Reply to ffbumblebee
The best time to build a pond is in late autumn after rains have helped rehydrate the soil. This is nothing to do with wildlife, but makes it easier to dig. Wildlife will find its own way fast enough, often water skaters, dragonflies, damsels arriving as the water is going in. There are often worries about introducing spawn from other ponds because they may be carrying disease, but I suspect that if you can get spawn from a relatively close neighbour and put it into a virgin pond you can;t be doing too much damage.