Document ID: chunk:federal_register_of_legislation:F2025L00287:reg:3:p176
Version: federal_register_of_legislation:F2025L00287
Segment Type: reg
Provision Reference: reg 3 (pt 176/276)
Character Range: 655295–658191

8). Australian National Parks and Wildlife Service, Canberra.

Sula dactylatra—masked booby

Conservation significance
EPBC Act Listing Status: Marine, migratory.
State Listing Status: Listed as Vulnerable under the Biodiversity Conservation Act 2016 (NSW).
Non-statutory Listing Status: Described as Least Concern in the Action Plan for Australian Birds 2020 (Garnett & Baker 2021).

Distribution
The masked booby (Sula dactylatra) is widely distributed throughout the tropical and subtropical seas of the world. In Australia it breeds on islands off north-east and north-west Australia.
In the Norfolk Island Group, the species nests regularly on Nepean and Phillip islands. Boobies have attempted to nest on rocky islets off the coast and began establishing a colony at Rocky Point on the main island, which persisted for a few years before some birds were killed and the colony dispersed. Long-term banding of this species has suggested a marked decline (Christian 2005). Coyne et al. (2015) estimated substantial variation in the number of pairs on Nepean Island each year between 1978 to 1995 (ranging from 140 pairs to 1090 pairs). Numbers banded between 1978–1984 were higher than between 1996–2007, suggesting a decline in the breeding population size over that period (Coyne et al. 2015). In 2006 the population on Phillip Island was estimated to exceeded 300 breeding pairs, based on previous years of fledgling banding (Priddel et al. 2010).
In recent years, a growing population has formed on the northern cliffs of Fisherman's Lane (on Norfolk Island) as a result of targeted and coordinated pest animal control by private landholders.

Ecology
Has a protracted breeding season from August to February with the main egg-laying period occurring in October. Incubation is 45 days, and the period from hatching to fledging spans 120 days. Out of a clutch of two eggs only one fledgling is raised. Lost eggs will be replaced.Nests on the ground in high open areas.
Diet consists of squid and fish.

Habitat
Marine, pelagic mainly in tropical and subtropical waters. Breeds on high open areas so it can take off into the wind.

Threats
The main threat to the masked booby is reduction in the quality of foraging areas through climate‑related shifts in oceanic resources. Predation from cats and disturbance from humans, rats and dogs limit breeding on Norfolk Island.

Impact on other species
None known.

Management actions
Protect nesting areas. Every three years, carry out a census of breeding pairs (by drone counts in early November) to detect significant changes. Retain status of pest-free Phillip Island through detection monitoring for introduced vertebrates and invertebrates.

Relevant literature
Christian M (2005) Norfolk Island … the birds. Green Eyes Publications, Norfolk Island.
Coyne P, Evans B, Evans O & McCoy H (2015) The Tasman Masked Booby Sula dactylatra tasmani