@tonyrebelo @jeremygilmore @botswanabugs @paradoxornithidae @ish_crew @matthewinabinett @chris_whitehouse
On 14 August 2001, I visited Kosierskraal Game Farm, southwest of Bredasdorp (https://en.wikipedia.org/wiki/Bredasdorp) in Western Cape province, South Africa. The precise location is shown in https://www.inaturalist.org/observations/101930627.
My guide was the owner, Mick J D'alton.
The location is on the Agulhas Plain (http://www.maphill.com/south-africa/western-cape/swellendam/bredasdorp/maps/physical-map/), extending slightly on to the lower slopes of the 432 m-high hill Soetmuisberg (https://mapcarta.com/19068450 and https://za.geoview.info/soetmuisberg,3361386), which forms a northern boundary to the Agulhas Plain.
The area of the property was 750 ha, of which 250 ha bad been cleared of natural vegetation. 550 ha was game-fenced, of which 250 ha was still natural fynbos (Elim Flats dwarf fynbos, still in good condition, although rather grassy). An additional 250 ha, also game-fenced was being leased on an adjacent property.
There was an additional area (200 ha) of natural vegetation - belonging to a third landowner - on a slope adjacent to Kosierskraal, where Leucadendron platyspermum (https://www.inaturalist.org/taxa/589081-Leucadendron-platyspermum) was being commercially picked.
The total area for wild ungulates at Kosierskraal was 800 ha, of which about 500 ha retained fynbos vegetation.
The substrates are mainly sandstone and gravel. Ferricrete (https://en.wikipedia.org/wiki/Ferricrete) was visible as a heap where earthworks had occurred.
VEGETATION
I visited a population of Protea pudens (https://www.inaturalist.org/taxa/592534-Protea-pudens). This threatened species regenerates germinatively. The population in question had been subject to foraging by the common eland, the black wildebeest, and even the springbok (which requires short vegetation).
I also visited an area of Elim Flats dwarf fynbos, last burnt about 7 years before, that lacked proteas and was characterised mainly by Restionaceae.
I noted Erica regia (dark pink) https://www.inaturalist.org/taxa/570046-Erica-regia
I also noted Erica cerinthoides, scattered but conspicuous, in fynbos still short, having been burnt on 23 December 1999 (I observed Nectarinia famosa in this area, https://www.inaturalist.org/taxa/13300-Nectarinia-famosa).
Mick D'alton pointed out that
Parts of the formerly cultivated lands were now covered with tussock grassland of Eragrostis (?curvula, https://www.inaturalist.org/taxa/76850-Eragrostis-curvula), which I assume to be a fairly palatable grass, although not lawn-forming.
I observed the introduced species, Eucalyptus luehmanniana (https://www.inaturalist.org/taxa/883158-Eucalyptus-luehmanniana), killed by fire, but with seedlings apparent.
UNGULATES
Bontebok (Damaliscus pygargus pygargus)
Although fully indigenous to Kosierskraal, the bontebok fared poorly here. A population of 45 individuals declined to 15, and never recovered.
Black wildebeest (Connochaetes gnou)
Body size:
The largest male individual probably weighed >150 kg; its carcase weight was recorded as 80 kg. However, mean carcase weights here averaged: males 75 kg, females 60-65 kg.
I observed excavations made by the black wildebeest in fynbos vegetation, where the substrate was sandy.
Common eland (Taurotragus oryx oryx, https://www.inaturalist.org/observations/115898959)
Body size:
A large male individual about 8 years old, killed in 2001, weighed 800 kg, with a carcase weight of 360 kg. This was considered average for this area. At 'Armskor' (https://www.saairforce.co.za/the-airforce/bases/8/air-force-base-overberg), elsewhere on the Agulhas Plain, carcase weight reached up to 400 kg.
Reintroduction at Kosierskraal began with 1 individual from Salmonsdam Nature Reserve (https://en.wikipedia.org/wiki/Salmonsdam_Nature_Reserve), followed by 5 from De Hoop Nature Reserve(https://en.wikipedia.org/wiki/De_Hoop_Nature_Reserve), totalling a founder population of 6. By 1990, these had increased to 75, with 25 having been culled. Remarkably, the population increased from 6 to 100 in one decade.
