milewski's Journal
October 06, 2022
Compendium of photos of Raphicerus sharpei on the Web, part 1
Raphicerus sharpei is among the most obscure species of antelopes in the national parks of southern Africa, being scarce, small, cryptic in colouration, timid, non-gregarious, and nocturnal.
Therefore, nobody would be surprised to find that few photos of this species have been posted on the Web.
The reality is surprising: there are so many photos available that it is hard to Post them all.
The following is a compendium of all the photos of R. sharpei that I can currently find, excluding those on iNaturalist.
Collectively, they provide excellent documentation of the appearance of this species.
October 05, 2022
Summary of my recent observations: diagnostically pale features on the hindquarters of bovid bambis (Ourebia, Raphicerus, and Madoqua)
@joni_overbosch @beartracker @davidbygott @tonyrebelo @ludwig_muller @jeremygilmore @tandala @dejong @michalsloviak @oviscanadensis_connerties @capracornelius @tbutynski @zarek @simontonge @jwidness @johnnybirder @calebcam @jakob @henrydelange @wasinitourguide @geichhorn @paradoxornithidae @jacqueline_llerena @koosretief @justinhawthorne @happyasacupcake @marcelo_aranda @enricotosto96 @diegoalmendras @michaelweymann @fionahellmann
The following aspects of adaptive colouration have previously been overlooked. They may additionally be diagnostic, taxonomically.
OUREBIA
Ourebia ourebi differs from Ourebia montana in possessing a bleeze on the hindquarters.
RAPHICERUS
Raphicerus campestris campestris exceeds all other subspecies in the degree of development of a buttock flag.
MADOQUA
Madoqua damarensis differs from Madoqua kirkii in lacking white on the buttocks.
Madoqua kirkii/hindei differs from Madoqua thomasi/cavendishi in possessing white on the buttocks.
ILLUSTRATIONS
I have selected the following to illustrate the diagnostic features mentioned above.
OUREBIA
Presence of bleeze on hindquarters in Ourebia ourebi:
https://www.inaturalist.org/observations/98375681
Absence of bleeze on hindquarters in Ourebia montana:
https://www.inaturalist.org/observations/33557962
RAPHICERUS
Well-developed buttock flag in Raphicerus campestris campestris: https://www.inaturalist.org/observations/85907385 and https://www.inaturalist.org/observations/126223294 and https://www.alamy.com/a-male-cape-or-southern-grysbok-raphicerus-melanotis-running-through-the-veld-in-the-boland-region-of-the-western-cape-province-of-south-africa-image187402642.html?imageid=8D98430A-FCFE-41F4-AA29-B6B781700C2F&p=77702&pn=1&searchId=886c6fde8e008fc7cc881b5daa323fb1&searchtype=0
Relatively poorly-developed buttock flag in other sspp. of Raphicerus campestris: https://www.istockphoto.com/photo/steenbok-in-kruger-national-park-gm1419290036-465690019?phrase=steenbok and https://www.inaturalist.org/observations/13490802 and https://www.inaturalist.org/observations/72501302
Fibular flag in:
Raphicerus melanotis https://www.inaturalist.org/observations/26439871
MADOQUA
Absence of white on buttocks in:
damarensis https://www.inaturalist.org/observations/1818615
thomasi/cavendishi https://stock.adobe.com/search?k=dikdik&asset_id=71439139
Presence of white on buttocks in:
White on the buttocks: a previously overlooked species-difference in dikdiks of the Madoqua kirkii-Madoqua damarensis complex?
@joni_overbosch @beartracker @davidbygott @tonyrebelo @ludwig_muller @jeremygilmore @tandala @dejong @michalsloviak @oviscanadensis_connerties @capracornelius @tbutynski @zarek @simontonge @jwidness @johnnybirder @calebcam @jakob @henrydelange @wasinitourguide @geichhorn
In recent Posts, I have shown previously overlooked variation among the species/subspecies in two genera of bambis, namely Ourebia (https://www.inaturalist.org/journal/milewski/70050-the-three-main-types-of-oribi-ourebia-at-a-glance#) and Raphicerus (https://www.inaturalist.org/journal/milewski/70293-the-bambis-part-9-bleezes-flags-and-semets-in-the-bovid-genus-raphicerus#).
I now turn to another genus of bambis, namely Madoqua (https://www.inaturalist.org/observations?place_id=any&taxon_id=42358&view=species).
The species and subspecies of Madoqua may seem too taxonomically complicated for many naturalists to disentangle.
De Jong and Butynski (2017, https://www.lolldaiga.com/wp-content/uploads/De-Jong-Butynski-2017-Madoqua-E-Africa.pdf) have greatly clarified the distinctions among various forms in the kirkii-complex and superficially similar Madoqua guentheri.
However, they seem to have overlooked what is perhaps major variation in adaptive colouration among the species and subspecies in this geographically bewildering set of taxa.
I refer to the incidence, extent, and flaring of whitish pelage on the buttocks - which in some taxa is displayed to potential predators.
