Sometimes, it seems, large whales and talking dolphins get all the attention. Yes, we love these animals, too – how can you not? A humpback whale launching itself from the sea like a giant, blubbery rocket and crashing down with a triumphant spray of seafoam can impress even the most curmudgeonly of whale watchers. But the pantheon of cetaceans includes far more than just our charismatic, coastal kin. Preferring deeper water and diving for more than an hour at a time, some species of whales and dolphins are rarely seen, and seldom studied. These animals slip stealthily between the waves at the surface and retreat into a deep blue world that we still know very little about. It takes a determined observer to learn the patterns of a pod of dwarf sperm whales, for example, and predict where they’ll surface next. [caption id="attachment_226081" align="alignright" width="350"] Searching for rare animals. (Jessica M. Aschettino)[/caption] Robin Baird, a biologist at the Cascadia Research Collective, has spent years doing just this, in the waters around the Hawaiian Islands. He once lived on Maui, but now visits the islands several times a year, looking for the region’s rarest and most elusive whales and dolphins. Rising straight out of deep ocean water, the Hawaiian Islands offer easy access to the realm of deep-diving creatures. Baird's work, part of which is funded by the U.S. Navy, is providing unprecedented insights into the animals' social structures, the risks introduced by human activities in the region, and how the different species share the waters around the islands. By now, Baird and his colleagues have probably logged more hours studying these unusual species than any other crew on the planet. They recently published a study summarizing 1,758 sightings between 2000 and 2012. Among other observations, the work included a calculation of how frequently a species is seen in the region: Average sightings per 100 hours on the water. Some whales, like humpbacks, will be seen hundreds of times in a 100 hours. Others, like false killer whales, come in at 0.64 -- or, almost never. Baird’s mission? “We work with every species we encounter," he says. "But we spend the most time with the species we encounter the least often.” Above: Striped Dolphins Sightings per 100 hours: 0.53 Though Baird has uncovered many of the fascinating secrets kept by Hawaii's often elusive species, one of the animals that’s still a mystery to Baird is the striped dolphin. Unlike their compatriots in other parts of the world, Hawaii’s striped dolphins “really don’t like boats,” Baird said. As a consequence, the only conclusion he can make right now about this beautiful, seemingly water-colored species is that they live in really deep water. “We’ve never been able to get any biopsy samples or deploy any satellite tags,” Baird said. “While we have some photos of distinctive individuals, we’ve never been able to build up a large enough photo catalog to see whether we’re seeing the same individuals.” Image: Robin Baird

False Killer Whale Sightings per 100 hours: 0.64 Baird began his studies around the Hawaiian Islands in 2000, when he lived in the area. Back then, he focused mainly on the false killer whales living near Maui. “It’s a species I’ve been interested in for a long time,” he said. False killer whales are large, toothed whales, the third largest of the dolphin family (orcas are bigger). Most of what’s known about them comes either from stranded animals, or from studying the Hawaiian Island populations. A few years ago, Baird and his colleagues showed that Hawaiian Pseudorcas assorted into three groups, one of which is an endangered population that’s genetically distinct from the others. Further work demonstrated that these cetaceans maintain long-term bonds and social groups, and that some of the individuals photographed around the islands in the 1980s and 1990s are still there. False Killer Whales the least abundant of the 18 populations of toothed whales and dolphins that live around Hawaii, but perhaps the most likely to share their food – not only with each other, but also with humans on nearby boats. Images: Dan J. McSweeney (top), Robin Baird (right)

Pantropical Spotted Dolphin Sightings per 100 hours: 6.59 Baird'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 Baird

Rough-Toothed Dolphin Sightings per 100 Hours: 3.71 Now 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 Baird

Short-Finned Pilot Whale Sightings per 100 hours: 8.33 As 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 Baird

Cuvier's Beaked Whale Sightings per 100 hours: 1.17 In 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 Baird

Pygmy Killer Whale Sightings per 100 hours: 0.55 Now, 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 Baird

Melon-Headed Whale Sightings per 100 hours: 0.84 The 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 Baird