Monthly Archives: May 2015

Cape Honeybees, Fynbos, and Fires

By Geoff Tribe and Ujubee

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One of the major influences on the formation and maintenance of the fynbos biome is the periodic occurrence of fires which are regarded as necessary at intervals of every 15 years or so. Fynbos fires can be extremely hot if there is accumulated fuel and a wind driving the fire. Fynbos plants are adapted to fire and respond in various ways including serotiny where fire releases the seeds of various Proteaceae from their fire-resistant seed-capsules after the fire has passed. In response to the smoke these seeds which are stimulated by cooler tempertaures and rain germinate. Other plants may survive as underground bulbs or tubers and take the opportunity of the post-fire period of reduced competition to proliferate, with different species appearing on the surface and flowering in sequential waves.

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Figure 1. Aerial view of the swathe of destruction the fire caused in the Cape Point section of Table Mountain National Park in March 2015 (courtesy of Dr Jonathan Ball).

Cape bee nesting sites. The natural distribution of the Cape honeybee (Apis mellifera capensis Escholtz) is extremely limited and closely follows that of the fynbos vegetation of the winter rainfall region (originally covering only 90 000 km²). The Cape honeybee co-evolved with the fynbos and is well adapted to its environment. The wild fire following a lightning strike on 5 March 2015 which cut through a section of Cape Point Nature Reserve before it was extinguished (Fig.1) left a desolation of ash and sand in its wake (Fig. 2).The adaptation of various creatures to fire-prone fynbos gives some insight into the importance in the selection of nesting sites within the fynbos by honeybees. Within this swathe were three natural colonies which had been monitored for nine months prior to the fire. The colonies were between 1 and 2.5kms apart.

Figure 2. The aftermath: ash, sand and blackened skeletons of shrubs.

Figure 2. The aftermath: ash, sand and blackened skeletons of shrubs.

The colonies in the burnt area were visited on 15 May 2015. All three colonies escaped initial destruction by the fire and this was primarily due to where they had established their nests – under boulders at ground level. But none of the colonies escaped totally unscathed and all had declined in vigour and in the number of active foragers. The highest yearly annual wind speed in southern Africa is recorded at Cape Point and, in addition, the now loose sand is being blown into the fully exposed nests which is exacerbating their efforts to survive. The winter rains are delayed and severe downpours could result when they do arrive which could flood the nests with sludge.

The nest of Colony 1 which was constructed deep under a boulder (Fig. 3a) appeared to have escaped relatively unscathed due to the propolis wall which protected the nest but had melted due to the heat from the fire (Fig. 3b). Fourteen combs were visible but the population had dwindled considerably although there was foraging activity with pollen from Serruria sp. growing outside the burnt area being brought back to the nest. Prior to the fire, Colony 1 was fairly protected from the elements by the growth of vegetation around it (Fig. 3c).

Fig. 3a. Colony 1 whose nest under the boulder (the dark area at ground level in the centre) was protected by a propolis wall escaped destruction.

Fig. 3a. Colony 1 whose nest under the boulder (the dark area at ground level in the centre) was protected by a propolis wall escaped destruction.

Colony 1 prior to the fire.

Fig. 3c. Colony 1 prior to the fire protected from the elements by the growth of vegetation around it.

Fig. 3b. The nest of Colony 1 whose 14 combs had been protected from the fire by a propolis wall that covered the cavity.

Fig. 3b. The nest of Colony 1 whose 14 combs had been protected from the fire by a propolis wall that covered the cavity.

Fig. 3c. Colony 1 prior to the fire.

The nest of colony 1 prior to the fire.

Colony 2 (Fig. 4a) appeared to have been severely affected by the fire, which judging from the numerous rocks about the entrance that were cracked (Fig. 4b), the heat was intense. The propolis wall had melted and the combs had melted except for the comb mid-rib (Fig. 4c). During the examination of the colony in cold windy weather, two bees emerged but were unable to depart normally on flights as if both were too cold and starved to do so. However, on the following sunny day foraging activity was witnessed (Fig. 4d).

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Fig. 4a. Colony 2 is located to the right side of the foremost boulder below where the orange lichens start.

Colony 2 prior to the fire.

