Monday, July 18, 2016

Native bird loss: a tragedy told in colors.



The scale of the loss of Hawai`i’s native birds is beyond imagining.

It’s just icing on the cake that Hawaiian native birds are some of the most colorful, imaginatively plumed and outrageously beaked birds to be found. Or rather, to have lost.

A new book by Michael Walther, with paintings by Julian Hume, tells the story. It is “Extinct Birds of Hawai`i,” by Mutual Publishing.


Walther calls the loss of species “an ongoing bird catastrophe unequalled in world history during the last 700 years.”

There may be more, but 77 species and subspecies are known to have gone extinct. There are just 26 species of native land bird left.


Hume had to take some liberties with the coloration of birds that went extinct earliest, since many are only known from old bones found in caves and sinkholes. Many others, which have become extinct in the past couple of centuries, have been drawn from life by early birders or can be studied as museum skins, their colors still vivid. There are photographs of the ones lost during the last century. 

I was particularly struck by the photo of one of the last three Laysan apapane, singing while perched on a coral outcropping.

Before Captain Cook sailed up to Waimea on the Big Island, the Islands had already lost owls and petrels and geese, ducks and ibis and finches, an eagle, a harrier and a host of flightless crakes, plus some others, like the Kaua`i palmcreeper and the King Kong grosbeak..

Most of the big birds were long gone before Europeans arrived. Then began the decimation of the jewel-hued forest birds. 

Nowhere else on the globe has lost so many birds. New Zealand is second, with 50 to Hawai`i’s 77. The Mascarene Islands have lost 37, Tahiti 16, Madagascar 15, and so forth.

Islands accentuate the loss, partly because islands promote diversity, partly became small land areas are more vulnerable to habitat destruction and invasive species.

The Hawaiian avifauna, birdlife, was impressive. 

The giant Hawaiian goose was more than four times the size of the Hawaiian state bird, the nene. A thundering example of birdhood.

The favored food of the Molokai stilt own was the Maui Nui finch. We know that from deposits of the fecal pellets of the owl. Both are extinct now.  

There was a nukupu`u with a simply stunning bill—more than half the length of the rest of the bird. It was named the Giant Scimitar-billed nukupu`u.

“Species which took millions of years go evolve have been decimated in a geological blink of an eye,” Walther wrote.

The saddest story is not that we’ve lost so many, but that we’re still losing them.

This volume sparely tells the story, and the risk as we stumble into a vastly poorer and less interesting future.

© Jan TenBruggencate 2016

Saturday, July 16, 2016

New ways warming water and bleaching damage reefs



Warmer ocean waters that bleach reef corals can fundamentally change the makeup of the reef, maybe permanently.

That change will dictate what our reefs will be like in the future, according to researchers writing in the journal Science.

(Image: Starfish surrounded by decomposing coral on the Great Barrier Reef. Credit: XL Catlin Seaview Survey)

Reef-building corals are complex communities, and the more we study them, the deeper the complexity goes.

A reef coral head isn’t a single entity, but a colony of coral animals called polyps. They lay down a calcium skeleton, which forms much of the rocky part of the reef. Each polyp is host to marine plants called zooxanthellae, which conduct photosynthesis and help feed the polyp. But there’s more. It turns out corals also support a community of smaller life forms, a microbiome of bacteria that, once again, both support and are supported by the coral community.

Researchers Tracy Ainsworth of James Cook University in Australia and Ruth Gates  of the Hawai`i Institute of Marine Biology at the University of Hawai`i, write in the June 24 issue of Science that climate change and coral bleaching events dramatically change that microbiome. Their article is entitled, “Corals’ microbial sentinels: The coral microbiome will be key to future reef health.”

“Corals that survive the multiple impacts of climate change and local disturbance will form the basis of future reefs that will differ in fundamental ways from those considered healthy today,” they write.

Corals are accustomed to a range of ocean temperatures. When the water temperature rises beyond that range, the corals lose their algal partners, which leaves them looking white and “bleached.”

That process also causes changes in the collection of bacteria that form part of the reef’s life, and that can further weaken coral polyps.