In the early years, some of the female individuals bred continuously, giving birth every 10 months. Births were mainly in September (spring) and March (autumn). Males remained with the females when the latter give birth.
Females stopped breeding at about 13 years old, which is the same as for the European bost (see below).
During my visit, I observed an individual of the common eland that was unusually dark. Mick D'alton explained that one of the females at Kosierskraal, then 12 years old and near the end of its reproductive life, was 'black' (melanistic), this being inherited by some of her progeny.
In the drought of 1991, 50 individuals out of 75 died.
More recently, the population had been reduced to 13. At the time of my visit, this had increased to 35.
Wildfire swept through Kosierskraal in December 1999, followed by good rain in early 2000. The common eland (like the black wildebeest) then spent most of the time in post-fire fynbos.
It is well-known that adult males of the common eland produce a clicking sound from the carpal joint when walking. However, I learned that adult females and juvenile males also produce this sound, albeit softly.
Mick D'alton told me of a clear record of the common eland here eating the young inflorescences of cultivated (and fertilised) Protea compacta (https://www.inaturalist.org/taxa/320042-Protea-compacta). The property was Waterford (https://za.geoview.info/waterford,3359604), near Hagel Kraal (https://mapcarta.com/19079848), owned by Pietman Cilliers but subsequently sold to Eskom (https://en.wikipedia.org/wiki/Eskom). Here, a population of 15 of the common eland had been kept together with stands of P. compacta, planted for commercial purposes. The stomach of a culled individual contained many young inflorescences of P. compacta. Pietman Cilliers also directly observed the common eland eating the young inflorescences wholesale.
Mick D'alton told me that, at Kosierskraal, the common eland ate Carpobrotus in summer. It also sometimes uprooted Carpobrotus with its horns.
I observed a small group of the common eland in a stand of Acacia saligna, which was tall but thinned-out, and half-broken in the case of saplings 2-3 m high. I asked Mick D'alton if he had seem the common eland breaking A. saligna with its horns, and be said no. However, he told me that branches are broken somehow in the process of the young, green pods being eaten. I.e. the common eland forages roughly on A. saligna, and its attentions do not seem to benefit this plant species, but it seems incapable of breaking down and destroying a stand of A. saligna.
I observed a group of the common eland on a patch of pasture, with Cynodon dactylon. This group included a creche of juveniles (close aggregation of juveniles is typical of this species).
In the experience of Mick D'alton, the common eland dislikes being approached in dense vegetation; it flees into open vegetation, where habituation to human proximity resumes.
Springbok (Antidorcas marsupialis)
This species, although not indigenous to this area, fared well enough on grassy pasture and burnt fynbos at Kosierskraal.
Mick D'alton told me that he had a serious problem with predation on the springbok by the caracal (Caracal caracal caracal, https://www.inaturalist.org/taxa/42042-Caracal-caracal and https://www.inaturalist.org/observations/80090747).
Grey rhebok (Pelea capreolus, https://www.inaturalist.org/taxa/42336-Pelea-capreolus)
The population of this species was only 3 individual at Kosierskraal at the time of my visit; it had been hard-hit by the caracal.
On the mantlepiece, Mick D'alton displayed a noteworthy specimen of the hooves, 10 cm long, presumably from an old female individual, which I infer to have been kept captive on soft ground. Apparently, all four feet were distorted in this way. This shows how rapidly the claws of this species, adapted to rocky, abrasive terrain, grow in compensation for natural wear.
Southern bushbuck (Tragelaphus sylvaticus sylvaticus)
This species was absent from Kosierskraal. However, Mick D'alton told me that it was fairly common in the thickets of introduced Acacia at Pearly Beach (https://en.wikipedia.org/wiki/Pearly_Beach).
Cape duiker (Sylvicapra grimmia grimmia)
This species was fairly common at Kosierskraal.
Cape grysbok (Raphicerus melanotis)
This species was fairly common at Kosierskraal at the time, but was said to have been more common in the past.
Steenbok (Raphicerus campestris campestris)
This species was scarce at Kosierskraal at the time of my visit. Mick D'alton explained that the habitat was suitable, and the steenbok continued to be seen frequently outside of the game paddock. His view was that competition for food by the springbok had locally usurped the niche of the steenbok.
