Madeira Field Guides

We might be going on holiday to Madeira again this year, and this time I've been looking for a guide to birds and butterflies that can be found on the island so I have some idea of what to keep an eye out for.  I've came up with ONE bird guide that covers the area - A Field Guide to the Birds of the Atlantic Islands: Canary Islands, Madeira, Azores, Cape Verde (Helm Field Guides) - has anyone used this guide or guides by the same company and were they good?

Haven't found anything at all for butterflies and even Google fails at finding really useful websites!