Monday, 4 June 2012

Dead things ? - call in the sextons

Visitors often comment about all the dead things that are lying round the island and sometimes ask why we don't clear them up. The answer is that firstly things die out here. With some many creatures packed into a small area then death is often and obvious. Disease claims many like some of the rabbits and seals. Old age come to a few. And of course predation also is and has to be a daily happening. It is all part of the cycle of life. And a vital part of that cycle are the undertakers, the ones that clear up the dead things. One of the premier firms in the business are the sexton beetles which we have been finding in increasing numbers over the last few days in our moth traps. There are 6 species of sexton beetles found in the UK, 1 black one and 5 red and black ones. They get their name because their lives revolve around dead carcasses. They have a strong flight and a fantastic sense of smell and when they have sniffed out a fresh carcass they either bury it (small animals such as mice) or burrow underneath it (for bigger ones). They then lay their eggs on the carcass but to make sure it doesn't rot away before the eggs hatch they also inject into the body an antibiotic mix of chemicals that slow down the decay. You might think that interesting but it gets better, as once the grubs have hatched the parents stay with the body to look after them, something very unusual in insects. They tend the grubs as they grow, protecting them from predators and moving them to get the best out of the carcass. But they also cull some of the grubs if the carcass is disappearing to quickly to make sure that at least some of the larva reach adulthood. So if there was no death or we cleared up all the carcasses we would have no sexton beetles and the island would be a duller place.
A black sexton with its big carcass detecting antennae.

1 comment:

  1. Another great post packed full of great info, a different side to the island again. Although, rather than Sir Elton John's 'Circle of Life' I prefer one closer to home 'Ilkley moor baht 'at".