Tswaing Meteorite Crater

Tswaing Meteorite Crater as seen from the crater's rim.

On a recent visit to the Tswaing Meteorite Crater (also known as Saltpan) my wife and I were pleasantly surprised at all it has to offer nature lovers. Located approximately 40 km north-northwest of Pretoria (4), the impact crater is anomalously well preserved and home to a wide range of prolific fauna and flora. Due to its value to science and tourism the crater and its immediate surrounds form a protected area open to the public at a small entrance fee.

Impact, Geology and Archaeology:

Roughly 220 000 years ago a moderately sized meteorite hit Southern Africa forming the Tswaing Meteorite Crater. Like many meteorites the ‘Tswaing Meteorite’ was vaporised on impact. It is believed to have been 30-50 m in diameter as it sped to the Earth’s surface at 72000-108000 km/hour (2). The energy released by the impact was roughly equal to that of 1000 nuclear bomb explosions (2). Most, if not all, non-primitive life forms within a radius of about 20 km of the impact site was obliterated (2).

The Meteorite impacted the Nebo granite of the Bushveld Igneous Complex, overturning and tilting various portions of granite. Apart from the crater and structural geology of Tswaing, rapidly deformed quartz and feldspar crystals, as well as melt-breccias formed from the granite bear witness to the colossal impact event (4).

The rim of the crater has an altitude roughly 60 m higher than the surrounding country, while the crater floor lies roughly 120 m below the highest portion of the rim (1). The crater’s basin (i.e. floor) lies below the regional watertable (3). This resulted in the formation of a semi-permanent lake inside the crater, as ground- and rain water tend to flow into the crater basin (3). Due to a higher average rate of evaporation from the lake than the average rate of rain water addition to it, the lake has been saline for many millennia.

The saline character of the lake is responsible for much of the crater’s archaeological significance. Stone Age artefacts have shown that people hunted, gathered and collected salts at Tswaing from roughly 150 000 to 30 000 years before present. In historical times, between 1912 an1956, salt and soda was mined commercially at Tswaing by SA Alkali Ltd..

Biodiversity:

Black-winged Stilt is one of the bird species one is likely to encounter at the crater lake.

In terms of nature, Tswaing arguably has most to offer birders, though various mammals and numerous trees and plants occur in it. Roughly 260 bird species have been documented within the conservancy (2). This large array of birds can be attributed to the mixture of bio zones within Tswaing. They are Acacia woodland, mixed woodland (crater rim), river and wetland (wetland occurs in the north-eastern sector of the conservancy), areas where grasses dominate and the crater lake with its shores (2). The Acacia and mixed woodland attract species such as Crimson-breasted Shrike, Red-chested Cuckoo (in summer), Burchell’s Coucal, Southern Red-billed Hornbill, Cardinal Woodpecker, Fork-tailed Drongo, Brown-hooded Kingfisher, Pearl-spotted Owlet (2) and Acacia Pied Barbet (2). At the saline crater lake one can expect to see species such as Black-winged Stilt, Cape Teal, Little Grebe, Black-smith Lapwing, Pied Avocet (2) and Three-banded Plover. The wetland in the northeast of the conservancy hosts various Warblers (Willow, Icterine, Garden, Marsh, Great Reed and River), African Rail and African Purple Swamphen, to name a few (2). After high rainfall Harlequin Quail and Dwarf Bittern may visit the wetland (2). A final birding highlight I wish to mention is the African Hawk-Eagle pair that breed within the crater every year (2). The public is strongly urged not to approach the eagle’s nest, as this might interfere with the raptors’ breeding success.

Various small mammals such as rodents, mongoose, hares, genets and Vervet Monkey (2) occur at Tswaing. Larger mammals include Chacma Baboon and introduced antelope such as Impala.

Finally, for those with a passion for botany – many trees in the Tswaing have been tagged with numbers. Lists with the corresponding tree species names can be obtained at the Tswaing Museum (2).

