Bird with white eye rings in danger of disappearing from Seychelles’ main island
The endemic Seychelles white-eye or zwazo linet in Creole might soon become extinct on the main island of Mahe and an attempt is being made to relocate them to another island, said a conservation biologist.
Gérard Rocamora, who is a practitioner at the Island Biodiversity and Conservation centre of the University of Seychelles, told SNA that at the moment the population on Mahe is about 500 birds.
Classified as vulnerable on the IUCN red list, the Seychelles white-eye — a small grey bird with a narrow white ring around each eye — can currently be found on Mahe, Conception, Fregate, North Island and Grande Soeur.
“We currently have a one-year project, with the team still trying to find more funds to continue. The aim right now is to move some of the few birds left on Mahe to another island to ensure that the gene of the Mahe bird continues on,” he said.
He explained that a morphology and genetics study of the birds on Mahe and Conception showed that those on the main island were slightly larger, however, this did not mean that the two populations were different subspecies.
Rocamora has been studying the Seychelles white-eye since 1995 when he arrived in Seychelles, an archipelago in the western Indian Ocean. He was sent by BirdLife International to set up a programme for the monitoring of endangered species with the local environment ministry. At the time, little was known about the Seychelles white eye.
Rocamora has been studying the Seychelles white-eye since 1995 when he arrived in Seychelles. (Island Conservation Society) Photo License: All Rights Reserved
“Thanks to a few Seychellois naturalists like Mr. Chong Seng, I was able to see a few Seychelles white-eye at Souvenir, La Misere. Then we did a survey and we found about 35 birds on Mahe and estimated a population of less than 50,” said Rocamora.
In the late 1990s, the conservation biologist with other local partners started a mission to save the endemic species after 200 of the species was found on Conception Island.
Under a new project, Rocamora carried out more research to understand why the species was doing so well on Conception and not on Mahe.
Rocamora and his team found out that on Conception there were brown rats, a species that does not climb trees much, contrary to the black rat on Mahe.
“This meant that the brown rats could not predate the white eye as well as the black rat. This explained why they were doing much better on Conception than on Mahe. We also found a lot of trees producing berries, but it is not the case on Mahe, maybe because for years there were not many white eyes to disseminate the seeds,” he added.
Another part of the rescue mission was to find out if the Seychelles white-eye could be transferred to other islands to create alternative and new populations as has been done with some other endemic species.
“Together with Joseph Francois, we started working on Conception, ringing birds, and studying their reproduction,” said Rocamora.
The team wanted to go forth with a transfer to another island and went to Curieuse and Fregate to look at the vegetation, the richness in insects, and fruit-bearing trees.
Fregate was seen as the best option and in 2001 and 37 birds were transferred to the island. A further 25 birds were transferred in 2007 to North Island. The same year the team eradicated the brown rats on Conception because there was evidence that the pest was still killing and eating the birds. After that, the number of birds on the island increased to more than 300.
In 2017, Rocamora and his team noticed that there was an invasion of black rats on Conception.
“We had no time to do anything and by 2018 when we went there, there were only 15 birds that were left. All the others had been eaten by rats it was not just the eggs of the fledglings but the adults as well. This was a disaster and we were really shocked because we had been fighting for many years to protect this population,” said Rocamora.
He added that “this was our mother population and now it was almost gone. Thankfully we had transferred some of the population to Fregate and North Island. We took 30 and 17 from both islands respectively and brought them to Grand Soeur in 2018.”
The last census done on Fregate in 2017 recorded 240 birds and on North Island in 2018 recorded 140 birds, indicating that the population had developed and flourished.