Wednesday, June 22, 2011

Masters of camouflage

I've just finished putting together a presentation about huntsman spiders for the upcoming Australian Invertebrates Conference in Melbourne. One of the species featured in the presentation is the Lichen Huntsman, Pandercetes gracilis. It is the sole member of the genus in Australia, and up close, a very spectacular animal. I needed a few extra photos for my presentation so I had a quick look in the yard and to my delight found 5 no more than 10 metres from the house.

These spiders sit on the tree trunks both day and night, unlike most other huntsman which hide by day to avoid predation. Pandercetes get away with it due to their superb camouflage. Their bodies are coloured and patterned to match the patchwork of lichens that occur on the tree trunks. They also have clusters of hairs on their legs which fan out and effectively break up their outline. To the untrained eye, they are almost impossible to see until they move.
These huntsmen are fast moving hunters, and in a blink of an eye they will have caught a passing insect.
There s a great deal of individual variation in the colour forms of this species. The five I photographed in the yard are all different. Some predominantly green, others shades of brown.