From 18-23 September 2011 Dieter Oschadleus from SAFRING (South African Bird Ringing Unit) was on Cousin Island Special Reserve conducting training on ringing birds for the island’s wardens. Ringing and releasing birds is delicate work and ringers need skill and experience.The training was mostly on mist-netting of seabirds and land birds, a method used in bird ringing. A total of 478 birds were caught and ringed including recaptures. Riaz Aumeeruddy, Nature Seychelles Science and Conservation Coordinator was at the training and we took the opportunity to ask him a few questions. Following are his answers.
Why do we ring birds?
There are different reasons for ringing birds. One is to be able to identify birds individually in a population, usually using a combination of different coloured rings. This is what is done on Cousin with the endemic Seychelles magpie robin and the Seychelles warbler, where each bird is colour ringed. Usually most ringing programs involve only putting a metal ring with a unique ID on one of the legs of a bird. This will allow, if the bird is recaptured, to get information on its movement (on the island itself or inter-island), on its longevity (eg. a Seychelles fody ringed in 2002 on Cousin was recaptured during the training course, showing the the bird lives at least 9 years, information on the longevity of the Seychelles fody has never been published before) and social associations. Bird ringing can help answer a number of questions relating to causes and factors contributing to population movement, dynamics and behaviour.
Which types of birds do we ring?
On Cousin, we systematically ring two species of land-birds: the magpie robins which are ringed by the Cousin staff, and the Seychelles warblers that are ringed by the scientists from the warbler research group. Ideally all the birds of these two species are ringed, to know the exact population, and the territories in which they live on the island. Other landbirds are ringed for specific projects; the Seychelles fody was ringed on Cousin by a student who was doing her PhD on that species. Some species of seabirds are also ringed on Cousin, for example the White-tailed tropicbird and the Lesser Noddy are ringed during study of their breeding success (parents and chicks are ringed when they are on the nest).
What do the different colors mean?
Colour rings are used in a unique combination (2-3 rings) which helps identify each bird. For the magpie robin, 1 colour ring is attached to the right leg to identify the island (eg. Cousin uses a Red ring) so if a bird flies from one island to the other, we can know from which island it is from, and 2 colour rings are attached to the left leg to identify the bird. With this system, the whole genealogy of a bird can be determined. For the warblers, 1 colour ring is used to identify the year the bird is ringed, and 2 colour rings for identifying the bird.
What was the outcome of the exercise
Four wardens, the science officer and myself attended the training course. All the participants received certificates. We need to thank Dieter Oschadleus from SAFRING for conducting the training, and the warbler team (Martijn Hammers, David Wright and Sjouke Ann Kingma) for their assistance during the course.
Dieter has also reported on this ringing exercise here and has provided a table of the species and numbers ringed.