It’s been another two week gap without a blog due to university work, so this weeks species is a real stunner: the Rhinoceros Beetle (Sinodendron cylindricum)! Sinodendron roughly translates to ‘hollow tree’, which may refer to the habitat where the Rhinoceros Beetle is usually found: deadwood. cylindricum refers to the body shape of the beetle, being quite cylindrical! This beautiful beetle is one of three British members of the family Lucanidae, the other two being the Stag Beetle (Lucanus cervus) and the Lesser Stag Beetle (Dorcus parallelipipedus). The Rhinoceros Beetle is a fairly large beetle, usually just over 15mm in length, but is dwarfed by the others members of the family. Lesser Stag Beetles can be over 30mm, and Stag Beetle males can be 70mm! Here is the Rhinoceros Beetle:
And here’s the Lesser Stag Beetle:
As you can see, Rhinoceros Beetles are very distinctive! Males can easily be told from females by the presence of the horn at the front of the head, which is absent in females. The horn may be used to compete with other males for mates and resources. Adult Rhinoceros Beetles feed on tree sap, whereas their larvae feed on rotting wood. The individual in my photo was found (along with several other Rhinoceros Beetles) by my friends Ben and Max, whilst chopping wood for a fire. I suspect those beetles may have been newly hatched, or going into torpor for the winter.
Adults are strong fliers, and are active from March to October. During these months, they could turn up just about anywhere with a few trees, from gardens and parkland, to ancient woodland and farmland. The Rhinoceros Beetle is widespread throughout Britain, but is scarce in Scotland, and much of the extreme South and East of England. The Beetle in my picture above was the first that I’d ever seen! Here’s its distribution map:
This charismatic little invertebrate is well worth seeing, even if (like me) you can’t find your own and have to cycle a few miles to see it! I think it’s the first beetle I’ve ever twitched!
(For any non-birders, twitching is going out of your way to see an unusual or rare bird, or beetle, in this instance).