Colony 2 prior to the fire.

4b. Rocks around the entrance to the nest cracked from the heat of the fire.

4b. Rocks around the entrance to the nest cracked from the heat of the fire.

Fig. 4c. The almost deserted combs of Colony 2.

Fig. 4c. The almost deserted combs of Colony 2.

Fig. 4d. Foraging activity at Colony 2.

Fig. 4d. Foraging activity at Colony 2.

From inspection, Colony 3 (Fig. 5a) had a propolis wall which enclosed the entire nest but which was melted by the fire – as had some of the combs which consisted only of the comb mid-rib (Fig. 5b). On a subsequent visit, of the seven combs that were visible, the bees were clustered on the end three combs but were still actively foraging (Fig. 5c).

Figure 5a. The entrance to Colony 3 lies under the boulder with a seemingly horizontal crack in it and to the right of the reddish, lichen covered rocks (situated bottom left in the picture).

Figure 5a. The entrance to Colony 3 lies under the boulder with a seemingly horizontal crack in it and to the right of the reddish, lichen covered rocks (situated bottom left corner in the picture).

Colony 3 prior to the fire.

Colony 3 prior to the fire.

Fig. 5b. Bees of Colony 3 clustered on some melted combs. Note the remains of the melted propolis that once encased the nest entrance.

Fig. 5b. Bees of Colony 3 clustered on some melted combs. Note the remains of the melted propolis that once encased the nest entrance.

Fig. 5c. Bees of Colony 3 clustered on some combs while the others are deserted.

Fig. 5c. Bees of Colony 3 clustered on some combs while the others are deserted.

Propolis and beeswax: It has been recorded that during the heat from a fire, bees keep the colony ventilated by vigorously fanning their wings to prevent the combs from melting (Root 1950). At temperatures of 25-45°C propolis is soft and pliable and most varieties will melt between 60-70°C and some only at 100°C. Beeswax melts at about 63°C. Honeybees maintain a hive temperature of 34°C within the brood area. Propolis is a mixture of different plant resins and gums collected from unopened flower buds, especially of Leucospermum and Protea species within Cape Point. Because it consists of the defensive chemical exudates of plants, it has many anti-bacterial and anti-fungal properties and is aromatic. The major components of propolis are resins (45-55%); waxes and fatty acids from both beeswax and plants (25-35%); essential oils (10%); protein – mainly pollen (5%); and trace elements – mainly iron and zinc (5%). Propolis used within the hive may have beeswax added to it to be more pliable but can also consist of pure plant exudates in outer structures. Its thickness depends on the purpose of the structure under construction. In the case of the colony which survived the fire, the propolis wall (pro = before; polis = the city) built at right angles to the combs, did indeed protect the nest. It appears that the main function of the propolis barrier was the exclusion of rain and cold. Propolis has many uses in that it can be used to control ventilation, waterproof the interior of a nest, to control temperature and humidity within the nest, and to exclude various pests from entering and hiding within the nest. The prolific use of propolis by the African honeybee may also be as a result of attempts to deny hiding places within the hive to the small hive beetle (Aethina tumida) by sealing crevices. Natural nests are often located in cavities which afford many hiding places to the small hive beetle, thus lining the cavity with propolis effectively seals the nest off from its immediate surroundings (Tribe 2000). The extent to which propolis may be used to insulate a nest was illustrated in the complete enclosure of combs hanging from under a branch of a tree in Pretoria, allowing bees to forage from just a few small openings in the propolis sheath (Tribe & Fletcher 1977).

Cape Point Nature Reserve: Unlike the summer rainfall honeybee race (Apis mellifera scutellata) of southern Africa, the Cape bee nests are more often located within shrubbery at ground level. This does not preclude them from constructing nests in elevated places like those for A. m. scutellata. In fact, in suburbs of Cape Town, Cape bee nests have been located several meters high in exotic palm and pine trees. Data on Cape bee nesting sites recorded in Cape Point thus far indicate that about 90% of selected sites are located under or within rock crevices (Fig. 6).

Figure 6. Colony in the cliff face at Cape Point Nature Reserve.

