E2 EZ EE THE WASHINGTON POST.TUESDAY, JULY 28 , 2020
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HEALTH & SCIENCESCIENCE NEWSsan jose — Is California —
home to Tesla, solar panels ga-
lore and gobs of scientists — t he
g reen-energy paradise it’s made
out to be? A new, peer-reviewed
study in the Proceedings of the
National Academy of Sciences
journal reinforces the idea.
California households emit
33 percent less carbon than any
other state, while only two other
Sun Belt states consume less
energy, said researchers at the
University of Michigan, who ana-
lyzed the environmental impact
of 78 percent of the nation’s
housing stock (about 93 million
homes), using 2015 data.
San Francisco’s household
emissions were nearly three
times lower than the national
average — 1.03 tons of carbon
dioxide per capita vs. 2.83 for the
United States — and lower than
any other major city included in
the research paper. In Los Ange-
les, the average household con-
tributed 2.28 tons of carbon diox-
ide for the year, compared to 3.64
in Oklahoma City, 3.11 in Denver
and 2.69 in Boston.
One strong correlation to
greenhouse gas emissions was
geography.
The West had some of the
lowest carbon emissions: Califor-
nia (23 carbon dioxide equiva-
lents per square meter of a
house), Oregon (34), Washington
(34), Utah (34), Idaho (37) and
Nevada (40). All eight of the
highest-emitting states were in
the central and southern parts of
the country: North Dakota (74),
West Virginia (70), Missouri (69),
Oklahoma (67), Kansas (65),
Iowa (64), Mississippi (63) and
Kentucky (63).
Examining data in 8,858 Zip
codes, researchers also found
households in high-income
neighborhoods contributed
25 percent more carbon dioxide
than households in low-income
neighborhoods. In the Los Ange-
les metro area, for example, theaffluent Hollywood Hills, Brent-
wood and Sherman Oaks Zip
codes had among the most
greenhouse gas emissions, while
Inglewood, Fullerton and Hun-
tington Park had some of the
lowest.
“ The tendency for affluence
and (average floor space) to in-
crease together is a key emis-
sions driver for wealthier house-
holds,” researchers wrote.
As temperatures rise, Bay Area
cooling centers present an obsta-
cle during a pandemic.
While increased density, com-
monly associated with a smaller
carbon footprint, did show some
correlation, the apparent effect
from the income gap was far
wider.
“ Variation in (greenhouse gas)
intensity among the ZIP codes
likely reflects differences in cli-
mate, building characteristics,
and carbon intensity of the elec-
trical grid, such that the overall
relationship between density
and emissions is attenuated,” re-
searchers wrote.
Households in states with
warmer climates consumed less
energy, measured by kilo-
watt (kW) hours per square me-
ter. The national average is
147 kW hours per square meter,
while Florida (97), Arizona (103)
and California (109) had the
lowest rates in the nation. L os
Angeles consumed even less than
the state, at 103 kW hours per
square meter.
Researchers began with the
goal of identifying where in the
nation’s households are likely to
need the most aggressive action
to meet the 2025 and 2050 goals
set forth by the Paris Climate
Agreement. Residential emis-
sions account for 20 percent of
the total in the United States,
they said, and would by them-
selves be the world’s sixth-largest
polluter of greenhouse gases, on
the scale of Germany.
— San Jose Mercury NewsCalif. households are far ahead of those in other
states in cutting carbon emissions, report saysSCIENCE SCANThe waters of the North Atlan-
tic are a playground for some of
the biggest creatures on Earth.
Although baleen whales are ma-
jestic, their lives depend on the
delicate balance of their ocean
ecosystem. Now, a new study has
revealed that four of the six types
of baleen whales in the Atlantic
Ocean have changed their move-
ments, seemingly in response to
shifts in the climate.
In a paper in the journal Global
Change Biology, more than 30 re-
searchers from institutions in the
United States and Canada consid-
ered over 35,000 recordings taken
from passive acoustic recorders.
The underwater microphones
ranged from western Greenland
to the Caribbean Sea, and the data
represented whale calls recorded
between 2004 and 2014.
The researchers found that fin,
sei, humpback and blue whales all
spent more time in northern lati-
tudes over the decade. After 2010,
the time they spent in the Gulf of
Maine, the land off the coasts of
New England and Nova Scotia,
declined.
Baleen whales eat by filtering
large amounts of krill, small fish
and plankton out of the water and
into their mouths. They tend to
return to the place where they
were fed when they were young,
and the Gulf of Maine has long
been an important feedingground. But the once fertile gulf is
changing quickly.
The area is warming faster than
99 percent of other oceans, and
that has changed feed availability
and animal behavior. Instead of
lingering there, the whales fol-
lowed their food to the western
North Atlantic.
The hydrophones also revealed
a surprise: blue whales travel
much farther than once thought.
The massive animals were once
thought to prefer northern waters.
The data, however, showed blue
whale calls as far south as the
shores of North Carolina.
Recordings suggest that can-
yons and continental shelf breaks,
where the edges of continents
slope down toward the ocean floor,
are important potential habitats
for the deep-swimming whales.
The researchers say the newly
identified whale habitats need
more protection from human
threats like noise pollution and
shipping. Now that scientists
know more about how whales
move and where they thrive, their
work can guide policy decisions
that could make waters more hos-
pitable to the animals.
— Erin BlakemoreCETOLOGYBaleen whales may be changing their travels
in the North Atlantic because of warming trendsNew study on North Atlantic
whales and global climate
Global Change BiologyBY CHRISTINA LARSONPerched on a flowering shrub
on a windy Andean mountainside,
the tiny Ecuadoran hillstar hum-
mingbird chirps songs of seduc-
tion that only another bird of its
kind can hear.
