The question set for this competition seemed simple, but there were some traps in it. We asked for the weight of the Lesser horseshoe bat after hibernation. MORE It was presumed that the bat in question when, after building up fat reserves in Autumn, it went to hibernate, weighted 10g, that is less than the project fudge (12g). Lesser horseshoe bats caught after Winter time were recorded to weigh as little as 3,5g, and according to personal communication a living specimen of 2g was found in Poland.

The participants of the competition (at least those who supported the answer with their comments) took two approaches to find an answer. One was to check for the reported span, and under assumption that the animals are thinnest after hibernation, choosing the lower limit for an answer. Another approach tried to estimate the loss of the body mass over the Winter season or even daily and calculate the final result for this particular 10g individual.

Of course all such answers had to assume average conditions. There are many factors affecting the actual result, such as a hibernation place conditions (temperature, humidity, draughts), length of the Winter, number of wake-ups, especially those, resulted from disturbance, and probably some individual features of the bat. The safest answer would be “do not know”, and that’s why all the answers indicating substantial loss of the body mass were considered correct. We could not approve the answer stating 10g, as even though the hibernation slows down the metabolism, the energy loss still occurs. In early Spring bats have to “refuel”. Prey is very limited and so they are desperate to hunt even during the day in full sun.

The random selection picked as winners: Marzena Misaczek, Bob Gratton, Michał Miklas.

The winners receive promotional gadgets such as T-shirts, reflective badges and project fudges.

Everybody is welcome to participate in the monthly competitions, the April edition to be announced soon.