Robyn Williams: I suppose you've seen those thrilling pictures in the
papers of thousands upon thousands of pelicans gathered in the centre of
Australia. They've flown to the wet, and once they're there, they do what
pelicans do so well: breed like there's no tomorrow.
Now if you look at a great big pelican, with its crew cut, philosopher's
frown and vast undercarriage, you're impressed, yes, by its sheer weight as
well, but despite the look and the hefty size, it doesn't tell you how they know
when to fly, or why they should leave the seaside, which is surely pelican
heaven, to go off to some red sand desert, just because it's flooded for a week
or two.
Well Libby Robin has some answers. She's senior editor of the book Boom
and Bust: Bird Stories for a Dry Country, and she has a remarkable story to
tell.
Libby Robin: Why do pelicans fly inland after rain, even though they
never saw it falling? They somehow 'know' that this is the moment to go and
breed. When they go inland they find huge lakes, pulsing with life, in country
that's most often waterless and without fish. Knowing when desert rivers are
flowing and the fish are breeding is essential to the survival of pelicans. They
take the chance to breed when the moment is right.
Pelicans have evolved to work with the 'boom-and-bust' cycle of the
Australian desert. They have adapted to the world's most variable climate, the
climate of inland Australia. It is this that saves them from being an endangered
species at a time when their habitat is changing rapidly. Pelicans know how to
find and exploit the resources of marginal places that are only sometimes
wetlands.
Pelicans in coastal areas live with new difficulties. There are a lot more
people living near them. Urban and semi-urban settlements now sprawl through
their former breeding haunts. Wetlands are good for pelicans, but bad for
developers, so they are often drained. In rural areas, the chemicals added to
farmlands and the responses of acid sulphate soils to agricultural exploitation
pollute many remaining wetlands.
We are lucky that despite all the changes we still see these splendid birds
in coastal areas. While people demand the certainty of dry land for housing, and
seasonal agricultural production, pelicans have an alternative rhythm. They need
places to fish all year round, and places with extra resources to breed and feed
hungry chicks. Now that coastal wetlands are severely limited, the pelicans turn
to alternative inland wetlands, where, for short times, there are extraordinary
resources to grow and fledge their chicks. The opportunity to breed comes, not
annually in spring, but when the fish are plentiful. And it must be taken
quickly. Pelicans survive because they can breed at the times and places when
the fish breed; as long as people don't mess up these ephemeral inland wetlands
too.
Pelicans are not the only birds that have adapted to both the people and
climate of Australia, but they are familiar. We know them from their beachside
haunts, big, clumsy birds out of water, gracious in. We know them one at a time,
they are each around 8 kilograms. The ecologist, Julian Reid, tells us about
different pelicans, inland pelicans, pelicans in bulk. He is watching the
rhythms of inland Australia as he lies on his back while thousands of pelicans
take off above him. Thousands of kilograms of bird mass soaring upwards in
spirals, riding the thermals, then at a great height one individual bird breaks
out and the rest follow in a V-shape toward a distant lake. Successive skeins of
birds repeat the pattern in a staged manner to the new feeding ground. These are
familiar birds made unfamiliar by sheer numbers.
The idea of a Boom-and-Bust rhythm is abstract: it needs a pelican to
remember it with. I can swat up abstractions for exams, but they disappear
quickly afterwards. Many years ago I tried to teach myself Spanish. I can't
remember any grammar or vocabulary now, but I can still sing every word of a
little Spanish song from the tape. It is the unconscious mind that remembers
songs and stories. How do we engage our unconscious with the big environmental
changes of our time? The answer? Stories.
In a land where floods and droughts are natural parts of a bigger ecological
cycle, birds depend for their survival not on regular rains but on how long they
can stretch out their resources between big flooding events. They need to seize
the booms and lie low in bust-times.
Drought is normal in Australia. In the arid lands of Australia, 'normal'
ecosystems do not follow the annual seasons, as they do in other parts of the
world, but rather boom (or 'pulse') after rare rain events. Flowers, seeds,
seedlings, baby birds and other animals all follow at different times after the
events, but the 'pulse' produces activity, and then inactivity. During the long
dry times between booms, the natural systems wait. The technical term is that
they 'reserve' their energy. They are waiting, not strictly 'busted'. But if the
wait is too long, they will not survive.
How long can they wait? Birds and other creatures, adapted to the long breaks
between rain in arid Australia, have evolved special coping strategies. It is
not simply that it's a long wait but that it is an uncertain one. It's not like
a bear hibernating for the winter months, then waking in spring. There are no
regular seasons in this country. Rain is carried south on the monsoon and
sometimes blown north by sub-Antarctic winds. But this country is at the extreme
edge of both. The survival of creatures depend on how well they can wait and
cope with the uncertainty of the wait, and then how quickly they can respond to
opportunity, whenever it arises.