Personal experience:

Upon entering Tswaing the first two birds we saw were Brown-hooded kingfishers...

I’ve only visited the Tswaing Crater once, but the experience has definitely motivated me to want to go again. Upon entering Tswaing the first two birds we saw were Brown-hooded kingfishers, the third species, I believe, was a White-winged Widowbird – both of which you would rarely see in Pretoria. The most prominent birdcall, evident throughout our visit, was that of the Red-chested Cuckoo, which we spotted in flight a handful of times. Other prominent vocals were those of Burchell’s Coucals and Arrow-marked Babblers.

The environment within Tswaing, especially near the crater, seemed healthy and thriving. Walking in-and-around the crater evoked a feeling of being in a remote part of Africa. This feeling was probably due to elevated humidity, pristine woodland, and the strange geomorphology of the crater.

One thing I want to do differently if I visit Tswaing again in summer – is to take lots of mosquito repellent. As soon as we started descending into the crater, we started loosing blood!

Access, facilities and costs:

The Tswaing Crater is open to the public from 07:30-16:00 everyday (2). Entrance costs R15 per adult and R20 per car (optional) and is payable at the Tswaing Museum. One may leave one’s car at the museum and enter Tswaing on foot. The entrance to Tswaing is located roughly 200 m north of the museum along the M35. Obtaining a permit for one’s car gives one access to a limited portion of the conservancies’ road network - enabling one to drive up to near the crater’s rim. A clearly marked hiking trail exists, for which a map is given on the information brochure obtained at the museum. The full length of the trail is 7.2 km (2). Day visitors can make use of the picnic area which includes braai facilities and toilets (2). Finally, camping and chalets are available at Kgotla Camp (2). For more information phone 012 790 2302.

Conclusions:

The Tswaing Crater is a must-see for Gauteng nature lovers, especially to those that enjoy birdwatching. Being only about 40 km from Pretoria – visitors from our Capital City could easily do just a morning- or afternoon visit. Visitors from further a field would probably do best to make a day-visit of Tswaing, or to sleep over at Kgotla Camp.

Denni Raubenheimer

info@wildlifestockimage.com

References:

1) Brandt, D. and Reimold, W.U. (1995). The geology of the Pretoria Saltpan impact structure and the surrounding area. South African Journal of Geology, 98 (3), 287-304.

2) Marias, E. and Peacock, F. (2008). The Chamberlain Guide to Birding Gauteng. Mirafra Publishing, Cape Town. – 384pp.

3) McCaffrey, L.P. and Harris, C. (1996). Hydrological impact of the Pretoria Salt Pan crater, South Africa. Journal of African Earth Sciences, 23 (2), 205-212.

4) Partridge, T. C., Demenocal, P. B., Lorentz, S. A., Paiker, M. J. and Vogel, J. C. (1997). Orbital forcing of climate over South Africa: a 200,000-year rainfall record from the Pretoria Saltpan. Quarternary Science Reviews, 16, 1125-1133.

Gauteng Nature: Austen Roberts and Pretoria Botanical Gardens

Nature oases within large cities’ limits might be prone to unnatural elements, but, as is the case with the Austen Roberts Bird Sanctuary and the Pretoria National Botanical Gardens, may offer a wealth of natural beauty. And though the fauna in such havens might be aware of human activity around them, they often continue with their required daily activities as if we were not there.

1) Austen Roberts Bird Sanctuary

This White-faced Duck was photographed through one of the viewing holes in the wall built along the path leading to the Sasol Hadeda Hide.

The Austen Roberts Bird Sanctuary is located on the site of an old clay quarry in the suburb of Nieuw Muckleneuk and was established in 1958. Though it apparently took a while for a wide variety of birds to start roosting and/or abiding in the sanctuary, it soon became a refuge and prime foraging site to a large number of bird species.

