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Location Australia, Queensland
Central coordinates 139o 16.37' East  16o 16.09' South
IBA criteria A4ii
Area 51 ha
Altitude 0 - 16m
Year of IBA assessment 2009

BirdLife Australia

Summary The islands support more then 1% of the global populations of Brown Booby and Lesser Frigatebird.

Site description Rocky and Manowar Islands are both small islands in the southern Gulf of Carpentaria about 40 km distant from the nearest substantial land on Mornington Island. The two slightly raised islands support large numbers of breeding seabirds, particularly Brown Booby on both islands and Lesser Frigatebird on Manowar Island. The climate is monsoonal with an extended dry season from May to November and a hot wet season from December to April.

Key Biodiversity Large numbers of Australian Pelican and small numbers of Eastern Reef Egret, Osprey and White-bellied Sea-Eagle breed on the islands.

Non-bird biodiversity: The islands are notable for basking by Green Turtle between breeding attempts in the winter (Garnett et al. 1985). An undescribed legless lizard, Lerista aff. orientalis, has been recorded from Rocky Island (Garnett and Crowley 1987a), and must be a relic from the Pleistocene when lower sea level meant the islands were connected to the mainland.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Lesser Frigatebird Fregata ariel breeding  1991  7,700 breeding pairs  good  A4ii  Least Concern 
Brown Booby Sula leucogaster breeding  1991  9,000-12,000 breeding pairs  medium  A4ii  Least Concern 

IBA Monitoring

2008 high not assessed not assessed
Medium - based upon reliable but incomplete / partially representative data

Human intrusions and disturbance recreational activities happening now whole area/population (>90%) no or imperceptible deterioration low
Invasive & other problematic species, genes & diseases invasive non-native/alien species/diseases - named species happening now majority/most of area/population (50-90%) slow but significant deterioration high


IUCN habitat Habitat detail Extent (% of site)
Coastline Sand cays, islets & bars; Sea cliffs, rocky shores & rocky islets  20%
Sea Open sea  80%

Land ownership Traditional owners are Lardil people: Rocky Island known as Kalamburriya, Manowar Island known as Delmerriya or Wudma. Native title exists over the islands.

Land use

Land-use Extent (% of site)
fisheries/aquaculture 80%
other 20%
Notes: Indigenous land use

Access/Land-Owner requests Permission to visit islands should be sought from Mornington Island Shire Council.

Acknowledgements THe nomination was prepared by Stephen Garnett.

References Carpentaria Land Council Aboriginal Corporation (2006) Thuwathu/Bujimulla Sea Country Plan: Aboriginal Management of the Wellesley Islands Management Region of the Gulf of Carpentaria. Department of Environment and Heritage, Canberra.

Garnett, S.T. and Crowley, G.M. (1987a) Rocky Island. Corella 11, 75-76.

Garnett, S.T. and Crowley, G.M. (1987b) Manowar Island. Corella 11, 73-74.

Garnett, S.T., Crowley, G.M. and Goudberg, N.J. (1985) Non-nesting emergence by Green Turtles in the Gulf of Carpentaria. Copeia 1984, 262-264.

Walker, T.A. (1992) A record Crested Tern Sterna bergii colony and concentrated breeding by seabirds in the Gulf of Carpentaria. Emu 92, 152-156.

White, H.L. (1917) North Australian birds. Emu 16, 117-158.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Manowar and Rocky Islands. Downloaded from on 23/10/2016

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