Vultures in southern Africa have been colour-marked for more than 30 years, mostly using plastic colour rings fitted to the birds’ legs in a combination of colours unique to each individual. More than 8000 vultures have been ringed using this method over the years. By far the most vultures to have been fitted with colour-rings were Cape Vulture (Gyps coprotheres) nestlings. The intrepid members of the original EWT Vulture Study Group were brave enough to abseil down precipitous cliff faces to fit the rings in the nests of these birds at most of their breeding colonies in the region during the seventies and eighties. Colour-ringing was also used on other species such as African Whitebacked Vulture (Gyps africanus), Lappetfaced Vulture (Torgos tracheliotus) and White-headed Vulture (Triginoceps occipitalis), but in much smaller numbers.

The success of any colour-marking effort is measured by the number of birds that are either re-sighted or recovered after being ringed. The re-sighting and recovery rate of vultures fitted with colour rings have been rather low with less than 10% of birds being reported to- date. Many of these birds were carcasses of nestlings recovered below breeding colonies by vulture monitors after the breeding season and not of free-flying birds seen after dispersal from their natal areas.

Free-flying birds with colour-rings often perched in such a way that the rings were covered by their feathers or obscured by vegetation. Another problem identified was that some birds were quite adept at removing some of the plastic rings from their legs, thereby rendering the colour combination useless. These combinations were also quite difficult for the lay-person to record and the colour of the rings often faded or changed due to the effects of ultra-violet. Despite this, interesting information on bird movements and dispersal were obtained.

Due to the mould for the plastic rings being lost by the manufacturer in 2004, the Birds of Prey Working Group (BoPWG) of the Endangered Wildlife Trust decided to investigate alternative options for the colour-marking of vultures in southern Africa.
The option decided on needed to meet the following criteria:

• The proposed system should be simple, user-friendly and facilitate consistent implementation across southern Africa.
• The welfare of the birds should be of paramount importance at all times and should not inhibit its normal life cycle and behaviour.
• The marking method to be used must have a proven track-record of durability, resistance to discoloration and prevent removal thereof by the bird itself.
• The system should be cost-effective and affordable.
• It should facilitate an optimal rate of return with regard to re-sighting and recovery.
• The system must be effectively managed and coordinated.

Testing of the various options was conducted during 2005 and the first quarter of 2006 and involved a number of BoPWG staff, fieldworkers, volunteers and associate organizations who participated in the various aspects of assessing various methods. The options assessed included an up-to-date version of plastic colour rings, two types of PVC rings that could be engraved with specific codes and patagial tagging. The assistance of veterinarians was invaluable in assessing the physical welfare of birds during the testing of the various methods and ensured that no birds showed physical injuries, infections or signs of discomfort. The De Wildt Vulture Unit of the De Wildt Cheetah and Wildlife Trust outside Pretoria kindly provided their captive birds for testing methods under controlled circumstances. This allowed for close physical inspection of birds that have been fitted with the various rings and tags tested to ascertain if they had any behavioural or physical effect on birds.

As plastic and PVC rings have previously been tested on wild, free-flying birds in southern Africa, the BoPWG decided to only test patagial tagging on a small sample of birds and use the results from populations of already ringed birds to compare to that of tagged birds. Patagial tagging refers to the fitting of a plastic tag to the “patagium”, or frontal flap of skin to the wing of a bird and has been used worldwide with great success on a wide range of bird species, including vultures and condors in Europe and America.

During October 2006, African Whitebacked Vulture nestlings were fitted with tags at breeding colonies outside Kimberley and Vanzylsrus in the Northern Cape to assess the potential impacts on nestlings and their parents. No negative effects could be observed and parent birds continued caring for their young with the same dedication shown prior to the nestlings being tagged. The nestlings in the Kalahari were fitted with blue tags that each carried a unique alpha-numeric code that enabled the identification of individual birds.

A further opportunity to colour-mark free-flying birds offered itself in the form of 17 vultures that were successfully rehabilitated by the Moholoholo Rehabilitation Centre in the Lowveld after a poisoning incident near Hoedspruit. These birds, a single immature Hooded Vulture (Necrosyrtes monachus) and sixteen African Whitebacked Vultures of various ages were ringed and tagged using yellow tags on the 4th of November 2005. The birds were released at the Moholoholo vulture restaurant on the same day. A concerted effort was made to create awareness among conservationists working on Lowveld reserves, including the Kruger National Park, as well as members of the public visiting the area to report any of the birds that are re-sighted.

The results of the awareness campaign exceeded all our expectations and more than 200 reports of birds being re-sighted in the area have been received from reserve managers and the public. Of the 17 birds tagged, 13 have been re-sighted. This represents a re-sighting rate of 76% from a small sample of tagged birds compared to the less than 10% from all colour-ringed birds in the preceding 30 years! Most birds have been seen a number of times and vulture restaurants and predator kills in areas such as the Kruger National Park have also made a major contribution in birds being re-sighted and reported. All birds seen were reported to be in good condition and competed successfully for food at carcasses.

In view of the results of the assessments, the BoPWG, with the unanimous support of the almost 70 delegates attending its Annual General Meeting in March 2006, decided to implement patagial tagging as the preferred method of colour-marking of vultures in southern Africa in future. A detailed protocol for this method was compiled with input from a wide range of ornithologists and other experts and has been distributed to all participants in vulture ringing in the region. The BoPWG has also undertaken to present practical training to all fieldworkers prior to this method being applied at the various sites where vultures are to be ringed and tagged in future. The Group will also be responsible for the acquisition and distribution of the tags and equipment used to fit them to its various fieldworkers and associates throughout the sub-region. This has been made possible with the kind support of Sasol who has been supporting the EWT’s vulture conservation activities for almost 20 years.

Exciting recent developments that served to confirm the potential value of patagial tagging of vultures in southern Africa was the re-sighting of 2 fle