African White-backed Vultures: the “American football team”

The following article was originally published at OutdoorPhoto.co.za and written by Mark D. Anderson.  I have communicated with Mark and he has kindly given permission for the republication. Per Mark, White Backed Vultures are found within Chobe National Park.

For American Football fans, it is now obvious that our game is viewed by my Springbok friends as dirty, smelly and disgusting.  Oh well, at least there watching…..  and with no further discussion, here is Mark’s review:

African White-backed Vulture  Photo supplied by Mark

African White-backed Vulture Photo supplied by Mark D. Anderson

Written By:Mark D. Anderson

“Dirty”, “smelly” and “disgusting” are some of the adjectives that are used to describe one of my favourite birds, the African White-backed Vulture (AWbV). A bit of research will however show that they are actually quite clean and they take a bath after most meals (not something that us humans do!) and they are exceptionally good parents (and judging by the kids I see walking around shopping centres late at night, I cannot say that all humans are good parents!).

Many of us in South Africa are very lucky, as we do not have to travel far to see AWbVs. I am exceptionally fortunate as I see them almost every day of my life, as Kimberley (my home city) is surrounded by several hundred breeding pairs and they even regularly fly over the city itself. The AWbV is in fact one of the most numerous and widespread vultures in Africa, possibly numbering 100 000 pairs. This vulture is fairly widespread in southern Africa, but in South Africa it is mainly found in the Kruger National Park and surrounding areas, KwaZulu-Natal, and the northern parts of the Northern Cape and North West provinces. It is thought that the population in South Africa numbers about 3500 pairs. They breed on the top of trees, especially Acacia trees so generally where you find the right trees you should find breeding AWbVs. These vultures have however recently taken a liking to nesting on steel electricity pylons and 22 pairs breed on these towers in the Kimberley area during 2006. As we all know, these tall, sturdy structures are not in short supply, so AWbVs potentially have plenty of places to breed.

AWbVs like going walkabout! They forage over large areas and Kimberley’s population of 300 odd breeding pairs occasionally venture into the Karoo to feed on dead sheep. It would be really exciting to fit satellite transmitters to a few AWbVs and to then monitor their daily movement patterns. During the past few years marked vultures from the Kimberley area have been seen (or recovered dead) in northern Namibia and near Hoedspruit in the Limpopo Province!

The best places to see and photograph AWbVs are probably the Kruger National Park and Kgalagadi Transfrontier Park. They are however not uncommon in some of the northern KwaZulu-Natal conservation areas, and of course the Kimberley area. Some of the nicest images of these vultures are perhaps individuals interacting at a carcass or flight shots of bird spiralling down to partake with their kin at a smelly feast. Although the new fast digital cameras and autofocus lenses make flight and action photography relatively easy, I do not think that we have fully exploited the opportunities of the comings and goings of vultures at a carcass. Come on folks, let’s see some stunning action photos!

One of the best places to photograph vultures is from the shelter of a hide at a vulture restaurant and during the past few years the hides at Lichtenburg, Pilansberg and Dronfield (Kimberley) have been popular vulture-watching and photographing destinations. The hide at Giant’s Castle is most well known for photographing the AWbV’s larger cousin, the Cape Vulture, and the attractive Bearded Vulture.

The Endangered Wildlife Trust’s Birds of Prey Working Group (BoPWG) and its various associates have been actively promoting the conservation of vultures for the past few decades. Although the tide has probably not turned for, in particular, the Cape Vulture, some of the AWbV colonies seem to be stable, including the population around Kimberley (which may even be increasing in numbers). The threats facing AWbVs include declining food availability, poisons and electrocution on electricity pylons. Believe it or not, voltaren, or more specifically sodium diclofenac has been responsible for the virtual extinction of the AWBV’s cousin, the Oriental White-backed Vulture, in Pakistan and India. This drug, which is used to treat sick, lame and lazy cattle, is deadly for Gyps vultures. Spare a thought for about a million dead Oriental White-backed Vultures next time you generously apply voltaren to your aching joints and muscles!

