Tuesday, November 13, 2018

Do humans always wipe out the big animals, or can they sometimes coexist? Evidence from Madagascar.



Scientists generally accept the theory that once humans arrive at an isolated landscape, they quickly destroy the big animals there.


Some call it the blitzkrieg hypothesis. But there's new evidence that, at a minimum, raises questions about this theory.

(Image: Bones with tool cut marks of the Madagascar Aepyornis, the giant elephant bird. Credit:  V. Pérez, Science Advances, 5:9 (2018))

In the Hawaiian Islands, the big flightless ducks that have been called moa nalo were in the islands when the first Polynesians arrived, but were gone soon thereafter. Smithsonian researcher Storrs Olson reported that the moa nalo—which represents a class of extinct big birdsdisappeared during the early human occupation of the Islands.

Fossils of numerous such species are "contemporaneous with Polynesian culture. The loss of species of birds appears to be due to predation and destruction of lowland habitats by humans before the arrival of Europeans," Olson wrote. 

In New Zealand, the class of giant moa birds (Dinornis sp.) also disappeared with the arrival of the humans. New Zealand Geographic has a piece on that loss. 

In Madagascar, the arrival of humans has been linked to the loss of the giant elephant birds, Aepyornis maximus and other species.

But recently, researchers in Madagascar found Aepyornis bones more than 10,000 years old with human tool marks on them. Until now, humans were not believed to have been in Madagascar until 2,500 years ago or at most 4,000 years ago. Some came from Polynesian origin societies to the east and some from Africa to the west.

And Aepyornis are believed to only have gone extinct in the last couple of thousand years.

So, 10,500 years ago?

"Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar," write the authors of this paper, Early Holocene humanpresence in Madagascar evidenced by exploitation of avian megafauna


An article in Science reviews the issue. 

In it, paleoecologist David Burney says it's a big deal: The findings"fly in the face of all that we thought we knew about human arrival in Madagascar." Burney has worked extensively with the Kaua`i-based National Tropical Botanical Garden, and has also done considerable work in Madagascar.

If humans were there that early, why didn’t they earlier wipe out the big birds and big mammals as the theory suggests they do? And if humans were there that early, why haven't archaeologists found evidence of the human presence?

For now, two theories arise.

1) It was perhaps a small, temporary human presence—maybe a visiting group of people that killed and ate some creatures and then left, or died out.

2) Maybe they haven't found evidence because they haven’t been looking for archaeological sites that early.
That said, scientists for four decades have understood that when humans arrive, they conduct a "blitzkrieg" that wipes out many big animals. Is it possible that in Madagascar, humans were able to coexist, to survive for thousands of years without wiping out megafauna?

Depending on what researcghers uncover next, it is at least possible.

Well, and then there's the question of how humans were voyaging across oceans as early as 10,500 years ago. That's more than 5,000 years before Polynesians began plying the Pacific in their voyaging canoes.

© Jan TenBruggencate 2018

Thursday, November 8, 2018

Climate forecast: 2019 to be an El Nino year


It's been a while coming, but federal climate researchers say there's now robust evidence that the Pacific is moving into a new El Nino cycle.

For our Islands, that means a possibly dry winter, and the potential of a higher hurricane count than normal in 2019.

The Climate Prediction Center issued its new outlook today (Nov. 8, 2018), and you can look at it here

It concludes that there is now an 80 percent chance that an El Nino will form, and will stay in place right through next winter—meaning it's there during the entire 2019 hurricane season.

There are now warmer-than-normal water temperatures across the equatorial Pacific, although right now the assessment is that conditions are still neutral.

Climate forecasters' best guess is that the 2019 El Nino will not be a strong one, giving those concerned about hurricane patterns a little good news.

The International Research Institute for Climate and Society at Columbia University publishes lots of detailed information on climate forecasts, and if you're interested in a whole lot of colorful spaghetti charts summarizing different climate models, look here

© Jan TenBruggencate 2018

Friday, November 2, 2018

Where are the electric pickup trucks?


Tesla's prototype pickup truck: Tesla

The electric vehicle market won’t make significant inroads in Hawai`i until there's a robust EV pickup truck available to buy.

Pickups are must-have vehicles for many Hawai`i families. They carry the surfboards, the coolers and beach chairs, the trash to the dump, the yard waste, the tools, the beach camping gear, and all the rest.

In Hawai'i, about 200,000 of our 1.2 million vehicles are light trucks and vans, about 16 percent.

But it's the Neighbor Islands where light trucks shine. Only about 12.5 of O`ahu's vehicles are light trucks. But it's 19 percent on the Big Island, 18 percent in Maui County and a whopping 24 percent on Kauai.

