Complex sentence: Hill made the islands a private home for the rich species of bird life that visited or lived on the islands, and subsequently provided species from the islands to various wildlife refuges in exchange for different species for Birdland.
Split into simpler sentences: Hill made the islands a private home for the rich species of bird life that visited or lived on the islands. Len would go on to provide species from the islands to various wildlife refuges in exchange for different species for Birdland.