44 | New Scientist | 20 February 2021
to minimise covid-19 risk, after a pandemic-
induced hiatus.INDUS RIVER DOLPHIN
(Platanista gangetica minor)
Status: Endangered
This river dolphin, a subspecies of the South
Asian river dolphin that relies on echolocation,
is found only in the Indus river basin, mostly
in Pakistan. In 1923, British colonial authorities
built the first of 19 barrages across the Indus to
divert water for irrigating crops, fragmenting
the dolphins’ habitat. Once found throughout
the 3000-kilometre-long Indus, their range
shrank to 1300 kilometres. By 2001, numbers
had dropped to 1200.
Satellite tracking in 2009 showed that
the dolphins can sometimes pass through
the barrages, but they often strand and die in
the irrigation canals that run off them. Fishing
nets pose a further problem. The barrages
can’t simply be removed, says Uzma Khan
at WWF-Pakistan. Acoustic devices help deter
the dolphins from entering the canals, but
educating fishing communities and recruiting
local people for ecotourism and monitoring
has been the key to an uptick to some 1800
animals, says Khan. “I initially saw it all as
a scientist,” she says. “I learned you cannot
do anything without communities.”MOUNTAIN GORILLA
(Gorilla beringei beringei)
Status: Endangered
The first case of gorillas contracting covid-19 –
announced by San Diego Zoo in California
on 11 January – raises a worrying new risk
for the mountain gorilla. This subspecies of
the eastern gorilla, the largest living primate,
survives in two populations split across
rainforest on extinct volcanoes in Rwanda,
Uganda and the Democratic Republic of the
Congo. It is a poster child for conservation
rooted in ecotourism that brings people
to their habitat.
Poaching and forest felling for agriculture
reduced mountain gorilla numbers to
around 250 in 1981. After earlier attempts
to establish protected areas antagonised
some local communities, ecotourism took
off and made gorillas more valuable alive
than dead – permits to see the animals can
cost $1500 each, says Bennett.
Numbers now stand at a minimum of 1063 –
the only great ape that is on the up. Continuing
threats include disease and snares set to poach
other animals, says Cath Lawson at WWF-UK.
“We consider it to be a conservation success
story, but it’s not a done deal,” she says.
Rwanda and Uganda are now resuming
tourist visits, and these will include stepsEuropean bison
graze in Poland’s
Białowieża Forest“ The blue whale recovery shows what
humans can do if they leave things alone”
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