Australia’s vibrant and cute spider-form of sexy male peacocks

by on Nov.28, 2012, under Fauna, Information, Invertebrates, Uncategorized

Australia’s vibrant and cute spider-form of sexy male peacocks

 By Amy Prendergast

The male peacock is the classic example of how under sexual selection males have evolved spectacular gaudy adornments to impress choosy females.

Evolution of extravagant courtship displays and coloration signalling a male’s sexiness to seduce females is ubiquitous throughout the animal kingdom and is by no means restricted to birds. An epitome of sexual selection in favouring astounding male courtship displays and appearance occurs in peacock spiders. Whilst measuring a mere 5mm, like their namesakes, male peacock spiders are arguably even more outrageous when it comes to bright appearances and behaviours to entice the comparatively drab brown (yet well camouflaged) female peacock spiders to mate with them.

It is not just the manifestation of the male peacock spider that is magnificent: so too is his behaviour. Upon locating a female (a task enabled by the acute vision provided by their two large front eyes typical of jumping spiders) he becomes visibly excited and launches into a frenzied routine advertising his sexiness to the prospecting female. Attempting to woo the female, the male performs a most spectacular courtship dance.  During his performance he displays his brightly patterned abdomen whilst opening up and shimmering wing-like extensions on the sides of the abdomen also bearing the colour pattern that lie otherwise concealed except when displaying to the females. The males also posses lengthened, thickly-bristled black 3rd pair of walking legs with white little muffs on the tips which they wave-about erratically as they stage their courtship performance. As part of the performance routine, he dances to-and-fro, and his brush-tipped legs act as “flags” whereby he “frames” his flared, bright, vibrating abdomen with both 3rd legs to then bring them down suddenly. A search on YouTube will come up with some videos where you can witness this captivating display!

If sufficiently impressed by the male’s performance, following the dance’s finale the male’s efforts will be rewarded and the female will accept his amorous advances and allow him to copulate with her. However, this is a very risky business: if the female is pregnant, she is highly intolerant towards potential suitors and if the unwelcomed male attempts to proceed to mate with her she may even attack and consume the male!

These spiders have only a short lifespan and so there is a premium on males to ensure they mate before their time is up. At the end of the breeding season after all that energetic and vigorous courting male’s beautiful hues have faded and end up perishing by midsummer. Females have a slightly longer life-span and can still be found well into summer as they guard their egg-sac containing a small clutch of eggs. By autumn all adults have died-off, but this is when some juveniles begin to emerge. Juvenile males are initially drab like females and only acquire their spectacular breeding attire after their final moult that occurs around September. Peacock spiders mature in the spring and the males seem to appear before the females.

Peacock spiders are members of the very large arachnid (spider) family Salticidae, otherwise known as jumping spiders. These amazing arachnids are in fact Australian and so we are lucky to have the chance of actually encountering them, if one is perceiving enough to find these tiny critters. For, whilst the males are brilliantly adorned, and conspicuously colourful, their small size (only 4-6mm in length) and fast movements makes them difficult to spot. If you do chance to observe them however their fascinating antics are unrivalled and they put on a marvellous show. During the start of spring when the breeding season commences I’ve been lucky enough to frequently encounter numerous males in my very own backyard as they commence their quest to find mates. The images below are of some of these males of the species known as the common peacock Maratus pavonis that I’ve had the pleasure of encountering.

A number of other species of Maratus found within W.A. There are nine described species of peacock spiders, five of which occur in WA. The different species most easily be distinguished apart based on different colour and patterns adorning the abdomen. Various species sport a dazzling array of brilliant hues, including purple, azure blue, emerald green, sulfur yellow, burning orange, and bright red which contrast markedly and are produced by both pigments and refracted light. Moreover, the male’s abdomens glimmer due to iridescent hairs. The Maratus genus has a broad geographic range, extending across southern Australia including Tasmania, and all species in the Maratus genus are endemic to Australia (have evolved here and occur nowhere else). The species below, Maratus pavonis, is the most widespread species of Maratus. Not only does it occur in W.A. (like this author), but it also can be found in S.A., Tasmania, Victoria, NSW and southern QLD. Maratus pavonis is unusual for unlike most peacock spiders it is able to live in “disturbed” habitat like domestic gardens where I commonly encounter them. They are fairly terrestrial so your best chance at glimpsing the spectacle of peacock spider courtship is by carefully scrutinizing the ground or low-level native vegetation during September to December.

 

 

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