Dr. Jo Peace, Research Fellow from Auckland University looks at the stomach contents of Antipodes Island mice….
“It’s one thing to “know” that mice must be having an impact on native species and quite another to prove it – it takes some fairly glamorous detective work to do so…
So when I was presented with ten small tubes each containing a mouse stomach, the past owners formerly of the Antipodes Islands, I put on my lab coat and my Sherlock Holmes hat!
Firstly a mouse stomach is small, so the whole procedure is pretty fiddly stuff –
The size of the mouse stomach (~1cm2) means that everything inside is even smaller. The first puzzle is to get the stomach contents out of the stomach and separated from any bait, e.g. sticky, oily, peanut butter, that was used to catch the unlucky individual.You may never look at a tea strainer in the same way again! The stomach contents are rinsed to remove tiny fragments and as much peanut butter as possible.
Then the invertebrate bits are counted and identified as well as possible. A minimum number of each general type of invertebrate is estimated. For example if I find seven beetle legs I can safely say the mouse chomped at least two beetles. Luckily for us we found the remains of three weevils that still were intact enough to be identified through to species.