Nearly 1 700 abandoned Cape cormorant chicks have been rescued from Robben Island.
The chicks were retrieved in a joint operation by Robben Island Museum (RIM), the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), the Two Oceans Aquarium and the National Sea Rescue Institute (NSRI) on Tuesday January 12 and Wednesday January 13.
They were boxed, transported by boat and admitted to SANCCOB in Table View after being abandoned by their parents.
The chicks were rescued after SANCCOB and RIM’s penguin and seabird ranger alerted RIM’s environmental unit and SANCCOB that the adult cormorants did not return to their chicks after a few hours.
The NSRI’s Table Bay station immediately responded, and chicks were boxed and transported to the mainland.
The estimated 3 000 breeding pairs of Cape cormorants on the island usually each hatch two to three chicks each summer, so the abandonment put thousands of chicks at risk as they cannot fend for themselves.
On admission to SANCCOB’s seabird hospital, each chick was weighed and hydrated to quickly stabilise it and reduce its stress, then placed in designated pens according to its weight.
Ronnis Daniels, public relations officer at SANCCOB, said the chicks vary in size, as small as 200g to many of them over 400g. The smallest chicks are approximately three to four weeks old, while the larger chicks are around four to six weeks.
A complete veterinary assessment was then conducted on each chick.
Ms Daniels said the team was able to rescue all live cormorants over the course of two days. However, prior to the rescue, it is estimated that several hundred chicks died due to predation, hydration and starvation.
“They get predated by Kelp gulls and Sacred ibis, both species breeding on the Robben Island and are natural predators of Cape cormorants eggs and chicks. They would also have died due to the heat exposure, as adults give shade to smaller chicks, and then due to cold temperatures during the nights as there were no adults to keep the chicks warm.
“After a few days, they would also die of starvation when adults don’t return to feed them.”
SANCCOB’s researchers suspect lack of food to be the main reason for the abandonment, but investigations are still under way.
SANCOBB’s research manager, Dr Katta Ludynia, said Cape cormorants feed mainly on anchovy, and to a smaller extent, on sardines, and these small pelagic fish species are at very low levels at the moment.
“We are seeing dramatic population declines in all seabird species that rely on these fish species: the African penguin, the Cape gannet and Cape cormorant are all listed as endangered by the International Union for Conservation of Nature (IUCN) and lack of sufficient food is the primary factor for the most recent declines observed.”
It was initially suspected that adult birds had begun flying out to sea to cool down during the hot weather of the last two days, but Dr Ludynia said that had this been the case they would have been seen rafting close to the island and eventually return to their chicks when the temperature dropped.
“Cape cormorants are summer breeders: their main breeding season is between October and December and they breed along the coast of South Africa and Namibia, into Angola, so they should be used to heat.
“A recent study on the behaviour of Cape cormorants and other cormorant species did not observe abandonment at high temperatures comparable to what we had in recent days.”
Thabo Seshoka, Robben Island Museum’s Head of Heritage and Research, agreed that the abandonment is unusual, and that quick intervention helped ensure the birds’ best chance of survival.
“It’s an anomaly that both RIM and SANCCOB are studying. Annually, 186 bird species, including the endangered African Penguin, breed on the Island, which underpins the need for responsible tourism on the island, which is a Marine Protected Area and World Heritage Site.”
SANCCOB is focusing on providing the veterinary and rehabilitative care for the cormorant chicks until eventual release, while simultaneously rehabilitating other, existing seabird patients.
Ms Daniels said depending on age of the chicks, release might be earlier, but he suspects that the birds will stay for two to three months.
“They will undergo health checks and daily rehabilitation prior to release and then we will ring them to be able to follow them in the future. Once each bird is assessed by the veterinary and rehabilitation teams, they will be released at an agreed site with the conservation authorities.”
In light of this crisis situation, SANCCOB will need the support of public to help in their fundraising endeavours to contribute to medication and fish for the chicks.
Ms Daniels said the costs of food, supplements and veterinary medicine only is R3 000 per day right now, which will increase as the chicks grow and consume more food.
She said the public can assist with:
- Financial contributions to help buy fish and medication.
- Financial contributions to help buy fish and medication.
- Financial contributions to help buy fish and medication.
- Financial contributions to help buy fish and medication.
To donate or volunteer, contact Hedwich Tulp at Hedwich@sanccob.co.za or Ronnis Daniels at Ronnis@sanccob.co.za, or call 021 557 6155.