Biodiversity:
More than 160 species have been recorded in the sanctuary and in addition to birds some antelope (Common Duiker and Blesbok) and Leopard Tortoises call the sanctuary home. Slender Mongoose, though not confined to the sanctuary, is also often seen. Some of the birds one is likely to encounter are Blue Crane, Sacred Ibis, White-faced Duck, Knob-billed Duck, Yellow-billed Duck, Egyptian Goose, Little Grebe, Reed Cormorant, African Darter, Black Crake, Warblers (Lesser Swamp, Little Rush and Willow), Southern Masked Weaver, Thick-billed Weaver and Village Weaver. Kingfishers are common (Pied, Giant and Brown-hooded) and various elusive species, such as the Black-crowned Night Heron and Little Bittern, might also be seen.

This female Giant Kingfisher took a breather on a tree adjacent to the Sanctuary’s main dam and next to the walkway leading to the Sasol Hadeda Hide.

Access and facilities:
The general public may not venture into the sanctuary itself, but can view it either from the walkways that follow the sanctuary’s fence, from the Blue Crane Restaurant, which borders and overlooks much of the sanctuary and from the Sasol Hadeda Hide. The walk around the fence may sound dull, but a number of small dams are located close to the fence and one is sure to see a good number of bird species and some antelope if one walks around the whole perimeter. The Blue Crane Restaurant allows a good view over the sanctuary’s main dam, especially from its top deck. With a pair of binoculars one can utilize the restaurant’s vantage point to the full, although the view itself is scenic and many birds should be well within range to observe without optical aid. If one is a birder then a visit to Austen Roberts is not complete without making use of the Sasol Hadeda Hide. This hide is well designed with a walkway leading to the hide that largely conceals the visitor from birds. Furthermore, this walkway also has eye-level gaps in its concealing wall that allow for intimate close-up views of a number of ducks and other birds. The hide itself looks out onto a small stream on side, an embayment fringed by reeds and much of the sanctuary’s main dam. Look out for Warblers and Black Crake around the hide and upon entering and leaving the hide scan the nearby trees that fringe the dam for Kingfishers. Another feature of the sanctuary is the small museum located between the restaurant and hide. It features displays of a number of birds preserved by taxidermy and would be enjoyed by most children, though adults (like myself) are not exempt.

The birds, and certain antelope like the Common Duiker, in the reserve are quite habituated to humans, which allows for close views and many photo opportunities. Whether one is a serious birder and/or nature photographer or just a nature lover, the Austen Roberts Bird Sanctuary has something to offer. Its tranquillity and beauty allow the mind to escape from the hustle and bustle of surrounding suburban Pretoria.

2) Pretoria National Botanical Gardens
Apart from being a nice picnic spot, the Pretoria National Botanical Gardens offers access to patches of bush of pristine flora and a healthy diversity of birdlife. Situated near the N1-N4 interchange, the gardens were established in 1946 and span a large area of 76 hectares. A quartzite ridge runs through the gardens and separates its southern and northern portions. Apart from the woodland biozone defined by the ridge, portions of natural grassland occur, while the remainder of the gardens is composed of a mosaic of mini-gardens, all having different themes, and lawns that are interspersed with trees.

When the fig trees that grow on the quartzite ridge that runs through the gardens develop ripe figs one is likely to find the beautiful African Green Pigeon along with various other frugivores gorging themselves on these fruit.

Biodiversity:
The botanical gardens are home to a wide spectrum of life, from plants and trees to reptiles, amphibians, mammals and birds. Roughly 200 species of birds have been recorded and one may well be surprised to encounter species you might not expect well within Pretoria such as Crimson-breasted Shrike, Acacia Pied Barbet, African Green Pigeon and in summer Grey-headed Kingfisher. A mammal rather ubiquitous on the quartzite ridge is the Rock Hyrax (Dassie) and if you’ve never seen these large rodents in a tree – this is a common spectacle in the gardens. I have not seen any, but I’m sure mongoose, genets and various snakes are also resident in the gardens. Finally, I wouldn’t be doing the gardens due honour by neglecting to mention its floral diversity. More or less 1000 and 500 species of flowering plants and trees occur in the gardens, respectively. The gardens’ diversity in trees is impressive considering that it accounts for more than half of our indigenous tree species. Furthermore, many of the trees occurring in the gardens are labelled - displaying their common and scientific names.

