Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p107
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 107/152)
Character Range: 334791–337649

South Island of New Zealand, Stewart Island, the Chatham, Auckland and Snares Islands off the coast of New Zealand, and Flinders and Cape Barren Island off the north-east of Tasmania. It is also a winter visitor to Australia, from south Queensland to Tasmania and west to South Australia.

This species can be found in coastal areas, nesting on rocky or sandy beaches and shingle islands in rivers, also on coastal cliffs and deserted barges, often close to the surf. It feeds along the shore and in bays, and over oceanic waters in winter. It feeds almost exclusively on fish, but will also take shrimp, feeding in the surf zone or several kilometres out to sea. It often feeds in flocks by plunge-diving from 7-10 m with or without hovering, and by contact-dipping. Nesting takes place from October to December with most colonies containing 100-500 pairs, although solitary pairs are recorded at the edges of the range (del Hoyo et al. 1996).

Population Estimates and Trends
In New Zealand, S. s. striata has been considered to have a population size of
5,000-20,000 mature individuals, and S. s. aucklandoruna was considered to have a population size of 1,000-5,000 mature individuals (Robertson et al. 2017). In Australia, (S. s. incerta) the breeding population is considered to be 120 mature individuals (Garnett et al. 2011), however, there have been no surveys since 1986 when 13 breeding locations were known (Garnett et al. 2011). Based on the subpopulation trends and subpopulation sizes from Garnett et al. (2011) and Robertson et al. (2017), the species may be decreasing. The overall decrease depends on the population size, but would fall in the range 5.2–29.1 per cent over 3 generations (30.3 years) and is considered Near Threatened by BirdLife International (BirdLife International 2019).

Conservation Concerns and Actions
The species habit of nesting in densely packed colonies leaves it at considerable risk of predation by invasive predators (Mills 2013). It is also vulnerable to predation by native species, with an entire colony at Kaikoura (New Zealand) abandoned following chick predation by a single Northern Giant Petrel (Macronectes halli) (Mills 2013). There is also potentially a risk from the spread of the invasive weed Sea Spurge (Euphorbia paralias); however, this does not seem to be significant at present. It is possible that, in the future, the effects of climate change could have an adverse impact on food sources and breeding habitat.

Recommended Management Actions
        Quantify the breeding population in Australia
        Regularly monitor breeding populations at index locations
        Determine non-breeding areas and migration routes
        Control, or eradicate invasive species on breeding islands
      Implement best practice quarantine measures at breeding colonies to reduce the risk of any