It nests in burrows or under rock cavities and occasionally between tree buttresses from sea level to 900 m, but mostly between 500 and 800 m (Bester et al. 2002, Bester 2003). On Lord Howe, it breeds in forest, as once did the population of Norfolk Island, so the Phillip Island population is atypical, with burrows being in eroded cliffs of soft volcanic tuff (Priddel et al. 2010). It is a winter breeder, with birds from Phillip Island breeding at the same time as Lord Howe Island (Priddel et al. 2010). Adults arrive at Phillip from mid-April, a single egg is laid mid- to late May, hatching starts mid-July, and chicks are near-fledged by early November (Bester et al. 2007, Priddel et al. 2010). Adults land during daylight, often about 15.30 h (Priddel et al. 2010). A study on Lord Howe Island in 2000-2001 determined 54% breeding success in burrows visited twice and contents not handled, with 34-36% success in burrows repeatedly visited (Bester et al. 2007). Nests closest to burrow entrances had lowest breeding success, with the main causes of failure being flooding and predation of eggs and chicks by the endemic, threatened Lord Howe Woodhen Hypotaenidia sylvestris (Bester et al. 2007). A study in 2008 on Lord Howe Island found the breeding success in a small lowlands population to be three times higher (58%; n = 104) than in populations on Mount Gower (15%; n = 33) (D. Binder unpublished data). Additionally, adult provisioning trips were between 2–12 days (mean 4.8), with no evidence of a bimodal distribution of long and short trips (Binder et al. 2013). The adults feed predominantly on squid and fish with crustaceans less important. The most important prey item is bioluminescent fish from the genus Electrona; maximum diving depths have been recorded at 5 m (Bester 2003). It also scavenges for food taking fish offal and has been recorded scavenging on a Shining Bronze-cuckoo Chalcites lucidus (Bester 2003). It only occasionally follows fishing boats (Kuroda 1955, Bester 2003), but some fishing material has been reported in their diet (Bester 2003).

Conservation Actions Underway
The Lord Howe Island group was designated a World Heritage Site in 1982. Control of rats has been an ongoing process on Lord Howe. An initial eradication was locally successful (see Bester et al. 2007) and a widespread $16 m eradication programme began in winter 2019. Although initially thought to be successful, two rats were detected and killed in 2021, although these were suspected to be incursions from the mainland rather than survivors of the eradication (Lord How Island Board in litt. 2021).   In 2006, a proposal was submitted to eradicate all mammalian predators from all, or at least a significant part, of Norfolk Island (Holdaway 1999). Such measures might involve the establishment of an exclosure in the National Park in which all mammals are eliminated, and where chicks are translocated (Holdaway 1999, S. Garnett in litt. 2006). The small colony on Phillip Island is surveyed irregularly and monitoring of the main Lord Howe island population has occurred as part of research projects (Carlile et al. 2021).

Conservation Actions Proposed
Census the Lord Howe Island population at least once every five years, and the Phillip Island population every three years. Monitor breeding success on a 1-3 year basis. Eradicate cats and rat species from Norfolk Island (Holdaway 1999), or at least establish an exclusion area (Holdaway 1999, S. Garnett in litt. 2006). Consider translocation of chicks (Holdaway 1999, S. Garnett in litt. 2006). Implement bird-safe fishing practices in the Pacific Ocean fleet. Impose strict quarantine procedures on any vessels visiting Phillip Island and Lord Howe Island.