Monday, November 29, 2010

Waterbirds arrive at Lake Xau

The arrival of waterbirds at Lake Xau since it started filling has been less than spectacular! However, there is no doubt that the lake is Botswana 13th Important Bird Area (IBA) in the making.

The extent of flooding of the lake in 2010 (Photo: P Hancock)

By mid-November, the Boteti floodwaters, over 250 kilometres south of Maun and still moving, trickled out onto the long dry bed of Lake Xau. They extended about eight kilometres into the huge sump – the river’s natural terminus – and then spread out laterally and formed a shallow, open mudflat before stopping flowing. This waterbody has been colonized by a few dozen Red-billed Teal and Southern Pochard, and lesser numbers of Little and Cattle egrets and Grey Herons.

A Grey Heron drops in for a bit of fishing (Photo: P Hancock)

Wader numbers and diversity are still low, with a few Ruffs, Common Greenshanks, Wood Sandpipers and a single Black-winged Stilt being present. Other species seen at this time include Blacksmith Lapwing, Glossy Ibis and two Yellow-billed Storks.

The shallow mudflats are suitable for waders, including the Common Greenshank (Photo: P Hancock)

There have been quite good rains in the general area of Lake Xau, so that there is standing water on small pans and mudflats between Rakops and Mopipi, and this may have diluted the number of birds. However, the area is still worth a visit as it is likely to attract large numbers of waders still. The habitat is ideal for the incoming Palaearctic migrants and species such as Black-winged (and Collared) Pratincole and Caspian Plovers could reach good numbers. Birders visiting the area are requested to keep good records, and to send this information to Pete Hancock at birdlifemaun@gmail.com.

Thursday, October 28, 2010

Water reaches Lake Xau

Earlier this year, it was predicted that the Okavango floodwaters would reach Lake Xau at the end of the Boteti River. By September, the water had already flowed under the bridge near Mopipi, and it finally reached Lake Xau on 16th October. Pete Hancock was there to witness this momentous occasion.

The Boteti River near Mopipi during September 2009 (top) and 2010 (bottom) (Photos: P Hancock)

In an area where ambient temperatures soar above 40 degrees, and the grass is so desiccated and dry that it seems ready to spontaneously burst into flames, the arrival of fresh, flowing water is nothing short of miraculous. Shimmering mirages turn to real water as I advance into the long dry lake-bed of Lake Xau, to witness the return of the Okavango floodwaters to this distal terminus for the first time in 40 years.

A huge twister lifts the fine dust from the dry part of the lake-bed (Photo: P Hancock)

A towering dust-devil sweeping across the dry plain suddenly collapses as it reaches the water’s edge. As the flood waters slowly advance, they fill small holes and burrows and flush insects and rodents and other small creatures, but as yet there are no waterbirds present to capitalize on this bounty. Only a few wily Pied Crows wade in the shallows enjoying this unexpected bounty.

A Pied Crow catches a spider flushed by the water (Photo: P Hancock)

This is quite different from the first recent flooding of Lake Ngami in 2004, where Marabou Storks, Blacksmith Lapwings and other waterbirds followed the advancing floodwaters to the lake, making an ‘instant’ birding spectacle.

However, it is expected that there will be some similarities between the rebirth of the two lakes. Currently, Lake Xau is heavily overgrazed, so there are extensive, open, shallowly inundated mudflats which will soon attract the incoming summer migrant waders. Lake Xau, like Lake Ngami, is a nutrient sink, and all the accumulated cattle dung, once dissolved, will fuel food chains for aquatic invertebrates, fish, amphibians and ultimately birds. BirdLife Botswana is committed to monitoring these changes in the hope that Lake Xau will substantially boost local and migrant bird populations.

Friday, October 15, 2010

If at first you don't succeed ...

… try, try again!

With the water of Sua Pan evaporating fast, Dr Graham McCulloch’s chances of capturing several Lesser Flamingos to fit them with satellite tracking devices were fading too (see previous post dated 21/06/2010). However, the Independence Day long-weekend provided near ideal conditions for a last chance at flamingo capture – the remaining water was restricted to small pools in the Nata River, and four adult flamingos were present together with a number of immatures and juveniles. The challenge was to catch these adult birds before they left the area, so that data would become immediately available on their regional movements, but the window of opportunity to catch them was small ….

One of the few pools of water remaining in northern Sua Pan (Photo: P Hancock)

Long trap-lines were set in the remaining pools with the help of Nicky Bousfield, a qualified bird ringer with years of experience handling and caring for birds of all shapes and sizes. Success was immediate with one adult and several young birds being caught on the first day; the adult was fitted with a PTT backpack and ringed and then released. It remained in the area with the other flamingos, thereby enabling us to see how it reacted to its new hardware; the device fitted comfortably and apart from scrutinizing it closely and preening the feathers around it, the bird seemed quite unconcerned by its presence.

#50 with backpack slightly visible and its antenna protruding backwards (Photo: P Hancock)

The young birds were not targeted for the exercise as they are too small to comfortably carry the satellite transmitter; their capture was purely incidental, but nevertheless they were ringed before being released in the hope that they may still provide information on longevity and sources of mortality.

A juvenile Lesser Flamingo sports identifying rings (Photo: P Hancock)

After the initial success, the remainder of the flamingo group – particularly the adults – was wary, so the team (supplemented by a few local community members) tried a different capture technique. A long mist net, borrowed previously from researcher Tim Osborne in Namibia, was submerged in one of the pools with the aim of triggering it manually as the flamingos walked over it.

The net being quietly set at one of the remaining pools (Photo: P Hancock)

This however was not successful, and with time running out, we reverted to our original method of using the long traplines. Several more immatures and juveniles were caught, but unfortunately no adults.

The way the project stands at present, there are three adult Lesser Flamingos in total with satellite transmitters, and another three spare transmitters that will have to be fitted to flamingos next season. Some information is already coming in from the project, so watch this space for regular updates.

Monday, September 20, 2010

Annual BirdLife Botswana dinner

The annual BirdLife Botswana dinner will be on Saturday 25th September at 19:00 for 19:30 at the Gaborone Golf Club.

The guest speaker will be Mark Anderson, Director of BirdLife South Africa, speaking on the Lesser Flamingo project at Kamfers Dam near Kimberly, where he and colleagues managed to create an artificial island that was successfully adopted by the flamingos as the fourth breeding site for the species in Africa! This is a truly wonderful conservation achievement, but one which cost him his previous job!

Dress will be smart casual with a cost of P150 per ticket and all members are invited to attend. It should be an excellent affair and is one of the main events on our calendar. Members should buy their tickets early to avoid disappointment. They are on sale at the BLB Office in Kgale Siding and at the shop in the Craft Market, Broadhurst. There will be eight people to a table so you may reserve your table when purchasing your tickets. We have 80 tickets to sell on a first-come-first-served basis.

Monday, June 21, 2010

First catch your flamingo!

Dr Graham McCulloch has been monitoring the globally threatened Lesser Flamingo in the Makgadikgadi Pans for over a decade and, as is always the case with research, the more you find out about your subject, the more interesting it becomes and the more you realize how little you know!

One fact that is apparent from the monitoring data is that Lesser Flamingo numbers have been steadily increasing. A count of 77,491 Lesser Flamingos at Sua in 2009 exceeded the total estimate for Southern Africa (~65,000). This raises the interesting question: Has the Southern African flamingo population increased by improved breeding success due to better conditions, or has the local population been augmented by an influx of birds from further afield? Because flamingos are highly nomadic, and can travel vast distances, it has long been speculated that birds from East Africa sometimes visit Southern Africa, and vice versa. This could mean that there is one large population with birds moving to and from the best feeding and breeding conditions on the continent; if this were the case, it would have important implications for the conservation of the species.

To find out whether there is any connection between the Southern African and East African flamingo populations, two different but equally innovative approaches could be adopted. Firstly, now that DNA analysis is possible and commonplace, an investigation into the genetics of birds from both areas could tell if there is one large, intermixed population, or two distinctly separate groups. Recent studies comparing the DNA of populations from both regions, using blood samples from the Makgadikgadi, collected by Graham during some ringing excercises some years ago, and samples taken from the soda lakes in East Africa suggest similar DNA and favour a connection between the two populations, or the existence of one interconnected population. Secondly, and also resulting from technological advances, it could be possible to fit individual flamingos with tiny transmitters that send a signal to orbiting satellites which pinpoint their position and relay the information back to Earth! Incredible though this may seem, small transmitters weighing a mere 35 grams are now available with minute but efficient solar panels, that can be fitted to relatively small birds such as the Lesser Flamingo, and this is the approach adopted by Graham in his research.

During 2001, satellite transmitters were deployed on eight Lesser Flamingos from Sua Pan; these were battery-powered (without solar panels) and during the two years that they continued to function, Graham was able to determine that birds from Sua move all over Southern Africa, to the west coast of Namibia, Kamfers Dam in South Africa and even into southern Mocambique. Frustratingly however, none of these birds moved to East Africa! This does not mean that the Lesser Flamingos from Sua Pan don’t go to East Africa – only that these few individuals did not go there during the period of the study!

Base camp for flamingo capture (Photo: P Hancock)

Recently, Graham has been collaborating with the Max Planck Institute in Germany, and they have provided six of the latest solar-charged transmitters for fitting on Lesser Flamingos. This is easier said than done – just how does one catch a free-flying flamingo in the vastness of the Makgadikgadi Pans? In 2001, Graham caught the birds by setting hundreds of small noose-traps in the flamingos favoured feeding areas in the shallows of Sua Pan – once a bird’s foot becomes entangled in the noose, it can be captured without injury or undue stress. But there is more to this technique than betrayed by a simple sentence, as can be imagined! Firstly, it is important to identify the preferred feeding areas on a daily basis, and then set the snares at first light – thereafter, it is a question of waiting patiently at a distance until the birds eventually return and one gets caught!

The first flamingo capture exercise this year took place during early May, just as a practice run, since it was apparent that suitable conditions for initiating this part of the project were returning. It is important to fit the transmitters just before Sua Pan dries up, so that the birds can be relatively easily caught, and will soon start moving away from the Pan – it is pointless paying for the expensive downloads of data from the satellite if the birds are not travelling more than a few hundred metres from one feeding area to another! Two adults were caught in the same number of days – and then late rains put paid to any further capture attempts as Sua Pan filled with water!

A flamingo in the hand is worth measuring in as many ways as possible (Photo: P Hancock)

By mid-June, the shallow, saline waters of Sua had evaporated sufficiently to permit a second capture attempt to be made. Alas, after a few days of setting the trap-lines early in the morning and retrieving them in the evening, no flamingos had been caught - round 1 to the researchers, round 2 to the flamingos!

This is where the project stands at present – we are all looking forward to round 3 so that the real work can begin – that of unraveling the movements of these flambouyantly successful nomads. This blog will provide regular updates, particularly once data become available showing where the birds are, so that the information on their movements can be used to better conserve the species.

Weary team members return at sunset - empty-handed (Photo: P Hancock)

Friday, June 11, 2010

Birds of Lake Xau - 1964

Reading Smithers (1964) Checklist of birds of the Bechuanaland Protectorate and Caprivi Strip gives one an insight into conditions in the country during the middle of the last century. Particularly fascinating is his account of birds at Lake Dow (Xau) – the frontispiece of the book depicts a Gull-billed Tern foraging over Lake Xau, a Category A rarity (seen less than 10 times in recent years). Here are some of the waterbirds seen at the lake during the late fifties and early sixties, and which may be seen there again when the lake floods in future:

Pink-backed Pelican – January 1959 many were seen in immature plumage
African Darter
Black-crowned Night-Heron
Squacco Heron
Black Heron
Great Egret
Yellow-billed Egret
Little Egret
Grey Heron
Goliath Heron – individuals in immature plumage seen in January
Saddle-billed Stork
Marabou Stork – seen in flocks of 50 at a time
African Sacred Ibis
Glossy Ibis
African Spoonbill
Lesser Flamingo – no nests of this species found at the Lake
Fulvous Duck – occurs in large numbers, January 1959, flocks of 200 at a time
Egyptian Goose
Spur-winged Goose
Comb Duck
Cape Teal – a few seen on Inkokwane Pan near Lake Dow
Red-billed Teal – in huge flocks
Hottentot Teal – common, occurring in flocks of upwards of 50
Southern Pochard
African Fish-Eagle
Purple Swamphen
Red-knobbed Coot
Wattled Crane
Grey Crowned Crane
African Jacana
Water Thick-knee
Kittlitz’s Plover
White-fronted Plover
Chestnut-banded Plover – an immature, hardly able to fly, taken on 18 January
Caspian Plover
Greater Painted-snipe
Black-winged Pratincole
Grey-headed Gull
African Skimmer
Gull-billed Tern – recorded in January 1959
Whiskered Tern – in breeding plumage December 1962 and January 1963
Kurrichane Buttonquail – breeding 15 January 1959, c/4 fresh
Yellow Wagtail – particularly common at cattle kraals
Sedge Warbler
Lesser Swamp-Warbler
Southern Red Bishop – in breeding plumage
Yellow-crowned Bishop – in full breeding plumage in January
African Quailfinch

This variety of birds needs a diversity of habitats, including open water, reeds and sedges, aquatic waterweeds, and short grasslands near water, all of which would have been found around the lake fifty years ago. Difficult to imagine, isn’t it?

Wednesday, April 14, 2010

Mohamed bin Zayed funds raptor research

Photo: P Hancock
BirdLife Botswana is grateful to the MBZ Species Conservation Fund for financing a study to determine raptor trends throughout Botswana. The project involves counting raptors along fixed road transects – a standard method used throughout Africa – and already hundreds of birds have been counted along tens of thousands of kilometres. With a scientific study of this nature, one should not have any preconceived ideas in advance; however, many of our raptors are under serious threat from poisoning, habitat destruction and other factors, so the information – when compared with similar surveys from the 1990s and before – will help us to identify priority species for conservation action. Check this blog for regular project updates.

