The Washington Post - USA (2022-02-22)

E2 EZ EE THE WASHINGTON POST.TUESDAY, FEBRUARY 22 , 2022

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HEALTH & SCIENCE

SCIENCE NEWS

BY WILL DUNHAM

DNA testing on seized ivory shipments that reveals family ties among African elephants killed for their tusks is helping to identify poaching areas and trafficking networks at the center of an illegal trade that continues to devastate the population of Earth’s largest land animal. Researchers said last week they conducted DNA tests on 4,320 elephant tusks from 49 ivory sei- zures, totaling 111 tons in 12 Afri- can nations from 2002 to 2019. The results could help crack the transnational criminal organizations behind the trafficking and strengthen prosecutions. “Combining these results with evidence collected from our law enforcement collaborators en- ables us to collaboratively connect the dots across a massive criminal network,” said University of Wash- ington biologist Samuel Wasser, lead author of the study published in the journal Nature Human Be- haviour. Most ivory is exported in large consignments — up to 10 tons each — shipped as marine cargo and concealed among legal ex- ports crossing oceans on contain- er ships. The DNA testing matched two tusks from the same elephant or, more often, tusks from close relatives found in separate containers for shipment in the same port. Wasser said the largest amount of ivory is now being smuggled out of Uganda through the Mombasa seaport, with ports in Kenya and Nigeria also often used. Wasser noted that the ports used by smug- glers have changed over time. Previous research by Wasser and colleagues identified tusks from the same individual elephant that had been separated and smuggled by traffickers in different shipments before being seized by law enforcement at Afri- can and Asian ports. The new research expanded the testing’s scope to also identify tusks of elephants that were close- ly related, including parents, off-

spring, full siblings and half siblings. The researchers used DNA from elephant feces collected across Africa to compile a genetic reference map of various popula- tions. The new testing thus al- lowed them to identify the geo- graphic location where the elephants were poached and also connect seized shipments to the same transnational criminal organizations (TCOs). “We found that a small number of TCOs are responsible for ex- porting the majority of large ivory shipments,” Wasser said, with as few as three and probably less than six such organizations and with poachers returning repeat- edly to the same elephant popula- tions. Trafficking continues despite a worldwide ivory trade ban ap- proved in 1989, with demand strongest in Asia. Up to 2016, tusks were coming from elephants pri- marily from northern Mozam- bique north through Tanzania up to southern Kenya. Around 2016, there was a significant increase in tusks poached from a region twice the size of Britain called the Kavango-Zambezi Transfrontier Conservation Area that includes northern Botswana, northeastern Namibia, southern Zambia and southeastern Angola, Wasser said. This area is home to 230,000 of the remaining 400,000 African elephants, a population that includes two separate species — sa- vanna and forest elephants. The study did not involve the world’s third elephant species, the Asian elephant. “We are losing as many as 50,000 African elephants per year,” said Wasser, co-executive di- rector of his university’s Center for Environmental Forensic Sci- ence. Special Agent John Brown, a U.S. Homeland Security criminal investigator and study co-author, said DNA forensic analysis has provided a road map for multina- tional collaborative investiga- tions. — Reuters

Research on elephant tusk’s DNA helps locate poaching areas and expose ivory traffickers

SCIENCE SCAN

BY ERIN BLAKEMORE

NASA’s James Webb Space Telescope has gotten a lot of media attention lately — and for good reason. The $10 billion device was launched in December to much fanfare, and it’s expected to provide never-before-seen information on some of the most mysteri- ous objects in the universe. But the JWST has a smaller sibling, and the first science images it recently beamed back to Earth are spectacular. It’s called the Imaging X-Ray Polarimetry Explorer (IXPE), and it’s a telescope designed to sense polarized light. Unlike light from sources such as a lightbulb, whose light waves ran- domly fluctuate, polarized light waves are lined up in one direction. (Think a laser as opposed to the sun.) Polarized beams are born in the extremes of the universe, and the direction of the light can help researchers understand more about the origin and properties of phenomena such as pulsars and black holes. Now that IXPE is orbiting about 370 miles above our equa- tor, its instruments can sense polarized light that would usual- ly be blocked by atmosphere and other light sources on Earth. And the first object it has studied is