What I have noticed, after perusing hundreds of photos, is that there is a range of apparency of white on the hindquarters, as follows:
- maximal in M. guentheri, minimal in M. damarensis (restricted to southern Africa), and intermediate in the kirkii-complex of East Africa, and
- within the kirkii-complex: maximal in nominate kirkii and hindei, vs minimal in thomasi and cavendishi.
In M. guentheri, there is a well-developed, white buttock flag (https://www.inaturalist.org/observations/85335207). This is normally folded out of sight, but is activated in alarm.
In M. damarensis, there no buttock flag. Furthermore, whitish pelage is absent from the buttocks, being restricted to the inner surface of the uppermost hindleg, where it is obscured from view (https://www.alamy.com/damara-dik-dik-on-arid-landscape-image265477351.html?imageid=9918B4C6-E7A2-4558-A9A9-8A4C5986763B&p=925654&pn=2&searchId=812e1b51f3bb17a7cc79ddae25b30690&searchtype=0), even when the animal flees.
In thomasi and cavendishi, the white pelage on the inner upper hindleg hardly reaches the inner surface of the buttock (cavendishi: https://www.inaturalist.org/observations/35760408 ; cavendishi/thomasi: https://www.inaturalist.org/observations/19457512).
Instead, there is a darkened effect, owing to the grey, grizzled pelage on the inner buttock being viewed from a certain angle (also see https://www.inaturalist.org/observations/16658138 and https://www.alamy.com/stock-photo-a-damara-dik-dik-antelope-in-tarangire-national-park-tanzania-125863282.html?imageid=D2243709-A771-41B3-8555-80339AB1FF98&p=149870&pn=1&searchId=a091ff7a0a8c31eef18a8931488c16a4&searchtype=0).
In nominate kirkii and (to a lesser extent?) hindei, considerable whitish is normally apparent on the buttocks. It remains unknown whether this can be activated by piloerection.
What emerges is that, w.r.t. the colouration of the buttocks, the southern and western forms of the kirkii-complex in East Africa may be more similar to the widely disjunct damarensis of southern Africa than they are to nearby kirkii, the nominate, northeasternmost form.
This raises the possibility that there are two species, one of them extremely disjunct - in a biogeographic parallel to sympatric Raphicerus campestris, which also shows wide disjunction between southern and East Africa.
These would be
- a southwesterly species, comprising damarensis (disjunct), thomasi, and cavendishi (https://www.inaturalist.org/observations/57105762), and
- a northeasterly species, comprising nominate kirkii (https://www.alamy.com/stock-photo-dik-dik-madoqua-species-meru-national-park-kenya-the-animal-is-facing-34546136.html?imageid=3A6956A3-7664-4DCD-8AE0-84154B73F32F&p=33818&pn=1&searchId=a091ff7a0a8c31eef18a8931488c16a4&searchtype=0 and https://www.inaturalist.org/observations/137631006) and hindei (https://www.inaturalist.org/observations/66784701).
If so, the basic geographical feature separating the two spp. would be the eastern arm of the Great African Rift (https://en.wikipedia.org/wiki/Great_Rift_Valley#/media/File:Great_Rift_Valley.png), from Lake Turkana (https://en.wikipedia.org/wiki/Lake_Turkana) in the north to Lake Manyara (https://en.wikipedia.org/wiki/Lake_Manyara) in the south.
Such geographical separation would be analogous with that previously recognised between
- Connochaetes albojubatus and Connochaetes mearnsi, and
- Kobus ellipsiprymnus and Kobus defassa.
The following show the buttock flag in Madoqua guentheri:
https://www.inaturalist.org/observations/108449533
https://www.inaturalist.org/observations/109570355.
The following shows that there is no analogous flag in cavendishi/thomasi:
https://www.inaturalist.org/observations/34632953.
GUENTHERI
Many photos of M. guentheri show a whitish horizontal mark on the hindquarters (just below the small tail), which I have never seen in any other species in the genus:
https://www.inaturalist.org/observations/44891973
https://www.inaturalist.org/observations/48668687
https://www.inaturalist.org/observations/92503134
https://www.inaturalist.org/observations/46592563
https://www.inaturalist.org/observations/42815125
https://www.inaturalist.org/observations/34171472
https://www.inaturalist.org/observations/10498051
This indicates a fur-fold which opens out into a broad, white, buttock flag.
This resembles the buttocks in Raphicerus campestris (https://dewetswild.com/tag/steenbok/#jp-carousel-37747). However, it is more pronounced, with a more complex, origami-like unfolding - both vertically and horizontally - of panels of pelage.
KIRKII (nominate)
The following show that there is more extensive white on the hindquarters than in damarensis.
This white pelage is visible without any particular activation, partly because the panel of grizzled, grey pelage of the outer buttock is shorter than in damarensis, thomasi, and cavendishi.
