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• Text account
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• Reference and further resources

The site was identified as important in 1998 because it was regularly supporting significant populations of the species listed below, meeting ('triggering') IBA criteria.

Populations meeting IBA criteria ('trigger species') at the site:

Species	Red List1	Season	Year(s)	Size	IBA criteria
African Penguin Spheniscus demersus	CR	resident	-	3,050 breeding pairs	A1, A4ii
African Penguin Spheniscus demersus	CR	non-breeding	-	9,000 individuals	A1, A4ii
Crowned Cormorant Microcarbo coronatus	LC	resident	-	60-238 breeding pairs	A1, A4i
Crowned Cormorant Microcarbo coronatus	LC	non-breeding	-	150-500 individuals	A1, A4i
Cape Cormorant Phalacrocorax capensis	EN	resident	-	35,580 breeding pairs	A1, A4i
Cape Cormorant Phalacrocorax capensis	EN	non-breeding	-	100,000 individuals	A1, A4i
Bank Cormorant Phalacrocorax neglectus	EN	breeding	-	uncommon	A1
African Oystercatcher Haematopus moquini	LC	resident	2000	27-67 breeding pairs	A1, A4i
African Oystercatcher Haematopus moquini	LC	non-breeding	-	160 individuals	A1, A4i
Hartlaub's Gull Larus hartlaubii	LC	breeding	-	110 breeding pairs	A4i
Hartlaub's Gull Larus hartlaubii	LC	non-breeding	-	280 individuals	A4i
Kelp Gull Larus dominicanus	LC	breeding	-	88-130 breeding pairs	A4i
Kelp Gull Larus dominicanus	LC	non-breeding	-	200-500 individuals	A4i
Greater Crested Tern Thalasseus bergii	LC	breeding	-	300 breeding pairs	A4i
Greater Crested Tern Thalasseus bergii	LC	non-breeding	-	750 individuals	A4i
A4iii Species group - seabirds	n/a	resident	-	100,000-499,999 individuals	A4iii

1. The current IUCN Red List category. The category at the time of the IBA criteria assessment (1998) may differ.

Ideally the conservation status of the IBA will have been checked regularly since the site was first identified in 1998. The most recent assessment (2014) is shown below.

State (condition of the trigger species' habitats)
Habitat	Quantity (% remaining)	Quality (% carrying capacity)	Result
Marine Coastal/Supratidal	moderate (70-90%)	good (> 90%)	near favourable

Pressure (threats to the trigger species and/or their habitats)
Threat	Timing	Scope	Severity	Result
Invasive and other problematic species and genes	happening now	some of area/population (10-49%)	moderate to rapid deterioration	high
Climate change and severe weather	likely in short term (within 4 years)	some of area/population (10-49%)	moderate to rapid deterioration	medium
Pollution	happening now	some of area/population (10-49%)	slow but significant deterioration	medium
Residential and commercial development	happening now	small area/few individuals (<10%)	no or imperceptible deterioration	low
Biological resource use	happening now	small area/few individuals (<10%)	no or imperceptible deterioration	low
Human intrusions and disturbance	happening now	some of area/population (10-49%)	no or imperceptible deterioration	low

Response (conservation actions taken for the trigger species and/or their habitats)
Protected areas	Management plan	Other action	Result
Whole area of site (>90%) covered by appropriate conservation designation	A comprehensive and appropriate management plan exists that aims to maintain or improve the populations of qualifying bird species	The conservation measures needed for the site are being comprehensively and effectively implemented	high

Year	Protected Area	Designation	% overlap with IBA
1988	Dyer Island Provincial Nature Reserve	Nature Reserve	5
1988	Geyser Island Provincial Nature Reserve	Nature Reserve	1

The Local Conservation Group(s) listed below are working to conserve this IBA.

Name	Year formed
Dyer Island Conservation Trust	0

For more information on BirdLife's work with Local Conservation Groups, please click here.

Habitat1	Habitat detail	% of IBA
Marine Coastal/Supratidal		major (>10)
Marine Intertidal		major (>10)
Marine Neritic		major (>10)

1. IUCN Habitat classification.

Land use	% of IBA
nature conservation and research	100
tourism/recreation	-
urban/industrial/transport	-

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Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Dyer Island Nature Reserve (South Africa). Downloaded from https://datazone.birdlife.org/site/factsheet/dyer-island-nature-reserve-iba-south-africa on 23/11/2024.