“The drastic impact of bleaching on the coral animals and, ultimately, its microbiome, can influence the immune system, alter the metabolic capacity and impair the stress resistance of the surviving corals,” Ainsworth and Gates write.

Since some of those bacteria are critical to the health of the corals, their disappearance can increase things like tissue death and disease. The community of corals, alga and bacteria may reach a new steady stage, but it may be a very different community after significant bleaching events occur, the authors write.

“The emergency of new ecosystem norms on coral reefs will be underpinned by changes to the microbiome and the microbial contribution to organism health and stress resistance, under new environmental norms,” they write.

© Jan TenBruggencate 2016

New ways warming water and bleaching damage reefs



Warmer ocean waters that bleach reef corals can fundamentally change the makeup of the reef, maybe permanently.

That change will dictate what our reefs will be like in the future, according to researchers writing in the journal Science.

(Image: Starfish surrounded by decomposing coral on the Great Barrier Reef. Credit: XL Catlin Seaview Survey)

Reef-building corals are complex communities, and the more we study them, the deeper the complexity goes.

A reef coral head isn’t a single entity, but a colony of coral animals called polyps. They lay down a calcium skeleton, which forms much of the rocky part of the reef. Each polyp is host to marine plants called zooxanthellae, which conduct photosynthesis and help feed the polyp. But there’s more. It turns out corals also support a community of smaller life forms, a microbiome of bacteria that, once again, both support and are supported by the coral community.

Researchers Tracy Ainsworth of James Cook University in Australia and Ruth Gates  of the Hawai`i Institute of Marine Biology at the University of Hawai`i, write in the June 24 issue of Science that climate change and coral bleaching events dramatically change that microbiome. Their article is entitled, “Corals’ microbial sentinels: The coral microbiome will be key to future reef health.”

“Corals that survive the multiple impacts of climate change and local disturbance will form the basis of future reefs that will differ in fundamental ways from those considered healthy today,” they write.

Corals are accustomed to a range of ocean temperatures. When the water temperature rises beyond that range, the corals lose their algal partners, which leaves them looking white and “bleached.”

That process also causes changes in the collection of bacteria that form part of the reef’s life, and that can further weaken coral polyps.

“The drastic impact of bleaching on the coral animals and, ultimately, its microbiome, can influence the immune system, alter the metabolic capacity and impair the stress resistance of the surviving corals,” Ainsworth and Gates write.

Since some of those bacteria are critical to the health of the corals, their disappearance can increase things like tissue death and disease. The community of corals, alga and bacteria may reach a new steady stage, but it may be a very different community after significant bleaching events occur, the authors write.

“The emergency of new ecosystem norms on coral reefs will be underpinned by changes to the microbiome and the microbial contribution to organism health and stress resistance, under new environmental norms,” they write.

© Jan TenBruggencate 2016

Saturday, July 9, 2016

Eastern Polynesians made long canoe voyages right into the time of European exploration



Is it possible that the most important trade goods in the Polynesian Pacific were blocks of rock?

Increasing evidence indicates that stone tools and tool blanks were carried during numerous heroic long-distance canoe voyages, and that those voyages continued at least into the period when Europeans appeared in the Pacific.

Perhaps the more important message of the traveling stones is that the Eastern Polynesian island communities stayed connected for centuries after initial colonization. 

“In East Polynesia, long-distance interaction between island societies was a fundamental colonization strategy linking parent with multiple daughter communities to support the establishment of socially and economically viable groups,” says a new report in PNAS, the Proceedings of the National Academy of Sciences. 

The authors of “Cook Island artifact geochemistry demonstrates spatial and temporal extent of pre-European interarchipelago voyaging in East Polynesia” include an international set of geological and anthropolical superstars: Marshall Weisler, Robert Bolhar, Jinlong Ma, Emma St Pierre, Peter Sheppard, Richard K. Walter, Yuexing Feng, Jian-xin Zhao, and Patrick V. Kirch.

