Food fight
Photographer Alwin Hardenbol
LOOKING forward to your festive
dinner? Spare a thought for
these spotted nutcrackers on
the Vitosha mountain massif in
Bulgaria. They must ward off rivals
and maybe even dig through
snowdrifts to reach their meal.
This exquisite image was
taken by Alwin Hardenbol, a
conservation biologist and wildlife
photographer living in Finland.
It is one of 6000 photos he took
of this confrontation, and received
an honourable mention in the
2019 Royal Society Publishing
Photography Competition.
It shows the fiercely territorial
behaviour of two spotted
nutcrackers (Nucifraga
caryocatactes), a species found
across northern Europe and Asia,
as they fight over buried stores of
their main food source, pine nuts.
Before winter, the birds gather
these seeds by pecking open pine
cones and then cracking the nuts’
hard shells with their bills. Their
tongues are specially adapted to
help them with this shelling. They
have been known to use trees and
rocks as vices to hold larger nuts
in place. The birds also have an
expandable food pouch that can
hold up to a fifth of their weight.
Each spotted nutcracker buries
thousands of nuts and seeds in
small caches. In winter, stores can
be covered by almost a metre of
snow. How the birds remember
the site of these caches is unclear,
but they recover around 80 per
cent. And some of those left
behind will sprout, maintaining
the tree population. ❚
Bethan Ackerley
21/28 December 2019 | New Scientist | 37