Because honeybees will reoccupy any site previously inhabited by other honeybees, it is likely that many of these sites have been in use for centuries. What was amazing was that bees often issued in a steady stream from a relatively small hole in the soil at the base of a rock at some of these nests. How were these bees able to locate such hidden nesting sites which must occupy a substantial cavity size below the rock of say, about 42 litres – which is the capacity of a Langstroth hive? It is probable that such nesting sites were located by scouts in the past when they were more exposed, possibly as a result of a fire followed by winds and then heavy rainfall which revealed the cavity under the rock. With an average fire frequency of 15 years, the debris and plant growth during this time around the site could have closed off most of the cavity, the bees maintaining only the narrowed entrance.

Are nesting sites a limiting factor? Is the availability of nesting sites a limiting factor on the number of colonies able to reside in Cape Point? This is difficult to answer without knowing how many reproductive swarms are issued each year from the established swarms.

Fig. 7. Swarm of Cape bees during the canola flow at Caledon

Fig. 7. Swarm of Cape bees during the canola flow at Caledon

An individual colony may issue none or several reproductive swarms a year (Fig. 7) – largely determined by the capacity to expand within the nesting space (i.e. over-crowding), the strength of the colony (nectar and pollen reserves) and the vigour of the queen. Usually the old queen departs with flight-experienced workers, leaving behind several queen cells from which virgin queens will shortly emerge. If the colony is still over crowded, one or more additional swarms may leave with virgin queens – but this is more common among A. m. scutellata. However, at least one swarm at Cape Point was unable to find a secure nest and built their combs from interlacing branches within a fynbos thicket. Any approach to this nest elicits an immediate hostile reaction, presumably because of the odour of crushed vegetation underfoot. In the event of a fire, this colony would be incinerated.

Abscond? What remains to be seen is whether the three colonies which escaped the fire will remain where they are or will abscond. The Cape Point fire was extinguished and foraging still exists outside the burnt swathe, although the foragers will have further to fly. In the past similar wild fires would burn over a vast area, leaving little or no forage for many weeks. For example, a wild fire in the Cedarberg burnt for six days and covered 13 500ha (Jarman 1982) turning the entire area into a wasteland for bees with no forage. However, the resilience of the fynbos was revealed at Cape Point in the appearance of fire-asparagus (Asparagus lignosus) shortly after the fire which began flowering within weeks – to the benefit of the numerous bees visiting it. Also emerged in response to the fire were Haemanthus sanguineus and a smattering of plants such as Oxalis which were also visited by foragers.

Honeybee predators: Cape Point Nature Reserve no longer has honey badgers (Mellivora capensis) which possibly occurred there in the past, thereby eliminating one of the honeybees’ most destructive enemies. Had they been present, there would be the annihilation of those colonies accessible to them, followed by the later re-establishment by reproductive swarms from other areas within the park – thus creating an on-going dynamic. Although baboons also readily raid honeybee nests and are prevalent in the reserve, none of the 31 colonies has thus far been raided by baboons.

 

References

Jarman, M. 1982. A look at the littlest floral kingdom. Scientiae 23(3): 9-19.

Johannsmeier, M.F. (Ed.). 2001. Beekeeping in South Africa. Plant Protection Research Institute Handbook No 14, Agricultural Research Council of South Africa. 228pp.

Root, A.I. 1950. The ABC and XYZ of Bee Culture. The A.I. Root Company, Medina, Ohio, U.S.A. 703pp.

Tribe, G.D. 2000. A migrating swarm of small hive beetles (Aethina tumida Murray). South African Bee Journal 72(3): 121-122.

Tribe, G.D. & Fletcher, D.J.C. 1977. A propolized nest in the open. South African Bee Journal 49(4): 5-7.

Acknowledgment: The permission granted by SANParks to locate and analyse the nesting sites of honeybees in the Table Mountain National Park is gratefully acknowledged.