They report on the provenance of stone adzes and associated materials found in a venerable rock shelter on the Cook Islands island of Mangaia. The shelter is called Tangatatau, and it was used for hundreds of years. The stone adzes were found in layers of sediment that could be dated.

Here is a report on the research from the Australian network, ABC. 

Researchers have known for some time that adzes did a lot of traveling. We reported in 2007 on an adze found in the Tuamotu chain, which came from an adze quarry on Kaho`olawe, in Hawai`i.

So it was, perhaps, not surprising that the Mangaia rock shelter had adzes from around the eastern Pacific. Some sources were just a few hundred miles away, in the Cooks and the Austral Islands, but there was also material that could be linked to quarries in Samoa and the Marquesas—more than 1,000 miles away. Those were significant distances, and there were indications of repeat voyages.

The Samoan connection is notable because Samoa is considered part of West Polynesia. It is considered the jumping-off point for inhabitation of the Eastern Pacific Islands (Tahiti, Marquesas, Hawaii, Cooks, Australs. Rapa Nui, Pitcairn, etc.) And until now, it was assumed that contact between West and East Polynesia died out early, allowing the Eastern Polynesian culture to develop on its own. 

“This evidence for continued voyaging contact between the Cook Islands and Samoa is … of considerable import because it has often been tacitly assumed that there was little or no contact between the island groups of East Polynesia and the West Polynesian homeland region, after the initial settlement of East Polynesia,” the authors write.

Another issue is why is all the stone tool voyaging only brought tools into Mangaia, and not the other way. Why were the Marquesas, Samoa and the Australs entirely exporters of stone, and Mangaia entirely an import culture?  Or will further archaeology show it was a two-way transport?
Two big questions: Why did the voyaging continue for so long? And why did it end?

Here’s how Weisler and his team answer the first question.

“Postcolonization voyaging and interaction supported socially mediated imperatives such as the acquisition of high status goods, the fostering and maintenance of strategic alliances, and establishing individual and group prowess or ‘mana.’”

They assume some ceremonial component, since Mangaia has its own adz quarries, unlike the Tuamotu archipelago, where most islands are atolls and hard basalt rock is difficult to acquire. Mangaia didn't need the stone, but still, voyagers brought the stone.

The authors don’t have a ready answer for the second question—why the voyaging stopped. There is indication that the most distant island groups dropped out of the trade web earliest. Hawai`i is by far the most distant group from the others, and its presence in the artifacts of the South Pacific thus far has only been established by the one adze found on the Tuamotu atoll of Napuka, 2,500 miles from Kaho`olawe.

The researchers of the Mangaia stone tools report that materials continued to flow in a one-way pattern into Mangaia for as long as 300 years.

“A large corpus of radiocarbon age determinations and associated imported adze material from Tangatatau documents the time span of interarchipelago voyaging from the early AD 1300s to at least the 1600s,” they wrote.

The paper does not address it, but there was something else happening in the Eastern Pacific about the time of the end of voyaging. 

European ships were appearing.

The Portuguese explorer Magellan came through the Pacific from east to west in 1520, although he missed Polynesia and made his first landfall on Guam. 

The Marquesas were visited perhaps as early as 1526 by the Spanish, and were given their European name by Spanish explorer Alvaro de Mendana in 1595. De Mendana also spotted Pukapuka in what would be the Cook Islands. His navigator de Quiros was in the Tuamotu in 1606, and walked on the Cooks’ Rakahanga shortly afterward. 

The Dutch were in the region in 1616 (Schouten and Le Maire), 1643 (Tasman) and again in 1722 (Roggeveen). 

The British didn’t show up until the late 1700s, but ended up spending more time in Eastern Polynesia than any of the others. Capt. James Cook spotted Mangaia in 1777, the year before he sailed into Hawai`i.


But it was the Polynesian voyaging era that was the most historic. The Europeans came through in discovery vessels. But the Polynesians migrated. They brought their whole culture and created new island communities.

“Oceania, the last region settled on Earth, witnessed the greatest maritime migration in human history,” wrote authors of the Mangaia stone artifact study.

© Jan TenBruggencate 2016