We tend to keep our trucks a long time. The mean age of pickups is north of 9 years. If you're interested in going EV, you might want to stretch that just a bit. We're still a year or two from folks being able to replace their old gas and diesel pickups with electric versions.

Elon Musk just energized the EV pickup arena with details on Tesla's entry into the pickup truck market, and his is certainly not the only one on the horizon.

But Musk's airing of a "futuristic-like cyberpunk" sure looks hot, with its aerodynamic design, all-wheel-drive (to get you out of the mud at the greenwaste swamp), and high-tech suspension. Here's USA Today's piece on it. 

Musk gets excited about this truck: "Well I can’t talk about the details, but it’s gonna be like a really futuristic-like cyberpunk, 'Blade Runner' pickup truck. It’s gonna be awesome, it’s gonna be amazing. This will be heart-stopping. It stops my heart. It’s like, oh, it’s great."

One downside is that it's not scheduled to be the compact pickup that many Hawai`i drivers seem to prefer. It's a large version—a pickup big enough to carry a pickup in its bed. Musk has suggested that another, smaller pickup might be in the pipeline behind that one.

Bollinger's pickup: Bollinger
There might be something like an electric pickup available from Tesla as early as next year, but we'll see. The electric truck has been just-around-the-corner for a long time now. Several look like they might be only a year or two out.

Bollinger Motors has announced a boxy EV pickup with a 200-mile range, which folks say will be for sale at $60,000. 

Bollinger's B2 looks like a cross between a Jeep and a Land Rover, but with better performance than either. Production is to start in 2020.

Condor pickup: EV Fleet; Bison: Havelaar 
EV Fleet has a pickup, the Condor, that has a 140 or so mile range. The front end of this looks like a cross between a VW Bug and a Deux Chevaux, and you can select the kind of bed you want—flat, panel, tool setup, whatever. It starts at $50,000 or so. 

The Canadian company Havelaar has its electric Bison, reportedly in the $50-60,000 range. It reports a 186-mile range, which would get you most anywhere in the Islands and back, unless you're doing long-distance cruising on the Big Island. I'm waiting on details on whether it's going to be available in the Islands. 

The company Workhorse has announced a plug-in electric pickup with 80-mile electric range on battery. It's a hybrid so you can use fuel to extend that range to north of 300 miles. 

But then all the major manufacturers have hybrid options with various levels of pure electric range. there's a Ford, a Dodge, a Chevy, a Toyota…and so on.

Pickups are clearly a big part of the market, but pure electrics are taking their time getting to mainstream. 
© Jan TenBruggencate 2018

Wednesday, August 8, 2018

Kane`ohe corals more resilient to bleaching after 50 years of hot


Montipora capitata coral. 
Credit: Keisha Bahr
Corals in Kane`ohe Bay seem more resilient to bleaching in warming waters today than they were 50 years ago—the first evidence that coral may be gaining tolerance to rising global temperatures.

It may not be enough to keep up with the pace of climate change, but it's a hopeful sign.

“Although these results are encouraging in their indication that acclimatization/adaptation of corals and their symbionts can occur at an unexpectedly rapid rate, increased bleaching tolerance may not be enough for widespread coral survival,” said researcher Ku‘ulei Rodgers

A complex study by University of Hawai`i and Bishop Museum researchers looked at how corals responded to hot spells in 1970, and then in 2017 when the research team repeated the earlier studies. They found that corals today take longer to respond to superheated water, that they recover more readily and start growing again more quickly.

There are caveats here, but the indications are hopeful for the future of our reefs.

The new study in the journal PeerJ: The Journal of Life and Environmental Sciences, is entitled "Evidence of acclimatization or adaptation in Hawaiian corals to higher ocean temperatures." The authors are UH Institute for Marine Biology scientists Steve L Coles, Keisha D. Bahr, Ku'ulei S. Rodgers, Stacie L. May, Ashley E. McGowan, Anita Tsang, Josh Bumgarner and Ji Hoon Han. Coles, a veteran coral scientist who also works with Bishop Museum, was part of the original 1970s study.

Science Daily reported on the study. 

Reef corals are two-part organisms. The coral polyp provides a home to single-celled algae called zooxanthellae. It's a mutual relationship, and corals get both their color and some of their food from the algae. When corals are stressed, as when water temperatures rise, they eject their zooxanthellae and begin to starve. They also look white, bleached.

The 1970s experiments studied how corals responded to periods of abnormally warm water. The 2017 experiments recreated those studies.

"Re-running a 50-year old experiment using the same coral species, same experimental setup, and same observer allows us to directly test changes in coral temperature tolerance,” said co-author Keisha Bahr.

