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Cry of the curlew
By
Tania Schuett,
2003
The haunting, eerie, mournful sounds heard at
night on Magnetic Island are the cries of the Bush
Stone-curlew. Stone-curlews belong to family Burhinidae
represented throughout the world by nine species in two
genera. Two species are found in Australia, one from each
genus: the Bush Stone-curlew (Burhinus grallarius) and the
Beach Stone-curlew (Esacus neclectus).
The Bush Stone-curlew, also known as Bush
Thick-knee, Southern Stone-curlew, Southern Stone-plover,
Weeloo, Willaroo, Angelbird and Scrub curlew, was once found
across much of Australia, except for very arid regions and
heavily forested areas. It is now rare to totally extinct in
closely settled parts of Australia and dwindling in numbers
elsewhere. In some states it is listed as vulnerable or
threatened. Ground-feeding, ground-nesting woodland birds that
are larger than 500 grams are the bird species most endangered
in Australia and the Bush Stone-curlew fits every one of these
criteria. This bird is the emblem of Moorabool Shire in
Victoria because Moorabool is local Aboriginal for 'the place
of the curlew' or 'the voice of the curlew'. But for the last
50 years curlews have not been seen there.
Identification Bush Stone-curlews are
nocturnal, cryptic and very well camouflaged. They are fairly
large ground-feeding, ground-nesting woodland birds. Adult
total length is 55-60cm, wingspan 80-105cm and weight 550-750
grams. They stand at around 50cm and when sitting down are
about 30cm high. The dark grey bill is 5-6 cm long, thick and
straight. Curlews have large yellow eyes, a long neck,
camouflaged grey-brown upper parts with bold black streaks and
cream under parts. Their long legs are thin and delicate with
thick knees which they fold backwards when sitting. Their
three front toes show traces of webbing but there is no hind
toe. Ecologically they behave like woodland birds while
technically they are classified as waders and therefore
possibly do not breed until they are 2-3 years old. There is
no known way of sexing Bush Stone-curlews externally; so far a
blood test is the safest and most reliable method.
Behaviour Curlew presence is most often
indicated by their wailing calls after dusk. They are most
active from dusk to early morning and are particularly active
on moonlit nights. Their eerie cry is persistent during mating
and nesting time or when rain is about. Those wailing,
screaming, haunting cries signify disturbance, danger,
communication, territorial disputes or the loss of an
offspring or partner. Curlews can fight fiercely for various
reasons, pinning the opponent to the ground, attacking it on
the neck, the back, between the wings, or grabbing it by the
tail and swirling it around. At times they kneecap their
opponent.
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 Curlew
adult with chick
Photo R Schaer
|
They fly only when frightened or to gain better
feeding ground or to socialise. They are shy
and watchful, moving slowly with their heads
outstretched. They run a short distance, stop, peer and
flick their tails then repeat the process again and
again. Their resting positions are standing on one leg,
sitting or lying stretched flat.
On Magnetic
Island the behaviour pattern of Bush Stone-curlews has
changed dramatically in recent years. Lowland areas are
mostly residential, development is taking over their
habitats and there is greater activity and disturbance
from humans and domestic animals. Consequently they now
depend on friendly property owners, residents and
visitors.
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Habitat During the day curlews normally
shelter on the ground in lightly timbered habitats among
fallen tree debris where their mottled plumage forms
camouflage and the open terrain offers good visibility. They
need this type of habitat with sparse grass cover and abundant
fallen tree litter for feeding and roosting. Curlews are
usually not found in grasses higher than themselves. Some
native grasses do grow tall but not densely and this allows
the birds to see predators. Curlews mainly inhabit lowland
open forest, woodland and sandy creek beds but they are also
on golf courses, in parks and many other locations.
Food Curlews eat a variety of foods such
as crustaceans, grasshoppers, spiders, lizards, centipedes,
snails, small frogs, small reptiles, ground beetles, crickets,
caterpillars, seeds and small fruits. They eat only what is on
the surface and do not scratch for food.