The adaptive colouration thus seems to confirm that damarensis is a different species from nominate kirkii, and not merely a subspecies.
second photo in https://www.inaturalist.org/observations/130962038
https://www.inaturalist.org/observations/104469910
https://www.inaturalist.org/observations/104465769
https://www.inaturalist.org/observations/56610068
https://www.inaturalist.org/observations/127865878
https://www.inaturalist.org/observations/6998029
https://www.inaturalist.org/observations/19215378
https://www.inaturalist.org/observations/54460753
https://www.inaturalist.org/observations/104983315
https://www.inaturalist.org/observations/53348887
https://www.inaturalist.org/observations/36294376
https://www.inaturalist.org/observations/135184955
https://www.inaturalist.org/observations/66263881
https://www.inaturalist.org/observations/104982491
https://www.inaturalist.org/observations/66064513
https://www.inaturalist.org/observations/104982477
https://www.inaturalist.org/observations/104982469
https://www.inaturalist.org/observations/66101649
https://www.inaturalist.org/observations/104982481
https://www.inaturalist.org/observations/104982488
https://www.inaturalist.org/observations/104982474
https://www.inaturalist.org/observations/104982464
https://www.inaturalist.org/observations/94054422
https://www.inaturalist.org/observations/94037750
https://www.inaturalist.org/observations/54885436
https://www.inaturalist.org/observations/67329073
https://www.inaturalist.org/observations/43545138
https://www.inaturalist.org/observations/57490463
The following shows that the whitish on the buttocks can be seen at some distance:
https://www.inaturalist.org/observations/67328340
The following is the only photo of nominate kirkii, in posteriolateral view, that could be confused with damarensis on the basis of the colouration of the hindquarters: https://www.inaturalist.org/observations/104982462.
HINDEI
The following show that considerably more white is visible on the hindquarters than in damarensis. This seems, at least partly, because the pelage of the outer buttock is shorter than that of damarensis.
Whether this qualifies as a buttock flag remains unclear, because this would depend on
- a flaring mechanism (see https://www.inaturalist.org/observations/59156961) that remains to be observed, and/or
- an ultraviolet aspect to the colouration of the pelage.
https://www.inaturalist.org/observations/93574203
https://www.inaturalist.org/observations/106353312
https://www.inaturalist.org/observations/69253350
https://www.inaturalist.org/observations/65705924
https://www.inaturalist.org/observations/104985979
https://www.inaturalist.org/observations/88356487
https://www.inaturalist.org/observations/38088841
https://www.inaturalist.org/observations/49698957
https://www.inaturalist.org/observations/9839405
https://www.inaturalist.org/observations/120567853
https://www.inaturalist.org/observations/106400612
https://www.inaturalist.org/observations/136176636
https://www.inaturalist.org/observations/132019130
https://www.inaturalist.org/observations/106400622
https://www.inaturalist.org/observations/7094056
https://www.inaturalist.org/observations/104985978
https://www.inaturalist.org/observations/103589197
https://www.inaturalist.org/observations/63258767
https://www.inaturalist.org/observations/68337080
The following, at the lower Tana River in eastern Kenya, do not show any white on the buttocks:
https://www.inaturalist.org/observations/8035356
https://www.inaturalist.org/observations/8035355.
CAVENDISHI
The following show that, if white is more evident on the hindquarters of cavendishi than on those of damarensis, the difference is slight.
https://www.inaturalist.org/observations/102103762
https://www.inaturalist.org/observations/121609294
https://www.inaturalist.org/observations/121987458
https://www.inaturalist.org/observations/28289382
https://www.inaturalist.org/observations/130009932
https://www.inaturalist.org/observations/126027728
https://www.inaturalist.org/observations/54027328
https://www.inaturalist.org/observations/108501982
https://www.inaturalist.org/observations/108373392
https://www.inaturalist.org/observations/107139654
https://www.inaturalist.org/observations/107139648
https://www.inaturalist.org/observations/105392544
https://www.inaturalist.org/observations/103901346
https://www.inaturalist.org/observations/95525881
https://www.inaturalist.org/observations/85640172
https://www.inaturalist.org/observations/68957254
https://www.inaturalist.org/observations/31994682
The following individual shows the maximum extent of whitish on the buttocks:
https://www.inaturalist.org/observations/43172082.
THOMASI
https://www.inaturalist.org/observations/21312691
https://www.inaturalist.org/observations/7812390
https://www.inaturalist.org/observations/764507
https://www.inaturalist.org/observations/61868136
The following does show some white on the buttocks:
https://www.inaturalist.org/observations/15041808.
INTERGRADATIONAL between cavendishi and thomasi, in Tarangire and Lake Manyara National Parks, Tanzania:
https://www.inaturalist.org/observations/19944469
https://www.inaturalist.org/observations/103939955
https://www.inaturalist.org/observations/135088492
https://www.inaturalist.org/observations/1818614
https://www.inaturalist.org/observations/864173
https://www.inaturalist.org/observations/105631501
https://www.inaturalist.org/observations/27609142
https://www.inaturalist.org/observations/104807392
https://www.inaturalist.org/observations/128035858
https://www.inaturalist.org/observations/102033238
https://www.inaturalist.org/observations/97421799
https://www.inaturalist.org/observations/93832001
https://www.inaturalist.org/observations/90118758
The following, in Arusha National Park, look like thomasi rather than hindei:
https://www.inaturalist.org/observations/67200531
https://www.inaturalist.org/observations/8708916.
