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April 2020 | SMITHSONIAN 330
The Comeback
Decades after the world
fi rst became aware of
the terrible plight of
mountain gorillas, the
latest population fi gures
are encouraging
Photographs
by Neil Ever Osborne
Text by Mark Jenkins44
Surge Engine
Tidal power is a renew-
able energy source that
has never quite lived up
to its potential. Now it is
getting a boost from an
innovative experiment
in Nova Scotia
by Elizabeth Royte58
The Ship in the Ice
An international team
of scientists has sailed
to the Arctic and
attached their fl oating
laboratory to an ice
fl oe. The goal of their
historic expedition? A
better understanding
of our changing climate
Photographs
by Esther Horvath
Text by Michelle Nijhuis11 American Icon: A magazine
for our times- Covering the globe
14 Art: Visual history
16 Earth Day: Car trial - What’s driving emissions
24 Data: Cloud control
26 National Treasure:
Earth Day fl ag
28 Crossword: Grid yourself
features
A mountain gorilla in Virunga National Park, Democratic
Republic of Congo. To observe one in the wild is to consider
what we have in common with our fellow primate.prologue
68
Mind Craft
As Asian elephants
increasingly clash with
farmers and villagers
over disappearing
land, researchers are
trying to aid the great
pachyderms by solving
the puzzle of how
they think
by Jennie
Rothenberg Gritz80
Wild Man
An ecologist eager
to restore America’s
blighted environments
urges us to proceed one
backyard and offi ce
park at a time. Tear out
the invasive plants, he
says, for the animals’
sake—and ours
by Jerry Adler06 Discussion
108 Ask Smithsonian
You’ve got questions.
We’ve got expertsCover: A semi-captive Asian elephant
at the Myaing Hay Wun camp in
Myanmar, where Smithsonian-
affi liated researchers are studying
the species’ behavior.
Photograph by Justin Mott05550
05
0
50
YEARS OF
EARTH DAYSmithsonian
magazine’s50
TH
Anniversary
In celebration of
our fi rst half-century,
we look back a little,
and look ahead
with hopeVisit the Smithsonian
Institution’s con-
servation initiative:
earthoptimism.si.edu