bright indeed. Cassiopeia A is the remnant of a supernova explosion that took place when a gigantic star col- lapsed in the 17th century. It’s visible in the night sky about 11,000 light-years away — and it shone bright when IXPE looked at it this month. The telescope mapped the in- tensity of its X-rays and its polarization. When combined with research performed by NASA’s Chandra X-Ray Observa- tory, which launched in 1999, the supernova presents an image crackling with energy. Researchers will study the data for more information on the direction of the rays, Cassiopeia A’s position in the sky, and other facets of the object. The results, they hope, will reveal more about what’s happening inside, providing details of things such as what the light passes through, what kinds of magnetic fields supernovae pro- duce and more. Objects such as Cassiopeia A are just the beginning: This year alone, the telescope will study 40 celestial objects, including the Vela pulsar and the Centaurus A galaxy.

SPACE EXPLORATION

How NASA’s IXPE telescope is shedding light about Cassiopeia A, a remnant of a supernova

NASA’s IXPE Sends First Science Image NASA

NASA An illustration of NASA’s Imaging X-ray Polarimetry Explorer, a telescope designed to sense polarized light.

BY DIANA LEONARD

The extreme heat and dry con-
ditions of the past few years
pushed what was already an epic,
decades-long drought in the
American West into a historic
disaster that bears the unmistak-
able fingerprints of climate
change. The long-running
drought, which has persisted
since 2000, can now be consid-
ered the driest 22-year period of
the past 1,200 years, according to
a study published in the journal
Nature Climate Change last week.
Previous work by some of the
same authors of the study had
identified the period of 2000
through 2018 as the second-worst
megadrought since the year 800
— exceeded only by an especially
severe and prolonged drought in
the 1500s. But with the past three
scorching years added to the pic-
ture, the Southwest’s mega-
drought stands out in the record
as the “worst” or driest in more
than a millennium.
“Without climate change, this
would not be even close to as bad
as one of those historical mega-
droughts,” said Park Williams, a
climate scientist at the University
of California at Los Angeles, and
the study’s lead author. “The
thing that is really remarkable
about this drought period is that
temperatures have been warmer
than average in all of the years but
one.”
The double whammy of sear-
ing heat and persistent drought
in recent years reflects the steady
increase in global temperatures
brought on by the burning of
fossil fuels. The authors attribute
19 percent of the severe 2021
drought, and 42 percent of the
extended drought since the 21st
century began, to human-caused
climate change.
Scientists refer to this com-
bined hot and dry effect as “aridi-
ty” — a warm and thirsty atmos-
phere that can pull moisture from
soil and plants, melt snow and
intensify heat waves.
“All of the climate models agree
that when greenhouse gases go
into the atmosphere and temper-
atures rise, that’s going to en-
hance the ability of the atmos-
phere to pull water out of ecosys-
tems,” Williams said.
This “background drying”
brought on by a warmer atmos-
phere can dwarf occasional wet
or cool periods. For example, the
Southwest’s 2021 drought main-
tained its grip despite robust
monsoon rains and record sum-
mer precipitation in some areas,
in part because of extraordinary
heat waves early last summer,
and generally above-average tem-
peratures.
The study uses tree rings from
sites across western North Ameri-
ca to reconstruct soil moisture
and snow water content dating
back to the year 800, along with
climate models to assess the con-
tribution of greenhouse gases to
the observed changes in soil