DAMARENSIS
The following show that the occurrence of whitish on the hindquarters is limited to the inner surface of the upper hindleg, with hardly any sign of any extension on to the buttocks.
https://www.inaturalist.org/observations/41807012
https://www.inaturalist.org/observations/37693539
https://www.inaturalist.org/observations/86033865
https://www.inaturalist.org/observations/99881333
https://www.inaturalist.org/observations/37625508
https://www.inaturalist.org/observations/9704334
https://www.inaturalist.org/observations/52150014
https://www.inaturalist.org/observations/39830600
https://www.inaturalist.org/observations/14293979
https://www.inaturalist.org/observations/128717848
https://www.inaturalist.org/observations/14702761
https://www.inaturalist.org/observations/25626334
https://www.inaturalist.org/observations/33784213
https://www.inaturalist.org/observations/107650742
https://www.inaturalist.org/observations/90441472
https://www.inaturalist.org/observations/85993599
https://www.inaturalist.org/observations/85739109
https://www.inaturalist.org/observations/83787773
https://www.inaturalist.org/observations/33126151
Second photo in https://www.inaturalist.org/observations/74072495
https://www.inaturalist.org/observations/65453512
https://www.inaturalist.org/observations/59859034
tail raised, revealing the black bare skin around anus:
https://www.inaturalist.org/observations/66833293
The following does show some white:
https://www.alamy.com/a-damara-dik-dik-or-kirks-dik-dik-maquoda-kirkii-in-grass-during-the-wet-season-at-erindi-reserve-in-erongo-region-namibia-image367603484.html?imageid=BE2F0F65-D863-4D63-B019-455BE8C48547&p=767630&pn=1&searchId=a091ff7a0a8c31eef18a8931488c16a4&searchtype=0.
October 03, 2022
An attempted photo-guide to the subspecies of the steenbok (Raphicerus campestris) is partly a self-refuting exercise
@tonyrebelo @jeremygilmore @ludwig_muller @capracornelius @simontonge @tandala @geichhorn @michalsloviak @colin25 @alanhorstmann @jakob @jwidness @dejong @davidbygott @koosretief @gigilaidler
Today, I set out to illustrate - in the spirit of a field guide-book - the various subspecies of the steenbuck (Raphicerus campestris, https://www.inaturalist.org/taxa/42375-Raphicerus-campestris).
I was only partly successful, and this was not because of a lack of photos on the Web
Something important to realise, which has not emerged in the literature, is the following.
The northern subspecies (https://www.awl-images.com/stock-photo-kenya-taita-taveta-county-tsavo-east-national-park-a-steinbuck-image00398991.html) is only slightly different from the subspecies found in eastern South Africa (https://www.alamy.com/steenbok-raphicerus-campestris-adult-female-standing-on-the-ground-mpumalanga-south-africa-image384329875.html).
This is despite a wide geographical disjunction and the associated reproductive isolation.
It is instead the southernmost subspecies, living in a temperate zone, that is recognisable in photos.
What this means is that only two subspecies can be claimed with confidence, viz.
- nominate campestris, and
- neumanni, in a broadened sense.
The remaining subspecies (capricornis and steinhardti) are recognised mainly because of an assumption that their own wide geographical and climatic spread, from the edge of the Namib desert to the edge of miombo woodland in Zimbabwe, must surely be reflected in subspeciation.
It remains possible that even the adaptation to aridity within this species is (https://www.alamy.com/stock-photo-steenbok-raphicerus-campestris-desert-rhino-camp-damaraland-namibia-91113533.html?imageid=222AA12F-6CFE-4847-893B-A221FB5DEA88&p=71799&pn=2&searchId=61806f9903717abe80887586aa50fbc7&searchtype=0) is merely a matter of ecotypes, rather than a matter of subspeciation.
Another important point is that there is enough individual variation in the steenbok to blur any subspecies-distinctions.
The result:
The distinctions among neumanni, capricornis, and steinhardti are so slight that I have found it hard to compile any 'typical' photos of them, in which the subspecific differences are self-evident.
The following is my best attempt, after sifting through thousands of photos.
RAPHICERUS CAMPESTRIS CAMPESTRIS
Western Cape and adjacent parts of Northern Cape and Eastern Cape, South Africa
ground-colour dark
https://www.inaturalist.org/observations/98597843
https://www.inaturalist.org/observations/78046023
https://www.inaturalist.org/observations/52877690
forehead rich-hued
https://stock.adobe.com/ro/images/big-ears/441156073?prev_url=detail
white features (except for buttocks) minimal, particularly on face and inner upper hindleg
https://www.shutterstock.com/image-photo/cape-grysbok-184337792
https://www.istockphoto.com/photo/grysbok-cape-gm1134456769-301460055?phrase=grysbok
RAPHICERUS CAMPESTRIS STEINHARDTI
southern Angola, most of Botswana, Namibia except for eastern Caprivi, part of Northern Cape of South Africa
ground colour pale
size of ear pinnae maximal
radial gland noticeable
RAPHICERUS CAMPESTRIS CAPRICORNIS
Mpumalanga, Limpopo, northeastern Kwazulu-Natal, eSwatini, southern Mozambique, Zimbabwe, eastern Caprivi of Namibia, eastern and northeastern Botswana, southwestern Zambia
forehead rich-hued
size of ear pinnae minimal
radial gland noticeable
RAPHICERUS CAMPESTRIS NEUMANNI
Kenya, Tanzania
Despite the geographical isolation of the East African part of the species-distribution, I have failed to find any consistent difference between this supposed subspecies and capricornis.
