Early reports
Cato Island, and then Bird Islet, were found by Captain John Park in the India man Cato (ship) and Lt. Robert Fowler in HMS Porpoise (1799) on 17 August 1803. The latter ran aground on Wreck Reef. Matthew Flinders (1814) on the Porpoise reports that all the cays held many birds, laying in the period August–October
Cato Reef continued to present a hazard to shipping plying between Australia and Canton (moden day Guangzhou) or India (where cargo was collected on the way home from Australia to Europe). In due course the southern reefs were surveyed by Captain H. M. Denham (ms, 1860) in the HMS Herald in 1858-60
The area was also visited by increasing numbers of whalers during the off season in New Zealand, in search of the many wintering Humpback Whales and fewer Sperm Whales in the middle of the 19th century. Denham reported that in July 1863 the islets only had two or three plants, including a bush 3–4 m high, and were frequented by sea turtles weighing 60–100 kg
On 12 October 1858 Denham reported that Cato Island was more substantial than other cays in the area, measuring ⅓ by 1/6 miles, rising to 19 ft, and covered in coarse tufted grass,Rottboilla; a creeping plant, Nyctagin portulaca; and a sort of buttercup Senebiera crucifera, undermined and fertilised by burrowing mutton birds, the only species that the sailors wished to eat. There were dense colonies of gannets, man-of-war birds and boatswain birds, terns and noddies, with eggs and chicks, and he shot a godwit and a brace of plovers. There were records of repeated visits by whalers but now only one Humpback was reported offshore. Rayner also recorded a Limosa, Charadrius, Strepsilas interpres, and a land rail. When they returned with plants from the Percy Isles and seeds from Sydney to provide succour for castaways in August, 1859, Denham again reported that the birds formed a cloud hovering 60 feet above the island, though “a few visits like
