Page 514 - Atlas Sea Birds Ver1

Table 2: Estimates of numbers of Hartlaub’s Gulls (pairs) breeding in southern Africa in Williams et al. (1990), Kemper et al. (2007), for
2018–2022 and for five decadal periods, 1970s, 1980s, 1990s, 2000s and 2010s. Also shown are the most recent values for each site,
the years of those observations and their percentage contribution to the total of the most recent values. The decade of observations is
colour-coded and the percentage contribution of values from different decades to the sum of the most recent values is indicated. Sites
that qualify as IBAs are highlighted in grey

Decade of most 1970s 1980s 1990s 2000s 2010s IBA based on most recent count at site ≥ 10 pairs
recent estimate
Maximum breeding pairs % contribution to sum of most recent estimates
This % 1970s 1980s 1990s 2000s 2010s
Williams Kemper Most Year of contribution
Site et al. et al. study recent most to sum of 0.00 7.13 0.00 2.13 90.73
recent
(1990) (2007) 2018– estimate estimate most recent Maximum pairs observed at sites in different
decades
(pairs)
1984– 2022 estimates
1970s 1980s 1990s 2000s 2010s
1989
Namibia
Swakopmund 42 0 0 2022 0.00 75 42 0
Saltworks
Swakopmund 160 160 1984 2.75 5 160
Sewage Works
Walvis Bay Harbour √ √ 1986
Walvis Bay Bird 195 195 1984 3.35 500 195
Paradise
Walvis Bay Saltworks 8 8 1987 0.14 8
Namib Desert 2 2 1986 0.03 2
Mercury Island 25 2012 0.43 25
Ichaboe Island √ 34 97 21 2022 0.36 20 318 410
Seal Island 186 186 2022 3.20
Penguin Island √ 148 148 2022 2.54
Shark Island; Lüderitz 247 72 0 0 2022 0.00 963 247 601 72
Harbour
Halifax Island 1 68 0 0 2022 0.00 8 252 27 68
North Long Island 50 1980 0.86 50
Possession Island 912 124 124 2006 2.13 29 912 124
Northern Mining Pond 12 12 2021 0.21 0
N83
Northern Mining Pond 8 0 2021 0.00 8
N47
Northern Mining Pond 34 4 2021 0.07 0
S2
Other Namibian sites 455
South Africa
Orange River Estuary 700 0 0 2018 0.00 62 700 0
Alexander Bay 26 0 2019 0.00 26
Sewage Works
Alexander Bay 24 24 2018 0.41 24
Harbour
Tweepad 60 0 2019 0.00 60
Papendorp Saltworks 8 0 2022 0.00 8 8
Bird Island, Lambert's 160 0 0 2020 0.00 0 0 205 12 2
Bay
Wadrifsoutpan 75 0 2021 0.00 187 393 0 75
Rocher Pan 1 0 0 2021 0.00 1 39 0 0
Velddrif Saltworks 0 0 2018 0.00 100
Lower Berg River 600 0 0 2018 0.00 174 600 300 207 63
Saltworks
Sandy Point 100 14 14 2021 0.24 250 158 432
Malgas Island 11 1357 130 130 2020 2.23 350 11 610 1357 379
Marcus Island 792 231 0 0 2020 0.00 749 792 660 231 0
Saldanha Harbour 300 58 10 10 2019 0.17 240 300 130 600 15

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