Page 514 - Atlas Sea Birds Ver1
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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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