Late last month observers discovered a small green pond at the bottom of Halema’uma’u Crater at Kilauea volcano. Water inside the crater is rather amazing since Kilauea is the active volcano on the Big Island of Hawai’i that erupted violently in 2018, destroying parts of Leilani Estates, Highway 132, Vacationland and Kapoho.
Geologists wondered if the green spot was a rock or algae so they flew over the crater several times looking for a telltale reflection to indicate it was water. Yes, it’s wet.
Bristle-thighed curlews are so rare and hard to find that they’ve been called the birders’ Holy Grail. The word “Tahiti” in their scientific name, Numenius tahitiensis, tells us why. These birds are Pacific Islanders. Their remote breeding location in Alaska was not discovered until 1948.
Adult bristle-thighed curlews spend only two months on their breeding grounds at the central Seward Peninsula and Yukon Delta. They arrive in late May and begin nesting almost immediately.
When the eggs hatch in June, the chicks are precocial and soon walk off the nest.
At 3+ weeks old they learn to fly but they aren’t independent yet. At 5 weeks their parents leave them with a few caretaker adults and depart for the staging grounds at the Bering Sea.
There they fatten up for the first leg of their journey home — a non-stop 2,500 mile flight to Laysan, Midway Atoll in the Hawaiian islands. For some curlews the final destination is much further, as shown on the map below. (Red spots are breeding range, white arrow is first stop, blue circles are wintering locations.)
Young curlews follow the adults a few weeks later. They won’t return to Alaska until they’re three to four years old.
This year I happened to visit Hawaii and Alaska on the same schedule as the bristle-thighed curlews. My Life Bird curlew was a fly-by at Kahuku Golf Course, Kauai on February 28, photographed here by Michael McNulty. Then I saw curlews on their breeding grounds near Nome, Alaska in June.
Every year the curlews travel from Hawaii to Alaska. With a worldwide population of only 7,000 birds and sea level rise due to flood their home islands, this amazing bird is vulnerable to extinction.
p.s. Bristle-thighed curlews are closely related to whimbrels, whom they resemble. We saw and heard both species in western Alaska.
They’re different species in the same genus, Zosterops.
It turns out there are 100 species in the Zosterops genus (minus three recently extinct). They range from Africa to India, Southeast Asia, China, Japan, Australia and many islands in the Indian and Pacific oceans.
These versatile little birds — only the size of a chickadee — usually arrive at new locations on their own. They showed up in New Zealand in 1832 and 1856, presumably blown east in a storm from Australia.
Humans helped white-eyes get to Hawaii. We introduced Japanese white-eyes to Oahu in 1929, but these resourceful little birds have now spread to all the other Hawaiian Islands.
Wherever they go, Zosterops tend to differentiate themselves quickly and become new species. Maybe the Japanese white-eye in Hawaii will morph into the “Hawaiian white-eye” in a few hundred years.
See more about the silvereye in this vintage blog: Eye Ring.
In Hilo, Hawaii there’s a palm tree in the city’s bayside park with metal rings on its trunk. Each ring is marked with a year and the height in feet. The highest one (arrow on my photo above) says “26 feet, 1946.” It memorializes a tsunami that spawned the Pacific Tsunami Warning System.
Tsunamis, sometimes called tidal waves, are seismic sea waves caused by earthquakes, underwater landslides or explosions. They happen when the ocean is abruptly displaced, as shown in this tsunami animation.
In the wee hours of 1 April 1946 a massive underwater earthquake struck offshore in the Aleutians near Unimak Island, Alaska. It was so massive that it created a 114-foot wave that swept away Unimak’s new lighthouse. The rest of it raced across the Pacific Ocean at 500 miles per hour and hit Hilo five hours later around 7am.
Hilo had no idea the tsunami was coming. Some people were mesmerized as the bay sucked loudly out to sea and exposed floundering fish. When the water returned in five surging waves, the highest was a 26 foot wall of water. Everyone ran away. 159 people died. The town was destroyed. (Note the wave in the background of this photo taken as the tsunami arrived in 1946.)
