7 December 2019 | New Scientist | 11Animals Briefing
Michael Marshall Adam Vaughan
FEMALE brown bears with cubs
seem to hang around near people’s
homes. It may be a way to avoid
males, who would force the females
to abandon their young earlier.
Joanie Van de Walle at
Sherbrooke University in Canada
and her colleagues studied brown
bears living in a rolling landscape
of managed forests, bogs and lakes
in Sweden. The area was dotted
with houses and cabins.
Female brown bears keep their
cubs for 1.5 or 2.5 years. A female
who keeps offspring for 2.5 years
can bestow more care, perhaps
raising survival chances, but may
come into conflict with males who
want to mate with her. Males may
kill a cub outright, or drive it off.
“Males would have an interest
in shortening the period of maternal
care,” says Van de Walle. “We
thought females might come
up with counter-tactics.”
To check this, her team used
GPS collars and helicopters to track
23 male bears and 16 female bears
with cubs. They found that females
that only kept cubs for 1.5 years
had similar habitats to males, but
females that spent more time close
to human homes kept cubs for
2.5 years (Behavioral Ecology and
Sociobiology, doi.org/dgbj).
In Sweden, hunters aren’t
allowed to kill family groups, so
females with cubs have little to fear.
In contrast, males and lone females
are fair game, so have good reason
to avoid places where people live.
“It’s a really interesting
observation to see these differences
in females,” says Dieter Lukas at
the Max Planck Institute for
Evolutionary Anthropology in
Leipzig, Germany, who has studied
infanticide by male animals.
However, he isn’t convinced that
the risk of infanticide is what pushes
females to venture close to homes.
He points out that cubs that go solo
aged 1.5 years normally survive. ❚
Savvy brown bears
stay near people to
keep their cubs safe
What is COP25?
The Conference of the Parties:
United Nations jargon for
the annual meeting of
nearly 200 countries to
talk climate change.Where is it happening?
There has been a game of
musical chairs concerning
who is hosting. Originally, it
was Brazil, which later backed
out. Then Chile stepped in, but
social unrest in Santiago saw the
conference moved to Madrid in
Spain at the eleventh hour.Who is going?
Around 30 heads of state,
plus the UN secretary general,
António Guterres. Climate
campaigner Greta Thunberg
crossed the Atlantic Ocean in
a catamaran to attend, as she
didn’t want to fly back from the
US, where she gave a passionate
and often angry address at UN
climate talks in September.What is the aim of the talks?
They are largely a stepping
stone to 2020, the most
important year for global
climate efforts since the Paris
deal was agreed in 2015. That is
because countries are expected
to upgrade their carbon-curbing
plans and potentially outline
their long-term plans to get to
net-zero emissions, ahead of a
crunch summit in Glasgow next
year, COP26. In the meantime,
the talks in Madrid need to tidy
up outstanding questions about
the rules of the Paris Agreement.Like what?
Largely technical stuff – but with
real effects. One issue is how
international carbon trading
between countries, known as
Article 6, will work. The key
there is to ensure the rules avoid
double counting carbon credits.
Timelines and clarity for when
countries should submit carbon
plans in 2020 should also be set.What are the expectations like?
Mood music for COP25 has
set the bar low. That’s partly
because the UN summit that
Guterres organised in New York
in September failed to catalyse
significant new action by world
leaders. The hope is that, at a
time when the US has begun
to formally withdraw from the
Paris Agreement, countries will
reaffirm their commitment to
the framework that secured the
deal. “I think COP25 can deliver,
at the very best, a promise to do
what governments agreed in
Paris,” says Mónica Araya, a
former climate negotiator
for Costa Rica.Who are the key players?
The US played a vital role
in the run-up to Paris, which
continued until Donald Trump
became president. Araya sees
leadership in smaller nations,
such as New Zealand, which
recently passed a law to hit net-
zero emissions by 2050. But the
focus is on China and the EU.Why are they so important?
The EU’s member states
could reach an agreement
on a net-zero 2050 target on
12 December. The expectation is
that the EU and China will make
an announcement at a joint
summit next September in the
run-up to COP26, detailing their
more ambitious carbon plans,
in a similar way to an influential
move by the US and China
before the 2015 Paris summit.
But tensions have flared
between China and the EU over
the latter’s recent proposals for
a “carbon border tax”, which
could complicate matters. ❚Your guide to this week’s
UN climate summit
RAFA
EL^
MARC
HANTE/REU
TE
RSThunberg arrives in
Portugal by boat on her
way to the Madrid talks