If you were travelling along the A509 between Sherington and Emberton on 2nd April 2001 on a cold sunny day, you might have been puzzled to see two elderly men wrapped up against the cold, wearing Wellington boots, gazing at a plastic bag on what appeared to be a piece of tube. Were they collecting fungi? Sampling the soil? Collecting rubbish from the road verge? Well no, they were weighing a common shrew, the first catch of the morning, and feeling quite pleased with themselves. That site yielded 9 mammals of which 6 were common shrew, 2 wood mice and one house mouse (which was caught twice). Weights ranged from 7½ grams to 15 grams.
Well what was it all about? We were two volunteers taking part in a nation wide survey of grass verge small mammals using Longworth traps. These first had to be primed with soft nesting material, a generous feed of cereal, and about 40 casters [fly pupae] to feed any shrews caught as small mammals need to feed at regular intervals. The traps are then placed in pairs one metre apart, seven metres between pairs. This means 20 traps to set up and inspect, three times at each location. They had to be carefully hidden in dry herbage at the start but by May there was plenty of new growth to cover them. The temperature, weather and wind were recorded along with the weight and species of each animal. The animal's condition - pregnant, lactating, perforate or imperforate female(i.e. whether she is open for breeding or closed), breeding or non-breeding male (i.e. whether his testes are showing) - is also recorded.
It all looks very simple on paper but believe me it's very tricky with an animal that weighs only 7 grams. And to think, I was told as a lad that you had to shake them and if they rattled they were boys and if they didn't they were girls. Well we live and learn!
We were also asked to record the amount of cut verge, amount uncut, amount
of herbage, ditch, hedge, stream, crop in adjacent field, what did you have for
breakfast? (Just kidding!) Each of these checks had to
be carried out in a 10 km. square. We chose a square covering the centre across
the top of
Some days it rained, some days were bright and sunny. Some days it was so
cold you could hardly hold a pen. One morning we caught a wood mouse for the
second time. On release he sat in the hedge eating some food while we watched.
We felt that was good as we had not frightened him. One morning on the road
from
Total animals checked: 48
Maximum trapped on one site: 10
Minimum trapped on one site: 1
Species: Woodmouse, House Mouse, Common Shrew, Bank
Vole
Recorders: Mike Killeby and John Prince
John Prince