Lesser Sulphur-crested Cockatoos make up a group of small versions of the The Great Sulphur-Crested bird. Their average size is about thirteen inches, which makes them easier to house than the Greater. This group includes the most common Lesser, a stocky bird with a broad beak and a thick crest, and the Citron-crested, which is slightly larger than the Lesser and has an orange-hued crest. These are clever and amiable parrots whose energetic activity makes them a pleasure to watch. As with the larger cockatoos, a good deal of their performance is directed at their human audience and they will often get wilder and wilder if their audience shows signs of leaving. Speaking is not among the top skills of the Lesser Cockatoos, but they are capable of mimicry as well as some unclear mutterings.