Friday, 1 September 2017

North island myna eradication project as told by Claire and Sarah

What is the Common Indian Myna (Acridotheres tristis)? The myna is a bird native to India and South East Asia which has been introduced to various countries around the world. The myna was introduced to the Seychelles potentially to manage the number of insects damaging crops and other vegetation, however this is not confirmed. Is is an aggressive bird that has been known to injure and kill endemic birds as well as damage the eggs.  This has had a severe impact on breeding success and population numbers of endemic species across the islands.

North Island is working towards restoring the island to how it was before it became a farm for fruit, vegetables and coconuts in 1826. Removal of the myna is a huge step in this process and once completed endemic species can then potentially be reintroduced. The Myna Eradication Programme is a partnership of North Island, Green Island Foundations, Chris Feare of Wildwings Bird Management and endorsed by Ministry of Environment,Energy, and Climate Change.  The current programme commenced May 2016 and has since removed 924 myna from North Island.

Photo: partial view of North island seen spa hill  (CWaters)

Our current volunteers, Claire Waters and Sarah Atkinson took over in April 2017 for the final stages of the eradication. We are now reaching a very exciting part of the project where we are starting to see huge progress and can see we are reaching the end of the eradication process. The eradication of the myna has been successfully completed on two other islands in the Seychelles archipelago (Fr├ęgate and Denis); which have shown a notable dramatic increase in the native bird population on those islands. The eradication of the majority of mynas on North Island is already benefiting the native species on the islands and is thus proving its conservation importance.

In order to remove the myna, the methodology has changed since the beginning of the project to adapt to the birds’ changing behaviour. In order to be successful in removing the mynas, efforts need to be invested in understanding the bird behaviours and adapting methodologies accordingly. We are now in the process of carrying out surveys throughout the day to locate the remaining birds, which are thought to be in very low numbers.

So what do we do every day? Each day starts at 5:30am where one of the two Myna Eradication Officers, Claire or Sarah, start with a dawn survey at various locations across the island. This involves listening and looking for a dawn chorus, which is easily distinguishable from other birds around the island. Surveys then continue throughout the day, tracking the remaining birds and covering all areas of the island, from the plateaus to the top of the hills along the hiking trails. The other volunteer will begin work at midday, and will carry out the same survey at dusk to locate the birds as they select a tree to roost in overnight.
Photo: Sarah and Claire observing mynas (ASanders)

Interestingly, a previous Myna Eradication Programme on Denis Island found that the myna would roost in one tree together overnight. This has also been suggested to take place around the world. However, on North Island the myna have all been found to roost in pairs across the island. This is one example of the differing behaviour found in the myna on North Island and has made the project more challenging.

It has been found that as the number of myna on the island has dropped significantly, their behaviour has begun to change as well. Their vocalisations have altered to mimic native birds making it more difficult to locate them. This may be in response to low population numbers or in an attempt to disguise themselves. It is also possible that juveniles are learning from native birds in the absence of many adults to learn from. They have also become less confident and are no longer seen on the ground of the plateau. In the coming months, as we near completion of the eradication, there will then be an observation phase of the project, where the island will continue to be surveyed daily to ensure that we have eradicated all birds, this may take place for up to 6 months.

Since the start of the myna eradication, North Island staff have already noticed a significant increase in the numbers of endemic species. This includes the Seychelles Blue Pigeon (Alectroenas pulcherrima) and the Seychelles Sunbird (Necttarinia dussumieri) and is a huge positive step in restoring the island and conserving the unique wildlife of the Seychelles.

Photo: Seychelles white eye on North island (CWaters)

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