January 20, 2000
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Fossils reveal birdlife of Hawai`i's past
Strolling the desolate Mo`omomi Beach of Moloka`i's north shore some 30 years ago, a woman came upon what appeared to be the remains of a turkey dinner projecting from an eroded sea cliff.
The neatly laid-out skeleton was all there except for the head. The bones of the drumsticks looked familiar enough, but surely this bird must have been a disappointment to white meat lovers, for the breast bone showed no sign of a keel and was, instead, as smooth as the skin of a softball. Furthermore, the wing bones were so tiny that they should have belonged to a much smaller bird.
A phone call to Bishop Museum summoned the paleontologists, who immediately confirmed the obvious. Whatever this bird once was, it had walked the Earth but could never have flown. Detailed study revealed that the bird was an extinct, flightless waterfowl, a giant goose-like duck.
Discovery of the giant duck sparked the search for more Hawaiian bird fossils. Until then, fossil hunters had assumed that Hawai`i was not worth their efforts. Lava flows would, of course, have incinerated the remains of any dead animal, the thinking went, and nowhere in the islands were there the kinds of geological features (lake beds, river bars, etc.) that would have preserved the bones of ancient creatures. But now here was an environment that did - sand dunes.
And sure enough, the Mo`omomi dunes and some dune systems on other islands held the fragile bones of a long-gone bird world. Besides more goose bones, fragments of other species came to light: a crow, a long-legged owl very different from the pueo, and many kinds of honeycreepers, together with hundreds and hundreds of seabird skeletons. Amazingly, owl pellets packed with the bones of extinct honeycreepers documented the meals of these vanished night-hunters.
The discoveries didn't stop there. Archeologists found bird bones in limestone sinkholes at Barber's Point. Most importantly, ancient bird bones turned up in lava tubes on Maui and the Big Island.
So far, 33 new and extinct species of birds have come to light, and many other species wait to be described. Altogether, these extinct birds include at least 8 kinds of waterfowl, 2 ibises, 12 rails, an eagle, a hawk, 4 owls, and many species of songbirds. Many species of surviving native birds also turned up.
When did all these birds live? Carbon-dating has since disclosed that most of the bones are only a few thousand years old. A few birds appeared at archeological sites, evidence that Polynesians and long-extinct birds once shared the islands.
What happened to this lost world of birds? Like the original giant duck, many were flightless, including all the extinct waterfowl, ibises, and rails. Perhaps some of these birds met an end as food for their new human predators. But many could have perished with the changes brought about by human settlement. Forests were cleared for upland agriculture, while streams and ponds were transformed for kalo cultivation. Rats may also have wiped out ground-nesting species. We will never know, but these kinds of changes resemble the forces of extinction that now threaten the remaining native Hawaiian birds.
New fossil discoveries will undoubtedly be made and appear in the news. Readers can see the fossil giant duck on exhibit at Bishop Museum in Honolulu.
Eruption UpdateEruptive activity of Kilauea Volcano continued unabated during the past week. Lava is erupting from Pu`u `O`o and flowing through a tube to the sea coast. The ocean entry at Lae`apuki has been active, but weak, all week. Surface breakouts of this flow on Pulama pali and the coastal flats have provided good viewing at night from the end of the Chain of Craters Road to Highcastle. The public is reminded that the ocean-entry area is extremely hazardous, with explosions accompanying unpredictable collapses of the new land. The active lava flow is hot and has places with very thin crust. The steam clouds are highly acidic and laced with glass particles.
Another flow has crossed the eastern boundary of the National Park and cut the Royal Gardens access road in two places. The distal end of that flow is about 800 meters (0.5 mile) from the coast. A third has descended Pulama pali and is pooling at the base of the pali.
A resident of Mauna Loa Estates subdivision felt an earthquake at 11:11 a.m. on Sunday, January 16. The magnitude-2.9 temblor originated from 3 km (1.8) beneath the summit of Kilauea Volcano. A report of a felt earthquake at 9:30 a.m. on January 4 was received recently by HVO from a resident of Hawaiian Ocean View Estates. The magnitude-3.4 earthquake was located 15 km (9 mi) northwest of Na`alehu at a depth of 2.7 km (1.6 mi).
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Updated: 24 Jan 2000