As well as lawns interspersed with threes and woodland area, the gardens contain large patches of grassland that provide ideal conditions for many flowering plants, as well as prime foraging grounds for Spotted Thick-knee and the like.

Access & facilities:
The botanical gardens are open year-round from 08:00-18:00. Adults pay R18.00 for a day’s entrance, students R10 and children under ?? R??. Facilities include a visitor’s centre, an environmental education centre, a restaurant overlooking a small dam and ablution facilities. Note that the restaurant’s entrance is outside the gardens - fringing the gardens’ main parking area. Finally, the South African National Biodiversity Institute’s head office is located inside the gardens and has a commended bookstore.

So, whether one is in the mood for a picnic, a short hike, birding or just nature, the Pretoria Botanical Gardens offers a wide spectrum of natural beauty and diversity at an affordable price.

Denni Raubenheimer

PS: In writing this article I consulted ‘The Chamberlain Guide to Birding Gauteng’, a desirable book to any Gauteng birder.

Gauteng Nature: Pretoria, Rietvlei Nature Reserve (Entry 2)

Photo: Denni Raubenheimer www.wildlifestockimage.com

The first three places in Pretoria that I would recommend for nature lovers are Rietvlei Nature Reserve, the Pretoria Botanical Gardens and Austen Roberts Bird Sanctuary. It must be noted though, that the latter two cater more for bird lovers and bird photography. Also worth note, and by no means inferior, except arguably to Rietvlei, are Roodeplaatdam Nature Reserve and the Magaliesberg Mountain Range. Finally, for those seeking a relaxing walk through nature or to do some birdwatching in Pretoria East, the Fearie Glen Nature Reserve is a very affordable option. Please note that the series of articles I am writing on the nature areas in and around Gauteng will be limited to ones I have personally visited.

Rietvlei Nature Reserve is situated on the eastern outskirts of Pretoria adjacent to, and southwest of, the R50 to Delmas. One of the features of this roughly 4000 ha reserve is its wide range of mammals, ranging from mice and mongoose to black wildebeest, white rhino and a pair of cheetahs. The reserve also boasts a wide range of birds (roughly 280 species have been observed), including water-affinite species like African Fish Eagle, Kingfishers (Giant, Malachite, Pied and Half-collared are common) and Goliath Heron, a whole host of water birds and grassland species such as Korhaans (Northern Black, Barrows and Blue), Orange-throated Longclaw and African Grass Owl.

Grasslands, marshes, gently undulating hills and two dams dominate the landscape. Luckily the network of roads and 4 hides allow visitors excess to almost every nook and cranny of the reserve. Until recently there were only three hides, one at each of the dams and the other along the Vlei Route downstream of Marais Dam. The reserve’s new hide is situated on the eastern side of the Rietvlei Dam, roughly southeast of the camping area. In my opinion it is by far the best hide. It looks out onto a small island which hosts breeding colonies of Reed- and White-breasted Cormorant and allows the visitor a 270º viewing range. Grey-headed gulls, Reed-knobbed Coots, Little Grebes and African Darters are some species usually within sight. Furthermore, there are reedbeds on both sides of the hide that together with a half-drowned dead tree a few metres from the hide attract a number of birds, and offer Kingfishers desirable perches.

Another birding and photography hotspot is at the small bridge just downstream of the Marais Dam along the Vlei Route. Here my wife and I have had the opportunity to photograph Black-shouldered Kite and Malachite Kingfisher and I have read in more than one source that it is prolific for sightings of not only Malachite Kingfishers but also Pied-, Giant-, and Half-collared Kingfishers.

