13 February 2010

Secretaries with numberplates

Recently we had been busy with a research project of the Birds of Prey Working Group (BoPWG) of the EWT (Endangered Wildlife Trust – www.ewt.org.za). We being Dawie de Swardt ornithologist of the National Museum in Bloemfontein and myself. The purpose of the project is to do research on the post-nestling dispersal of Secretarybird chicks. We were issued with 20 patagial tags by the BoPWG to fit to the wings of the chicks before they leave their nests. The patagial tag has a unique number engraved with laser on it – and the idea behind this tag is to spot the live bird at a greater distance rather than rely on the recovery of the standard metal ring when birds have died. Little is known about the movements of the young birds when they leave the nesting area. The numbers on this series of tags start with NM – denoting a project of the National Museum. The research project is controlled by the conservation authorities as well – they have to issue the necessary permits for the capture, ringing and tagging of the birds.


Obelix fitted with numberplates




The patagial tag is the same as the tags with which cattle are fitted to identify the different individuals – they are cut a little bit smaller than the cattle tags. In the case of the birds the tag is fitted in patagium – the skinfold between the body and the "shoulder" in the wing of the bird. Two tags are fitted to each bird – one in each of the wings – and people with keen eyes should be able to read the engraved numbers easily. With a pair of binoculars the reading should be a whole lot easier and can be accomplished at an even greater distance. And photos taken of the birds can help to identify them easily with the large numbers on the "numberplates".

Willem le Roux, shepherd and citizen scientist, with one of the chicks

The first 9 birds have been fitted with their unique numberplates in this season – seven of them in the surrounds of Bloemfontein and a pair of chicks in the North Eastern Cape (near Floukraal, Aliwal North). The birds are ringed with the standard SAFRING stainless steel ring – as is required by the regulations for all birds being captured and ringed for research purposes in Southern Africa. Added to the standard ring on the leg come the 2 tags in the wings. Strict procedures are followed and everything possible is done to minimise the discomfort for the birds. Hygeine is of utmost importance as well to prevent the spread of disease, therefore equipment is properly sterilized after each application of a tag.

The first young birds tagged with these tags were named Romeo and Juliet and the second pair Asterix and Obelix (the one chick being considerably smaller than the other when tagged). In a follow up visit to the nest two weeks after the tagging, Asterix had made up good ground and weighed a mere 100g lighter than Obelix. At first their weights differed more than a kilogram. Up to now the birds were still in the nests where they were fed by the parents, but the first of the chicks are starting to leave the nest now. They will roam the area around the nesting site for the next few months returning at night to roost in the nest. And after that they leave the nesting area ...

The next part of the research project requires the participation of our citizen scientists – the general public – as there can never be enough field workers employed to keep watch on the movement of the birds. Birders spotting the tagged birds are kindly requested to relay the following information to the researchers – number on the "numberplate", date and time of sighting, place where bird(s) are observed (GPS coordinates will be of great help if at all possible), habitat in which bird(s) is observed. Reports can be made directly to myself (vdwarnold@gmail.com or 083-262 1273) or Dawie de Swardt (083-638 1604), or on the SAFRING website where sightings of all ringed (tagged and colourmarked) birds can be reported (http://safring.adu.org.za/retrap.php). The BoPWG can be informed as well at telephone number 011-486-1102.
The tag in the patagium of the bird

Without the kind cooperation of farmers allowing researchers on their farms to monitor nests, do tagging and visits to follow up on the progress of the chicks this kind of research is not possible. We are grateful for their enormous contribution to the scientific knowledgebase in the quest to understand birdlife better and to ensure that future generations will have the benefit of seeing this stately princes and princesses of the veld in their natural habitat.

1 comment:

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Truly yours