Courting Danger

By Chris Bentley

Rye Harbour Nature Reserve Warden

Most, if not all spiders employ some form of courtship when wooing a prospective partner. Courtship provides the female with a way to gauge the suitability of the male as a mate and for the male it identifies him as a suitor of the correct species. 

In spiders it is based on either touch, smell (and ‘taste’), sight or sound with species employing one or a combination of these senses, often depending on which are the best developed in that particular species, in turn related to their hunting methods. At one end of the scale we have the courtship of the Woodlouse Spider (Dysdera crocata) with the male only reacting to the female once he has touched her and any courtship being ‘swift and unelaborate’.  At the other extreme we have the elaborate ‘dances’ of the male jumping spiders which involve often bright colouring and complex patterns of leg waving and body movement. 

In spiders another important function of courtship is that it identifies the male as ‘not lunch’. This is quite important when the female is predatory, often considerably larger than her prospective mate and always on the lookout for her next meal, and male spiders often employ a range of additional methods to ensure that they don’t end up on the menu. In some species, such as the familiar Wasp Spider (above), males can often be found lurking around the edges of an immature female’s web waiting for the moment when she moults into an adult. At this stage her cuticle will still be relatively soft, her muscles won’t work so well and and she will be less mobile (and therefore less of a threat). For this particular species however this is just delaying the inevitable, as the male generally gets eaten by a female he is courting at some point. Others employ a bit of silken bondage, fairly perfunctory in some species of British crab spider but far more ‘binding’ in some foreign species. In some species males will wait until the female has prey in her web before attempting mating, taking advantage of the gustatory distraction to have their wicked way.

Male four-jawed spiders (above) have huge jaws which they use to hold the female’s jaws open during mating, while in the North American jumping spider Maevia inclemens some males have stripes and bright coloration on their legs and body which is thought to reduce female aggression by mimicking the warning coloration of poisonous or venomous insects.

However in some cases courtship actually increases the chance of the male being eaten! The male of the common Nursery Web Spider (above), for instance, presents the female with a wrapped prey item in order to increase his chance of mating and fathering offspring. While the male goes to great pains to avoid getting eaten (including playing dead) sometimes he does end up as a meal. He could avoid this by not presenting the gift but in this case he would reduce his chance of mating and producing offspring, so he takes the risk.