October 02, 2022
Selected views of the bambi genus Madoqua, plus noteworthy photos mislabelled as dikdiks on the Web
MADOQUA DAMARENSIS
https://www.inaturalist.org/observations/72199054
https://www.inaturalist.org/observations/11220482
showing anomalous whitish at knee
https://www.inaturalist.org/observations/92816759
https://stock.adobe.com/images/kirk-s-dik-dik/11627412?prev_url=detail
The following shows how the accentuation of the eye seems to undermine the cryptic colouration:
https://upload.wikimedia.org/wikipedia/commons/7/75/Damara_Dik-Dik.JPG
https://stock.adobe.com/search?k=dikdik&asset_id=77363734
https://www.sciencephoto.com/media/873025/view/damara-dik-dik
https://ekujasafari.com/hunting-darma-dik-dik-namibia/
https://stock.adobe.com/search?k=dikdik&asset_id=60051921
cavendishi? https://stock.adobe.com/search?k=dikdik&asset_id=280950356
MADOQUA KIRKII East Africa
https://stock.adobe.com/images/dik-dik/28620223?prev_url=detail
https://www.jungledragon.com/image/116371/dik-dik_antelope.html/zoom
https://www.vecteezy.com/photo/844782-kirk-s-dik-dik-madoqua-kirkii-damara-dikdik-kirk-dik
https://naturerules1.fandom.com/wiki/Kirk%27s_Dik-dik?file=96bf2c9bad44e82e8bc041c27497e5d9.jpg
https://wildlifesafari.info/kirks_dikdik.html
https://stock.adobe.com/search?k=dikdik&asset_id=357153060
https://stock.adobe.com/search?k=dikdik&asset_id=46502141
https://stock.adobe.com/search?k=dikdik&asset_id=245343557
https://stock.adobe.com/search?k=dikdik&asset_id=315354748
https://stock.adobe.com/search?k=dikdik&asset_id=464916173
https://stock.adobe.com/search?k=dikdik&asset_id=437570754
https://stock.adobe.com/search?k=dikdik&asset_id=308981505 and https://stock.adobe.com/search?k=dikdik&asset_id=308981470
MADOQUA SALTIANA
https://upload.wikimedia.org/wikipedia/commons/5/5d/Salts_Dikdik.jpg
MADOQUA GUENTHERI
https://stock.adobe.com/search?k=dikdik&asset_id=64450247
https://stock.adobe.com/search?k=dikdik&asset_id=94546206
October 01, 2022
A new hypothesis for the steenbok (Raphicerus campestris) in the Highveld of South Africa: it was naturally absent
@paradoxornithidae @matthewinabinett @dejong @tonyrebelo @jeremygilmore @ludwig_muller @dewald2 @henrydelange @koosretief @jakob @justinhawthorne @botswanabugs @capracornelius
It is easy to assume that the steenbok (Raphicerus campestris) was indigenous to the Highveld (https://en.wikipedia.org/wiki/Highveld) when European explorers arrived.
However, I suggest that it was actually absent.
This would help to explain why its current taxonomic status in the Highveld is so nebulous (https://www.inaturalist.org/journal/milewski/70638-the-steenbok-raphicerus-campestris-in-the-highveld-a-simple-question-gone-impossibly-complex#).
My argument is based on an ecological rationale, but seems consistent with the historical record.
The steenbok tends to be taken for granted as widespread and ecologically tolerant. However, it is more ecologically specialised than first it seems, in diet and habitats.
This species is part of a guild of relatively small herbivores including
- Antidorcas marsupialis (https://www.inaturalist.org/observations/66931375),
- Redunca fulvorufula (https://www.inaturalist.org/observations/74576197),
- Ourebia ourebi (https://www.inaturalist.org/observations/100711449), and
- Lepus capensis (https://www.inaturalist.org/observations/68999642).
All eat both grasses and dicotyledonous plants, in various combinations according to the seasons (https://www.researchgate.net/publication/230164079_The_feeding_ecology_of_a_very_small_ruminant_the_steenbok_Raphicerus_campestris).
Because it has so many competitors, R. campestris may have been somewhat limited in occurrence in prehistoric South Africa, when the full fauna of the Holocene remained.
The Highveld contained by far the most complex fauna of ungulates of any region of treeless grassland on Earth (https://www.sciencedirect.com/science/article/pii/S0254629915003051 and https://www.researchgate.net/publication/282619832_Why_was_the_Highveld_treeless_Looking_laterally_to_the_Pampas_for_global_edaphic_principles_beyond_biogeographical_accidents). This may have precluded a niche for R. campestris under natural conditions.
