Slumber party

We went to the beach for a blow and I lifted up some rotten planks in the corner of the car park. These snails were overwintering on a plastic underside - they choose the smoothest possible surface so that they can create a tight seal. It's not technically hibernation because they only do it if the temperature drops below a certain point (there seems to be no consensus on what that is.)

What I'm never clear about is why they so often congregate like this. Is it chance i.e. they all happen find the same suitable parking site? Or is it to maximize the possibility of finding a reproductive partner when they wake up? (But snails don't actually need one since they are hermaphrodites.) Or maybe clustered together they are better insulated from cold draughts? And why do some  clamp on to the shells of others? 

These questions are not of course important in the wider scheme of things... but wait, perhaps they are. As our climate heats up will snails and other animals even need to hibernate? And if they don't what will be the consequences for them and other animals without the winter rest period? Snails may be  OK because they can also aestivate during summer heat but other animals.... ? (Information here provides evidence that they are severely jeopardised.)

This current news item reports on the KlimaSeniorinnen, a group of active senior women in Switzerland who, concerned about the effects of the rising temperatures on them in particular (studies have shown that older women may be especially vulnerable to heat) and on people generally, are aiming to take their government to the European court of human rights for failing to take measures to combat global heating. They don't expect to win but they hope to draw attention to the issue and to encourage others to follow their lead as active campaigners.