European stag beetle

Those jaws are for wrestling, not biting. A male grips a rival, rears up and flips him off the branch. The old line is that the female bites harder, but when biologists finally measured the bite of a Southeast Asian relative, the male bit six times harder than the female.

This card reads Not Evaluated because the stag beetle has no global Red List assessment. It has two regional ones, and they disagree: Near Threatened in Europe, where it has declined sharply in the north and centre of its range, and Least Concern in the Mediterranean region. Neither covers the whole species, which also lives in Turkey and the Caucasus.

The adults do not eat. For their few weeks above ground they only drink, from sap runs on damaged trees and the juice of fallen, rotting fruit.

The bigger beetle usually wins. Males fight over sap flows and females, and a well-matched pair can wrestle for a long time before one is lifted off its feet and thrown.

In Britain it lives mainly in southeast England, and London is one of its strongholds. Old stumps, dead wood left in gardens and parks, and even buried fence posts feed the grubs.

Its decline is mostly a shortage of dead wood. Tidy forests and cleared stumps remove the only food the grubs can live on.