I suspect that it was only when the fauna was disrupted by human settlement that R. campestris spontaneously entered the Highveld, from the west and north.
The idea is that it filled in for the species virtually exterminated by settlers, particularly the formerly abundant and migratory A. marsupialis.
This is not to claim that R. campestris became abundant in the Highveld, but merely that it became viable there because of, rather than despite, anthropogenic disturbance.
Three subspecies were thus hypothetically recruited to the Highveld, then mixing there through hybridisation. These are R. c. campestris (southwesterly origin), R. c. steinhardti (northwesterly origin), and R. c. capricornis (northeasterly origin).
Another basis for my hypothesis is habitat, particularly the natural availability of cover.
In its original state, the Highveld was treeless over extensive areas, partly owing to the intense natural herbivory. This hypothetically made the grassland too open for R. campestris.
There are two situations, in the Highveld today, with some shrubby indigenous cover, viz.
- perennial drainage lines, and
- scattered rocky outcrops.
However,
- the former are typical habitat of the somewhat competitive Sylvicapra grimmia (https://www.inaturalist.org/observations/57811991) and Lepus saxatilis/victoriae (https://www.inaturalist.org/observations/11873978), whereas
- the latter were, I suspect, negligibly woody under the original regime of intense herbivory by Taurotragus oryx (https://www.inaturalist.org/observations/13007563 and https://www.inaturalist.org/observations?place_id=50327&taxon_id=75192&view=species) in particular.
The settlement of the Highveld has boosted the incidence of woody plants, for various reasons.
I have before me du Plessis S F (1969, The Past and Present Geographical Distribution of the Perissodactyla and Artiodactyla in Southern Africa).
On page 100, du Plessis states for 'Orange Free State':
"Though no doubt occurring everywhere in this province in the past, practically no written records could be traced...Only Smith (Kirby, 1939) in 1835 mentions it as being common near the confluence of the Riet and Modder rivers".
This location (https://en.wikipedia.org/wiki/Riet_River) is actually west of Free State province and the Highveld, being located in the current Mokala National Park (https://en.wikipedia.org/wiki/Mokala_National_Park).
Much of the Highveld occurs in the former Transvaal (https://en.wikipedia.org/wiki/Transvaal_(province)). However, once again du Plessis (1969) largely draws a blank in the historical record.
The exceptions are as follows:
- "Mauch (Petermann, 1870): north of Lydenburg"
- "Holub (1881): near the Vaal River in western Transvaal"
- "Holub (1890): between Bloemhof and Christiana"
- "Baldwin (1894): the vicinity of Potchefstroom"
- "Randall (1895): the open flats in the Barberton District."
The relevant locations mentioned are:
- https://en.wikipedia.org/wiki/Lydenburg
- https://en.wikipedia.org/wiki/Bloemhof
- https://en.wikipedia.org/wiki/Christiana,_North_West
- https://en.wikipedia.org/wiki/Potchefstroom
- https://en.wikipedia.org/wiki/Barberton,_Mpumalanga.
All of these are rather marginal to the Highveld, except for Potchefstroom. However, the latter is located in the valley of a major drainage line (https://en.wikipedia.org/wiki/Mooi_River_(Vaal)).
On page 103, du Plessis states the incidence, as of 1969, as follows:
"Orange Free State: Van Ee (1962): fairly generally distributed throughout the province with the greatest numbers along the rivers and in the mountainous districts of the east, especially in the Fouriesburg, Tweeling, Petrus Steyn, Boshoff, Theunissen, Brandfort, Hoopstad and Koffiefontein districts. Roberts (1963): 45 in the Willem Pretorius Game Reserve".
The status in Transvaal (page 104) was similarly widespread, as of 1969.
So, dear readers, please prove me wrong in my suggestion that the steenbok was naturally absent from the Highveld, including virtually the whole of what is now Free State.
One way to do so might be to consult a work to which I currently lack access. This is by Skead (https://en.wikipedia.org/wiki/CJ_Skead), covering that part of the Highveld falling within the Eastern Cape (https://ace.mandela.ac.za/Historical-Incidence-of-the-Larger-Mammals/Authors/The-works-of-Cuthbert-John-(Jack)-Skead),
In the meantime, the following is a compendium of all the current photos of R. campestris, located in the Highveld, in iNaturalist:
https://www.inaturalist.org/observations/129166689
https://www.inaturalist.org/observations/105216875
https://www.inaturalist.org/observations/108317173
https://www.inaturalist.org/observations/69266940
https://www.inaturalist.org/observations/127743228
https://www.inaturalist.org/observations/127670769
https://www.inaturalist.org/observations/98953074
https://www.inaturalist.org/observations/130857789
Only four of the above observations show the animals clearly.
September 30, 2022
The steenbok (Raphicerus campestris) in the Highveld: a simple question gone impossibly complex?
