The Young Rangers' Club
A Club for Children interested in Wildlife & Conservation

Nature Detectives
1st September 04

Found! - a Dor Beetle.

 

Wildlife is sometimes difficult to spot unless you know how and where to look for it. In this meeting we started learning how to be nature detectives.

First of all, Harry brought in some very interesting finds for everyone to look at.

One of these was the discarded outer skeleton of an intriguing insect. This skeleton required the use of our detective skills almost immediately!

Cicada nymph skeleton We knew that the skeleton was from an insect because it was an exoskeleton. (Unlike humans, insects have their skeleton on the outside, rather than the inside.) We could also see that it had originally had six legs.

Instead of being made of bone, insect skeletons are made of a hard material called chitin. Discarded skeletons look like an empty mould of the animal which once lived in it.

You could see the hole on the back of the skeleton where the insect had pulled itself out when it shed its skeleton. (Insects have to shed their skeletons when they grow.)

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Cicada nymph skeleton The skeleton was quite brittle and had lost some of its legs, but we could still see that it had very big claw-like front feet.

In addition, the skeleton had small wingbuds on the back. This told us that it was from the young stage of the insect, rather than from an adult.

Identifying the skeleton took more detective work after the meeting. After some research, the skeleton was found to be that of a cicada nymph. (A nymph being the young stage.) While adult cicadas live on trees, the nymphs feed on roots underground. This explains their very large front legs, which are used for burrowing and digging. The front legs are quite different in the adult, because it has no need to dig.

More detective work was now required, because cicadas live mainly in tropical areas. They are very rare in England and only one species is found. This species is called the New Forest Cicada (Cicadetta montana) and it is only known from the New Forest, in Hampshire. Harry had told us that the skeleton was given to him by his neighbour in Honiton. Now we wondered, had New Forest Cicadas come to Honiton?!

Another enquiry revealed that Harry's neighbour had found the skeleton in France, which being warmer, has several species of cicada. So cicadas had not arrived in Honiton and the puzzle was finally solved. However, it shows that one needs detective skills to find out about wildlife!

Continuing the theme of skeletons, Harry had also brought in the skull of a rabbit for the other Rangers to look at.

Rabbit skull Again, deciding what animal a skull came from, may sometimes require a bit of detective work.

The skull was small (rabbit-sized) with large sideways-facing eye sockets. Even though few of the teeth were left, this eye position tells you that the animal is likely to be a herbivore.

Eyes on the side of the head are useful when you have to keep a close watch all around for predators which may eat you!

The predators will instead have forward facing eyes so that they can better focus on catching their prey.

Rabbit Skull, scale and vertical view.

 

After looking at the skeletons, Ranger Alan led us on a nature hunt to the Heathland Project Area at the Centre. We were to help get some information on the animals which live on the heathland.

 

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