Cape Cormorants

Image via: Facebook / SANCCOB saves seabirds / Leon-Niel Wauts

Cape cormorants: SANCCOB to release 2 000 rescued birds

SANCCOB will gradually reintegrate the Cape cormorants it rescued from Robben and Jutten islands, into the wild.

Cape Cormorants

Image via: Facebook / SANCCOB saves seabirds / Leon-Niel Wauts

The South African Foundation for the Conservation of Coastal Birds (SANCCOB) announced that it is gearing up to begin releasing more than 2 000 Cape cormorant chicks it rescued from Robben and Jutten islands in January 2021 back to the wild. The hand-reared birds were taken in for rehabilitation as they were suffering from heat stress and dehydration after being abandoned by their parent birds.

“The rescue intervention was deemed necessary due to their high conservation value. Releases will take place regularly in the weeks ahead, most likely through to May until all birds are back in the wild where they belong,” said SANCCOB.

The birds are being released in batches of 40 to 100 birds, according to the organisation’s release criteria. The Cape cormorants need to pass a variety of tests before they are released. Ideally, they should weigh more than 1kg, have waterproof plumage and be in generally good health.

“Blood tests are also conducted on all birds before release to ensure there are no blood parasites or other blood conditions that could affect their survival,” said SANCCOB.

To ensure the birds do not associate food provision in the wild with humans, staff will feed the birds dressed in black head-to-toe garments.

A ‘SOFT RELEASE’ WILL EASE THE BIRDS BACK INTO THE WILD

A temporary aviary was built on Robben Island in February in preparation for the release of the seabirds. Release-ready Cape cormorants will be housed in the aviary for 48 hours and fed twice a day. Then, the gates will be opened and hopefully, the birds will integrate with the wild cormorants roosting near the enclosure.

Food will be left to the birds near the aviary for as long as necessary. According to SANCCOB, this is the most viable option because Cape cormorants usually provide ‘extended parental care to their young’ even after the birds have fledged.

THE MYSTERIOUS DISAPPEARANCE OF CAPE CORMORANT PARENT BIRDS

Researchers suggest food shortage and extreme heat conditions are the reason Cape cormorant parent birds abandoned the chicks.

“If the birds were already struggling to find sufficient food due to overall low food availability – their main prey being sardine and anchovy – then the heat will have added to the parent birds choosing to fly off as the heat increases the birds’ demand for energy, i.e. food,” said Dr Katta Ludynia, SANCCOB’s research manager.

Ludynia added that the abandonment was probably not precipitated by a single-disturbance event because the abandonment of the Cape cormorant chicks on Jutten Island started “on exactly the same day”.

BIRDWATCHERS AND THE PUBLIC URGED TO KEEP AN EYE OUT FOR ‘RINGED’ CAPE CORMORANTS

All the Cape cormorants from SANCCOB will be equipped with metal rings while some will be individually marked with colour bands that make identification easier. CapeNature encouraged the public to look out for these ringed birds along the Western Cape coastline, in a Facebook post on Friday 26 March. Ring resightings can be reported to the South African Bird Ringing Unit (SAFRING) SANCCOB.

“SANCCOB encourages the birding community and general public to keep an eye out for Cape cormorants along the Western Cape coastline as birds will move to other locations once having joined wild flocks,” said the organisation.

Extensive post-release monitoring of the birds allows SANCCOB to assess how successful their intervention has been and provides insight into the post-fledging movements of Cape cormorants.

“This information will be crucial to better protect the species in future,” said SANCCOB.

Sightings can be reported to SAFRING (www.safring.birdmap.africa) or to SANCCOB (katta@sanccob.co.za).

READ: Share the Shores: How you can help to protect South Africa’s seabirds