Visitors may enter the reserve between 05:30 and 17:00 in summer (Sept.-Mar.) and between 06:00 and 16:00 in winter. Entrance is R35.00 per person, but no fee is charged for children under the age of 12. The reserve offers accommodation in the form of two overnight huts, as well as camping in a separate portion of the reserve. Please note that the camping fee does not include entrance to the other part of Rietvlei. Finally, guided hikes and game drives are also available to the public.

All in all Rietvlei is a jewel of Pretoria that is well maintained and managed. It offers a wide variety of fauna and natural beauty in close range of the Pretoria CBD at prices affordable to the average Joe.

In my next entry I will be discussing the Pretoria Botanical Gardens and Austen Roberts Bird Sanctuary.

Denni Raubenheimer
info@wildlifestockimage.com

PS: In writing this article I consulted ‘The Chamberlain Guide to Birding Gauteng’, a desirable book to any Gauteng birder.

Gauteng Nature: In and Around (Entry 1)

Photo: Denni Raubenheimer www.wildlifestockimage.com

Gauteng. Economic and industrial hub of South Africa. Probably the Province most synonymous with the rat race. With all the development and industry associated with this region, what does it still have to offer nature lovers? In my opinion, still quite a lot.

In my next entrees I will be focused on the nature reserves, wilderness areas and nature oases in and close to Gauteng. Being based in Pretoria I will start off with “Jacaranda Stad” and her surrounds and by the end I hope I will have done justice to a still beautiful Province.

Please feel free to suggest locations in and nearby Gauteng that you would like to be discussed, or to comment on your experience of such places.

Denni Raubenheimer
info@wildlifestockimage.com

Dubbelsnip Gallinago media (great snipe) op die plaas Doornfontein.Verskyn in ‘Laniarius’: nr. 101, winter 2006.

‘n Dubbelsnip Gallinago media (Great Snipe) op die plaas Doornfontein 374 tussen Modimolle (Nylstroom) en Vaalwater

Willem Boshoff

Op 26 Desember 2005 het ek die plaas Doornfontein besoek en ek was verstom oor hoe droog dit op die plaas was. Die normaalweg standhoudende spruit, die Sandrivier, was gereduseer tot ‘n baie klein lopie waaroor ‘n mens met redelike gemak kon spring. Weerskante van die stroom was daar plekke waar dit goed modderig was en hier en daar was daar klein modderige pannetjies met byna geen water nie. Hierdie deel van die spruit is tans onder die vlak van ‘n damwal, sowat 100 meter verder stroomaf, maar die dam was waarskynlik nie meer as 5% vol nie. Daar was net ‘n klein poel water digby die wal.

Met die afstap dam toe het ‘n snip naby die spruit uit die kort oewerplante reg voor my opgevlieg. Drie kenmerke het my onmiddellik opgeval: eerstens was die buitestertvere spierwit en besonder opvallend, tweedens het die snip met ‘n redelik stadige vlerkklap, byna moeisaam of rustig, gevlieg, derdens het die snip slegs ‘n kort entjie met ‘n boog direk van my af weggevlieg, gaan sit en tussen die plantegroei in verdwyn. Ek het om twee redes onmiddellik gedink dat dit nie ‘n Afrikaanse Snip (Gallinago nigripennis, African Snipe) kon wees nie: die vliegpatroon was heeltemal verkeerd en die snawel het vir my te kort gelyk. Kenmerkend van die Afrikaanse Snip is juis dat hy gewoonlik nie reguit nie, maar met ‘n sigsag-patroon, ver wegvlieg voordat hy weer gaan sit. Dikwels kan ‘n mens hom weer vind in die omgewing waar hy gaan sit het. Voorts is sy opvallende lang snawel vir my ‘n kenmerk in vlug.