Farmers hereabouts believed that the caracal had greatly depleted the small wild ruminants, which it prefers as prey over the domestic sheep (Ovis aries). However, it was also true that the domestic sheep had reduced the cover required by the small ruminants.
Fallow deer (Dama dama)
Mick D'alton told me that this species thrives in this area, going feral, and becoming elusive, secretive, and self-sufficient; it hides and forages in the local thickets of Acacia saligna. He emphasised that the fallow deer was as successful as the indigenous ruminants, given the availability of non-indigenous thickets.
Thickets of Australian spp. of Acacia had also favoured the southern bushbuck. I infer that any given patch of non-indigenous thicket was utilised by one or another of these ruminants, but not both.
Domestic goat (Capra hircus)
At Kosierskraal, this species
- ate the mature foliage of Acacia saligna, particularly if cut down,
- did not avidly eat the seedlings of A. saligna, which seem to be heavily defended chemically,
- did not seem to eat Carpobrotus, which increased in a paddock devoted to the domestic goat.
Mick D'alton also told me that, in another paddock inhabited by the domestic goat at a low-lying position topographically, Leucadendron spp. (including Leucadendron linifolium, https://www.inaturalist.org/taxa/589072-Leucadendron-linifolium) seemed to survive heavy browsing.
He also told me of an experiment to see if the domestic goat could control invasive stands of Acacia saligna. This was conducted on the farm Tripolanda Trust. However, the experiment failed, in the sense that, in the paddock concerned, the fynbos was damaged to the same extent and degree as the introduced acacia.
Domestic sheep (Ovis aries)
This species, although kept elsewhere on the Agulhas Plain, was absent at Kosierskraal.
European bost (Bos taurus)
This species fared well enough at Kosierskraal, normally reproducing every year up to 10 years old. Females produced their first infant in their third year, after mating during their second year.
Culling was applied once an age of 10 years was reached. After this, production was subeconomic.
At Kosierskraal, the European bost
- routinely ate fuzzy, low restios,
- ate Carpobrotus in summer (like the common eland),
- nibbled at juveniles of A. saligna; I watched an infant browsing a sapling of this species, about 1 m high, and
- preferred to eat the foliage of A. saligna one day after this was cut down, presumably because this reduces the secondary compounds.
MANAGEMENT OF UNGULATES
Lightning was the confirmed cause of wildfire hereabouts, in the summer of 1999/2000.
Nutrient deficiencies:
Copper-deficiency was known to be a regional problem for ungulates. Therefore, Mick D'alton put out a copper-based lick block.
However, none of the ungulates ever accepted any lick block.
Mick D'alton recorded no geophagy (https://en.wikipedia.org/wiki/Geophagia) here, but osteophagy (https://en.wikipedia.org/wiki/Osteophagy) was frequently recorded.
Drought:
A drought had occurred 10 years previously, in 1991. So little grass was available that the European bost could not survive. However, no food supplements whatsoever were given to any of the ungulate species.
Both the black wildebeest and the common eland lost condition, despite being given sufficient water. Both were foraging mainly in the same areas (with diets consisting partly of fynbos plants), as opposed to being segregated.
However, the black wildebeest survived the drought with few losses (only 2 of a population of 40, compared to 50 of 75 for the common eland, and 30 of 45 for the bontebok).
Most individuals of the common eland died in the drought, despite having access to Acacia saligna. Contrary to expectations based on indigenous status, the black wildebeest fared better during the drought than did the common eland.
Both species became susceptible to parasites under stress; the black wildebeest was not necessarily more resistant than the common eland to parasites.
The bontebok, too, fared poorly during this drought. It suffered from parasites.
OTHER ANIMALS
Termite-eating mammals:
The bat-eared fox (Otocyon megalotis) had recently become common hereabouts.
The aardwolf (Proteles cristatus, https://www.inaturalist.org/taxa/1306005-Proteles-cristatus) had been present about 8 years previously. Mick D'alton recorded three individuals (an adult plus two juveniles) as road-killed simultaneously on a road adjacent to his property. By the time of my visit, this species seemed to have disappeared from the area.
However, as I write, I note that there is a recent observation of a road-killed specimen in the immediate vicinity of Kosierskraal (https://www.inaturalist.org/observations/79498114).