After nearly five decades of increasingly warm oceans, those corals seem to behave differently now, the team said. They keep their zooxanthellae longer, and recover quicker after waters return to normal temperatures. The warming trend has been carefully tracked, and offshore sea temperature rise amounts to 1.13 degrees Centigrade from 1958 to 2014, the report says.

Why are the corals more resistant to warming?

It isn’t clear whether that's because corals are adopting more resilient zoozanthellae or whether the corals themselves are more temperature resilient. And Coles warns that it might also have something to do with cleaner waters in Kane`ohe Bay, where in the 1970s, nutrient-rich secondary treatment sewage effluent was being dumped in the bay.

"Elevated levels of dissolved nitrogen have been implicated in stimulating coral bleaching," Coles said.

"Available evidence indicates that the lower concentrations of nutrient pollutants, particularly dissolve organic nitrogen, have played an important role in the increased temperature tolerance of corals after nearly 50 years as was determined by these experiments," the paper said.

In other words, corals can respond better to change when the water is cleaner.

This evidence from a single location is important in a special way, the authors said.

"Our experiments are the first to demonstrate thermal acclimatization/adaptation to elevated ocean  temperature for corals of the same species and from the same location over the past half-century."

The three species of corals they studied are Lobactis scutaria, mushroom or plate coral, Montipora capitata, called rice or pore coral, and Pocillopora damicornis, the cauliflower or lace coral.


© Jan TenBruggencate 2018

Tuesday, August 7, 2018

Random climate science: Hot seas, marine debris, changing forests and, of course, goats


They've been taking temperature measurements at San Diego's Scripps Pier for 102 years.

And on Aug. 1, 2018, they measured the highest temperature in all that time: 78.6 degrees. And summer's not even over yet. 
The same day, a half-mile offshore they measured 79.7 degrees, second highest at that location after a 2015 El Nino year measurement. 

Yeah, that's just one location, and you can get isolated peak temperatures, but large scale temperature data continue to move in one direction. The image at upper right represents global land and sea temperatures from 1880 to 2015. It comes from the National Climate Data Center.

There are still plenty of skeptics out there, but the science seems clear.

We all know about rising sea levels, California wildfires, increasing droughts, acidification of the oceans and so on. But what are some of the likely impacts that we don't hear much about?

For the Hawaiian and Pacific Islands, a warming climate has other kinds of implications. Marine debris, for example, can not only be a nuisance, an entanglement threat to turtles, an ingestion threat to seabirds, but a bunch of other things.

Climate change can alter storm frequency, change current patterns, and move plastic debris into new parts of the sea and the coast, according to a study in the journal Aquatic Invasions.  

"Climate change may also increase the frequency and magnitude of storm activity capable of washing the immense amounts of plastic material now poised on the edges of the world’s coastlines into the sea," the authors write.

Have a child interested in medical school? Suggest a career in treating parasitic worms. There's evidence that a warming climate will increase the populations and virulence in a range of nasty bugs that like to bore into human tissue.

In the PLOS journal Neglected Tropical Diseases, there's this paper: " Global 'worming': Climate change and its projected general impact on human helminth infections." 

Not every nasty parasite will increase but many will, and some of those will be able to move into areas where they now don’t exist. And here's a word to get familiar with: ancylostomiasis. It is caused by a hookworm and can cause anemia in humans. Here's another: ascariasis, a disease caused by a roundworm. Both are expected to thrive in a warming climate.

There are a lot of folks in the Midwest who have felt secure that climate change will impact them minimally, since, after all, they aren't going to be impacted by rising seas or tropical storm systems. But there's increasing evidence that they can expect disruptions, too.

The Indiana Climate Change Impacts Assessment suggests that the growing season will be longer, but that with more spring floods and summer drought, the state might not be able to take advantage of it. 

And not just Indiana. 
Northern European forests will see big species changes, with declines in species like silver fir, beech, common ash and common oak, and a better habitat for alien species like the Douglas fir, red oak and black locust. With the change in species will come a dramatic change in the natural species that rely on those forests, said a paper in the journal Global Change Biology called "How much does climate change threaten European forest tree species distributions?" 

Should you get used to goat-milk ice cream? One research paper suggests that in a more extreme environment, goats present the best option for milk and meat. 

"Goats have numerous advantages that enable them to maintain their production under extreme climate conditions. Principally, goats have higher capacity than other farm raised ruminants to effectively convert some feed sources into milk and meat," write authors Nazan Koluman Darcana and Nissim Silanikoveb in the journal Small Ruminant Research.

Additionally, they produce less methane than cattle, they write.
©Jan TenBruggencate 2018