Hi, sorry it’s been a while. Too many things happening and not enough time to do them.
Anyway… this is a creep out shot for me and considering I had the camera on close up and just free hand took them (without lining it up at all) I was amazed I even got the subject in the frame.
People, please meet one of Australia’s many mean spider boys or girl as this case is with this specimen – a redback. Apparently only 14 deaths have been recorded as a result of redback bites in Australian history – none since the introduction of an anti-venom in the 1950’s. Still, I don’t like them and this girl was building up a nice little stock of food right near my front door. I say was because there may have been a slight tragedy shortly after these photos were taken.
The beetle in the picture is what I call a Christmas beetle. It’s about averaged sized of about 2cm in length if that helps to give you an idea on how big the spider is/was. I found it interesting the number of ants she had woven with the beetle for later. I couldn’t see any egg sacks so hopefully I got her before she made more of her kind, redbacks can lay between 40 and 300 eggs in one sack according to Wikipedia. It also says it’s a good and bad life for the males but I’ll let you be the judge of that and read directly from them.(reference: http://en.wikipedia.org/wiki/Redback_spider)
The redback spider is one of only two animals to date where the male has been found to actively assist the female in sexual cannibalism. In the process of mating, the much smaller male somersaults to place his abdomen over the female’s mouthparts. In about two of three cases, the female fully consumes the male while mating continues. Males which are not eaten die of their injuries soon after mating.
Sacrifice during mating is thought to confer two advantages to the males. The first is the eating process allows for a longer period of copulation and thus fertilisation of more eggs. The second is females which have eaten a male are more likely to reject subsequent males. Although this prohibits the possibility of future mating for the males, this is not a serious disadvantage, because the spiders are sufficiently sparse that only 20% of males ever find a potential mate during their lifetimes.
It does refer to the spider as one of two “animals” as well as saying they are sparse even thou there seems to be more and more around my place so maybe it doesn’t tell the whole truth – who knows.