| ROEBUCK
BAY AND ITS BIRDS
THE BAY
Roebuck Bay is situated to the east of the Broome Township.
It is the beautiful expanse of azure water that dominates
any view not obscured by the rich mangrove habitat.
The Bay’s northern point is the jetty at Broome Port
and its southern limits are Yardoogarra Creek, Sandy and
Bush Points. This gives Roebuck Bay a total area of 48,500
hectares, of which 17,500 are the rich mudflats exposed
twice a day by the huge tidal movements in the region.
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Eastern
Curlew,
the largest shorebird in the world and a common sight
on Roebuck Bay's mudflats. |
THE MUD
The tides’ ebb and flow uncovers the rich tropical
mudflats the famous migratory birds rely on. These mudflats
and the animals that live in and on them have been intensively
studied in collaborative projects between Environs Kimberley
(EK), Broome Bird Observatory (BBO), Department of Conservation
and Land Management (CALM) and the Netherlands Institute
for Sea Research (NIOZ).
These surveys have revealed Roebuck Bay as possibly the
most bio-diverse mudflat to have been studied in the world.
Over 200 species of invertebrates have been identified,
some new to science.
| Terek
Sandpiper,
a charismatic shorebird of Roebuck Bay, often seen
sprinting after tiny crabs. |
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THE BIRDS
This abundance of invertebrates enables huge numbers of
birds to live on Roebuck Bay. The Bay is used by different
species in subtly different ways.
The migratory shorebirds or waders come in the greatest
numbers. These birds breed in northern Asia and the Siberian
Arctic when the food source is at its greatest, during the
brief northern summer of late May to late July. The thousands
of birds seen during that time here in Roebuck Bay, our
winter or dry season, are all immature birds not yet ready
to breed. They do not undertake the arduous journey to Siberia.
At this time of year the birds are predominately grey and
brown in colour.
From mid-August right through until October the adults
and the year’s chicks return. The more southerly breeding
species arrive first and the juveniles of the most northerly
breeders last. On their return some adults still show the
bright breeding plumage they grew to attract mates. The
juvenile birds are hatched in the Arctic and leave the nest
within hours of hatching.
After an intensive period of only 2 to 5 weeks, the young
birds are fully feathered and have gained enough weight
to undertake the journey of up to 10,000 kilometres to Roebuck
Bay. Both the adults and the chicks then stay here, feasting
on the rich food source in the Bay until the following March
and April, when the adults leave once again on their epic
journey.
This is an even better time to visit the Bay and see the
fine breeding colours of the shorebirds. If you see flocks
of birds heading north in neat formations, spare them a
thought: they may not touch land again until 3 or 4 days
later, after a single non-stop flight of 6000 kilometres!
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A
huge flock of migratory shorebirds roosting on the
beaches near Crab Creek. The potential for disturbance
as Broome grows is a cause for concern. |
THERE ARE LOTS OF THEM, SO THEY’RE SAFE?
Unfortunately it’s not that simple. In the rapidly
developing nations of eastern Asia, particularly China and
Korea, huge coastal reclamation projects are planned for
the coming decades. Vital shorebird habitat that sustains
the birds during their migratory journeys will be lost.
Shorebirds face potential problems here as well. While
Roebuck Bay is currently in very good ecological condition,
the town is growing quickly and pressure on the Bay and
its wildlife is increasing. Excessive recreational use of
the accessible northern beaches, where thousands of the
migratory birds roost, is of special concern.
Pollution from various sources is a threat, more insidious
and difficult to assess, which could face the Bay in the
years to come. It is important that all sectors of the community
work together to keep the Bay in its current healthy state.
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