Nature's undertakers

Wildlife undertakers

Burying beetles or sexton beetles (genus Nicrophorus)
This one I filmed is Nicrophorus americanus about 3cm long

Nothing goes to waste in nature.
A dead mouse lies dead on the forest floor and its decaying odour attracting the super senses of the buying beetles. There is a rush to find the fresh carcass and get it buried as quickly as possible before other carrion eaters find it.
The beetles will excavate the ground under the mouse with amazing speed. This mouse was buried within 10 minutes. Building the burying chamber will take a further 8 hours to construct
Underground the beetles will wrap the mouse into a tight ball.

They shave the fur away, biting and spitting saliva on the bare skin which slows the decay of the carcass and prevents the smell of rotting flesh from attracting competition.
The adults mate and she lays eggs on the wall of the chamber.

A couple of days later the eggs hatch the tiny larvae climb in to the carcass and into a pit that the parents have created.
Biparental care is unusual in beetles yet the male will stay around to protect their food ball from intruders and also help feed the larvae by regurgitating a liquid food for the larvae to feed on. Although the larvae are able to feed themselves, both parents feed the larvae.

This probably speeds up larval development.
At an early stage, the parents may cull their young.

This infanticide behaviour is to match the number of larvae to the size of the carcass so that there is enough food to go around.

If the male leaves too soon another male will be able to kill the growing larvae and mate with the female.

I filmed the underground sequence through grass in an air tight chamber so the beetles didn’t abandon the mouse ball.
I use daylight balanced fibre optic lights that don’t give off heat and which I could gradually build up the light levels sufficiently to film.

The sequence appeared on the ‘The Sexual Imperative” series for Channel 4

Complete Garden advice software for PC & Mac

No comments: