African traveler - the Marabou Stork

Recently, when catching vultures to fit them with satellite transmitters, we have incidentally caught a number of Marabou Storks – these we tagged before release in order to learn more about their movements. The tags are yellow patagial tags (attached to both wings), and each bird has a unique number engraved in black on its tags. The tags are quite conspicuous as shown in the photograph, but of course they are useless unless people know what to look out for, and to whom sightings should be reported. Information should be sent to Pete Hancock, birdlifemaun@gmail.com, including the following details: date, locality (preferably with GPS co-ordinates), and tag number and colour. A digital photo would be very useful as the numbers can often be clearly seen on the image. It would be great if other people would use their networks to spread the word further, as we need wide coverage since we believe that these birds travel as far as central Africa. Why do we think our tagged birds will be seen outside Botswana when most southern African field guides state that the Marabou is resident and nomadic with local movements? Marabou Storks have very few breeding sites in southern Africa, there being a single colony (of about 30 breeding pairs) in Swaziland, while Botswana has the largest breeding population in southern Africa, of a mere 100 pairs. The species does not breed in South Africa or Lesotho, and there are a few minor sites in Namibia and Zimbabwe. Against this background, how does one explain the fact that in Botswana, the Marabou Stork often occurs in congregations of 3,000 to 5,000 birds? Could the relatively few breeding birds be maintaining a population of tens of thousands of storks? Or is it more likely that birds are coming to Botswana from elsewhere? Simple arithmetic, based on a clutch of two to three eggs per pair per annum shows that it would take a long, long time to produce this number of birds; it seems more probable that there is a regular influx of storks from further afield. Information on the movements of Marabou Storks has important implications for their conservation. It is speculated that the central African population in Uganda and Kenya (where the species has its stronghold) may well be providing most of the storks in southern Africa.

As the vulture flies ...

BirdLife Botswana, in conjunction with the CKGR Research Group and the Denver Zoological Foundation, recently deployed satellite tracking devices on a pair of adult White-headed Vultures in Khutse Game Reserve. These are the first birds of this species to be fitted with satellite transmitters to determine their movements. The White-headed Vulture is classified as Vulnerable on the IUCN Red Data List, but has been little studied and remains an enigmatic species. The White-headed Vulture research is part of a wider ranging Botswana vulture project aimed at providing a sound scientific base for their conservation. The five major Botswana vulture species are all globally threatened, and are nationally regarded as Birds of Conservation Concern. The White-headed Vultures were captured using a compressed-air powered cannon net, activated remotely from a concealed hide; this technique has been used by the team to catch relatively large numbers of Lappet-faced and White-backed vultures as well. The vultures were measured and weighed, and also fitted with unique numbered wing tags to aid future identification, before being released. Although it is early days yet, it is interesting to note that the pair has temporarily split up, with the male moving a few hundred kilometers northwards into the Central Kalahari Game Reserve; the female has remained in the vicinity of the capture site at Molose Pan in Khutse. Dr Richard Reading prepares to release the male (Photo: Pete Hancock). We would like to thank the Department of Wildlife and National Parks for their unstinting support of the project, and Kanabo Conservation Link for providing additional funding to facilitate the capture of the birds.

Birds and People # 37

Pharaoh's Chicken visits Botswana

Photo: Brent Harris.

In southern Africa, the Egyptian Vulture is known affectionately as Pharaoh’s chicken, and is viewed with a great deal of interest since it is exceedingly rare. It is extinct as a breeding bird in our area, with the last definite breeding attempt in the region being in 1923. It is a vagrant to Botswana, and there have only been a handful of authenticated sightings in recent times, making it a Category A Rarity (less than 10 accepted records). It is not just in southern Africa that it is rare – it is regarded as a globally Endangered species and there is concern worldwide about its future survival and well-being. This species was last seen in Botswana during 1998, so the sighting of an immature bird at Wilderness Safaris’ Kalahari Plains Camp in the Central Kalahari Game Reserve caused a great deal of excitement in birding circles. The bird was seen and photographed by Brent Harris on 20th February, and the photos are quite conclusive. The bird is a subadult in its second or third year, with quite a bit of cream-coloured plumage which immediately differentiates it from an immature Hooded Vulture, the only other species with a slender bill (but which doesn’t normally occur in the Central Kalahari). Well done to Wilderness Safaris’ for recognizing the importance of this sighting and reporting it to the BirdLife Botswana Records Subcommittee.

Pete Hancock
BirdLife Botswana

Botswana's National Bird List

The recent addition of the Angola Cave-Chat to the Southern African bird list, and the ‘rediscovery’ of the Green Tinkerbird after a hiatus of 55 years, brings home clearly the dynamic nature of bird movements and distribution. Even in well-studied areas, bird checklists are always changing with the addition of new species and, regrettably, the removal of those which no longer occur. This recently-past Christmas and New Year has been an exciting time for birders in Botswana too. Just prior to this period, the BirdLife Botswana Records Subcommittee announced the acceptance of four additional records to the Botswana National Bird List: they are Lesser Yellowlegs, Rosy Starling, Shelley’s Sunbird and Long-tailed Pipit. This brings the current total for Botswana up to 591 species. However, this total is likely to be increased soon once the Christmas/New Year observations have been scrutinized by the Records Subcommittee. Andy Solomon couldn’t believe his eyes when he saw an African Pitta in his back garden in Maun, and had the good sense to call Mark Muller and Richard Randall to corroborate his sighting. The nearest regular locality for this elusive forest species is western Zimbabwe, but it is known as a migrant which sometimes overshoots its range and ends up in unexpected places. Photographic evidence of the bird’s presence was obtained, and this means that confirmation by the Records Subcommittee is something of a formality. On New Year’s day, an Isabelline Wheatear was seen at Lesoma, another exciting record! This presence of this species in Botswana has been somewhat controversial to date, with a claim by Hockey (1988) being subsequently rejected by the Botswana Bird Club Records Subcommittee (as it was then known - see Herremans, 1997). However, like the pitta, this is also a migrant, and so can pitch up in central and southern Africa irregularly. This is in fact a new record not just for Botswana, but for southern Africa, since previous records are in doubt. An Eastern Nicator from Kasane during December 2012 completed the trio. This is normally a tropical, coastal species which in this case, has probably moved up the hot, humid Zambezi Valley where suitable riverine woodland and thickets exist. It has previously been recorded regularly in extreme western Zimbabwe not far from the Botswana border i.e. it is extralimital, but its presence in Botswana is not entirely unexpected. It is important to emphasise that the jury is not yet out on these observations; nevertheless the point remains that birders who spend their Christmas birding are likely to be rewarded by very exciting sightings!

Whose vulture is this?

Satellite tracking of birds is an expensive undertaking, but the results are invariably worth the cost. This has proved to be the case with a joint project being undertaken by BirdLife Botswana in partnership with CKGR Research and the Denver Zoological Foundation. The project aims to determine the movements of Lappet-faced Vultures in Botswana, specifically to ascertain whether the birds are able to meet their year-round requirements in Botswana’s large protected areas, or whether they scavenge in areas where they could be susceptible to poisoning by humans. The project is in its early stages, but to date we have captured five adult Lappet-faced Vultures using a cannon net, and attached satellite transmitters to all five – four in the Central Kalahari and one in the Makgadikgadi. The precise positions of the birds are recorded every two hours during the day, and initially it was clear that most of them were breeding as they remained in a fairly prescribed area around specific points which we presumed were their nests. Since the end of November, their home ranges have been expanding rapidly, and some spectacular movements have been undertaken. One particular bird made a long-distance foray into southern Namibia, and then returned a few days later, as shown on the map below.

It is important to note that the vulture flew southwest along the upper, slightly irregular route, and returned via the bottom route – which is incredibly straight, as though the bird was in a hurry to return and unerringly took the most linear course! The directness of this line-of-flight is uncanny – it would require a GPS or other navigational aid for a human to achieve this degree of precision! Apart from this feature, the 1,500 kilometre venture also raises some other interesting questions: Was this a deliberate sortie to a predetermined point for a specific purpose? What is at the place in Namibia where it turned around? Why did it return to its point of departure? It seems reasonable to believe that the foray was not accidental; wind direction is prevailingly from the east, and would have aided the bird on the outgoing leg of its journey, but hindered it on its return. It is clearly not being blown randomly throughout the region! When I asked Namibian colleagues what was at the turning point where the bird spent a short while before flying home, Chris Brown, Director of the Sustainable Solutions Trust and ornithologist of note, had the following information: “The map below shows the movement pattern, over more than five years, of a young Cape Vulture fitted with a satellite transmitter captured near Otjiwarongo by Maria Diekmann.

You will notice that the bird spent a lot of time in the Kalahari of south-eastern Namibia, in the same general area as your Lappet-faced Vulture. I went down there one weekend and spoke to the Manager of one of our Gondwana Parks/Lodges, Jaco Visser. Jaco grew up on a farm in the area and knows the farmers and their land uses. We had the specific farms on which the birds spent most time. Jaco immediately recognised these farms, not as game farms, but as commercial livestock farms where the farmers were well known to be poor farmers who regularly suffered high livestock mortalities. Most were sheep and goat farmers. I guess that, over time, these farms become areas well know to the vultures as profitable searching grounds and they keep an eye on what is happening there. The info system of vultures seems to operate at a SADC level!” This definitely adds another piece to the puzzle! It is apparently no coincidence that our bird should go down to the south-eastern part of Namibia to see what, if anything, was on offer there! The picture now emerging is as follows: Lappet-faced Vultures know all the good foraging areas in southern Africa, and it is quite simple for one of them to make a 1,500 kilometre round-trip to one of these locations to assess its current potential as a food source. A direct flight of 1,000 kilometres from the Central Kalahari could put a vulture in any one of seven southern African countries! Another Namibian colleague, John Mendelsohn, who was involved in monitoring the travels of several Cape Vultures said that ”Perhaps the most remarkable finding or all is that these birds avoided the Kgalagadi Transfrontier Park, rarely even crossing over its border for a sniff or look-see”. The information above immediately answers our fundamental research question about Lappet-faced Vultures: there is no protected area in southern Africa which is large enough to provide safety for this species from the potential dangers imposed by humans. In fact, the scenario is worse than ever anticipated – a single poisoning incident could annihilate a very large segment of the populations of all southern African vulture species, Lappet-faced included.

Birds and People #36

D002 re-sighted

On 14th November, 2008, Nicky Bousfield, Obusitswe Samuel and Cinistar Tjitemisa tagged a Lappet-faced Vulture fledgling in its nest in the Makgadikgadi – with wing-tags numbered D002. We hoped that this bird would be re-sighted some time in the future (preferably alive!) so that we could learn about its movements and survival.

Fitting wing-tags to the young bird. Nest in background. Almost four years to the day (on 16th November, 2012), D002 was re-sighted in the company of nine other Lappet-faced and 26 White-backed vultures at the waterhole near Camp Kalahari in the Makgadikgadi!

D002 with wing tags clearly visible, together with other vultures Although this is very close to where the bird was originally tagged, it shows that some young Lappet-faced Vultures do not disperse far from their natal area. In addition, judging from its behaviour and proximity to another adult Lappet-faced Vulture,D002 appeared to have a mate! According to vulture expert Dr Peter Mundy, Lappet-faced Vultures usually mature at six years of age; our information shows that this may take place earlier, although it would be nice to trace D002 back to an active nest to confirm this! Of the twelve Lappet-faced Vultures marked to date, two have died – one from poisoning in neighbouring South Africa, and one from unknown causes. Some of the others have not yet been re-sighted, but we encourage people to look out for them and report their whereabouts. I would like to thank Uncharted Africa for their ongoing assistance with this project, particularly Bousfield family and the staff of Jack’s Camp and Camp Kalahari.

Key sites for birds in the Okavango

The Okavango Delta is internationally recognized as an Important Bird Area following BirdLife criteria. Yet within this site, there are some areas which are more important than others – VIBAs (Very Important Bird Areas)! Red Cliffs in the Okavango Panhandle is one such site.

The Southern Carmine Bee-eater is an intra-African migrant which flies all the way from Central Africa to the Okavango panhandle to breed at a few riverbank sites. By early summer, the Okavango River is at a low ebb, exposing steep banks where the bee-eaters excavate their nest tunnels. The breeding site behind the Brigades in Shakawe is well-known, but in recent years has become disturbed, and so the Carmine Bee-eaters moved to a borrow-pit near Mohembo – this turned out to be an even worse site with untenable disturbance from people in the area, and the birds have had a low breeding success here over the past few years. The largest and best site available to the bee-eaters is Red Cliffs, a considerable distance downstream from Shakawe, where hundreds of pairs nest annually. BirdLife Botswana has identified this site as warranting special protection, and has been working with the Tawana Land Board to make recommendations to this end. It is important that no incompatible land use is permitted in close proximity to the site, otherwise it too would no longer provide the birds with a safe haven for breeding.

It is a bit difficult to be specific when defining a core protected area and buffer zone around the breeding site. What size should these areas be, and is there any empirical research on which recommendations could be based? Any readers who know of any research done on disturbance at bee-eater colonies should please get in contact with Pete Hancock at birdlifemaun@gmail.com at their earliest convenience.

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Open publication - Free publishing - More birdlife

BirdLife Botswana's reflections on Rio + 20

Reflections on Rio – reaffirming and renewing rhetoric but has anything really changed? I was fortunate, courtesy of financial support from United Nations Development Programme (UNDP) and the Ministry of Environment, Wildlife and Tourism, to have been part of the Botswana delegation to Rio+20, and thought to share my and BirdLife’s reflection of the event. As the 50,000 participants are settling back in their respective countries after ten days of discussing The Future We Want, the outcome document from the UN Conference on Sustainable Development (Rio+20), it’s time to reflect on the substance of what was agreed. For the first few days in Rio it looked as though there was only a slim chance of agreement, with just 40% of the document achieving consensus. However as the host country (Brazil) took over the reins, the text was further distilled, miraculously agreed upon, and made ready for heads of state to rubber-stamp on their arrival. But many observers had grave concerns. Much of what was agreed in Rio merely reaffirms commitments that governments had already made, some dating back 20 years to the first Rio Earth Summit in 1992. Governments continue to operate in the shadows of the inconclusive and often acrimonious climate change negotiations in Copenhagen in 2009. Worried that talks could break down completely, they appear content to settle for less, and to agree the lowest common denominator rather than compromise and reach consensus. One would have hoped that, given the substantial knowledge on the state of our planet, the unacceptable poverty of billions, the continued steep declines in biodiversity and the changing climate, governments would have approached Rio+20 with a renewed sense of urgency. Bold and decisive actions were needed to steer us along the pathway to sustainable development. This pathway should recognise the value of the three pillars of sustainable development: economic, social and environmental. But the necessary integration of these continues to be held hostage to economic fortune, perhaps more than ever given the financial uncertainty in the West. Finance to support sustainable development at the scale required was simply not on the table in Rio, as signalled through the weak statement on phasing out fossil fuel subsidies from the G20. Moreover, many great and inspiring words were spoken by over 100 Heads of State. New schemes supporting sustainable initiatives were announced and a lot of good ‘thinking’ outlined. But we need more than thinking – we need implementation and action. Positive points in the outcome text include the affirmation of the importance of the Strategic Plan for Biodiversity 2011-2020, agreed in 2010 by the 192 Parties to the Convention on Biological Diversity, which encompass the Aichi Biodiversity Targets that integrate economic, social and environmental concerns. This reaffirmation of these targets as a part of The Future We Want is very welcome. Governments must now work with urgency to realise these targets, which if reached will make a significant contribution to sustainable development. Other positive points in the outcome text include GDP+, which recognises that we need broader measures of progress to complement GDP (Gross Domestic Product) and asks UN statisticians to begin work on this. Steps were also taken towards developing Sustainable Development Goals (SDGs), to replace the Millennium Development Goals which expire in 2015. The contribution of the green economy to sustainable development and poverty eradication was recognised. But for all these initiatives, the outcomes do not give nature the recognition it deserves. Further methods of accounting for natural wealth and social well-being must be incorporated within any new measure of GDP. The SDGs must re-address the balance between development and environment, and clearly recognise the underpinning role of nature and biodiversity; and the green economy must operate in harmony with nature, and respect environmental limits. Governments could and should have been braver, and listened to the voices of civil society, who have contributed considerably to the process. More ambitious decisions were needed on critical issues, such as subsidies in much of the developed world. There was not strong enough redirection of the perverse incentives that act to undermine sustainable development, such as subsidies that stimulate overfishing, destructive agricultural practices and the use of fossil fuels. Such key decisions have been pushed down the line to potential future processes – one can only hope they don’t get lost and further diluted along the way. There is no shying away from the fact that these are the most difficult and complex issues today’s society faces. It was heartening to hear of many great examples of local scale and community-led sustainable development. This is the future, but in order for local actions to lead to global change, we need a fair and just society that lives within environmental limits. Our leaders must stand ready to make bolder and more ambitious commitments, and do everything in their power to work with civil society, businesses and individuals to implement them. Civil society agencies, such as BirdLife Botswana, are willing and ready to engage with government and other partners that want all of us to realise The Future We want. Now, let’s talk less and get on with the action! Dr. Kabelo Senyatso Director, BirdLife Botswana

First catch your vulture!

Preparations are underway to catch five Lappet-faced Vultures in Botswana, to fit them with satellite transmitters to track their movements throughout the country. There are many ways to catch a vulture, but apparently they are all difficult! But catching the bird is the first unavoidable step in this project being undertaken by BirdLife Botswana in conjunction with the Denver Zoo and CKGR Research team. Traditionally, vultures in Africa have been caught successfully using a cannon-net – a cannon which fires a large net over a group of vultures. However, the conventional cannon-net is not a viable option any longer due to restrictions on the possession and movement of the explosives used to power the device. However, colleagues at the Denver Zoo have managed to find a similar device, called a Net-Blaster, which works on compressed air to fire the net. This item is shown below.

The vultures will need to be attracted to a bait within range of the Net Blaster, which can then be triggered remotely to fire the net over the birds. It all sounds very simple! We don’t want to rely on a single method, so we have a back-up option too. Colleagues in the region have done a review of vulture capture methods, excluding those utilising explosives. Top of the list is a walk-in cage trap which has been used successfully in South Africa and Namibia. We are in the process of constructing a portable version which we intend to deploy during June. The photo below shows what it will look like when complete:

In theory, the vultures enter the cage to feed on the bait; the curtain is then closed from a remote, concealed site, and the birds are trapped inside. While not wanting to tempt fate, there is a high possibility that one or both of these methods will be successful! Both however need two additional ingredients – patience and perseverance! The next post on this site will report on our experience with actually catching our target species, and fitting the satellite transmitters. Pete Hancock

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Open publication - Free publishing - More birdlife

Lake Xau comes up to expectations

Thousands of Ruffs have now discovered Lake Xau.

Lake Xau has been a dry dustbowl for the past three decades. However the exceptional 2011 floods from the Okavango coursed down the Boteti River for over 250 kilometres beyond Maun to reach Lake Xau late last year. Birds have been rather slower than expected in finding this huge, shallow waterbody, but waterbird counts conducted by BirdLife Botswana member, Chris Brewster, over the Christmas period, show that it is well on its way to achieving recognition as an Important Bird Area (IBA).

One of the criteria for an area to achieve IBA status is that it should harbour significant numbers of globally threatened birds. In this regard, the key dryland bird species such as Bateleur and Martial Eagle, and Lappet-faced and White-backed Vultures (long resident in the area) are now being joined by globally threatened waterbirds such as Wattled Crane and Black-winged Pratincole. Congregatory waterbirds have not yet built up to numbers which exceed the critical threshold (0,5% of the global or regional population) but numbers of Ruffs and Great White Pelicans are already notable.

At present, it is the number of Black-winged Pratincoles at the lake (2,000) which is of special interest. In a recent article in Africa Birds and Birding magazine, Phil Hockey (Director of the Percy Fitzpatrick Institute of African Ornithology) suggested that this species might be in serious trouble. Very few pratincoles relative to 20 years ago are now being seen (cf the sighting of 10,000 by Penry and Tarboton at Lake Ngami during the 1980s). Phil Hockey suggested that the pratincoles may have shifted their non-breeding range northwards into northern Botswana but this is unlikely to be the case given the few sightings we have. Chris Brewster's count of 2,000 at Lake Xau is the best news we have had for this species in recent years, and highlights the importance of this 'new' wetland.

Apart from the pratincoles, there is much of interest to be seen at Lake Xau - it is certainly a spot worth watching!

Birds and People #31

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Alive and well - Ross's Turaco in Botswana

In a previous blog (26/7/11), a challenge was issued to birders to look out for Ross's Turaco, which has only been recorded once in Botswana - in 1974. Well, some serious guides working for Okavango Wilderness Safaris have risen to the challenge, and followed up the sighting made by Victor Horatius in the Linyanti Concession recently.

Russel Crossey saw a single Ross's Turaco in the same vicinity shortly after Victor (possibly the same bird), and this prompted Dave Luck to keep a sharp look out for it when he was there during August. Whether it was Dave's skill or just luck that he saw one at Boscia Lagoon not far from the previous sightings is immaterial: this is now the third reputable guide reporting the species from the same place, and a proper submission has been made to the BirdLife Botswana Records Sub-committee.

Although the official verdict is not yet out, word has spread among the birding fraternity and the information has caused quite a stir. Rumours started that this is the first record for the Southern African Sub-region, that of Tim Liversedge in 1974 having been "thrown out" because it was subsequently proved to be a joke and not a genuine record. I contacted Tim Liversedge for his comment - he just laughed and said that it was after much deliberation that he 'collected' the bird he saw, and sent it to MPS Irwin at the Bulawayo Museum, because he knew that no-one would believe him - there can be no more concrete evidence than the specimen in a museum! However, he was thrilled that the bird had been seen again, not least because now no-one could accuse him of having shot the first and last one!

At the time of the first record, it was predicted that there would be other sightings and that this was not just an isolated bird. Tim believes that Ross's Turaco, being a forest bird, is likely to move down the riparian woodland of the Kwando River during wet times. However the long intervening period between sightings shows that it is unlikely that the species is resident or even a frequent visitor to Botswana. The current high flood levels in the Kwando-Linyanti system are quite comparable with those of the 1970s, so the wetter conditions may result in other individuals coming into the region. It should be looked out for in northern Botswana, the Caprivi Strip and western Zimbabwe.

So, well done to Vic Horatius, Russel Crossey and Dave Luck for re-confirming the presence of this species in the region. Many keen birders, like myself and Dave Luck, have seen Ross's Turaco in Uganda, and it is an awesome bird. It is however very difficult to photograph, so we are still encouraging photographers to keep an eye out for these magnificent birds, and to send their images to BirdLife Botswana.

Vultures curb spread of disease

With the recent news headlines in northern Botswana focused on a possible anthrax outbreak, I become nervous lest some misguided person try to implicate vultures in spreading the bacteria. This has happened in the past, so it is worth reading the views of anthrax expert, Peter Turnbull, below:

Nature's clean-up squad in action (Photo: J Bestelink)

"At the time of death in an animal dying of anthrax, the blood and body fluids are loaded with anthrax bacteria: there are more bacteria than red blood corpuscles in the blood. On exposure to the oxygen of the air, these start to form spores - the hardy forms of the anthrax agent which can survive for decades in the soil where blood and body fluids from such an animal have spilled. Vultures, in demolishing the dead animal before much of this sporulation can occur, contribute to reducing the environmental contamination left by the carcase. In theory, the faster the carcase is consumed, the less the chance of sporulation and residual contamination. And, at least to a point, more vultures = faster consumption. Faster consumption aldo reduces the chance of spread of the disease by flies.

The vultures do, of course, get the infected blood and gore on their beaks and feathers and they will go to nearby water to wash this off. However, unsporulated bacteria are fragile and die off quickly in water (they are also quickly killed within the vulture's digestive system). So, although the water may derive some anthrax spore contamination from bacteria that have started to sporulate, this will be low - bacteriological testing has proved how difficult it is to detect anthrax spores in such bodies of water. By the time the birds are airborne again, numbers of spores on their feet, beaks, feathers and in their guts is back to zero or very low.

Vultures are very clean, and bathe regularly (Photo: P Hancock)

Contrary to what you might expect, knowing the infamy of anthrax, it is not a highly infectious disease. That is to say, an animal generally needs to ingest or inhale a large dose of spores to become infected. So, small numbers of residual anthrax organisms on the feet, beaks, feathers or in the guts of vultures constitute essentially zero risk or threat to animals elsewhere. There is again scientific evidence for this.

The decline in the numbers of vultures around is probably already apparent to you where you live and you are probably well aware of the particularly catastrophic decline over the past two decades on the Indian sub-continent largely from inadvertent diclofenac poisoning, but also from other human-made causes also at play in Africa - habitat destruction, deliberate poisoning, capture for traditional medicines, drowning in reservoirs, powerline collisions and electrocution and so on. The apparent consequences of this population crash are not nice. Substantial increases in numbers of rats and of feral dogs have been attributed to the decline in vultures and with that, vastly increased numbers of cases of at least rabies and distemper. In addition to the health issues, there have been consequent costs to the economy estimated at billions of dollars. One British Medical Journal article has even suggested a link (albeit unproven) between absence of vultures and a rise in human anthrax cases.

In Africa, loss of our vulture populations can be expected to lead to similar disturbances in other scavenger popul;ations, again with possible concomitant increases in rabies, distemper and plague. Botulism from decaying carcasses is another strong possibility.

It also needs to be remembered that vultures rely on other vultures to detect carcasses; when vulture populations decline, their ability to find carcasses deteriorates at an accelerating rate.

So, as well as helping to reduce residual contamination at the site of an anthrax carcass and minimizing fly-borne transmission, thereby playing an important role in curtailing the spread of anthrax, the importance of vultures to the overall health of the ecosystem should not be underestimated.

Also not to be forgotten is that circling vultures have always been, and continue to be, the best signal to game managers and farmers that deaths have occurred within their boundaries, enabling prompt action as needed.

In summary, persecuting vultures as an approach to anthrax control is folly, and in the long run, can be expected to increase problems associated with both anthrax and other diseases."

Peter Turnbull, with thanks to Orr Spiegel, Hebrew University of Jerusalem, Steve Bellan, University of California, Berkeley, and Kerri Wolter, VulPro South Africa, for most helpful comments.

With water comes life . . .

It is a well-known fact that the 2011 Okavango flood is one of the highest on record - water has surged past Maun (especially when the bridge over the Xotego River broke!), down the Nhabe towards Lake Ngami, and down the Boteti for over 250 kilometres to Lake Xau. While this has had its downside (such as the escape of numerous crocodiles from flooded enclosures at the Sitatunga Crocodile farm!), the news for birds has been overwhelmingly good. BirdLife Botswana has long realised that Lake Xau is likely to become a birding hotspot as it fills, although this did not really materialise last year when the water barely reached the lake-bed. We have been monitoring the situation closely, and BirdLife members Pat Nurse and Ray and Val Lovett recently conducted a partial count of the now extensive lake.Marabou Storks are among the first birds to find new areas such as Lake Xau

Highlights of their count are as follows:
Little Grebe 6
Grey Heron 12
Goliath Heron 1
Great Egret 2
Yellow-billed Egret 9
Little Egret 20
Cattle Egret 20
Squacco Heron 3
Marabou Stork 15
Glossy Ibis 163
White-faced Duck 1
Red-billed Teal 65
Southern Pochard 19
Spur-winged Goose 2
Wood Sandpiper 2
Black Crake 1
Common Moorhen 2
African Jacana 1
Kittlitz's Plover 3
Crowned Lapwing 30
Blacksmith Lapwing 76
Wattled Lapwing 1
Common Greenshank 6
Black-winged Stilt 11
Collared Pratincole 18

The lake is still filling, and it is early days yet. The lake-bed is very uneven with ridges and channels so the water is spreading out into a system of fingers of water. Migrant waders are only just now returning, so it is going to be very interesting to keep an eye on this exciting new birding destination.