 

 

Restio Species as a Source of Pollen in Autumn in the Fynbos

By Geoff Tribe

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The cavity dwelling Western Honeybee inhabiting temperate regions relies on its honey stores to tide it over the seasonal dearth periods which is a feature of its natural environment. The fact that they live in cavities allows ample stores to be accumulated for this purpose. It is this behaviour of hoarding surplus honey that is exploited by commercial beekeepers to their advantage by migrating hives from one honey-flow of exotic crops to the next. In the summer rainfall highland areas a typical seasonal cycle may start with the Highveld gums (a variety of Eucalyptus species) in spring, then on to sunflowers, soya beans, Eucalyptus grandis plantations, and finally to the Aloe greatheadii var. davyana honey-flow in winter. The seasonal dearth period for the Cape bee (Apis mellifera capensis) which inhabits the winter rainfall region of South Africa occurs during the summer months from January to March when few indigenous plants are in flower under a hot cloudless sky. Yet the honeybees survive, albeit in some areas with the help of exotic plants, the most valuable being several Australian Eucalyptus species.

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Fig. 1. A view of DanielsHoogte Private Reserve nestled on the top of Aurora Mountain 800m above sea level.

An exploration of the mountain (Fig. 1) above the West Coast town of Aurora in the first week of May 2015 revealed an abundant but unexpected source of pollen for Cape honeybees in the form of a Cape reed species belonging to the Restionaceae family. Fynbos vegetation is distinguished by its constant association with these tufted reeds which have been used to provide thatching material from the time of early European settlement. In the summer rainfall regions the Restionaceae are replaced with grasses. Restio species are usually dioecious with male spikelets drooping and female spikelets erect and are wind pollinated.

The fynbos covered Aurora Mountain is surrounded below in the Sandveld by potato and wheat fields and is contiguous with the Piketberg Mountain. The mountain fynbos here comprises of at least five species of Restionaceae and five Protea species of which Protea laurifolia (fig. 2) and Protea nitida (Fig. 3) were in flower.

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Figure 3. Many insects including honeybees visited the flowers of Protea nitida.

One species of Bruniaceae (Fig. 4) had just begun to flower as a result of the heavy coastal fog which envelops the mountain in the early morning (Fig. 5). However, around the farmhouses (32° 41’ 04’’S 18° 32’ 10’’E) were some ancient Eucalyptus globulus trees which were in flower. A commercial beekeeper had placed hives (Fig. 6) in groups of three at four localities within the fynbos vegetation. They were placed on recycled plastic containers filled with sand and strapped down to prevent the honey badger from accessing them – the mountain still inhabited by leopards, lynxes, mongooses, and various antelope including klipspringers and exotic fallow deer.

Figure 5. The morning coastal fog seen through the ‘vensterklip’ which can completely envelope the mountain.

Figure 5. The morning coastal fog seen through the ‘vensterklip’ which can completely envelope the mountain.

Figure 6. Beehive placed on top of a sand-filled container and strapped down to prevent access by the honey badger.

Figure 6. Beehive placed on top of a sand-filled container and strapped down to prevent access by the honey badger.

At this time of year the fynbos was drab and the prickly undergrowth showed very few natural resources on which the bees could forage. During the hikes around the outer rim of the mountain, no natural honeybee nests were discovered – not even in the 17 aardvark holes that were inspected. However, in several small secluded valleys there was a Restio species, Elegia tectorum, growing in thick clumps which reached to one’s elbows and which released clouds of pale yellow pollen as one pushed through it. It was here that the bees were encountered in large numbers collecting pollen (Fig. 7).Only pollen collectors were observed. No bees were visiting the female flowers (Fig. 8). It was observed that pollen was not available early in the morning, especially not until the mist had lifted, but became available only during the hotter part of the afternoon when the inflorescences were dry.

Figure 7. A honeybee collecting pollen from male Elegia tectorum flowers.

Figure 7. A honeybee collecting pollen from male Elegia tectorum flowers.

Figure 8. Female Elegia tectorum flowers not visited by honeybees.

Figure 8. Female Elegia tectorum flowers not visited by honeybees.

Elegia tectorum, or Cape thatching reed (as its name tectorum = ‘roofing’ implies), may grow to over 3m in height and occurs naturally in marshes and seeps on deep sand from Clanwilliam to Port Elizabeth. Male and female flowers occur on separate plants; the flowers are small and borne in compound branched inflorescences and flower in autumn (from March to April) which lasts for about four weeks. Large areas of several metres in diameter of either just male or female plants were observed on Aurora Mountain in close proximity to each other. Small black seeds are produced with smoke greatly increasing their germination rate.

