Tuesday, September 23, 2008

Success in tag returns!

We are excited.
In previous posts during the first part of this trip you would have noted that we were frantically tagging turtles in a hope to get ‘tag returns’ when they came back to nest again after a couple of weeks. Flatbacks may nest 2 or 3 times in a season and the time in between nesting is known as the ‘renesting interval’. This is currently unknown on Crab Island – no one has ever identified the renesting interval for these particular turtles, which is important for identifying reproductive output. Last Thursday we were excited to pick up our first tag return – turtle number K96033, the 33rd turtle we had tagged back on about the 3rd day. Since then we have identified another 80 turtles which we had tagged previously on this trip!! Every night we go out now we are picking up more and more. On average, turtles are coming back to renest after 16 days.

We have also identified close to 30 turtles which have been tagged in previous seasons. This is important as it will help us identify ‘remigration intervals’ for the first time – another aspect currently unknown for Crab Island. We think that they will have a relatively short turn around of between 18 months to 2 years. Green turtles usually remigrate after 5 years and often as much as 7!

We are now focussed on identifying reproductive output by counting eggs and identifying hatching success of clutches. We are also prioritising getting Dna samples of turtles and collecting morphometric data of hatchlings.

Last week we finished up most of our tagging run and have tagged over 650 turtles!! This should provide us with a wealth of data into the future. We have very sore hands from writing and tagging! But we are not complaining…

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