The palm tree was there when it happened. The 26-foot marker shows the debris line left by the 1946 tsunami plus three other large tsunamis that passed the tree: 15 feet in 1960, 12 feet in 1952 and 8 feet in 1957. This video from September 2018 explains the markers (starting at the 1:19 timemark with the narrator’s face).
The following video shows After and Before photos taken in 2010 and taken at the moment the tsunami hit the trees.
Ultimately, the disaster had a positive outcome. By 1949 the U.S. had installed a warning system, now called the Pacific Tsunami Warning Center, to detect earthquakes and warn of potential tsunamis. Throughout Hawaii you’ll see signs and sirens to tell you where to evacuate and when to leave.
It was a terrifying 26-foot wall of water but it led to a safer future.
Greater koa finch. Koa forest cut down. Last seen in 1896.
Hawaii mamo. Last seen in 1898.
Greater 'amakihi. Land cleared. Last seen in 1901.
Black mamo. Last seen in 1907.
Laysan honeycreeper. Extinction by rabbit in 1923.
Hawai'i 'o'o. Last seen in 1934.
O'ahu akialo'a. Last seen in 1940.
Maui 'akepa. Last seen in 1988.
Po'ouli (black-faced honeycreeper). Last seen 26 Nov 2004.
By now in my series on Hawaii you’ve probably noticed that the rarest birds on the islands are threatened with extinction. Sadly this situation is normal. So many Hawaiian species have gone extinct and so many are on the edge today that Hawaii is known as the Extinction Capital of the World. The group of forest birds called Hawaiian honeycreepers are a case in point.
Five million years ago a flock of finches similar to redpolls (Carpodacus erythrinus)arrived from Asia, flying non-stop for more than 4,000 miles. When they arrived, Oahu and the Big Island didn’t exist, but over millions of years they spread out and evolved into 59 species of Hawaiian honeycreepers with a wide variety of beaks for exploiting Hawaii’s food sources. They diversified more than Darwin’s finches.
Each bird was perfectly evolved to survive Hawaii’s dangers but had no defense against off-island threats. Their exposure came with the arrival of humans. We came in two waves.
Polynesians arrived in Hawaii around 400AD and were here alone for 1,400 years. During that period 30% of the Hawaiian honeycreepers went extinct.
In 1778 Captain James Cook was the first European to see Hawaii, prompting immigration from the rest of the world. Since then, in just 240 years, another 39% of the honeycreepers have gone extinct. 18 species remain but six are so critically endangered they may be gone soon.
Hawaii’s endemic birds go extinct so easily because of …
Habitat loss: Humans cleared the forest for settlements. Some species had such a small range or specialized food that when their patch was gone, they were too.
Introduced species, especially rats, cats and mongoose: The birds don’t know to move their nests out of reach.
Avian malaria and avian pox: Honeycreepers have no immunity.
Mosquitoes: Avian diseases, carried by mosquitoes, arrived with introduced birds. Honeycreepers don’t know to brush mosquitoes away. They catch malaria easily and it kills them.
Climate change: There’s safety from mosquitoes at high elevation but climate change is heating the mountains. The mosquitoes are moving uphill.
Avian diseases caught from mosquitoes are the big problem. Fortunately there’s a silver lining. One of the honeycreepers, the Hawai’ian amakihi, can now live with avian malaria and is expanding its range within mosquito territory.
This 27-minute video, made in 2005 by Susanne Clara Bard, tells the story of the Hawai’ian amakihi’s survival. Though this video is a lot longer than I normally post, it’s worth even a short look to learn why Hawaiian birds face so many challenges.
The Hawai’ian amakihi evolved to survive malaria in only 200 years.
(images from Wikimedia Commons; click on the links to see the species account at Wikipedia)
Tour Day 9: Leaving the Big Island of Hawai’i for home
We have so many crows in Pittsburgh in the winter that it’s hard to imagine any crow becoming extinct but this species, the Hawaiian crow or ‘alala (Corvus hawaiiensis), declined rapidly in the 20th century from disease, habitat loss, and predation. They are now extinct in the wild.