It strikes me that the relationship between Raphicerus campestris (https://www.inaturalist.org/taxa/42375-Raphicerus-campestris) and the Highveld (https://en.wikipedia.org/wiki/Highveld) is particularly complicated and obscure.
On the face of it, one might have expected this relationship to be simple.
After all, R. campestris is typical of open, grassy vegetation, and the Highveld is a fairly discrete region within which it would be reasonable to expect just one, easily recognisable, subspecies of R. campestris.
But, in reality, there are at least four factors that cloud everything.
Firstly, the 'sour' type of Highveld, consisting of unpalatable, fire-prone grasses on poor soils under relatively copious rainfall, lacks R. campestris completely.
Secondly, even within the 'sweet' type of Highveld, consisting of palatable, fire-free grasses on rich soils under relatively sparse rainfall, R. campestris seems oddly uncommon, and overlooked/ignored in the records of the first European explorers of the 1800's.
Thirdly, the history of scientific collection of R. campestris happens to have been such that, as if by accident, the maximum uncertainty has arisen in the relationship of candidate sspp. fulvorubescens, 'natalensis', zuluensis, and capricornis to the Highveld.
Fourthly, the political (country/province) boundaries in the Highveld are complex and (https://www.intergate-immigration.com/blog/south-african-provinces/), have changed names recently, and have scant relationship to ecological boundaries.
So much so that they continue to hinder, rather than help, any biogeographical study of the region.
For iNaturalists other than South Africans, I can summarise this problem as follows.
The Latin specific name 'campestris' simply means 'of the veld'.
('Veld' is Afrikaans for 'field'.)
The main/typical area of 'veld' is the Highveld.
Yet, as things stand, it seems beyond us to account for the occurrence of R. campestris in the Highveld, past or present, in any coherent way, including even the subspecies concerned.
South Africa has been intensively studied by naturalists.
Yet, somehow, we seem to remain as mystified about the steenbok - possibly the 'commonest' small wild ungulate in the country - on the Highveld as we might be about some newly-discovered species of duiker in the equatorial Congo.
September 29, 2022
A gland new to Science, hiding in plain sight on the steenbok (Raphicerus campestris)?
There seems to be a gland in the steenbok (Raphicerus campestris), plainly visible in hundreds of photos (e.g. https://stock.adobe.com/search?k=steenbok&asset_id=404356409), that has not been recorded by any zoologist - until now.
This apparently glandular feature is noteworthy, because
- its location seems unique among ungulates, and possibly among all animals, and
- no trace of this dark vertical streak is visible in the other two spp. of the same genus, namely Raphicerus melanotis and R. sharpei.
I will call this feature the radial gland, because it is situated on the outer surface of the upper foreleg, where the main bone is the radius (https://www.inaturalist.org/observations/6316536).
This location is near the carpal joint. However, it differs from that of a gland long-recognised in other genera. I refer to the carpal gland, located on the anterior surface of the carpal joint.
Estes (1991, page 45) states that the scent glands of R. campestris comprise "smallish preorbital glands, larger in male, pedal glands in all feet, no inguinal glands, and possibly a throat gland (Smithers 1983)". He apparently overlooked research by Cohen, showing an intermandibular gland in both sexes (https://journals.co.za/doi/pdf/10.10520/AJA00382809_3949).
The following show the intermandibular gland in the form of a swelling under the lower jaw (https://www.canstockphoto.com/close-up-of-steenbok-ram-head-with-18371818.html and https://www.canstockphoto.com/close-up-of-steenbok-ram-head-with-18303890.html).
However, no author has mentioned any gland on the upper foreleg of any species of Raphicerus.
For comparison, Estes (1991, page 57) states that the scent glands of Ourebia ourebi comprise "very large preorbital glands in males (unused and possibly undeveloped in females); black spot below ear underlain by apocrine glands which diffuse scent into air (Kingdon 1982); deep inguinal pouches; carpal glands beneath brushes of long hair on front legs (as in gazelles), shorter brushes below hocks; well-developed glands between all hooves".
The carpal glands of Gazella and Ourebia presumably function by means of kneeling (https://blog.londolozi.com/2022/01/04/the-secret-life-of-a-steenbok/), which the animals perform every time they lie down or get up from the resting posture adopted for rumination. This would leave scent on the earth or herbage.
In the corresponding position on the front of the carpal joint, R. campestris simply has a small callus (https://en.wikipedia.org/wiki/Callus).
The hair-tufts covering the carpal glands are clearly visible in the following, because of their pigmentation:
- Gazella subgutturosa https://animalia.bio/goitered-gazelle
- Gazella bennetti https://www.gettyimages.com.au/detail/photo/photographic-image-royalty-free-image/1141952662?adppopup=true
- Ourebia montana cottoni https://www.alamy.com/stock-photo-female-oribi-in-the-northern-serengeti-125863317.html?imageid=7E57F6A1-9093-405A-97DE-830F18C9C806&p=149870&pn=1&searchId=3066f7aee4fda0c5aa30eb635704b2fc&searchtype=0
- Ourebia ourebi ourebi https://www.alamy.com/female-oribi-gorge-nature-reserve-kwazulu-natal-south-africa-image360755992.html?imageid=6DE2BF8C-90E5-4307-BDF0-B46358254D86&p=311300&pn=1&searchId=3066f7aee4fda0c5aa30eb635704b2fc&searchtype=0
The location of the radial gland in R. campestris is different enough from that of the carpal glands to make a similar function unlikely.