moisture and drought severity. The tree-ring record also pro- vides a sobering view of what is possible in the West. “The tree rings tell us that there can actually be very, very extreme dryness in the West without the help of climate change at all,” Williams said. “Even without climate change, we can have monumen- tally severe and long-lasting droughts.” The study finds that the 21st century has been substantially drier than the previous five decades, with 8.3 percent less precipitation, and nearly 1 degree Cel- sius (1.8 Fahrenheit) warmer than the period from 1950 to 1999. It also finds that “no other 22-year period since at least 1901 was as dry or as hot” as the current drought. Faith Kearns, a scientist at the California Institute of Water Re- sources, said the current period is driving home that climate change must be integrated into water planning efforts, work that many water agencies have yet to take on. “Water infrastructure in Cali- fornia and much of the western U.S. was developed during a wet- ter time that was assumed by many to be largely stable,” she wrote in an email. “I worry about this from an equity perspective and feel that we need to be sup- porting water operations in inte- grating climate change into all planning efforts across all water systems, in the western U.S. in particular.” And scientists have made clear that future warming could bring even more crippling and frequent droughts. Last summer, a report by the U.N. Intergovernmental Panel on Climate Change found that even as global warming can bring more extreme rainfall and flood-

ing in some areas, it can also fuel more intense drought in many regions. That analysis found that at the current warming trajectory, droughts in drying regions that previously occurred only once ev- ery 10 years are now happening about 1.7 times per decade, on average. If the Earth warms 2 degrees Celsius, scientists expect those once-rare events to take place roughly 21 / 2 times per decade, on average. But the West’s most recent megadrought isn’t just written in scientific data. It has manifested in the shrinking water levels of Lake Mead and Lake Powell, which last summer reached their lowest on record. These reser- voirs have declined during the 21st century with rising temperatures, despite intermittent wet years. The intensifying drought looks to continue in 2022 — unless a miraculous spring season brings a return of the storm track and moisture-rich atmospheric riv- ers. While the study covers only the period through 2021, drought conditions have taken a turn for the worse in 2022. After a promis- ing start to the wet season in December, unusually dry conditions have persisted over much of California since January. California’s snowpack declined to just 73 percent of normal as of last week, after being at 160 percent of normal in December. The Central Sierra Snow Lab run by the University of Califor- nia at Berkeley tweeted that its snowpack lost 5 percent of its water content amid unusually warm weather over the past weeks. At its monitoring site, the snowiest December on record has been followed by a record streak of 37 days without precipitation.

The parched conditions laid the groundwork for a recent record-setting winter heat wave in California. From Feb. 9 through Feb. 13, the National Weather Service in Los Angeles issued the first heat advisory on record during the winter months in Southern Cali- fornia. Scores of record high temperatures were set, from San Di- ego to San Francisco. Death Valley soared to 94 degrees on Feb. 11, its highest tem- perature recorded so early in the season. The hot, dry weather, combined with gusty winds, fueled several brush fires in Southern California recently. California has seen more than 12 million acres burn in the past decade, and 18 of the top 20 largest wildfires in state history have occurred in the past two decades. Forecasters at the National Weather Service predict drought conditions to persist through the spring. The authors of the paper also see no end in sight to the West’s arid reality. “This drought will very likely persist through 2022,” they wrote, “matching the duration of the late-1500s megadrought.” Williams said that tree-ring records do provide some reason for hope — megadroughts do eventually end when the rains return. Those rains are arriving in increasingly intense bursts as the atmosphere warms. “The way you get out of droughts in the West is probably changing,” he said. Droughts may end abruptly during extremely wet years, like 2017, but then quickly reverse course again into another multiyear dry spell.

Brady Dennis and Jason Samenow contributed to this report.

CAPITAL WEATHER GANG

Southwest drought called most extreme in 1 ,2 00 years

DAVID PAUL MORRIS/BLOOMBERG NEWS Houseboats float, amid extreme drought, on California’s Lake Oroville in October 2021.