Honeybees will be found in even the most desolate desert areas throughout southern Africa in which they find the means to survive. Within the mountain fynbos of the West Coast, restios appear to play an important, if unacknowledged, role in supplying pollen to honeybees at a time of year when such resources are in short supply. More than 400 species in about 40 genera of the Restionaceae family occur in the winter rainfall regions of South Africa and Australia, with outliers in Africa, Madagascar, Indo-China and Chile. There are about 168 restio species in South Africa which are confined mainly to the fynbos biome. They appear to play a far more important role in the ecology of the Cape honeybee than that of a wind pollinated species might warrant.

References

http://www.plantzafrica.com/plantefg/elegiatectorum.htm

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A harvester termite nest found at Aurora.

The prehistoric looking 'koringkriek' or corn cricket, Hetrodes pupus, active on the mountain

The prehistoric looking ‘koringkriek’ or corn cricket, Hetrodes pupus, active on the mountain.

The presence of rock art in caves on the mountain indicates that it has been inhabited for many centuries

The presence of rock art in caves on the mountain indicates that it has been inhabited for many centuries.

 

Rock Art Paintings of Honeybee Combs in the Western Cape

By Geoff Tribe

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Wild honeybee nests in southern Africa have been robbed for millennia by Bushmen (San) who were the original inhabitants of the sub-continent before the arrival of the Bantu tribes from the north and the European settlers from the south. Honey was possibly the only sweetness known to them which was obtained not only from honeybees but also from stingless Trigona bees. Bee brood was also a much relished source of food. Honeybee nests were marked in some way and individually or tribally owned and were robbed at the appropriate season when the combs were full of honey. Being nomadic, the San travelled vast distances following the availability of food according to the seasonal cycle.

There are many thousands of paintings on the walls of caves or rock overhangs in southern Africa which are thousands of years old, with some extending into the early colonial period. The San (Bushman) painters covered a wide variety of subject matter, the interpretation of some of them fill many scholarly books. Honeybees also played an important role in their mythology (e.g. Pager 1974; Lewis-Williams & Dowson 1989).

One painting that occurs in many parts of southern Africa and which was initially thought to depict a necklace was subsequently shown to represent combs of honeybees. Necklaces were worn by the San and were made out of small pieces of ostrich egg shells in which a hole was drilled and then strung together with a piece of string. However, a Zululand commercial beekeeper, Robin Guy, on visiting the preponderance of paintings in the Natal Drakensberg identified these ‘necklaces’ as depicting hanging honeybee combs within a honeybee nest.

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Fig. 1 The hanging combs of a nest of Apis mellifera scutellata hanging under the branch of a pine tree in a suburb of Pretoria.

There is no mistaking their resemblance to the combs of a wild honeybee nest (Fig. 1). This was further confirmed where at some of these sites, the catenary combs were accompanied by dots or bees with red bodies and white wings (Fig. 2a & b).

Frequently the artists made use of the varied surface relief of the walls of the cave to incorporate certain blemishes or imperfections into their paintings. Examples include the painting of an eland around an inclusion in the wall which is used to represent its eye, or a procession of antelope which appear to be emerging from a crack in the wall. The figure of a woman may be painted around a hole in the wall to represent a female’s abdomen or womb (Anderson). In this painting (Fig. 2a) it appears as if the bees are flying out of a crevice in the wall – very much as they would in the wild where many colonies make their nests within rock crevices. The large number of bees, especially concentrated at the lip of the crack and spreading outwards, indicates either an orientation flight or an absconding swarm. Botha’s Shelter contains 899 magnificent paintings including that of combs painted below the stomach of an eland and a bird associated with the bees which in the context could represent a honeyguide (Pager 1971).

Rock art depicting honeybees appears to be rather scarce along the western seaboard of southern Africa as compared with that of the eastern seaboard. And the West Coast paintings most often depict hanging combs which occur in such places as overhangs along the Oorlogskloof Hiking Trail (Fig. 3); on a farm in the Swartruggens Mountains overlooking the Tanqua Karoo (Figs 4 & 5); and in a cave in the Aurora Mountains above the town of that name (Fig. 6). Here again (Fig. 4) the artist has made use of the natural shape of the cave wall to incorporate the convex bump on which to paint the catenary combs. This gives a more realistic three dimensional effect of what a real nest would look like if viewed from below. Similarly, honeybee nests are often found hanging under projecting rocks, and the artist (Fig. 3) has made use of the small projection from the cave wall under which to paint the combs – simulating what occurs in nature.

