Historic accounts likely referring to the bird by the name "mehonui" suggest that it was red-brown in colour, and it has been compared to the weka in ecological habits, using its beak to probe decaying wood for invertebrates.

Hawkins's rail likely became extinct due to overhunting by the islands native inhabitants, the Moriori, and the bird is known from skeletal remains found in their kitchen middens.

He named the species Aphanapteryx hawkinsi in honour of Hawkins, placing the bird in the same genus as the extinct red rail from the Mascarene island of Mauritius in the Indian Ocean.

An 1895 letter from Sigvard Dannefaerd belonging to Walter Rothschild describes the appearance, behaviour, and Moriori hunting method concerning the species: The Large Rail that Forbes Clased as Aphenapteryx the Moriori Name for same is “Mehonui” (nui mens Large) I hunted ap the oldest Moriori Chief on the Island and ther tradition of the Bird is, it ware Larger than a Goase and had a verry loud Cry like Tue-ck it always walked with the Head down pecking in decaed wood on the Ground, the would often catch them by walking stret ap to them from the front of them, but they could not cam over them from the side, and the yused to Sleep together in Colonies and the Morioris yused to find out ware a Colony had ther Sleeping plase, then sneek quietly ap and make a rush and Kill the hole Colony.

The described them as of a Dull Brick Red ColourA second account was published by Alexander Shand in 1911, in his writings on Moriori cuisine: For variety they had Fernroot (Eruhe) and Karaka nuts (of which latter, in good seasons, they preserved very large quantities); together with birds of the forest, such as the wood pigeon (Pare or Parea), Koko (Maori, Tui), Komako (Maori, Makomako), Mehonui, a species of the New Zealand Kākāpō (Stringops habroptilis), larger than a goose, and the Mehoriki, a bird about the size of a small hen.

It kept its head continually on the ground looking for food, chiefly fernroot, which it burrowed for and dug out with its powerful bill, making, it is said, a rooting like a pig; any one, however, coming from the side or behind was quickly detected, and the bird made off.

The accounts suggest that the bird was dull brick-red in colour, that it spent much of its time pecking for invertebrates in decaying wood, similar behaviour is known from weka.

Due to the strength of its beak it has been suggested to have been capable of consuming a wide variety of prey, including on ground dwelling chicks, such as those of petrels.

[5] The presence of detailed accounts from the late 19th century suggest that the extinction of Hawkins's rail was more recent than previously supposed, and that the birds survived long after the arrival of the Moriori.