Die klein illustrasie van Newman se veldgidse (1984:105, 1996:105) het dadelik by my opgekom. Daar dui hy ‘n slingerende vliegpatroon vir die Afrikaanse Snip en ‘n direkte boogvlug vir die Dubbelsnip aan. Nadat ek die veldgidse van Newman (1984:104-5, 1996:104-5) en Sasol (2002:186-7) geraadpleeg het, het ek geen twyfel gehad oor die uitkenning nie. Alhoewel Newman nie in die teks gewag maak van die helder wit aan weerskante van die stert nie, beeld sy klein illustrasie van die Dubbelsnip in vlug dit wel uit. Albei se beskrywing van die Dubbelsnip as “’n seldsame somerbesoeker” het my egter huiwerig gemaak om te opgewonde te raak. ‘n Opmerking in die Transvaalse atlas, wat deur Viljoen geëggo word, het my egter agter die boeke laat inskuif toe ek later by die huis kom: “Any future Transvaal reports of this species should be carefully documented and verified” (Tarboton et al 1987:100) en “Enige moontlike waarnemings moet aangemeld word” (Viljoen 2005:204). Ek het die waarneming ook telefonies met Mostert Kriek en Peter Milstein bespreek en hulle het albei gemeen dat die kenmerke op ‘n Dubbelsnip dui. Peter Milstein het ook sonder meer twee foto’s beskikbaar gestel wat hy op 11/9/1971 tydens beringing by die Chualemeer in Mosambiek van ‘n Dubbelsnip geneem het. Die foto’s word hier met sy toestemming gepubliseer.

Op 30 Desember 2005 is ek saam met Koos Pauw en Ray en Helen Biran terug plaas toe om te gaan kyk of ons die snip weer kon opspoor. Byna onmiddellik nadat ons by die dam aangekom het, het ‘n Afrikaanse Snip voor ons opgevlieg en al die kenmerkende Afrikaanse Snip dinge gedoen: hy het vinnig, slingerend en laag vir omtrent 60 meter weggevlieg en gaan sit waar ons hom ‘n rukkie later weer opgejaag het en hy dieselfde weer in die teenoorgestelde rigting gedoen het. Ons het hom drie kere gesien en kon die kenmerkende wit onder die pens duidelik sien, terwyl die spierwit buitestertvere van die Dubbelsnip ooglopend ontbreek het. Daarby was sy lang snawel elke keer in vlug opvallend. Hierdie kenmerke en gedrag het bevestig dat die ander snip nié ‘n Afrikaanse Snip was nie.

Toe ons in die gebied kom waar die rivier normaalweg in die dam invloei, het Koos Pauw en Helen Biran ‘n snip gesien wat van die modder af op ‘n dooie boomstomp geklim het. Toe ons beweeg het hy opgevlieg en skaars vyf meter weg buite sig op die modderoewer gaan sit. Ek het nader beweeg en net toe ek naby kom het hy met ‘n direkte boogvlug dwars voor ons verby in die lang riete in gevlieg en omtrent tien meter verder gaan sit en verdwyn. Die spierwit buitestertvere was duidelik uitkenbaar en die relatief korter snawel Ons het genoeg gesien om te bevestig dat dit ‘n snip was en dat die vliegpatroon totaal anders was as die Afrikaanse Snip wat ons toe reeds verskeie kere dopgehou het. Die belangrikste kenmerke (wit buitestertvere en direkte en kort boogvlug) was baie duidelik te sien en ek het geen twyfel oor die uitkenning van die Dubbelsnip nie. ‘n Besoek aan die plaas tydens die daaropvolgende naweek deur Trevor Hardaker het niks opgelewer nie.

‘n Oorsig oor die literatuur

Die beste beskrywings en illustrasies van die Dubbelsnip het ek in drie boeke oor waad- en jagvoëls (Viljoen 2005:203-4; Hockey & Douie 1995:247-8; Richards 1988:123-4) en in Lars Jonsson (1993:252-3) se Europese veldgids gevind. Veral Jonsson en Hockey & Douie se illustrasies was van baie groot hulp.