Rock art depicting the robbing of bee nests occurs more frequently along the eastern seaboard of South Africa. For example, a painting in Eland Cave in the Drakensberg Mountains depicts a honey hunter with a bag on his back climbing a forked ladder to reach a honeybee nest around which bees are flying in agitation (Pager 1973). Similarly, three bees’ nests with ladders giving access to them may be seen in Anchor Shelter (Crane 1983). Near Bergville in KwaZulu-Natal, there is a ladder in close association with two bees’ nests depicted in a painting in Tugela Shelter (Crane 1983). In the Brandberg Mountains of Namibia a swarm of 376 bees are depicted in a painting. Yet the only depiction of a honey hunter in the Western Cape appears to be in a high overhang on a farm near De Hoek at the foot of the Swartbergpas 10km from the Cango Caves in the Oudtshoorn District. In this now faded painting, a man appears to be lowered from above with both hands gripping the rope above him and dots, presumably bees, all around his head. Attached to his body is what appears to be a flaming torch. In this ‘cave’, known as Buck krantz, because it also depicts antelope plummeting over the cliff, there are several honeybee nests in its walls even to this day. These nests are in holes in the wall which are entirely covered with propolis except for several tiny entrances through which the bees forage (Fig. 7).

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Fig. 7 Propolis covered entrances to honeybee nest in cavities in the wall of the Buck krantz rock overhang where a painting depicts the robbing of these same nests.

Also in the Klein Karoo is a painting of a swarm of bees amongst a group of dancing figures – the droning in the ears when in an altered state during a trance dance is recognised as the potent humming of bees (Rust & Van der Poll 2011). Here the bees are again depicted with red abdomens and white wings.

Why honeybees and robbing activity in rock art is more frequently encountered along the eastern seaboard could be because of a variety of reasons. Possibly the most important difference is that the eastern seaboard is much wetter and more rugged and thus honeybees are more prolific with many more and varied nesting sites available. In contrast, the fynbos and succulent Karoo of the western seaboard is far drier, with most honeybee nests located in outcrops of rocks or in the ground. At Buck krantz the depicted scene of the honey hunting can easily be visualized as occurring in the overhang – as with the antelope being chased over the cliff above the ‘cave’, but do single depictions of combs in the other caves, not always associated with other paintings, indicate a nest nearby and its ownership?

Selected references:

Anderson, G. (no date). Bushman Rock Art: South Africa. Art Publishers. 64pp.

Crane E. 1983. The Archaeology of Beekeeping. Duckworth, London. 360pp.

Crane, E. 2005. The rock art of honey hunters. Bee World 86(1): 11-13.

Guy, R.D. 1972. The honey hunters of southern Africa. Bee World 53(4): 159-166.

Lewis-Williams, D & Dowson, D. 1989. Images of power: understanding Bushman rock art. Johannesburg: Southern Book Publishers.

Pager, H. 1971. Ndedema. Akademische Druck- u. Verlagsanstalt, Graz/Austria. 375pp.

Pager, H. 1973. Rock paintings in southern Africa showing bees and honey hunting. Bee World 54(2):   61-68.

Pager, H. 1974. The magico-religious importance of bees and honey for the rock painters and Bushmen of southern Africa. South African Bee Journal 46(6): 6-9.

Rust, R. & Van der Poll, J. 2011. Water, Stone and Legend: Rock Art of the Klein Karoo. Struik. 128pp.

Tribe, G.D. 2000. A Bushman painting of a honey-hunter in an Oudtshoorn cave which still contains honeybee nests in its walls. South African Bee Journal 72(2): 84-87.

Woodhouse, B. 1984. When Animals were People: A-Z of Animals of Southern Africa as the Bushmen saw and thought of them and as the camera sees them today. Chris van Rensburg Publications. 120pp.

Dr Geoff Tribe

Dr Geoff Tribe