Page 178 - Atlas Sea Birds Ver1

between different localities and since the mid-1950s has Numbers (pairs) of Cape Cormorant breeding between Vöelsteen
been housed at Dassen Island (Crawford et al. 1995b). and Cape Point but excluding Robben Island and Cape Point,
Cape Cormorants colonised Robben Island in 1985 but 1978–2019
only 0–6 pairs bred annually until 2003. There was then
rapid growth to a peak of 2,166 pairs in 2012. Numbers Year Cape Town Duikerklip Die Josie
breeding farther north off west South Africa decreased and and surrounds
growth of the colony at Robben Island was seen as a re- 1978 10
sponse to the shift to the southeast of sardine and anchovy, 1981 28
which are staple prey items for Cape Cormorants (Craw-
ford et al. 2016). 2010 16
Numbers of Bank Cormorants breeding at Robben 2011 0
Island increased from an average of 64 pairs between 1978 2012 5 0 0
and 1982 to fluctuate around a level of c. 100 pairs from 2013 0 0
1985–2013 but then decreased to just 39 pairs in 2021. At 2014 0 0
localities where Cape rock lobster (Jasus lalandii) had not 2015 21 0
been severely depleted, Bank Cormorant numbers showed
a positive response to the local availability of lobster and 2016 28 0
modelling suggested that areas with no-take of lobsters at 2017 15 0
20–30 km around Bank Cormorant colonies would benefit 2018 15 0
the conservation of this seabird (Sherley et al. 2017). Rock 2019 0 0
lobster is a main prey of Bank Cormorants in South Africa
(Dyer et al. 2019). The marine environment within 1.8 km Numbers (pairs) of Bank Cormorant breeding between Vöelsteen
of Robben Island has been closed to rock-lobster fishing and Cape Point but excluding Robben Island, 1975–2020
since 1960 (Sherley et al. 2012). Nest failures of Bank Cor-
morants at Robben Island were related to wave height and Year Vöelsteen, Clifton Bakoven Duikerklip
air temperature, with reduced chick survival in years when Big Bay rocks rocks
major storm events occurred during peak breeding and in 1975 90
periods of warmer air temperatures (Sherley et al. 2012). 1979 41 81
The maximum recorded numbers of other seabirds that 1980 69 70 32
bred at Robben Island were two pairs of White-breasted 1995 23
Cormorant in 2004, 405 pairs of Crowned Cormorant in 1996 30 106 10 29
1988, 3,395 pairs of Kelp Gull in 2014 (this species colo- 1997 67 0 29
nised the island in 2000), 4,309 pairs of Hartlaub’s Gull in 2002 16
1979, eight pairs of Grey-headed Gull in 2011, 12,986 pairs 2005 5
of Greater Crested Tern in 2009 and one pair of Caspian 2006 12 4 10 10
Tern from 2010–2018.
2011 29 38 30 13
Localities other than Robben Island 2012 20 30 30 13
Numbers of pairs of seabirds breeding annually at other 2013 6
localities in the region are tabularised on tables applicable 2014 16 15 21 11
to the different seabird species, which follow the brief de- 2015 20 35 21 10
scriptions of the localities. 2016 22 25 17 10
2017 20 28 19 10
Vöelsteen, Big Bay 2018 16 25 18
Coordinates: 33.7939 S, 18.4490 E 2019 10 20 15
Description: Vöelsteen is a group of rocks that lie off Big 2020 15
Bay to the east of Robben Island. Inshore of the main group
of rocks is another group known as Kamer van Sweentien Numbers (pairs) of White-breasted Cormorant breeding between
(33.7922 S, 18.4520 E), on which a pair of Bank Cormo- Vöelsteen and Cape Point but excluding Robben Island and Cape
rants once nested. This observation was included under Point, 1947–2012
the count obtained for the main group of rocks.
Conservation status: It is not protected. Year Die Josie
Species and numbers breeding: Bank Cormorants bred 1947 28
at the rocks; the maximum number observed was 69 pairs 1981 19
in 1980 (Cooper 1981). Further details are given on the 2011 0
Bank Cormorant table that follows. 2012 0

Rietvlei Wetland Reserve Numbers (pairs) of Kelp Gull breeding between Vöelsteen and
Coordinates: 33.8383 S, 18.4944 E Cape Point but excluding Robben Island, 2011
Description: It lies along the Atlantic seaboard in the
northern sector of the Greater Cape Town Metropolitan Year Olifantsbos
area and comprises mainly permanent and seasonal 2011 10

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