Zebra spider

A much better day today! Pete has pretty much recovered,and after baking a batch of white chocolate-chip cookies, I had time to take the dogs to the river before our afternoon science session. The weather forecast had been for cloud, but it turned out sunny and spring-like, and there were plenty of very photogenic items on my walk - a comma butterfly basking on a bulrush head, a robin catching a worm and the ubiquitous sallow blossom.

Just as I was crossing the bridge back towards the car I spotted a zebra spider Salticus scenicus on one of the the metal rails. Zebra spiders belong to the family Salticidae (also known as jumping spiders) and are believed to have the best eyesight of any arthropod. This one was looking very hard straight at the camera when I took the photo. Shortly after it jumped and disappeared completely!

The BBC Science site has the following information about them:

Female zebra spiders are 5-7mm long and males are 5-6mm. The most distinctive feature of these spiders is their two very large eyes. Although they have eight eyes, the two at the front are the largest and give them excellent binocular vision. These tiny spiders are black with white hairs that form stripes.

Zebra spiders tend to hunt any insect or spider roughly the same size or smaller than itself. They have been observed feeding on mosquitoes, which are almost twice their length. hese spiders use their large front eyes to locate and stalk their prey. They move slowly towards their prey until they are close enough to pounce on top of their victim, and their hunting behaviour has been described as cat-like. Using their acute eyesight, they are able to accurately judge the distances they need to jump. Before jumping they glue a silk thread to the surface that they are jumping from so that if miss the target they can climb up the thread and try again. They ignore unappetising insects such as ants.

When these spiders meet, the male carries out a courtship dance involving waving his front legs and moving his abdomen up and down. The better the dance the more likely the female will want to mate, although arachnologists have yet to discover what it is the female looks for in a mating dance. Despite their good eyesight, males will sometimes accidentally perform a mating dance in front of another male. When this happens the two males usually fight. Males will also perform courtship dances in front of their own reflection in a mirror.

Females will stay with their egg sacs and will guard the young after they hatch. After the spiderlings have had their second moult they will leave the mother to fend for themselves.

Better viewed large! Unless you're an arachnaphobe!