Friday, February 26, 2010

Flamingos of the Makgadikgadi

PERFORMING AT THE NO.1 LADIES OPERA HOUSE (10-13 MARCH)

This production is a collaboration between internationally-acclaimed Theatre for Africa and a local Botswana company Showtime. It brings you one of Botswana’s greatest wildlife spectacles: the breath-taking flocks of flamingos in the Makgadikgadi. It is told through thrilling physical theatre and inventive design. This production will transport you back into the heart of the African bushveld. The show features Batswana actors who will enrich the story with Botswana’s cultural heritage through song, dance and storytelling. A journey through the Makgadikgadi unfolding without spoken language will move your spirit, tantalise your imagination and make you want to get straight into your car and head into the bushveld! It promises to be a highlight in this year’s cultural calendar and is a must-see for all!

Enquiries can be made to Catja Orford, Manager - No 1 Ladies' Opera House, cell +267 726 86 557. BirdLife Botswana has seen a short excerpt of the flamingo and eagle sequences which are excellent.

2010 membership fees due

To those of you who have not paid your subscriptions and renewed your membership for 2010, we kindly ask you to do so. We depend on having a large membership base as well as using your subscriptions to do work which we think is of value. You are very important to us.

BirdLife Botswana welcomes Japanese volunteer

A new recruit from Japan, Ms Yukiko Murakami will be starting with the BirdLife Botswana office in Gaborone towards the end of April. Her field is Environmental Education, which is where we plan to use her skills. However we will also use her wider mature experience in other fields as well, which will lead to her further career development. This posting has been kindly sponsored by JICA, the Japan International Cooperation Agency, for two years.

Volunteer website manager required

BirdLife Botswana is looking to engage a volunteer IT person to make our website even more attractive than it is at present. We would like to update our website at least twice a week, preferably more often, and to attract advertisers to our site. It is essential that this person should be fluent in written and spoken English, have a knowledge and interest in birds and have website management experience. The successful applicant may well have experience in marketing and in liaising with the press. This person would report to our Board member responsible for our website.

Fund-raiser required

BirdLife Botswana is looking at increasing and improving our fund-raising effort and have some ambitious plans. However we need a volunteer go-getter in Gaborone to be appointed as fund-raiser for the next year. This person will have marketing experience, be dynamic, like working with an ambitious and hard-working team and will be result-oriented. The successful candidate could be male or female and is probably living in Gaborone as the spouse of an expatriate. Nationality is not important; the person could be a Motswana or Mongolian, but should be fluent in English, have a sense of humour and be literate and numerate. There is no salary attached, the successful applicant will be motivated by achieving agreed financial targets. The successful candidate does not have to be a bird lover, but we think at the end of the assignment, he or she probably will be avi-friendly. Subject to satisfactory performance, it is possible that we may appoint the successful candidate to a permanent paid position after a year.

BirdLife Botswana AGM 2010

Please make a note of 15th May as that will be the date for our AGM, which will be held at Harold and Geraldine Hester's residence, Mogorosi, Plot 30a Notwane. The meeting will start at 18:00 and will be followed by a light supper. Closer to that date we will circulate the agenda and other details.

Monday, January 25, 2010

Water reaches Savuti Marsh

Water in the Savuti Channel reaches Savuti Elephant Camp (Photo courteousy Orient Express Safaris)

The high flood levels in northern Botswana during mid- and late-2009 caused great excitement and speculation, with the Boteti River in particular being the focus of attention for many people. However, the highest water levels in decades in the Kwando led to the hope and belief that the Savuti Channel would at last flow again. Indeed, the water soon reached Wilderness Safaris ‘Savuti Camp’ in the Linyanti concession, but as it approached the western boundary of the Chobe National Park it slowed down and lost momentum (most of the water having bypassed the mouth of the Savuti at Zibadianja, and flowed down the Linyanti and into the Chobe River). Eventually the water stopped several kilometres from the Savuti Marsh.

Much to the surprise of many people, the channel started flowing again in earnest in December, possibly due to heavy unseasonal rains that fell in mid-2009, as well as good local summer rains. By mid-January, the water had flowed past the safari lodges at Savuti and was close to the top end of the marsh.

The 2010 floods promise to be above average, with water levels in the Zambezi and Chobe systems having already risen considerably. With plenty of water remaining from 2009, there is a high probability of the Savuti Marsh being seriously inundated later this year. It is entirely possible that Savuti will once again become one of Africa’s most spectacular wildlife areas. Watch this space!