Friday 18 October 2013

A 4mm long peacock may be lurking in your backyard

It is not a bird and it is not a flea

Male peacock spider (Maratas pavonis), the species known from Victoria / Jurgen Otto photograph 

Following on from an episode in tonight's ABC Quantum program (17/10/2013) on Jurgen Otto's studies of the marvelous courtship displays of the tiny little peacock jumping spiders of the genus Marata, I had to learn more about them. The name of the Victorian species, pavonis, refers to Pavo - the peacock (bird). The video below is one of a series of 9 showing the behaviors of several different species that Otto has placed on YouTube, so you will see why my sudden interest.

 

My first question was, are these fascinating creatures likely to be found in Riddells Creek? So, I checked Natureshare and found only two observations of Maratus pavonis: One by Wendy M from Murray Street, Coburg, and the other by Jody Jackson from near Malcolm Creek in Cragiburn:

http://natureshare.org.au/observation/3309/
http://natureshare.org.au/observation/7904/

Exploring further, I found that peacock spiders are only known from Australia and range in size from 3.5 mm to 7 mm. Mosquito sized males have a multicolored wing-like flaps that they normally hold wrapped around their abdomens.

Darlington's peacock spider from the Stirling Ranges, WA on someone's finger (Jurgen Otto). His wing flaps are wrapped around his abdomen

Spider with his cape extended and gesturing with his third legs..


For more than 100 years, it was was popularly believed that these flaps were used to help the spider fly or glide. Waldock (1993, 2007) discovered that the cape was actually used like the male peacock's tail as a display to females.

The World Spider Catalog lists 35 species. Otto and Hill (2011) provide fabulous diagnostic photographs of 11 species, including 3 that have not yet been formally described. Otto and Hill also note that Julianne M. Waldock of the Western Australian Museum, who is reviewing and revising the genus, has said that there are probably around 15 more species from Western Australia that still have not been described.

Given that these mosquito sized guys can even be found in urban backyards in Coburg and Cragieburn, the conclusion I draw from this is that peacock jumping spiders can probably be found in Riddells Creek if you keep your eyes open for little jumping spiders. There may well even be more than one species here - especially in areas of remnant vegetation like Barrm birrm. If you find one that doesn't look like the Natureshare pictures, it is probably an undescribed species.

Keep a lookout for the little guys - they may well surprise you, and you might even get to name a new species!


 


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