Wednesday, November 24, 2010

Sun lover

Cockroaches aren't usually associated with sunbaking, however cockroaches in the genus Elipsidion are renowned for basking in the sun during the day. They are spectacular cockroaches with vivid markings, some even have transparent window-like areas in the pronotum. I photographed this specimen soaking up the rays in the dryer country west of Kuranda. It is a young specimen (a nymph), and will have fully functional wings once it matures. These cockroaches inhabit the foliage of various plant species, and most likely feed upon pollen, honeydew and fungi.

Our porch visitor

To our delight, a Yellow-bellied Sunbird, Nectarina jugularis, has made its suspended nest right next to our rear patio door. This species is a small nectar feeding bird, only 10-12cm in size. We were able to watch the bird produce its nest from the very early stages; the bird returning every minute or so with more building material. Once the pendulous nest was completed, the soon to be mother settled in and we have only seen glimpses of her through the nest’s small circular opening.

Yellow-bellied Sunbirds lay 1-2 eggs with an incubation period of 14 days. Young fledge 15 days after hatching although the survival rate for nestlings is only around 20%. Two nights after the nest was built we were awoken by a terrible shrieking sound coming from the nest. We suspected a Brown Tree Snake, Boiga irregularis, was attacking the bird, but upon inspection no such predator was present. The Sunbird has since been seen in her nest so everything appears normal again. We can only wait and see what happens and wish her luck.

The Yellow-bellied Sunbird halfway through nest construction

Friday, November 12, 2010

Experts in camouflage

One of the largest and most common katydids in northern Queensland is also one of the most seldom seen. The Spiny Tree Katydid (Phricta spinosa) has excellent camouflage and positions itself motionless on tree trunks through the day to avoid detection by visual predators. The specimen pictured below was beside a rainforest walking track, where I witnessed tourist after tourist wander by within 40cm of the katydid looking for nature, but obviously not looking hard enough...

The Spiny Tree Katydid resting on a small tree adjacent to the walking track.

A close-up of the head of the katydid. The spines, colour and pattern all help to break up the outline of the animal resulting in excellent camouflage.

Eight legs beats thirty

On a recent field trip to collect house centipedes (Scutigeridae) for the filming project we are working on, I found a large specimen but not quite in the way I expected. This one had just been caught by a Brown Huntsman (Heteropoda sp.) and probably wasn't going to be much use to us on set! These centipedes have 15 pairs of long thin legs, and needless to say they move very fast. As quick as huntsman are, it is still surprising that it managed to catch such a sensitive and rapid moving animal.

House centipedes have two large compound eyes contrasting with other groups of centipedes which have smaller simple eyes. They are predatory and venomous, injecting their venom through short modified legs which act as fangs. These 'venom claws' are located just below the mouths of house centipedes.

The name 'house centipede' originated overseas due to some species occurring inside houses. Ironically most species of house centipedes never come inside.

The Brown Huntsman (Heteropoda sp.) feeding on the house centipede.

A specimen we found a couple of nights later at the same site. This species can attain a body length of almost 60mm with a leg span of over 100mm.