Predator control led to increased breeding success in endangered Réunion cuckooshrike

© Thomas Ghestemme/SEOR/afrol News

afrol News, 7 September - The highly endangered Réunion cuckooshrike, only living on the Indian Ocean island, seemed to be headed towards extinction, but a conservation scheme has been producing positive and rapid results. Birdwatchers set up traps close to the cuckooshrike's nesting places, killing rats and cats that would otherwise have eaten its chicken.

Although the population of Réunion cuckooshrike remained fairly constant at around 120 pairs between the 1970s and the 1990s, it had been declining over the last decade. Currently males outnumber females by almost two to one, and the remaining population is estimated at fewer than 50 pairs and the species is classified as Endangered, according to the environmentalist group BirdLife.

It is thought birds once primarily occupied lowland forest of the entire island, but under the pressures of habitat loss and degradation, forest fires and predation by alien invasives, the cuckooshrike has retreated to a 16 km² patch of mountainous rainforest in the northern part of Réunion.

The cuckooshrike has faced the same fate as very many birds defined to only one island. With the arrival of humans to the islands, alien pests such as rats, cats and other egg and chicken eaters left the ground-nesting birds without defence.

Control of predatory animals had therefore been a key recommendation of the conservation plan, and already in Réserve Naturelle de La Roche Ecrite in northern Réunion it has led to four out of five pairs of cuckooshrike successfully rearing chicken, compared to just two out of six pairs raising young at a nearby site without control.

"We are delighted with these initial results," said Thomas Ghestemme of SEOR, a local conservation group who carried out the trial. "Following Mauritian Wildlife Foundation guidelines, we set baits in grids of 7–15 ha. Before and after the poisoning, we trapped rats to get an idea of how many were present. Early on, rat numbers were so high that it was necessary to replace the poison bait weekly for five months." Cats were also trapped in the grids.

The test results thus were even better than anticipated. "Next season, we will extend the control programme to protect at least 12 nesting pairs of cuckooshrikes," says Mr Ghestemme. "We will be joined in our efforts by staff from ONF, who co-manage the reserve, and SREPEN, an organisation who will inform visitors about recycling."

As Réunion remains a French Overseas Department, the production of the cuckooshrike action plan was partly funded by the EU, French Ministry of the Environment and local sources in Réunion Island.

By staff writer

© afrol News

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