Document ID: chunk:federal_register_of_legislation:F2022L01285:reg:13:p57
Version: federal_register_of_legislation:F2022L01285
Segment Type: reg
Provision Reference: reg 13 (pt 57/98)
Character Range: 383712–386676

March (Patterson et al. 2008, DPIPWE 2021a). Mean annual breeding success varies by location, with breeding success estimated at 62% on Macquarie Island (ACAP 2012n, DPIPWE 2021a). The Northern Giant Petrel has a wide circumpolar range across the southern oceans. Juveniles return to commence breeding when birds are 4-11 years of age (Voisin 1988). Generation length is estimated at 17.1 years (Bird et al. 2020).
Northern Giant Petrel are diurnal feeders at sea that also scavenge on land during the day and at night (Le Bohec et al. 2003). Birds take prey at sea by surface seizing, surface filtering, surface diving, and surface plunging up to 2 m in pursuit of prey (Harper 1987). They are aggressive opportunists scavenging prey from other smaller birds (Harper et al. 1985, Harper 1987). Females are smaller than males (80% by weight) with both sexes scavenging on seal and penguin carrion, and predating albatross chicks (González-Solis 2004, Dilley et al. 2013). During breeding periods, females also feed extensively on other marine food resources and show more pelagic habits than males (González-Solis 2004).
Northern Giant Petrel disperse widely throughout the southern oceans, mainly north of the Antarctic Convergence (Patterson & Hunter 1999, Patterson et al. 2008, Trebilco et al. 2008). At Macquarie Island most breeding birds forage within 100 km of the island (Trebilco et al. 2008). In winter, birds from Macquarie Island are found as far as southern Africa and South America and are frequently observed in southern Australian waters (Marchant & Higgins 1990, Reid et al. 2002, Trebilco et al. 2008).

Species distribution in Australia

Northern Giant Petrel nests on Macquarie Island (Figure 6). Tracking and banding studies indicate that dispersal is circumpolar, predominantly between 30-64°S and includes southern and sub-Antarctic Australia, however records at sea are subject to misidentification between the giant petrel species (Voisin 1988, BirdLife International 2004, ACAP 2012n). During the breeding cycle birds breeding on Macquarie Island generally forage southwards to the Antarctic ice edge or eastwards to South America (Trebilco et al. 2008).
The size of the breeding population of Northern Giant Petrel on Macquarie Island before human visitation is unknown. Harvesting of eggs and/or birds may have occurred during the 19th Century while the island was occupied by sealers (Cumpston 1968, Townrow 1988). Northern Giant Petrel is subject to ongoing long-term monitoring on Macquarie Island. An island-wide census of the breeding population on Macquarie Island was last conducted in 2013/14 with 1490 breeding pairs recorded, with the population currently monitored at a representative study site with 337 (248-391) annual breeding pairs recorded in 2019/20, and long-term breeding success estimated at 62% (DPIPWE 2021a).

Population estimates and trends

The breeding population of Northern Giant Petrel on Macquarie Island