Page 51 - BBC Wildlife Volume 36 #02

BUDGIES

Above: budgie particular budgie when the super-flock it flies into is able
super-flocks can change direction so swiftly and seamlessly.
travel hundreds of As Roland sat and watched them, the budgies seemed
kilometres to find
standing water. to land at the waterhole in wave after wave, with groups
Left: although the of birds taking it in turn to drink. As each bird departed,
size of flocks may another was always ready to take its place. Some sipped
change, bonded from the water’s edge, while others touched down briefly
pairs always
stay together. on the surface to quench their thirst. “They can land on
the water for one to two seconds,” Roland says. “Along
with an unusual species of Australian pigeon called the
flock bronzewing, they’re
the only land birds I know
WILD BUDGIES HAVE TWO SET that can do this.”
Budgie feathers, however,
are not waterproof. So if a
FLIGHT SPEEDS THAT THEY
bird lingers on the water
SWITCH BETWEEN ABRUPTLY.
too long and is pushed
under by an incomer,
TOP SPEED IS SAVED FOR USE
its plumage can become
waterlogged and the bird
IN CLEAR, OPEN SPACES.
struggles to take off. As
they haul themselves onto dry land they are sitting
have filmed budgies flying towards each other in a wind ducks (pardon the pun) for the large monitor lizards
tunnel and found that, to avoid collision, the birds follow an called goannas, feral cats and Australian ravens that wait
unexpectedly simple rule. They always veer to the right. opportunistically on the shore to seize them.
Moreover, wild budgies appear have two set flight Overall, this ‘collateral damage’ makes little difference
speeds that they switch between abruptly. They either fly to the size of the already swollen population. For wild
fast, at around 9.44 metres/second, or slow, at a more budgies, when times are harsh, there really is safety in
leisurely 5.44 metres/second. Top speed is saved for use numbers. Nor are the birds thought to be suffering any
in clear, open spaces, while ‘second gear’ is reserved for ill-effects from climate change. Although the total wild
cluttered environments. It’s a technique that Srinivasan population is unknown – it’s tricky to estimate because
thinks helps them to judge distance and avoid crashes. numbers fluctuate so wildly – the International Union
for the Conservation of Nature (IUCN) believes that the
SHAPE SHIFTERS population as a whole is increasing.
By flying at the appropriate speed, and always swerving Budgies have survived the harsh conditions of
in the same direction, the budgies are able to orchestrate Australia’s outback for millions of years, and they’re not
their amazing aerial displays without collision or showing any signs of buckling now. It means that one of
catastrophe. But why do it? Surely there’s more to these + FIND OUT MORE the continent’s best-kept and most spectacular secrets will
manoeuvres than just the joy of flying or showing off? Watch budgies be around for some time to come.
Scientists think that the budgies perform their swirling in this BBC clip:
www.bbc.co.uk/
murmurations in order to confuse the predators that are HELEN PILCHER is a science writer. Her book Bring
programmes/
inevitably drawn to this enormous avian buffet. It is hard Back the King: The New Science of De-extinction
p028f7qv
for a whistling kite or Australian goshawk, say, to target a (Bloomsbury Sigma, £16.99) is out now.
February 2018 BBC Wildlife 51