Hockey & Douie (1995: 247) vestig die aandag op die feit die Dubbelsnip nat toestande nodig het om te wei, maar dat hulle nie afhanklik is van oop water, soos damme of panne nie. Hulle verkies moerasagtige plekke soos vloedvlaktes en tydelik oorspoelde gebiede en hulle kom dikwels in dieselfde habitat as die Afrikaanse Snip voor. Clancey (1996:91) meld dat hulle in suidelike Mosambiek ook langs dreineringskanale, langs bewerkte lande voorkom. In sy veldgids vir Botswana meld Newman (1989:64) na ‘n uitstekende beskrywing dat die Dubbelsnip uiters sporadies in die Linyanti-Okavangostreek voorkom en dat hulle kort gras rondom alkaliese panne en droeër grond as die Afrikaanse Snip verkies.

Dis duidelik dat getalle van die Dubbelsnip gedurende die Twintigste Eeu dramaties afgeneem het. Richards (1988:123) dui die suidelike oorwinteringsgebied in Suider-Afrika aan as ‘n groot halfmaan wat van noordelike Namibië ooswaarts tot in Mosambiek sterk en dan suidwaarts tot in die Weskaap. Dit is grootliks onakkuraat. Meer akkuraat is die kaart in Sinclair & Ryan (2003:170) wat klaarblyklik van die resultate van die SABAP gebruikgemaak het en wat aandui dat die verspreidingsgebied nie ver suid van die Okavango- en Zambesiriviere sterek nie.
Hockey & Douie (1995:247) meld dat Dubbelsnip gedurende die tweede helfte van die Negentiende Eeu nie skaars was in die Transvaal, Natal en Oos-Kaap nie, maar die laaste rekord van die voël in Suid-Afrika is een wat tussen 1904 en 1907 in Pondoland geskiet is, totdat een weer in 1984 by die St Luciameer gevind is.
• Cyrus & Robson (1980:13) vermeld ‘n verdere waarneming gedurende September 1970, maar oordeel dat dit bevestig moet word en lys die Dubbelsnip onder die voëls van Natal waarvan die verspreiding merkbaar afgeneem het (1980:25).
• Tarboton et al (1987:100) dui dieselfde tendens vir die Transvaal aan en meld dat Ayers tussen 1876 en 1885 ten minste 15 Dubbelsnippe by Potchefstroom versamel het.
• In die Weskaap is ‘n Dubbelsnip gedurende die Negentiende Eeu op die Kaapse Vlakte versamel en onbevestigde berigte lui dat die voël ook by die Olifantsrivier en by Porterville waargeneem is (Hockey et al 1989:94).
• Wat die Ooskaap betref is die volgende inligting uit die Transkei ter sake: Die welbekende kunstenaar CG Finch-Davies was van 1893 tot 1914 in die Transkei gestasioneer. Quickelberge (1989: 57) meld dat Rev R Godfrey rapporteer het dat Finch-Davies die Dubbelsnip dikwels in vleilande by Lisikisiki en Bizana gevind het, maar dat dit nie so algemeen by Matatiele was nie.

Dit is interessant om te sien hoe Roberts en ander standaard studies, soos die SAOS Checklists traag was om die afnemende getalle van Dubbelsnip in Suid-Afrika te reflekteer:
• Gill (1940:143) meld dat uitsonderlike voorbeelde van Dubbelsnip omtrent op enige plek kan opduik, dikwels op redelik droë grond en gewoonlik, maar nie altyd nie, in die somer.
• Roberts (1940:104) beskryf die voël bloot as ‘n besoeker wat slegs gedurende die somermaande in Suid-Afrika verskyn (Roberts I).
• McLachlan & Liversidge (1957:135) beskryf die verspreidingsgebied soos volg: Aangeteken in die Oos-Londen distrik en van Potchefstroom af noordwaarts, met ‘n ou aantekening uit die Kaapse Afdeling (Roberts II; dit bly die beskrywing tot by Roberts IV, 1978).
• Die eerste Checklist of the Birds of South Africa (Winterbottom 1969:87) beskryf die Dubbelsnip as ‘n palearktiese besoeker aan Oos- en Suid-Afrika wat skaarser word hoe verder suid ‘n mens gaan.
• Die tweede SAOS Checklist of Southern African Birds (Clancey 1980:73) beskryf die Dubbelsnip as ‘n besoeker, veral aan die Ooskaap, Natal en Zululand en noordwaarts in die ooste. Dit is ook gelys in Namibië en is na bewering in die Suidweskaap versamel.
• Maclean (1984:254) sê die Dubbelsnip in suidelike Afrika is wydverspreid in noordelike Zimbabwe, suidelike Mosambiek, Transvaal; asook Owamboland; met geen onlangse rekords vir Natal tot by die Ooskaap nie. Hy meld dat die getalle oënskynlik afneem (Roberts V; dit bly so in Roberts VI, 1993).
• Hockey et al (2005:342-343) bied ‘n goeie oorsig van die historiese en meer onlangse waarnemings (Roberts VII).