Vultures on zebra carcass - photo supplied by Mark Anderson

Vultures on zebra carcass - photo supplied by Mark Anderson

In order to study AWbVs, especially to get information on movements and mortality factors, the BoPWG has during the past two years been coordinating a vulture marking project. The previous practice of fitting colour rings to the vultures’ legs was not yielding much data, mainly because the vultures pull the rings off with the powerful beaks! The rings are also not visible when the vultures perch on the top of Acacia trees or when they feed on a carcass in long grass. The new marking method involves fitting coloured tags (patagial tags in scientific terms, actually just plain old cattle ear tags) to the birds’ wings. These tags have a unique colour and an alphanumerical which is specific to that individual bird. Just today, as I write this article, a farmer reported to me that he found the carcass of an AWbV with a yellow wing tags with the letter and number W043. The vulture had caught its head in the fork of an Acacia tree. This vulture was recovered 280 km from where I had marked it as a nestling on Dronfield Game Farm, just north of Kimberley, during October 2006. Without the tags, it is unlikely that the farmer would have reported this mortality.

Thus far about 800 vultures (of five species) have been marked with wing tags, a very small proportion of the population of the various species. I recently saw about 100 AWbVs on two blue wildebeest carcasses and only three birds had wing tags and colour rings (and this is on Dronfield Game Farm, where we have marked more than 500 vultures during the past 13 years!). Despite the relatively few tagged birds, there have been more than 1300 sightings of tagged birds. Many of the resightings have been reported from the Kruger National Park and some excellent photographs have been submitted of tagged vultures! Surprisingly photographers have not been critical of this marking method, maybe because the odd tagged bird photographed amongst the feeding mêlée has simply had its tags Photoshopped away! Please report any sightings of tagged birds to André Botha, Manager of the Birds of Prey Working Group (andreb@ewt.org.za).

Some of my most enjoyable wildlife experiences have been at a carcass, watching the interactions of vultures as the squabble over bits of rotten flesh. I especially enjoy the bullying nature of the stately and dominant Lappet-faced Vultures and the sneaky way in which the small and timid Hooded Vulture steals tiny scraps of food. I sat four hours during a recent trip to Kenya’s Masai Mara Game Reserve watching and listening to dozens of vultures (of four species) interacting at zebra and wildebeest carcasses. The AWbVs in particular are great to watch and photography at a carcass and in their book, “The Vultures of Africa”, Peter Mundy and his colleagues state that “…a phalanx of these birds at a carcass reminds us in some ways of an American football team”. They further state elsewhere “We have seen some vultures land with such force that they tumble over and get up looking rather dazed; but a quick glance around re-orientates them and in they rush to the fray” and “It seems that every bird is engaged in frantic activity: rushing up to the carcass (if it can), feeding, being pushed aside, getting involved in fights on the fringes of the action, then rushing in again and repeating the whole process. Each individual may do this several times, even at a small carcass such as an Impala, and there may be 100 Whitebacked Vultures assembled (a combined, hyper-active mass of half a tonne!). Add to this a deafening noise and 200 feed flattening the sward over an area of perhaps 1000 square metres, and – but words can barely convey the impact that such a gathering may have on one’s eyes and ears, although the effects of all those feet in a tiny area is obvious. We call these birds the ‘American football team’, except that each vulture is in a team of one: the effect is one of pandemonium, the air is ‘blue’ with cackles, hisses, shrieks and grunts, and everywhere there seem to be ‘scrums’ between two birds.” Watching these birds at a carcass is infinitely more exciting than a Currie Cup rugby match!!

The next time you are in Kruger or the Kgalagadi, take time to watch and photograph the antics of vultures feeding at a carcass, and look out for tagged birds. By contributing your observations of marked birds you will assist biologists with their research and ultimately contribute towards the conservation of these threatened and magnificent scavenging birds!

Mark D. Anderson

E-mail address: manderson@half.ncape.gov.za

http://www.andersonafrica.co.za/index.html

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