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FAMILY PETALURIDAE
- This page contains pictures and information about Coastal
Petaltail Dragonflies that we found in the Brisbane area, Queensland, Australia.
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 - Body length 100mm, male
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- The Coastal
Petaltail Dragonflies are vary large in size, the largest dragonfly that
we found. They
are one of the very rare species and only found in Southeast Queensland.
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   -
- Their eyes are well separated.
They
have the black thorax with yellow spots. Their abdomen is yellow with black
pattern.
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- The pterostigma (darkened cell at the leading edge of each wing near the
tip) are thin and long. The males have the
anal appendages enlarged like the petal, and this is why they are called.
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Their Habitat
- The Coastal
Petaltail Dragonfly likes to hide among the thick vegetations and camouflage well,
hardly be seen a few meters away. In the above pictures, the dragonfly was
resting on Sword Grass (also known as Saw Sedge or Saw-leaf,
Gahnia aspera, family Cyperaceae). The grass is about one to two
meters tall, with skins-cutting edges. We had been cut many times before we
saw the dragonflies.
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- The Coastal
Petaltail Dragonflies only breed in swamp and boggy seepage. They seldom fly far away from their breeding
ground. They rest most of the time, with their body
hanging 45 degree from a branch among the thick vegetations. While searching
for them in the thick vegetations, you may suddenly see a small aeroplane-like
insect
fly away from two meters in front of you. Then you know that you just miss
another rare chance to look at them. They may not have the
very good eye-sight as other dragonflies. If you state motionless ( and you are lucky
enough), they
may land and perch near you.
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  -
- In Yugarapul
Park, there were a number of small pools covered with dance water
plants and surrounded by very tall grass. They are the breeding
ground of the dragonfly. The male Coastal
Petaltail Dragonflies perch on plants near those pool waiting for the
female. The male dragonflies defend for their territory when another male fly
nearby. We saw the male and female Petaltail
Dragonflies fly in tandem over those pools and mating
in wheel position. We also saw those huge dragonflies captured other smaller
dragonflies in the mid-air.
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  -
- In Yugarapul
Park, we sometimes found the Petaltail
Dragonfly resting very high up on the tree. It is believed that
they rest on trees at the swamp edge during night time. During the day they
rest on the swamp where they perch on top of low vegetation or hang 45 degree from a branch.
The dragonflies do not fly as good as the smaller dragonflies. Usually
they fly for a few meters then come down to rest. We never found them outside the site.
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Male advertisement
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- The about pictures show the Petaltail
Dragonfly perched on plants waiting for the female. Notice that the male's
petaltails were bright orange in colour under the sun. It was easy noticeable
even far away (in the first picture). We believed the bright colour petaltails
is the sexual advertisement
to the female.
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- We noticed that usually the Petaltail
Dragonfly rests with the body
hanging 45 degree from a branch, however, when the males were perching near
the pools, they rested at horizontal to 30 degrees position. We guessed they may
perch at an angle best for showing their petaltails bright colour.
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- We also noticed that when the male dragonflies perching near the pools, they
did not too care if we came very close. Some of the pictures we took were within one
meter range.
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Mating
   -
- We are lucky enough to record the Petaltail
Dragonflies mating. At about 2:00pm, we saw two huge dragonflies flying
in tandem over a pool 2 to 5 meters high in the sky. A few minutes later we saw a
mating pair in wheel position rested on grass about 1.5 meters above ground. We
were not sure if they are the same pair. We found that they remained in wheel
position for over half an hour. Then the female separated from the male. The
male flied away first. After about ten seconds, the female flied away at another
direction and disappear on a tree top. We did not see how the female lays her
eggs.
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- The female is about the same size as the male, with thicker abdomen and no
petaltail. The base of her hind wings are round instead of angular, otherwise,
look the same as the male.
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In
the web
  -
- The above first picture shows a Petaltail
male wrapped up in a spider web. By carefully inspect the contents,
as shown in the second picture, we found the Petaltail was wrapped up together with another smaller dragonfly, the Pale Hunter. Usually dragonflies 'know' where the
spider webs are and will avoid
them most of the times. We imagined that the Petaltail got caught in the
spider web was because it was chasing the Pale Hunter
and forgot the danger. We recorded another dragonfly get caught in spider web
with similar reason in the Australian Emerald page.
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The
Larvae
- The larvae construct burrows in the mud, which open to surface and they
are believed active at night. They feed on other insects which come need the
burrow entrance. They may also prey on dragonfly larvae and other creatures
in water via the underwater entrance. Their life cycle is very long, some
estimated being as long as 6 years.
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Dragon Hunting
 -
- On the 2001-02 summer, I joined the Australian Dragonfly Society
hunting team, leaded by Deniss Reeves and Ric Nattrass, to search for the Coastal
Petaltail Dragonfly in Yugarapul
Park. Yugarapul Park is a boggy seepage, a rather unique
habitat
in Brisbane suburbia. We were very lucky to have captured one male, so that we can let the
Brisbane City Council know that the area is an breeding place for a rare and vulnerable
species. May be we can get the park declared as Australia's first dragonfly reserve/preserve.
The above pictures show the captured dragonfly held in Deniss's hand.
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- Reference:
- 1. A Field Guide to Dragonflies of South East Queensland - Ric
Nattrass, 2006, p59.
- 2. The Complete Field Guide to Dragonflies of Australia - CSIRO, Günther Theischinger and John Hawking, 2006,
p108.
- 3. - NSW National
Parks and Wildlife Service 2006.
- 4. Southeast Queenslannd's Giant Dragonfly - Petalura litorea - Deniss Reeves,
Austrolestes-Newsletter of Australian Dragonfly Society, spring 2001.
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