It is often thought that frogs have great trouble coping with humans. However, provided that humans don't pollute the environment beyond recognition or destroy it, you often find frogs in some very man-made environments. The Australian Green and Golden Bellfrog (Litoria aurea) is one such example of man and frog living side-by-side.
The Bellfrog is normally found in wetlands on the eastern coast of Australia (from northern New South Wales through to Victoria). However the number of the frogs (which was once a common Australian species) has declined in the past 20 years. It is thought that the decline is a result of the destruction of suitable habitats, land irrigation and the spread of the mosquito fish (an introduced species which eats Bellfrog eggs and tadpoles). Over time, the frog has become restricted to a small number of areas in this range. It is currently listed as an endangered species.
Despite its apparent decline, an unknown colony of the Bellfrogs was discovered in 1992 as a result of the development of Homebush Bay for the Olympics. The colony was discovered in a brickpit (which is a bit bigger than it sounds, being effectively a 16-hectare depression), which was actually used to film the Mad Max movie "Beyond Thunderdome". As you might imagine, the site would not appear to be a great position for the frogs to flourish, yet they did (being home to in excess of 300 of the frogs).
Initially, the brickpit was to be developed to include tennis courts and an ampitheatre. Upon finding the frogs, plans were changed to allow the pit to remain part of the parklands of the Olympic site and utilise the pit for an Olympics recycled water system.
However, merely allowing the pit to remain as the froggy habitat was insufficient since after a number of storms in 1994, the frogs were found in a newly constructed pond almost a kilometre away (having crossed a couple of busy roads to get there). Hence, measures to protect the frogs were stepped up, involving a new breeding environment outside the pit, vehicle overpasses, frog underpasses, frog-proof fences near roads and removing frogs and tadpoles from development areas.
The frogs are being encouraged elsewhere in Sydney by, for example, the release of 1,400 tadpoles in the ponds and wetlands at the Long Reef Golf Club.