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!
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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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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.
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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. |
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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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