Breeding Magnetic Island curlews breed
between July and February. Breeding birds strongly defend
their territory but at other times of the year they are
non-territorial. Nests are consistently located in relatively
open areas on bare ground, often surrounded by a few sticks,
leaves and small stones. This enables the sitting bird to
achieve good ground vision in all directions. The same nesting
sites are re-used in successive years but nests may be
abandoned if surrounding grass becomes too tall or disturbance
is too severe. Curlews usually lay two eggs directly on the
ground. These are mottled grey-brown the size of hen eggs.
They are laid 24-48 hours apart and incubation begins with the
laying of the last egg. Occasionally two females lay their
eggs together, making a nest of 3 or 4 eggs. Parents take
turns in sitting, with the off-duty bird usually standing
guard nearby. Incubation takes 22-28 days. Parents can hear
chirps through the eggshells and they make soft clucking
noises to the chicks.
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Offspring
Curlew chicks can walk almost as soon as they hatch;
and when the parents eat the tell-tale eggshells as a
calcium supplement, the chicks are led away from the
nest to a more protected area. Newly hatched curlew
chicks weigh 26-34 grams and are covered with thick pale
grey down and are boldly marked with dark brown to black
stripes. Parents communicate with their young by making
low clucking noises. Sometimes dissecting food, they
then pass it directly to the chicks by dropping it in
front of them, clucking and stepping back. This
continues until the young are almost fully grown, except
when breeding begins again, often when chicks are only 3
weeks old. Pairs behave in different ways in these
situations: some allow their young to remain, feeding
them until the new clutch hatches; others viciously
chase them away, forcing them to try to fend for
themselves. |
Curlew
adult with chick
Photo R Schaer
|
Two clutches are common and even 4 clutches
may be produced in the same season, usually after the loss of
very young chicks. It is common to abduct or adopt offspring
from other pairs and raise them with their own. The last brood
remains with the parents until breeding begins in the next
season.
Curlews are sedentary and can live to 30
years. Most pairs stay together in the same territory
throughout life. Young curlews may be unable to establish
territories because all of the available habitat is already
taken by adult pairs. This is particularly apparent on
Magnetic island where pockets of 20 or more birds can be found
throughout the year.
Predators and other Dangers On the
mainland major threats are foxes, feral cats and dogs and
roaming domestic animals. More wildlife is harmed near rubbish
tips than elsewhere because of the populations of feral
animals there. Only goannas and some large snakes are known
natural predators of adult curlews, while young curlews also
fall victim to hawks, kites, eagles, kookaburras, owls, crows,
currawongs and other carnivores. When approached, all curlews,
even the newly hatched, either run or freeze - lying flat on
the ground, head and neck outstretched, relying on camouflage
for protection. Therefore it is truly difficult to see
camouflaged eggs, chicks or breeding adults and at times they
are accidentally killed by lawnmowers or slashers. As young
curlews cannot fly until they are about 50 days old, they are
vulnerable and most parents distract potential threats with
dramatic displays. Adults will also hiss, grunt and growl
loudly with wings outstretched, tail fanned and erect or they
will run from the threat. Most road-kills occur at dawn and
dusk, in overcast conditions and during or after rain.
Curlews, including the young, frequently run onto the road and
under streetlights to pick up insects or sit on the warm
bitumen. On Magnetic Island curlew numbers are rapidly
declining due to habitat loss and fragmentation, road-kills,
disturbance from domestic animals, both natural and feral
predators and food shortages. There are so many odds against
them.
With some consideration, we can save these
strange birds that fascinate almost every person who stays a
night on Magnetic Island and hears the cry of the curlew.
Researched, written and published by Tania
Schuett, Magnetic Island native bird carer since 1980
© 2003 Tania Schuett
Reprinted with kind permission of the author.
Also available
Native Wildlife-to Feed or Not to Feed?
Available from:
Queensland Parks and Wildlife Service, Picnic Bay
Magnetic Island History and Craft Centre Inc., Picnic Bay
Curlew family
Photo R Schaer
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