Finding Hawaiʻi’s Lost Fowl
Written by Jessie Krause, Bishop Museum Vertebrate Zoology Collection Technician
Gazing at the beach below us, the reflection of the sun shimmering on the ocean’s surface, I was struck once again by the beauty of these Islands. I decided to snap a quick photo before continuing to the shore and getting my hands dirty. Today I was part of a small group from Bishop Museum’s Vertebrate Zoology Department, on a quest to find fossils from ancient birds that once occupied Oʻahu in large numbers.
This expedition had originally been scheduled by Dr. Helen James, Curator of Birds at the Smithsonian Institution and an expert on Hawaiʻi’s prehistoric avian species. The quest was to be carried out by a team of fossil hunters comprised of Smithsonian and Bishop Museum staff, but then the coronavirus pandemic struck. We all know what happened next. Dr. James and her staff were unable to make the trip, but rather than canceling the hunt altogether, it was decided to see what specimens a few of us could find. We would get help identifying what we collected later. I ecstatically accepted the offer to go along and offer what assistance I could.
The thought of discovering some small piece of history that had been buried and hidden from human eyes for hundreds of thousands of years was thrilling. This was something I had dreamed of since I was a kid. The fact that I had the opportunity to do so in a place I loved and considered my second home made it even more special. I hoped we would be able to find something of importance to contribute to the Museum’s collection, to science, and to future generations. I was excited. I felt as if I had been waiting for this moment my whole life! It was then that I looked down at the sand beneath my feet and realized, I had no idea what I was doing.
“Hey, Molly, what exactly are we looking for?” I asked. I was suddenly very aware of how awkward it felt to be wearing tennis shoes in the sand, and decided my best course of action was to stick close to someone who did know what she was doing. I followed Molly Hagemann, Manager of Bishop Museum’s Vertebrate Zoology Collection, down the beach. We studied the sediment layers in the cliff wall together. She showed me the layer where most of the fossils would be concentrated, and what they looked like. This site had at one time been a volcanic crater, which had held a large lake and attracted many species of birds. Geologic studies estimate that the fossils found at this location are between 300,000–400,000 years old. This is quite young compared to dinosaur specimens, which can be many millions of years old, but they are the oldest known fossils in Hawaiʻi. Today this site is ideal for fossil collecting, as much of the crater has eroded into the sea and thousands of years of sediment layers are now clearly visible from the small beach along the shoreline.
Eventually, I wandered off on my own. It is amazing how quickly you can train your eyes to recognize and pick out certain colors and textures. Before I knew it, I had started filling up cotton-lined tubs with tiny little bones. Once I had collected all the specimens that were easy to reach, I began hunting for ones that were more difficult to obtain. This usually required scrambling up the side of the eroding cliff and either creating a foothold with a small shovel or finding a ledge to perch on and lean out from in order to gently remove fossils from their resting places in the cliff side.
We spent many hours searching for fossils that day. We had hoped to find more forest bird specimens to add to the Museum’s collection (see the blog entry, “Honeycreepers and Adaptive Radiation”). The tiny forest bird bones are the most challenging to detect because of their size. By dissolving clumps of silt in sea water and meticulously sifting the material, we were able to acquire over two dozen bones from passerine (songbird-sized) species. Some of these may belong to the Mohoidae family, which contained the ʻōʻō species, but further examination of the specimens will be needed to say for certain. As with previous trips to this site, most of our finds belonged to various species of dabbling ducks that once called the lake and surrounding area home.
Perhaps the most exciting part of the expedition was finding the bones of an extinct bird called the moa-nalo (Thambetochen xanion). Although they were the size of geese, they descended from ducks that populated the Hawaiian Islands around three million years ago. When these ducks arrived, they encountered a paradise free from mammalian predators. Without hungry predators chasing them, the ducks eventually lost the ability to fly and evolved large, heavy legs. For hundreds of thousands of years, these birds dominated most of the Islands as the primary land-dwelling herbivores, occupying a niche typically filled by ungulate species in other parts of the world. The moa-nalo, which in the Hawaiian language means “lost fowl,” were poorly equipped to defend themselves against the arrival of mankind and the pigs and rats that came with them. By the time Captain Cook arrived, these flightless, ground-nesting birds had been driven to extinction, presumably by hunting, as well as predation of eggs and chicks by introduced mammals.
Everyone knows Hawaiʻi is a special place. What a lot of people don’t realize, however, is just how exceptional it is from a biological standpoint. As the most isolated land mass in the world, over 1,800 miles from the nearest continent, Hawaiʻi has been home to some of the most unique species of plants and animals on the planet. Sadly, many of these species are now extinct or on the verge of becoming so, earning Hawaiʻi the unfortunate title of “Extinction Capital of the World.” In fact, there are more native species of plants and animals preserved in the collections of Bishop Museum than there are in the wild today. The collections are vitally important so that scientists can learn more about these plants and animals, and stories like that of the moa-nalo can be told to future generations.