126Wildlife Conservation Plan for Seabirds

126 Wildlife Conservation Plan for Seabirds

Common Noddy (Anous stolidus)

TABLE Species information for the Common Noddy (Anous stolidus)

The Common Noddy (Anous stolidus), also known as Brown Noddy, is the largest noddy, bigger and bulkier than Black Noddy (A. minutus) and Lesser Noddy (A. tenuirostris). The Common Noddy is a slender dark-brown seabird, with long rather stout bill, about the same length as head and appearing decurved over whole length. The Common Noddy is a tropical seabird with a worldwide distribution, ranging from the Pacific Ocean, including colonies off the Pacific coast of north-west South and Central America, the Indian Ocean including south-east Asia and in the Atlantic Ocean including a colony off the coast of Cameroon. Some colonies are also present in the sub-tropics with individuals from these colonies wintering in the tropics (del Hoyo et al. 1996). The species occurs around isolated, bare or vegetated, inshore or oceanic islands or coral reefs with rocky cliffs or offshore stacks (del Hoyo et al. 1996) and coral or sand beaches (Higgins and Davies 1996). It forages in the inshore waters surrounding such islands, often along the line of breakers or in lagoons (Higgins and Davies 1996), and disperses up to 180 km out into the oceanic zone to forage (Surman and Wooller 2003) and up to 950 km when not breeding (Surman et al. 2018). Out at sea it often rests on buoys, flotsam, ships and on the open water (del Hoyo et al. 1996). Although its migratory movements are poorly known and the species is present all year round at most tropical colonies, it is seasonally absent from subtropical colonies and is known to disperse to the open ocean after breeding (del Hoyo et al. 1996). The timing of breeding varies throughout the species range (del Hoyo et al. 1996). It may breed colonially in groups numbering up to 100,000 or more pairs (Higgins and Davies 1996) although it also nests almost solitarily depending on the availability of nesting sites (del Hoyo et al. 1996). Even when not breeding the species remains gregarious and can occur in huge flocks in some areas, although it is more usually observed in smaller flocks of 50-100 individuals (Higgins and Davies 1996). The nest may be a simple layer of debris or a more elaborate construction of seaweed and sticks (del Hoyo et al. 1996), and may be placed in a number of sites including flat shingle beaches, bare ground, cliff ledges, offshore stacks, low bushes and tall trees (del Hoyo et al. 1996). It nests in colonies that can be very dense or more open depending on the availability of nesting sites (del Hoyo et al. 1996). Its diet consists predominantly of small fish as well as squid, pelagic molluscs, medusae and insects (del Hoyo et al. 1996; Higgins and Davies 1996; Surman and Wooller 2003).

The global population is estimated to number between 180,000–1,100,000 individuals (Delany and Scott 2006; BirdLife International 2019). The global population is suspected to be stable in the absence of evidence for any decreases or substantial threats. Significant populations occur in Western Australia (130,136–151,636 pairs; Burbidge et al. 1996) and the Great Barrier Reef, Queensland (King 1996) but the total Australian population is unknown, and trends are not available. A 2019 survey of Ashmore Reef Marine Park found Common Noddies to be the second most abundant bird species at Ashmore with over 40,000 recorded (Cannell and Surman 2020).