I would LOVE to do this on a larger scale, turing 5 acres of land into my own nature reserve would be my idea of heaven. I am hoping to work in conservation in the future, but this obviously means working at established large scale sites, not creating my own. The thought of single handedly making my own wildlife sanctuary is almost too good to be legal.
Although my garden is no where near 5 acres, I have attempted to attract more wildlife to it. I decided the best way to do it was to give them as much food and variety of habitats as possible. Started with a native hedgerow at the back of the garden, which includes hawthorn and blackthorn, with the odd larger tree and shrub thrown in for some diversity, namely alder, rowan and pyracantha. That should provide losts of berries and also be host to numerous moth caterpillars. Planted a couple of flower beds to attract butterflies and their caterpillars. Again mainly native species, cuckooflower, nettles, scabious, knapweed, thistles, birds foot trefoil, the list is quite extensive. Also dug out a pond and filled that again with native plants. Left some shallow edges for the birds to bathe in and drink from.
As I said this is only the first year, so the flowers are yet to, well, flower and the trees and shrubs are still only little. Hopefully the next 5 years or so will see a marked increase in the wildlife, including birds, in my garden. American bittern in the pond wouldn't go a miss :-O
What you have done sounds amazing, well done!!
Adam