On Laysan, courtship and the start of nest-building was in April, with eggs being laid from May to June and the height of the nesting season taking place in June and July; there is a report of recently hatched young birds from Midway in March, but this seems to be unusually early. On Laysan, nests were built in tussocks of endemic "Cyperus pennatiformis" subsp. "bryanii", "kāwelu" ("Eragrostis variabilis") and introduced Bermuda grass ("Cynodon dactylon") around the lagoon, while on Midway, it nested in any shelter that seemed convenient, such as "naupaka kahakai" ("Scaevola taccada ") thickets and "pōhuehue" ("Ipomoea pes-caprae" subsp. "brasiliensis") stands. The nests were placed on the ground or inside the base of a tussock; in the latter case the birds would rearrange the dried dead leaves to form a roofed cavity reached through a small tunnel some long. Nests were lined with soft dried plant material and down of seabirds.