Anson Bay, Daly and Reynolds River Floodplains


Country/territory: Australia

IBA Criteria met: A1, A2, A3, A4i (2009)
For more information about IBA criteria please click here

Area: 265,648 ha

Protection status:

BirdLife Australia
Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2016 high near favourable low
For more information about IBA monitoring please click here


Site description
This IBA consists of all of the adjacent floodplains of the Daly and Reynolds Rivers, which have many waterbird colonies including large numbers of Magpie Geese, and Anson Bay which supports over (unidentified) 20,000 shorebirds. The Downs and Litchfield sections of the Reynolds floodplain are identified as of major importance for breeding and non-breeding Magpie Geese (Parks & Wildlife 2007). The Docherty floodplain, although poorly known, is mapped as having breeding Magpie Geese (Parks & Wildlife 2007), has similar habitat and is included for its inferred waterbird populations and its ecological role within the Anson Bay system. Many of these floodplain species may be attracted by the mixed open habitat whereas most flood plains in the Top End are dominated by solid stands of sedge and reed. The adjacent mudflats of Anson Bay support large numbers of birds from the North Peron Islands to Cape Ford. Waterbird colonies = ref W006, 7, 8, 9, 10, 11, 12, 14, 16, 17, 18, 19, 20, 21, 22, 24, 58, 59 (Chatto 2000).

Key biodiversity
The IBA includes several mixed waterbird colonies on the Daly and Reynolds river estuaries and floodplains. The Directory of Important Wetlands in Australia records at least ten breeding colonies of other waterbirds, supporting in total more than 40,000 adult birds; and significant numbers of Brolga, especially in the dry season. Maximum counts at colony W006 in paperbarks south-east of Billawock Hill included 3700 Little Black Cormorants, 3000 Little Pied Cormorants, 370 Pied Cormorants and 370 Darters in 1994 and 3000 mixed egrets in 1991. Maximum counts at colony W007 in rainforest between the floodplain and the coast near Cliff Head included 4000 Australian White Ibis, 4000 Intermediate Egrets, 750 Great Egrets and 500 Royal Spoonbills in 1999 and 500 Pied Herons in 1993. Maximum counts at colonies W008, 9 and 10 in paperbarks near Darkies Hole included 350 Little Pied Cormorants in 1994 and 1000 Australian White Ibis in 1995 and 300 Royal Spoonbills in 1993. Maximum counts at colony W011 in mangroves on the Daly River 20km upstream from its mouth included 7500 Cattle Egrets (1998), 3600 Intermediate Egrets (1993), 2500 Pied Herons (1999), 1500 Rufous Night Herons (1993), 700 Great Egrets (1994) and 500 Little Pied Cormorants (1999). Maximum counts at colony W012 in mangroves just north of the Daly River mouth included 6500 Cattle Egrets (1992), 5900 Intermediate Egrets (1993), 1000 Pied Herons (1994), 2500 Great Egrets (1994) and 1400 Little Pied Cormorants (1993). Maximum counts at colony W014 in reeds on the Reynolds River floodplain west of Welltree Station homestead included 350 Australian White Ibis in 1995. Maximum counts at colony W016 in paperbarks on the Reynolds River floodplain north of Bob's Knob included 300 Royal Spoonbills (1995). Maximum counts at colony W017 in reeds on the Reynolds River floodplain west of Welltree Station included 1000 Australian White Ibis in 1995. Maximum counts at colony W018 in paperbarks on the Reynolds River floodplain east of Bob's Knob included 1290 Little Pied Cormorants (1999), 1000 Little Black Cormorants (1995), 3000 unidentified cormorants (1995, 1999), 825 Darters (1999), 300 Great Egrets (1999) and 300 Royal Spoonbills (1995, 1999). Maximum counts at colony W021 on dunes on North Peron island included 5000 adult and 10,000 young Australian Pelicans in 1995. Maximum counts at colony W058 in paperbarks on the Reynolds River floodplain south-east of Bob's Knob included 500 cormorants 200 Royal Spoonbills in 1995. Maximum counts at colony W059 in paperbarks 5 km east of the mouth of the Daly River included 50 Royal Spoonbills in 1999 (Chatto 2000). These wetlands also support 1000s of Magpie Goose, Plumed Whistling-Duck, Wandering Whistling-Duck, Grey Teal, egrets, Glossy Ibis and Straw-necked Ibis. Many of these species are likely to exceed the 1% thresholds, notably Straw-necked Ibis which occur in 'very large numbers' in the dry season (Chatto 2006). The Perron Islands regularly support up to 15,000 White-winged Terns in March/April (Chatto 2006). Wader counts on Anson Bay show a peak in September and October when large numbers of Red and Great Knots occur. Specific counts are not available for Anson Bay but the IBA probably meets the 1% threshold levels for the near threatened Black-tailed Godwit (maximum count 2000) and the Great Knot, Lesser Sand Plover and Greater Sand Plover (Chatto 2003, Bamford et al. 2008). Regionally important numbers of seabirds occur at Cape Ford and the Peron Islands (Chatto 2001). There are also records of Australian Bustard in the IBA (NT Parks and Conservation Masterplan).


Recommended citation
BirdLife International (2018) Important Bird Areas factsheet: Anson Bay, Daly and Reynolds River Floodplains. Downloaded from http://www.birdlife.org on 18/12/2018.