Document ID: chunk:federal_register_of_legislation:F2022L00775:reg:18:p115
Version: federal_register_of_legislation:F2022L00775
Segment Type: reg
Provision Reference: reg 18 (pt 115/152)
Character Range: 356361–359435

sites. In South Africa Kelp Gulls are aggressive predators of other seabirds on offshore islands. The species is potentially threatened by marine pollution (Parsons and Underhill 2005) and is susceptible to avian cholera (Hockey et al. 2005, Leotta et al. 2006) and avian botulism (Blaker 1967, Hockey et al. 2005) so may be threatened by future outbreaks of these diseases. The species also suffers mortality from interactions with trawler warp cables (Argentina) (Gonzalez-Zevallos et al. 2007). However, none of these threats are thought to pose a genuine threat to the population at present. Birds are frequently observed feeding at garbage facilities.

152 Wildlife Conservation Plan for Seabirds

Species profiles

Recommended Management Actions
      Quantify the breeding population in Australia

      Regularly monitor breeding populations at index locations

      Quantify and manage the potential impacts of human disturbance

      Manage human garbage disposal sustainably

      Measure contaminant levels in all relevant life stages

Wildlife Conservation Plan for Seabirds 153
Species profiles

Silver Gull (Chroicocephalus novaehollandiae)

  Life History and Distribution
The Silver Gull (Chroicocephalus novaehollandiae) is a familiar small gull of Australian coasts and inland areas. Adults are readily identified by the bright red bill and legs and distinctive pattern of the underwing. This species can be found at both coastal and inland locations in a variety of habitats including artificial habitats such as rubbish dumps. It has a very varied, opportunistic diet including fish, marine and terrestrial invertebrates, seeds, insects and bird eggs. Kleptoparasitism has been observed. It breeds on small islands and points, mainly offshore, but also on freshwater and brackish lakes, and on causeways in salt-pans. The breeding season covers all months, with the exact timing varying depending on locality and age. It is colonial and occasionally solitary, with smaller colonies in the tropics (3-25 pairs) up to 10,000 pairs in southern Australia (del Hoyo et al. 1996; Carlile et al. 2017). Colony size depends on food availability. Individuals may wander widely outside the breeding season (del Hoyo et al. 1996).

  Population Estimates and Trends
  The species is thought to be abundant across its range. Presently increasing in south east Tasmania based on winter surveys 1980–2019 (E. Woehler pers. comm). The overall population trend is increasing, although some subpopulations have unknown trends (Delany and Scott 2006).

  Conservation Concerns and Actions
Frequently observed at garbage facilities feeding on human waste. At present there are no factors thought to pose a genuine threat to this species. It is possible that, in the future, the effects of climate change could have an adverse impact on food sources and breeding habitat (Woehler et al. 2014). Human disturbance at colonies and interactions with aquaculture has local effects.

  Recommended Management Actions
        Quantify the breeding