BY MARÍA LUISA PAÚL

The residential street in
Cuauhtémoc — a city in the
Mexican state of Chihuahua,
some 216 miles away from Texas
— was seemingly quiet when, in
one fell swoop, a cloud of birds
suddenly dropped from the sky.
In a matter of seconds, most of
the birds flew upward. But scores
of others were left as black and
yellow corpses on the ground.
The eerie and bizarre scene,
captured by a surveillance cam-
era on Feb. 7, has since gone viral.
It has also sparked an online
debate over what could have
possibly caused the birds to so
abruptly plummet to their
deaths.
Theories being bandied about
online range from electrocution
after smacking into a power line
to more outlandish suggestions,
such as the interference of 5G
technology or a collision with an
invisible spaceship. A local zoo
technician suggested the birds
had died after inhaling toxic gas
from the region’s high levels of
pollution — driven by the “use of
wood-burning heaters, agro-
chemicals, and cold weather in
the area,” according to local out-
let El Heraldo de Chihuahua,
which first reported the story.
But what seems strange and
ripe for speculation actually
makes more sense by under-
standing biology, birds and their
survival, experts said.
Kevin J. McGowan, an orni-
thologist at the Cornell Lab of
Ornithology, said “the only thing
that makes sense” was that the
birds were fleeing from a preda-
tor — and some mistakes were
made in their escape.
“This truly was an ‘oops’ mo-
ment for the birds,” he said. “A

really big ‘oops’ moment.” The birds that were too late to hit the brakes in the video are yellow-headed blackbirds, a migratory species first described in 1825 by the nephew of French Emperor Napoleon Bonaparte. Their calls sound like a rusty door opening, with raspy “oka- wee-wee” sounds. Fleeing winter weather, the yellow-headed blackbirds jumble into massive flocks, McGowan said, making their way from Canada and the northern United States toward Mexico during the year’s colder months. Chihuahua is a known location for these birds to winter. According to the Cornell Lab of Ornithology’s eBird program — a database compiling bird sight- ings from around the world — large flocks of some 3,000 yellow-headed birds have been spot- ted this year in the Mexican state. In 2010, McGowan said, over 30,000 were reported. Known for their golden head and black plumage, the species flies with a sort of herd mentali- ty, the ornithologist said. With- out a clear leader, McGowan said the robin-sized birds “have the same goal so they agree to move in the same direction” — much like a school of fish or an angry mob. When they are being attacked by a predator — such as falcons, hawks and owls, all of which inhabit Chihuahua — the birds inch closer together to create a tightknit pack. “The big flocks can make these quick twisting motions, move together very quickly and they all are following the one right next to them who makes the most decisive move,” McGowan said. “They’re wingtip to wingtip in

this tight bunch that makes it harder for the predators to actually pick out one and keep up with it.” But their survival mode is not always foolproof. They can sometimes misjudge their speed or the distance from the sky to the ground — resulting in the un- common, but not unheard of, visual of a flock of birds being dumped from the sky. Other scientists agreed with McGowan. Richard Broughton, an ecologist at the UK Centre for Ecology and Hydrology, told the Guardian that the flock looked “like a wave at the beginning, as if they are being flushed from above.” Ronald L. Mumme, an

ornithologist and biology profes- sor at Allegheny College, said the birds “dove, became disoriented, and many crashed to the ground and injured themselves,” News- week reported. The reason the other theories do not pan out comes down to bird dynamics, McGowan said. “Birds are light and fluffy, so they have a lot of wind resis- tance,” he said. “They don’t fall straight down very quickly, like a baseball. And in this case, they went flying down. It was a pur- poseful motion.” If they had died in the air from inhaling poisonous gases — or even hit a spaceship — the birds would have tumbled down with a different motion and not risen again after crashing to the ground. Electrocution, as others have posited, is also an unlikely candidate. “I mean with that many birds, they would’ve taken out the power line completely,” McGowan said. There is also no evidence that birds are affected by 5G technology — that is, unless they crash into a network tower. “There are a lot of conspiracy theories out in the world right now,” McGowan said. “This is weird and unusual, but it’s un- derstandable when you put all the pieces of biology and put in a couple of what-ifs. We do find these accidents happening. Ev- ery organism out there is going to die and sometimes they die in weird ways. This was one of those weird ways.” Now, for the thousands of yellow-headed blackbirds that survived and will make their way back north, the ornithologist had a piece of advice. “Please be more careful,” he said.

Here’s likely answer to bizarre mass death of birds

POLICIA SECCIONAL DE ALVARO OBRE/REUTERS A video image of some of the dead migratory birds on a residential street in Cuauhtémoc — a city in the Mexican state of Chihuahua.

The Washington Post - USA (2022-02-22)

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