Because the birds were obviously in trouble, a captive breeding program began in the 1970s but it wasn’t enough. By 2002 Earth’s only ‘alalas lived in captivity so scientists prepared carefully for their first release.
Five Hawaiian crows were released in the forest in 2016 but the attempt was unsuccessful. Three of them died, the majority killed by the i’o, the native Hawaiian hawk. The remaining two were brought back into captivity.
The ‘Alala Project revamped their strategy for the next release. The crows had lived in safety for generations and apparently didn’t realize the hawk was so dangerous, or they didn’t warn each other.
Since crows are safer when they stick together the team assessed each crow for its compatibility and hierarchy and chose the group accordingly. They also taught the crows to recognize and raise the alarm when they heard or saw a Hawaiian hawk. The alarm call is important.
Eleven birds spent nine months preparing for their release (read more in this Audubon article). Six were released in September 2017, five more at a nearby location in October 2017. They were monitored daily during their first year in the forest.
So far so good. As of fall 2018 they are thriving and they are vocal. Here’s a video from the ‘Alala Project taken during ongoing tracking of the birds and their sounds.
These Hawaiian crows have re-learned the wild. There’s hope they’ll be the start of a future ‘alala population on the islands.
A trip to Hawaii would not be complete without a visit to an active volcano at Hawai’i Volcanoes National Park. If it weren’t for volcanoes Hawaii wouldn’t exist.
The Hawaiian island chain is a string of mountains created by a volcanic hotspot under the Pacific plate. As the plate moves northwestward, the hotspot keeps bubbling up in a new location. The older islands have extinct volcanoes. The newest island, the Big Island of Hawai’i, is where all the action is.
Volcanoes are incredibly awe inspiring and deadly if not treated with respect. Explosions, fountains, and lava flows are obvious dangers. Volcanic ash clogs everything (including airplane engines) and the sulfur dioxide emissions can kill.
Hawaiian tradition says that Pele, the goddess of volcanoes and fire, lives in the crater of Kilauea and controls its lava flow. For centuries Hawaiians made religious visits to offer her gifts. Sometimes those visits ended badly. Wikipedia explains that “In 1790, a party of warriors (along with women and children who were in the area) were caught in an unusually violent eruption. Many were killed and others left footprints in the lava that can still be seen today.”
Kilauea has been continuously active since 1983. When it erupted violently from 3 May to 4 September 2018 its lava flows destroyed Highway 132, the beach towns of Vacationland and Kapoho, and parts of the Leilani Estates subdivision. By the time the eruption ended Kilauea had added 875 acres of new land to Hawai’i.
This U.S. Geological Survey video shows conditions at Leilani Estates in late May 2018 while a USGS team monitored the lava flow.
They also monitored it from the air in this flyover from lava fountain to the sea.
Meanwhile a new volcano is growing offshore. Lo’ihi is already 10,100 feet above the sea floor and only 3,000 feet below the waves. Right next to the Big Island, its shape is the pale orange semi-circle on the map below.
Hawaiians know there’s no way to control a volcano. All you can do is get out of the way!
(videos by USGS on YouTube, photos and maps from Wikimedia Commons. click on the captions to see the originals. )
The akiapola’au (Hemignathus wilsoni), or aki’, is a Hawaiian honeycreeper with such a small population and such a restricted range that he may well go extinct in this century. He’s hard to find, of course, but he’s well worth the effort.
The aki’s beak is most unusual but it’s perfect for gathering what he eats. He probes for spiders, beetles and caterpillars and, like a sapsucker, he drills rows of holes in an “aki’ tree” and returns when the sap wells up.
Despite his similar food requirements the aki’ doesn’t have a woodpecker beak. Instead his lower mandible is short and straight with a chisel tip while his upper mandible is long and thin, curved down, and flexible.
Each half of his beak has a different purpose. He chisels and pecks with the lower mandible or props it in place while he probes and scrapes with his upper mandible. As you can see in the top photo, there’s even a small gap between the two mandibles. How strange!