‘n Unieke patroon van veranderde verspreiding oor die afgelope eeu geld vir die Dubbelsnip.
• Waar daar vóór 1920 geen rekords van Dubbelsnip in Zimbabwe was nie, is die meerderheid van die veertig waarnemings sedert 1955, asook die grootste konsentrasie (van vier), juis in Zimbabwe aangeteken (Hockey & Douie 1995:247; Hockey 1997:770). Dit is veel minder as die groep van meer as twintig Dubbelsnippe wat in 1899 by Durban saam gesien is. Die veranderde verspreidingspatroon mag die resultaat wees van landbou-aktiwiteite in Suid-Afrika (waar vleilande drooggelê is) en Zimbabwe (waar vleilande oënskynlik beskikbaar gekom het) (Hockey & Douie 1995:247).
• Penry (1994:292) vermeld vyf waarnemings van Dubbelsnip in Botswana tussen 1967 en 1989. Hy meen die voël word maklik misgekyk en dat dit moontlik ‘n gereelde jaarlikse besoeker aan die noordelike vleilande kan wees.
• Underhill et al (1999: 85) meen dat die Dubbelsnip moontlik steeds ‘n skaars besoeker aan noordoos Namibië mag wees. Winterbottom (1971: 96) verwys na rekords uit Ondangwa, Namakunde en Omaruru. Brown (s.a.:26) dui die verspreidingsgebied aan as Ovamboland en Caprivi. ‘n Geringde voël is in Julie 1967 in Ondangwa, Namibië herwin. Die voël is tien maande tevore in Finland bering en die herwinningsdatum van 15 Julie is moontlik eerder die datum van aanmelding as die datum waarop dit werklik gevind is (Underhill et al 1999: 85).
• ‘n Verdere Dubbelsnip is op 11 September 1971 by die Chualemeer in Mosambiek (25° 01´ S, 32° 55´ O) deur P le S Milstein bering (persoonlike mededeling, sien meegaande foto’s) en Clancey (1996:91) meld ‘n waarneming by Marracuene, net noord van Maputo en verder verskeie waarnemings noord van die Saverivier. (Vir geografiese besonderhede: Clancey 1996:304, National Geographic Maps 2003:109).
• In suidelike Malawi word die Dubbelsnip aangedui as “seisoenaal redelik algemeen” by die Chilwameer, oos van Zomba en op die Mosambiekse grens (Newman et al 1992:55, National Geographic Maps 2003:140,149).
• In Zambië kan die Dubbelsnip in die somermaande op enige plek in nat grasveld opduik, maar dit kom voor in klein getalle en word min aangeteken (Aspinwall & Beel 1998:78).

Die Dubbelsnip is nie ‘n alledaagse verskynsel nie. Die waarneming op die plaas Doornfontein het my op ‘n ontdekkingstog in die literatuur geneem wat ek graag met ander voëlkykers deel. Ek vertrou dit sal iemand interesseer. Daarmee het ek ook probeer om iets te doen aan die versoek dat waarnemings van die Dubbelsnip sorgvuldig rapporteer moet word.

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