As the male sings, he inflates his
throat, causing iridescent throat
feathers to glisten princely purple.
The female may join in a courtship
dance — or chase him off.
For the first time, scientists
have shown that these humming-
birds can sing and hear in pitches
beyond the known range of other
birds, according to research pub-
lished in the journal Science Ad-
vances.
The male’s ballad is sung at
around 13.4 kilohertz (kHz).
That’s considered “ultrasonic” for
birds, which generally can’t hear
above 9 or 10 kHz.
“Something very interesting is
going on in the ears of these hum-
mingbirds to allow them to hear
such sounds,” said Christopher
Clark, a biologist at the University
of California at Riverside. He was
not involved in the study. “That’s
just an incredibly high pitch for a
bird.”
Among birds, only some owls
have previously been shown to
hear ultrasonic sounds — which
they use to find prey but not to
communicate. Biologists have
studied other hummingbird spe-
cies in South America that make
high-pitched sounds, but it has
been difficult to confirm whether
those birds also hear the sounds.
For the new study, scientists
climbed into the Ecuadoran An-
des to reach high grasslands
called paramos and find the hill-
stars’ breeding grounds. Therethey recorded the males singing,
then played back their romantic
ballads to test the reactions of
other birds.
Other hillstars craned their
necks and turned toward the
speaker as it played the high-
pitched chirps; one also flew over
the speaker to inspect it. In the lab,
the scientists verified that the partof the brain typically engaged in
auditory communication had
been activated.
“We confirmed that this song
has a social function,” said Fer-
nanda Duque, a study co-author at
Georgia State University, where
she researches hummingbird
brains.
Mammals generally hear a wid-
er range of pitches than birds.
Humans can hear pitches up to
about 20 kHz, but lose sensitivity
to high-pitch sounds with age.
During fieldwork, the younger
scientists could usually hear the
hillstar hummingbird songs, but
the older participants couldn’t,
Duque said.
The researchers believe the
birds may have evolved to sing at
high pitches so that their love
songs wouldn’t compete with
background noises in their envi-
ronment, such as mountain
winds, streams and the songs of
other birds, said Marco Monteros,
a study co-author and biologist at
the Universidad Técnica del Norte
in Ibarra, Ecuador.
“For some hummingbirds, it’s
like a private channel of commu-
nication — other bird species
don’t use these high-frequency
sounds,” said Timothy Wright, a
behavioral ecologist at New Mexi-
co State University, who was not
involved in the study.
— Associated PressHummingbird’s ultrasonic songs of seduction
FERNANDA G. DUQUE/GEORGIA STATE UNIVERSITY/ASSOCIATED PRESSA male hillstar hummingbird in Ecuador. According to a s tudy, this
tiny species in the Andes can sing and hear frequencies beyond the
range of other birds.PHOTOS BY KAREN OSBORN/SMITHSONIAN/REUTERSBY WILL DUNHAMFor fish inhabiting the im-
mense darkness of the deep sea,
being ultra-black offers great
camouflage in a fish-eat-fish
world. Scientists studying some
of these exotic creatures have
unraveled the secret behind their
extreme color.
These fish — like the fangtooth,
the Pacific blackdragon, the an-
glerfish and the black swallower
— have modified the shape, size
and packing of the pigment in
their skin to the point that it
reflects less than 0.5 percent of
light that hits it, researchers said
recently.
They studied 16 species that fit
this definition of ultra-black.
These spanned six different or-
ders of fish — large groupings
that each have a shared evolu-
tionary history — indicating this
modification evolved indepen-
dently in all of them.
“In the deep, open ocean, there
is nowhere to hide and a lot of
hungry predators,” said zoologist
Karen Osborn of the Smithsonian
Institution’s National Museum of
Natural History in Washington, a
co-author of the research pub-
lished in the journal Current Biol-
ogy. “An animal’s only option is to
blend in with the background.”
Very little sunlight penetrates
more than 650 feet below the
ocean’s surface. Some of these fish
reside three miles deep.
At such depths, biolumines-
cence — light emission by living
organisms — is the only light
source. Some of the ultra-black
fish have bioluminescent lures on
their bodies to coax prey close
enough to be eaten.
The skin of these fish is among
the blackest material known, ab-sorbing light so efficiently that
even in bright light they appear to
be silhouettes, as Osborn discov-
ered when trying to photograph
them after they were brought to
the surface.
The pigment melanin is abun-
dant in this skin and distributed
in an unusual fashion. By packag-
ing perfectly sized and shaped
melanosomes — pigment-filled
structures within the skin cells —
into tightly packed and continu-
ous layers at the skin’s surface,
the fish ensure that essentially all
light reaching them will hit this
layer and never escape.
“This mechanism of making
thin and flexible ultra-black ma-
terial could be used to create
ultra-black materials for high-
tech optics or for camouflage
material for night ops,” Osborn
said.
— ReutersStudy sheds light on camouflage traits
of ultra-black fish in deep, dark sea
TOP CLOCKWISE: Two Pacific
blackdragons and a fangtooth
are among the exotic creatures
known as ultra-black fish. Their
skin is among the blackest
material known, absorbing
light so efficiently that even in
bright light they appear to be
silhouettes. “In the deep, open
ocean, there is nowhere to hide
and a lot of hungry predators,”
a zoologist says. “An animal’s
only option is to blend in with
the background.”BEN MARGOT/ASSOCIATED PRESS
A worker i nstalls solar panels in Hayward, Calif. Households in the
state emit 33 percent less carbon than any other state, while only
two other Sun Belt states consume less energy, researchers say.