The aki’ is listed as Endangered for good reason. His population is small and declining. As of 1995 there were only 800 individuals left on Earth, scattered in severely fragmented areas in the mountains above 5,000 feet.
Many things contribute to the aki’s decline including habitat loss from logging and farming and predation by introduced species, especially rats, cats and dogs. The aki’ is also threatened by avian diseases carried by mosquitoes; Hawaiian birds have no immunity to them. The mosquitoes, accidentally introduced to Hawaii beginning in 1826, cannot live in the cold climate above 5,000 feet. That’s why Hawaiian honeycreepers like the aki’ still survive there.
Unfortunately climate change is warming the Hawaiian mountains and the mosquitoes are moving up. How long will we still be able to find this beautiful bird with such an unusual beak?
Today our VENT birding tour has special permission to enter the Hakalau Forest National Wildlife Refuge on the eastern slope of Mauna Kea where there are more native birds than anywhere else on the islands. We’re going to see a lot of birds and a lot of them are endangered.
The refuge, founded in 1985 to protect Hawaiian rainforest birds and their habitat, is closed to the general public because the ohi’a trees (pictured above) are dying of a fungus that’s spread too easily by humans. Rapid Oh’ia Death kills the trees within a few days or weeks. Hundreds of thousands of trees have died since 2013. This is especially scary because the ohi’a is the most common native tree and so many birds rely on it. Many of them have unusual beaks.
The I’iwi (Drepanis coccinea), at top and below, is nearly the same color as ohi’a flowers. Vermilion red with a decurved bill that’s perfect for probing flowers and sipping nectar, he perches like a songbird or hovers like a hummingbird. He was so common when Polynesians first arrived in Hawai’i that they made his feathers into royal cloaks.
The ‘apapane (Himatione sanguinea), below, also feeds on ohi’a flowers and is red and black like the i’iwi. However his color is scarlet, his undertail coverts are white, and his dark bill has a gentle curve.
The Hawai’i akepa (Loxops coccineus) is a tiny orange-red bird with brownish primaries. This endangered crossbill feeds on spiders, insects and nectar in the ohi’a forest. Yes, his bill is curved and crossed!
And finally, the Hawai’i amakihi (Chlorodrepanis virens) is certainly not red but he has a curved beak that’s useful for gleaning, probing, and sipping while he eats spiders, insects, sap, nectar and fruit. He’s a versatile bird whose population is doing quite well with 800,000 to 900,000 on the islands.
Tropical islands always have lots of seabirds but are often missing entire families of land birds. Sometimes a family is represented by just one endemic species. In Hawaii this is true of both crows (Corvidae) and hawks (Accipitridae). There is one endemic crow, the Hawaiian crow, and only one endemic hawk.
The Hawaiian hawk or i’o (Buteo solitarius) is in the same genus as our red-tailed hawk (Buteo jamaicensis) but he evolved to eat birds, such as rails and ducks, because there weren’t any small mammals on the islands. When humans brought rodents, lizards and game birds to Hawaii many of the hawk’s original prey disappeared so he switched to hunting introduced species.
The Hawaian hawk comes in light morph and dark morph plumage. Dark morphs are dark chocolate brown. Pictured here are light morph individuals — an adult above, a juvenile below. You can tell the males and females apart not by plumage but by size. Females are 50% heavier than males, the most sexually dimorphic of all buteos.
As with red-tailed hawks, juvenile i’os are easier to get close to.
The i’o is a loud bird whose Hawaiian name imitates his voice: “I’o.” “Eee Ohhh.” He often calls while soaring. Click here to hear.
The Hawaiian hawk used to inhabit four islands but is now found only on the Big Island of Hawai’i. The population declined for many years but is making a comeback. That’s good news for Hawai’i. This hawk is important to Hawaiian culture and a symbol of Hawaiian royalty.
(photo of adult (striped) hawk by Bettina Arrigoni on Flickr, Creative Commons license; photo of juvenile (pale) hawk from Wikimedia Commons. click on the captions to see the originals)
Tour Day 5: Travel from Kauai to the Big Island of Hawai’i, Kealakekua and Pu’u Anahulu