Our new book, Boom and Bust: Bird Stories for a Dry Country, tells
some of the stories of the workings of exceptional Australian ecosystems through
our charismatic birds. We are no longer writing about a 'natural' system, all
our birds live with people to a greater or lesser extent, so we need history as
well as ecology to tell these stories. Some birds, like the pelicans, adapt to
people and cope well with the uncertainties of never knowing when the bust (or
resource poor) time will end. But added to the old uncertainties for which birds
have evolved strategies are new uncertainties created by the great changes
wrought in the landscape by humans; these changes are in historical time, not
evolutionary. And we are still trying to make sense of this changing history,
and learning how birds and other creatures are responding to human-induced
change.
The first wave of human settlement was Aboriginal people who arrived about
55,000 years ago and burned vegetation to improve their hunt. These people
profoundly changed the vegetation patterns of the landscape. Human fires changed
the food sources available to birds as well as the structure of the vegetation.
When times change, it is better not to be a fussy eater. The huge duck-like
bird, Genyornis, taller than a man and weighing about 275 kilograms, was, it
seems, too particular about what it would eat. It died out about 45,000 years
ago, probably because its preferred food, chenopod shrubland (that's saltbush
and bluebush) became increasingly replaced by grasslands and open Eucalypt
woodlands. Without its preferred tucker in large quantities, Genyornis did not
survive. But Emu, another big bird that lived in some of the same places in the
Australian desert, adapted. It seized on available food sources and learned to
eat them. Changing its feeding pattern ensured its survival.
Then the second wave of humans arrived just over 200 years ago and introduced
European farming practices to the wide expanses of inland Australia. The
adaptable Emu discovered a taste for wheat and ate it with enthusiasm, much to
the chagrin of battling Western Australian farmers in country near the rabbit
proof fence. In 1932, the Commonwealth Minister for Defence declared an Emu war.
He sent in the Seventh Heavy Battery of the Royal Australian Artillery with two
Lewis guns and 10,000 rounds of ammunition. The opportunist Emu had made
wheat-growing tough, but its uncanny ability to run and dodge machine-gun fire
totally embarrassed the military. You can't fight opportunists with fixed and
inflexible artillery.
In the northern hemisphere, where most of our economic and many of our
ecological models are based, there's a historical certainty that resources come
and go with the sun: spring brings new growth, autumn harvests. Global and
national financial systems are similarly based on annual cycles that draw on the
deeply seasonal agricultural past of dominant western nations.
As global climate change affects ecosystems everywhere, certainty is
increasingly eroded: seasons fail, food supplies are no longer reliable, and
extraordinary weather patterns bring disasters on unprecedented scales. Now
uncertainty does not just affect marginal places like the Australian arid zone.
It is spreading and changing the functionality of places where certainty used to
be the norm. Boom times no longer appear annually on the calendar with the
harvest. The world seeks new ways to live with uncertainty, to adapt to
disasters and to wait out the increasingly uncertain stretches of time between
good seasons.
Australian Aboriginal people have a different calendar - and are consummate
story-tellers. They watch the birds and flowers and understand the structure of
each year on its merits. 'When the brolga sings out, the catfish start to move',
Daly Pulkara told Deborah Rose at Yarralin in the Northern Territory. Tellers
create a calendar, but the calendar is not cyclical or certain, rather
interconnected and ecological. The coming of rain, of fish, of edible seeds is
each an important season, but it is not necessarily annual. The order of events
is knowledge that is embedded in country; events are interdependent. This is the
story of a calendar that waits. And people who remember stories.
In uncertain times, we need Bird Stories for a Dry Country. Not all
birds are coping with all the new uncertainties. For the Nigh Parrot, the
changes wrought by human actions are too much. The wait between resources has
been too long. The story of the elusive 'fat budgie' of the inland continues to
tantalise and many grim human stories have become tied to its fate.
Most of southern Australia is a 'dry country' in broad terms. Even cheerful
urban birds like white-winged choughs, have evolved strange social behaviours to
adapt to drought. Like many Australian birds, they breed co-operatively, with
many helpers at the nest. Choughs are an extreme case, however. They are
obligate co-operative breeders: if there are chough babies, there must always be
more than a pair of bird-parents. Babies are so precious in the chough group's
world of limited resources that one group will sometimes gang up and conspire to
kidnap babies from another. A bigger group has a greater chance of successful
survival in tough times, in chough logic.
Ecological systems have booms (opportunities) and times of reserve. Humans,
like birds, need to know when to take opportunities to grow and when it is
better to wait and conserve resources. The Global Financial Crisis has everyone
talking about Booms and Busts. But it is always the busts that attract the
attention: busts are 'abnormal', while booms are the default, the normal
expectation. Good and bad economic times have always been interconnected and
interdependent. And there is no certainty when the next bust will come. Human
society has much to learn from stories of birdlife in Australia.
Robyn Williams: Well that's one angle to Anzac Day I never thought of:
having the army take on the emus, and fail. That was Libby Robin. The book is
called Boom and Bust: Bird Stories for a Dry Country, published by CSIRO.
And Libby Robin is at the National Museum of Australia in Canberra, by the
way.
http://www.abc.net.au/rn/ockhamsrazor/stories/2009/2551660.htm
