Emailing New Scientist - August 6, 2016

This 14-day-old great tit
nestling was ringed, weighed
and fitted with an RFID tag
before being returned to the
comfort of its nest
MARC SCHLOSSMAN FOR NEWSCIENTIST
cylinder and weighs it. A moment later
the bird is gone. They are very tolerant of
being handled, Sheldon says.
Each bird gets two tags: a metal ring on
one leg – the traditional approach – and a
RFID tag on the other. Introduced to Wytham
“In human terms, this is like
tracing bird families back to
the Norman conquest”
in 2007, RFID tags have revolutionised the
collection of data, enabling the team to track
the comings and goings of individual birds.
“By the end of each year, we’ve got in excess of
15 million location/date points,” says Sheldon.
After almost seven decades, you might
think surprises were hard to come by, but the
advent of RFID and other technologies means
that there are always new questions to ask.
Sheldon’s colleague Ella Cole recently
took some tagged great tits into the lab to test
their problem-solving abilities. It turned out
that the smartest birds occupied much smaller
territories in the woods. “Good problemsolvers
can manage much more effectively
in a smaller space – they can extract what
they need more efficiently,” says Sheldon.
The project’s historical depth can also
uncover secrets. The team can trace family
trees of tits back 40 generations. “In human
terms, that would be back to around the time
of the Norman conquest,” Sheldon says.
That gives them access to detailed data
from the decades before climate change was
a significant factor, and so offers some of
the best intelligence about how it can affect
ecosystems. “We are seeing big changes in the
annual life cycle. Key moments such as egg
laying happen about two and a half weeks
earlier now than in the 1970s,” says Sheldon,
“but the birds are coping quite well.”
Sheldon sees the project running far into
the future, but is excited by prospects in the
shorter term. “Within 20 years the tags will get
small enough, and smart enough, that we’ll be
able to track entire populations in real time,”
he says. Combining this with advances in
genetic analysis and forest sensor technology,
he says, “will enable us to understand many
ecological processes at scales that right now
we just can’t comprehend”.
While the technology in Wytham is racing
ahead, you wouldn’t know it from walking
through the woods. To them, 70 years is no
time at all. Sean O’Neill ■
6 August 2016 | NewScientist | 39