Bird ringing at Grotto Bay, 27 May 2023

The Biodiversity and Development Institute (BDI) hosted a Citizen Science Day, Saturday, 27 May 2023, with a focus on bird ringing at Grotto Bay Private Nature Reserve. The reserve has an area of 385 ha, and the vegetation consists of Strandveld and Sandveld.

Ringers had their nets up on a very cold morning, and it took a short while to start catching birds. Eventually we had a really good catch of 41 birds of 15 species. There were 3 recaptures from our previous session here (1 October 2022) – two White-backed Mousebirds and a Karoo Prinia.

Cape Spurfowl at the bird ringing at Grotto Bay
Spurs on the male Cape Spurfowl



A male Cape Spurfowl flew into one of the mistnets – he had very sharp spurs, measured at 19.9 mm long (read more about Cape Spurfowl spurs here). There was a good mix of fynbos species, including Karoo Scrub Robin, Long-billed Crombec, Bar-throated Apalis, Grey-backed Cisticola, Chestnut-vented Tit-babbler, and with seven White-backed Mousebirds topping the list.

Cape Spurfowl in moult at the bird ringing at Grotto Bay
Primary moult in the Cape Spurfowl, P6 growing and outer 3 primaries old



It was interesting to see the slight difference in width of breast band in a pair of Bar-throated Apalis. Wing, tail and tarsus were also slightly longer in the male than female, while mass was more or less the same.

Cape White-eye at the bird ringing at Grotto Bay
Special feathers make up the eye-ring of the Cape White-eye



Residents of Grotto Bay came to watch the ringing, learn about birds in the hand, and listen to two talks at the Grotto Bay Conservation Centre. Dieter Oschadleus gave some examples to demonstrate the value of ringing, starting with the 2000 Treasure oil spill and how valuable it was for conservation to ring over 20,000 African Penguins. Les Underhill spoke about citizen science, highlighting three projects that people can become involved in – SABAP2, the Virtual Museum, and bird ringing.

Dieter Oschadleus at Grotto Bay Nature Reserve
Dieter starting his talk to the Grotto Bay audience

Thanks very much to Michelle and Roy for catering and hosting us at the Grotto Bay Private Nature Reserve! Thanks to the many ringers and helpers! We look forward to the next time we go bird ringing at Grotto Bay.

To join a ringing course, see Events.

Numbers of birds caught at Grotto Bay, 27 May 2023

The highlighted species have species texts on the BDI website.

Sp noEnglishCount
181Cape Spurfowl1
391White-backed Mousebird7
543Cape Bulbul6
581Cape Robin-chat2
583Karoo Scrub Robin1
621Long-billed Crombec2
622Bar-throated Apalis3
638Grey-backed Cisticola1
658Chestnut-vented Warbler2
760Southern Double-collared Sunbird3
799Cape Weaver6
803Southern Masked Weaver1
873Cape Bunting1
1172Cape White-eye1
4139Karoo Prinia4



Dieter Oschadleus
Dieter Oschadleus
Dieter Oschadleus leads the BDI bird ringing expeditions, and is able to organise bird ringing courses (having run many courses in South Africa, and some in the Seychelles). Dieter is also a registered bird guide in South Africa, and has birded widely in Africa and the Indian Ocean islands. Dieter is able to act as a bird guide for day trips in Cape Town, and is able to customise birds tours in South Africa and beyond.