longman’s beaked whale.”Sunrise sees Baird and his colleagues leaving the safety of the shore, in a boat that doesn’t look much larger than an extended-cab pickup truck. If the weather is nice, they’ll stay out until mid-afternoon. When the seas become rough, as they often do, the team returns earlier in the day. Trade winds blowing from east to west make the eastern side of the islands a treacherous place to loiter, so the team stays within the relative safety of the western side. But “as the islands heat up, the disturbance increases the winds,” Baird says. "We'll go out in very calm water and come back in much rougher water."While on the water, onboard observers scan the sea in all directions, looking for dorsal fins slicing through the water, the nearly invisible blows of small dolphins, or the disappearing flukes of a diving whale.Then, the chase is on.Image: Robin BairdShort-Finned Pilot Whale
Sightings per 100 hours: 8.33As the researchers close in on a whale or dolphin, they identify which species it is and count how many individuals there are. Then, the cameras come out. High-resolution photos showing dorsal fins and body markings go into a photo-ID catalog, a visual reference library that researchers use to compare and identify individuals. "We carry some of our photo-ID catalogs on board, on an iPad," Baird said.By now, Baird and his colleagues have taken more than 70,000 photos of short-finned pilot whales, the species they see most commonly around the islands. These photos showed the researchers that the islands' pilot whales belong to two separate populations, not one large group. One population lives in shallower waters nearer the shore, and the other tends to live farther out, occupying a more flexible range.Images: Deron Verbeck (top), Robin BairdCuvier's Beaked Whale
Sightings per 100 hours: 1.17In addition to taking gorgeous images of these seldom-seen creatures, Baird and his team collect as much data as they can during each of their sightings -- everything from skin samples for genetic work to long-term location information.At first, the group focused on attaching suction-cupped tags to the animals; these tags carried depth and location sensors, and would tell them how deep their creature dove. Then, a few hours later, the tag would pop off.For animals like Cuvier’s beaked whales, which like to eat squid and octopus, those dives can bottom out around 3,000 feet below the surface, and last for as long as 40 minutes. At the surface, these somewhat oddly shaped whales keep a low profile, with a sparse blow that’s only about 3 feet tall.Of all the species affected by undersea noise, Cuvier’s beaked whales appear to be among the more sensitive to mid-frequency, naval sonar.Image: Robin BairdPygmy Killer Whale
Sightings per 100 hours: 0.55Now, Baird and his team leave the harbor armed with more than a dozen satellite tags. Unlike suction tags, which are manually pressed onto an animal, the satellite tags are deployed using air rifles, and hook into the dorsal fin. They stay on for longer, and can tell researchers where the animals like to go over periods of days or weeks.Researchers are also interested in studying rare whale genetics. Collecting skin biopsies, and then reading an individual's genetic sequence, is telling researchers about how related individuals in a pod are, and how different populations mix.Image: Robin BairdMelon-Headed Whale
Sightings per 100 hours: 0.84The Hawaiian Islands are no stranger to naval exercises, or to associated cetacean strandings. In 2004, between 150 and 200 melon-headed whales found themselves in Kauai’s Hanalei Bay during a naval exercise. The Navy was notified, the sonar turned off, and the whales rounded up and sent back to sea. Scientists think that in an attempt to avoid the sonar, the whales has bolted and ended up in undesirably shallow water.Other deep-diving species, like dwarf sperm whales and beaked whales, are thought to strand in response to sonar because of physiological damage and compression sickness.Now, the Navy is funding Baird’s work with satellite tags off Kauai, which he times to coincide with submarine training. “We put sat tags on animals prior to the submarine commander’s course, so that we can collect data before, during, and after -- habitat use and movement data,” Baird said.Image: Robin BairdBlainville's Beaked Whale
Sightings per 100 hours: 0.75The data Baird is collecting are helping him assemble a comprehensive picture of how these rare creatures live around the islands. In addition to studying diving and movement patterns, genetics, and response to sonar, he’s also looking at the different populations’ social structures.Not surprisingly, they span a range from simple to more complex. Some, like the Blainville’s beaked whales, tend toward the more complicated end of the spectrum. “If you had to compare them to some sort of terrestrial mammal, in terms of their social organization, probably somewhat similar to some species of deer,” Baird said. “The males basically fight to keep other males away from one or two females.”False Killer Whales tend to exhibit a similar structure to orcas: Stable, long-term associations, grouped into pods. A photo ID catalog started by Dan McSweeney, a researcher on the Islands, has revealed that some of the individuals who spent time together in the 1980s are still swimming with the same companions.Dwarf sperm whales? They’re a bit simpler. “Typically, you see a female and a calf and a male,” Baird said. “Or two females, two calves, and a male. They’re just out there trying to make a living and get enough to eat.”Still enigmatic, the dwarf sperm whale has historically behaved so unpredictably that researchers couldn't follow a pod long enough to learn anything. But, Baird said, after years of working with them, “we’ve learned to predict their behavior more and more.”Maybe, when Baird returns to Hawaii next, in October, he’ll start to uncover the secrets these deepwater creatures are keeping -- much as he’s done on previous trips, with false killer whales and their toothy, mysterious kin. It’s the thrill of discovery and of understanding that pulls him back to the windy Pacific waters surrounding the volcanic island chain.“To spend more time with a species and learn more about them than almost anyone in the world,” he said. “I find that really exciting.”