Mick D'alton reported having previously observed a road-killed specimen of the aardwolf at Akkedisberg Pass (https://en.wikipedia.org/wiki/Akkedisberg_Pass).
Birds:
Ostrich (Struthio camelus)
The ostrich was absent from Kosierskraal. However, I note that this species is present today, in this immediate area (https://www.inaturalist.org/observations/33745752 and https://www.inaturalist.org/observations/26587578).
Fork-tailed drongo (Dicrurus adsimilis, https://www.inaturalist.org/taxa/8268-Dicrurus-adsimilis)
I watched this species attending a group of 4 of the common eland, standing on the ground next to the hooves, and flying up to land on the withers. Mick D'alton told me he had observed this species flying up between the legs to pick something off the skin, without perching. (The fork-tailed drongo seems to act partly as an oxpecker here, not just taking insects disturbed by the ungulate, but actually taking invertebrates associated with the animal, including directly off its body.) Then, as we watched, this happened in front of us.
Blue crane (Anthropoides paradiseus, https://www.inaturalist.org/taxa/144286-Anthropoides-paradiseus)
I observed this species on an extensive anthropogenic lawn, now dull green during a relatively dry spell, of Pennisetum clandestinum and Cynodon dactylon, maintained entirely by the European bost and the reintroduced ruminants.
Insects:
Snouted harvester termite (Trinervitermes trinervoides)
I observed large termitaria (1 m high) of this species of grass-harvesting termite in Elim Flats dwarf fynbos, including in the vicinity of Protea repens (https://www.inaturalist.org/taxa/355849-Protea-repens and https://www.inaturalist.org/observations/141358640). At the time, I wondered whether it harvests mainly Restionaceae in fynbos, and today I still do not know.
Mick D'alton told me that fires in Elim Flats dwarf fynbos are intense enough - despite the low stature of this type of fynbos - that the termitaria of T. trinervoides subsequently collapse. I noted that a collapsing, fragile termitarium consisted of sandy clay loam, soft and brittle.
He also mentioned that the domestic bost had a habit of rubbing on the termitaria, thus destroying them. Removal of this species of livestock from a paddock allowed the number of termitaria to increase.
I observed an old, abandoned termitarium of T. trinervoides. Excavating this, I found large, robust roots of Acacia saligna reaching up through it. The accompanying odour was strong, resembling cut onions.
DISCUSSION
I find scant reference to Kosierskraal on the Web today, suggesting that the game farm is now defunct, at least as a tourist-attraction.
However, it is now one of the sites for the quagga re-breeding project (https://www.quaggaproject.org/ and https://www.inaturalist.org/observations/113812038 and https://www.inaturalist.org/observations/115584188). This is confirmed by https://www.inaturalist.org/observations/101930627), despite the misspelling 'Coetzeekraal'.
The special interest of this region, for me, was the combination of fynbos (which is regarded as unpalatable and unproductive for large animals) and the incidence of considerable populations of wild ungulates in prehistoric times on the Agulhas Plain.
I was surprised that the ungulates at Kosierskraal showed no interest in supplementary nutrients, in the form of lick-blocks.
I was also surprised that
- the black wildebeest fared as well as it did, given that the Agulhas Plain is far from its recent distribution, and
- the bontebok fared poorly, despite this being its typical habitat.
The black wildebeest at Kosierskraal foraged mainly on previously cultivated land.
I infer the possibility that these two alcelaphin grazers competed with each other, to the detriment of the bontebok. I suspect that, if Mick D'alton had not introduced the black wildebeest, the bontebok might have fared well at Kosierskraal.
It is clear that the common eland fares well on the coastal plains of the southwestern Cape, even when its original seasonal movements are no longer possible. Furthermore, it grows to its full genetic potential here, in contrast to populations conserved in the Drakensberg (https://hikingthedrakensberg.blogspot.com/2017/09/wildlife-of-drakensberg-story-of-eland.html and https://en.wikipedia.org/wiki/Drakensberg), where stunted-looking individuals have been typical (https://www.inaturalist.org/observations/64785188 and https://www.inaturalist.org/observations/10007389 and https://www.inaturalist.org/observations/11332783 and https://www.inaturalist.org/observations/92906834).