Sooty tern: Poaching of birds and eggs on Seychelles' Aride Island puts species under threat

The sooty tern is a medium-sized, highly pelagic seabird with contrasting black and white plumage and a distinctive wideawake call. (Gerard Larose)

(Seychelles News Agency) - Illegal poaching, overfishing and climate change are some of the biggest challenges the population of sooty terns is facing on Seychelles' Aride Island, said an official of the Island Conservation Society (ICS).   

Anthony Bentley, the Aride Island manager, gave details on the ICS annual census on the sooty tern. This year, through the census, ICS noted a 36 percent decline in the number of sooty terns on the island compared to last year. Bentley said that these impacts are especially apparent during breeding season.

The sooty tern is a medium-sized, highly pelagic seabird with contrasting black and white plumage and a distinctive wideawake call. They are extremely sociable, forming very large nesting colonies on open ground.

"A combination of factors is causing this decline on Aride and in the Seychelles. Overfishing and climate change are two of the biggest causes of the sooty tern population declines. Lack of food due to overfishing and shifts in climatic patterns affect sooty terns foraging and the impacts are higher during breeding season when adults need to have a more limited foraging area due to the necessity to return to the nesting sites to incubate eggs and feed chicks," he told SNA.

Bentley said that illegal poaching also "remains one of our biggest problems. As a protected island, the taking of eggs or animals is strictly prohibited, however, it still takes place every year. This year we have found evidence of poaching of both eggs and birds on the island which has a direct negative impact on the survival and breeding success of Aride."

Aride is the most northerly of the Seychelles granitic islands. (Gerard Larose) Photo License: CC-BY

The census found that this year the total population of sooty terns on Aride was 4,519, the second lowest on record, compared to 7,659 in 2023. Bentley said they are noticing the birds moving away from traditional nesting sites and nesting in enclosed forests in very low numbers.

Furthermore, there is a continued long-term decline across the Seychelles. The island nation has already lost 70 percent of sooty terns and areas like Aride are still seeing declines. Research in other areas of the western Indian Ocean concluded that the risk of extinction in sooty terns is 1 percent by 2,100.

On poaching on Aride, the most northerly of the Seychelles granitic islands, Bentley said the low breeding success of several colonies due to these interferences means a continuous decline in the population and that at least two sooty tern colonies had eggs poached. The colonies had 798 pairs, and only 11 chicks managed to fledge the nest.

"Sadly, it is not just eggs that poachers take, they also kill and take adult birds for bush meat. We found 15 dead sooty terns that were killed on the island last week. Along with four tropical shearwaters and 11 wedge-tailed Shearwaters. The poaching of birds and their eggs on Aride continues to add extreme pressure on an already struggling species. If these activities continue Seychelles and Aride could very easily see the extinction of the sooty Tern. History tells us that this is possible, many species of birds are now globally extinct due to exploitation by humans, the Passenger Pigeon and Dodo are prime examples of this," Bentley stated.

The Island Conservation Society does regular poaching patrols and necessary work to the landscape such as removing vegetation that gets in the way of the birds nesting, but is more to be done. He emphasised the urgent need to extend the existing two-year ban that was put in place by the Ministry responsible for Environment.  

Since 2021, ICS has been working with Ministry of Agriculture, Climate Change and Environment, to conduct national scale censuses of sooty terns and based on the information a national decline in populations was recorded hence an imposed ban on harvesting of sooty tern eggs until the 2025 season. 

"To better understand the impact on the population, ICS had recommended that the ban on sooty tern egg cropping should be for a minimum of two cycles, each cycle being at least six years corresponding to the time that a fledgling would require to return to an island and become a successful parent. Thus, the recommendation was for a 12-year ban. A review of the existing 2-year ban is highly recommended," said Bentley.

He emphasied the importance of spreading awareness and educating especially the youth in regard to issues such as poaching.

"ICS was fortunate to be granted funding from the Global Economic Fund for use on Aride and other islands. Some of this money will be used to tackle illegal poaching on the island. Equipment such as thermal imaging drones is to be purchased to help identify poaching activity that can be resolved quickly. Moving forward, educating the younger generation on the impacts of illegal poaching and other human impacts is essential. We must do all we can to ensure biodiversity in the Seychelles continues to flourish," he said.