A Life Member of Birds Australia, Lloyd Nielsen independently researches Australia's birds, the lesser-known species in particular, and records their distribution, breeding habits and so on.

He acted as a referee for HANZAB The Handbook of Australian, New Zealand and Antarctic Birds, and created the unique regional field guides Birds of Lamington National Park and Environs and Birds of Queensland's Wet Tropics and Great Barrier Reef. Rather than employing the conventional field guide format with which we are all familiar, he groups birds according to size, colour, obvious features (if any), habits and habitat.

Other books include his unique Birding Australia - the directory of Australian birding (in two editions - one for Australian birders, another for visiting international birders), Birding Australia Site Guide The South-East , and Daintree Jewel of Tropical North Queensland which is essential reading for every visitor to this World-heritage region.

His artistic photographs of Australian birds are published internationally. He also paints portraits of his favourite feathered subjects.