The Lyon Arboretum was established by the Hawaii Sugar Planters Association in 1918 and granted to the University of Hawaii in 1953.  In its formative early decades, the botanist who primarily oversaw the project was a Minnesotan named Harold L. Lyon.  When Lyon died a few years after the transfer, the University renamed the property in his honor.

The property is approximately 200 acres, planted with trees from all the world’s tropical regions.  The terrain is hilly and humid, and the trails are well-marked and maintained.  Like many of its trees, most of the arboretum’s birds are non-native species.  The main exceptions are Oahu Amakihi, which is fairly common, and Apapane, which is sporadic.

Frequently seen exotics include Rose-ringed Parakeet, White-rumped Shama, Red-vented and Red-whiskered Bulbuls, Warbling White-eye, and Red-billed Leiothrix.  Most famously, starting in the 1960s, released or escaped cockatoos have found sustenance in the arboretum’s blend of exotic tropical trees.  The numbers and diversity present have varied over the years, but three species have predominated: Tanimbar Corella (up to 30) Sulphur-crested (up to 11) and Salmon-crested (up to 8).  There have been multiples of both Yellow-crested and White (two each), plus a single Palm Cockatoo in the 1980s.  Local breeding has been confirmed, but thus far does not appear sufficient for any of the species to form a self-sustaining population.  Identification of large white cockatoos is not always easy, but more complicated here by a reported history of hybridization: Salmon-crested having interbred with both Sulphur-crested and White.