The Wirral Rangers organise volunteers to maintain Thurstaston and other areas. I've done it a few times and they are always very welcoming to new comers and you only do as much or as little as you want. Contact them via the council website. Vicky
Counting rodents etc (to make sure there's enough to feed the predators - not Rentokil!), and I've been around the Butterfly Park, they were looking for helpers to maintain the area.