Training was
delivered by Sarah Bird (Biodiversity Officer) and Paul Hill, freelance ecologist
with experience of captive rearing harvest mice. The event was commissioned by
the Mammals In a Sustainable Environment Project (MISE) to grow capability for
identification of harvest mice in Wales. From our local records centres we have
a total of just 60 records, most of which are old, with only 10 being recorded
in the last decade. Surely this has got to be an under recording or is it a
catastrophe?
Some years
ago the zoo arranged a reintroduction of harvest mice on fields alongside a
canal. We began our training event at this site unloading 20 traps which
revealed loads of voles (field and bank) and some wood mice but not what we
were looking for. Our second exercise was to search through the undergrowth for
the distinctive nests, balls of woven vegetation made mainly with leaves split lengthways, lashed together
without being severed from the plant. 15 minutes later we found our first
example, neatly built around the supporting trunks / main stems of a few reeds.
Once we got our eye in there was no stopping us and a further 4 were found
before returning to our lecture theatre.
We were
shown some brilliant ARKive footage to bring the subjects to life. See this as
an example:
The characteristics
and lifecycle were explained. Widespread distribution from UK to Japan but
absent from Ireland! Prehensile tails a very distinctive feature acting as a 5th
limb. Very small size, just 4 to 6 grams, a third or a quarter the size of a
field vole. Average life expectancy 6 months. Prolific breeders but 95% mortality
in winter, mainly February.
The
supposition is that they are in decline due to our changing farming practices
but we don’t have much data to confirm or deny this. Thanks to MISE and Chester
Zoo we are now going to get a fuller picture of what’s happening in Wales. If
you’d like to join in please contact the MISE project website.
Here’s a
short film of our training day:
The bears
have gone and their pit has been covered with a net and turned into an aviary.