Page 99 - BBC Wildlife Volume 36 #02

Q&A

Q AFRICAN MAMMALS
Q ARCTIC WILDLIFE
Can elephants be
right- or left-tusked?
A Yes. Just as humans are right- or left-
handed, elephants are known to use one
tusk more than the other. This favoured
appendage is sometimes referred to as
the ‘master tusk’ and often A Dogs – namely labrador retrievers – annual movements. Their research revealed
appears more worn. Tusks have played an important role in ringed seal that ringed seal subpopulations interbreed
are evolved from teeth and research, a challenge to carry out on the throughout the Arctic, reducing the species’
have all sorts of uses – in snowy wastes of Arctic sea ice. vulnerability to extinction; and that earlier
snowmelt, driven by climate change,
seal
about
‘
dogs
an
ter
learning
Af
from
’
defence, as weapons, for After learning about seal dogs from an snowmelt driven by climate change
stripping bark, foraging Inuit hunter, marine biologist Brendan is exposing the pups sooner and more
and digging. Sarah McPherson Kelly from the University of Alaska used frequently to the elements and predators,
labradors to sniff out breathing holes and such as polar bears and Arctic foxes.
lairs (caves dug in the snowdrifts over Michael Engelhard
breathing holes, which females use to rest
Seahorses – here a short-
snouted – can change and nurse their pups). The dogs
colour quickly, blending boasted an 80–85 per cent
into their habitat to success rate in a search area
hide from predators. 5–10km wide, pinpointing
up to 200 lairs and holes
in a month.
Thanks to their canine
assistants, Kelly and his
team were able to secure
samples of moulted skin for Named for its
DNA analysis, and to attach tags circular markings,
the ringed seal is the
to dozens of individuals to follow their
Arctic’s smallest and most
common seal species.
Q BIRDS OF THE WORLD
What’s a spotted owl’s
favourite type of tree?
A California spotted owls – endangered birds that live

in the mixed conifer forests of the western US – prefer
the tallest trees. Measurements taken by bouncing a laser
pulse from an aeroplane off the treetops in the Sierra
Nevada mountains revealed that these birds are drawn to
trees more than 32m high; that their favourite nesting
sites are in trees more than 47m high; and that they
avoid areas with lots of trees less than 15m high.
The discovery should be enormously helpful when
it comes to forest management. It was previously
thought that California spotted owls needed a canopy
with at least 70 per cent tree-cover, a density that
can make forests vulnerable to fire and drought.
Knowing the birds’ heads for heights
means foresters can now remove the
shortest trees, thus reducing the
canopy cover without destroying
valuable nesting habitat.
Large trees also host the nests of northern flying
squirrels, a key prey item that the owls hunt by perch-
and-pounce. The birds have low energy requirements,
California spotted
even by owl standards – an adult caring for young can
owls like the cool
survive on just one squirrel every 1.8 days. conditions of old-
Liz Kalaugher growth forest.
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