Furthermore, the radial gland seems bare of pelage, the dark appearance being that of bare but callus-free skin.
The following (https://stock.adobe.com/search?k=dikdik&asset_id=493868805) shows that the radial gland is at least as large as the preorbital gland (https://en.wikipedia.org/wiki/Preorbital_gland), which is the main gland associated with masculinity in R. campestris.
Casting some doubt on the glandular nature of this feature is the occurrence, in a few individuals of R. campestris, of a corresponding dark feature - where the hairs seem to have been worn off - on the hindleg:
Intriguingly, the available photographic evidence suggests that there is subspecific variation in the incidence of the radial gland.
This feature seems to be particularly poorly-developed in R. campestris campestris, which is also the most distinctive subspecies in general colouration.
The following show the presence of the radial gland in various subspecies and both sexes of R. campestris.
campestris, female:
https://www.inaturalist.org/observations/98392799
https://www.inaturalist.org/observations/41908928
campestris, male:
(many photos are available on the Web, but none show the feature in question)
capricornis, female:
https://www.istockphoto.com/photo/steenbuck-gm583977962-99962993?phrase=steenbok
https://www.istockphoto.com/photo/steenbok-standing-alert-gm524396756-92197869?phrase=steenbok
https://www.gettyimages.com.au/detail/photo/the-steenbok-royalty-free-image/636770832?adppopup=true
https://www.inaturalist.org/observations/94425108
capricornis, male:
https://www.istockphoto.com/photo/capricorn-in-green-savanna-gm1184254719-333285629?phrase=steenbok
https://www.istockphoto.com/photo/steenbuck-gm583977682-99962713?phrase=steenbok
https://www.istockphoto.com/photo/steenbok-gazelle-gm1077769610-288723218?phrase=steenbok
https://www.istockphoto.com/photo/capricorn-gm1286648370-383087965?phrase=steenbok
https://www.istockphoto.com/photo/steenbok-antelope-gm487464396-72932291?phrase=steenbok
https://www.tripadvisor.co.uk/LocationPhotoDirectLink-g312618-i1689945-Kruger_National_Park.html
https://www.inaturalist.org/observations/62689596
steinhardti, female:
https://www.inaturalist.org/observations/26661297
https://en.wikipedia.org/wiki/Steenbok#/media/File:Raphicerus_campestris_female_(Etosha,_2012).jpg
https://www.inaturalist.org/observations/100241068
https://www.gettyimages.com.au/detail/photo/steenbok-royalty-free-image/148697094?adppopup=true
https://www.inaturalist.org/observations/36941231
https://www.inaturalist.org/observations/36127710
steinhardti, male:
https://en.wikipedia.org/wiki/Steenbok#/media/File:Raphicerus_campestris_male_(Etosha,_2012).jpg
https://www.inaturalist.org/observations/53130004
https://www.inaturalist.org/observations/50249368
https://www.inaturalist.org/observations/36127707
https://www.inaturalist.org/observations/34610708
neumanni, female:
https://www.inaturalist.org/observations/18053713
https://www.inaturalist.org/observations/12006271
neumanni, male:
https://www.inaturalist.org/observations/32006732
FOOTNOTE:
The whole skin in Raphicerus campestris, apart from most of the anterior surface of the ear pinnae (https://stock.adobe.com/search?k=steenbok&asset_id=221530819), seems to be darkly pigmented.
This includes
- rhinarium,
- bare edges of the lips,
- perineum/anus (https://www.alamy.com/steenbok-raphicerus-campestris-female-namibia-image61805632.html and scroll in https://africawild-forum.com/viewtopic.php?p=234338#p234338),
- prepuce (https://www.istockphoto.com/photo/steenbok-raphicerus-campestris-gm495952950-78292117 and https://fineartamerica.com/featured/solitary-male-steenbok-antelope-cam-bornet.html),
- scrotum (https://www.alamy.com/steenbok-in-yellow-grass-image227670603.html?imageid=A505DDB3-255E-4003-8E22-67823FAA1EB0&p=95934&pn=1&searchId=30e86c64bd74ac276119489cea99aea1&searchtype=0 and https://stock.adobe.com/search?k=steenbok&asset_id=393358354),
- udder (https://www.inaturalist.org/observations/104420754), and
- a large bare area in the groin, extending to the junction of the hindleg with the flank (https://fineartamerica.com/featured/5-steenbok-raphicerus-campestris-roger-de-la-harpe.html).
The darkness of the skin shows through the pelage, around the eyes of R. melanotis and R. sharpei (but not R. campestris except for the antorbital gland), on the posterior surface of the ear pinnae in all three spp., and on the lower part of the buttocks of R. campestris when the pelage is matted.
Even the tongue is so dark-pigmented in R. campestris that it can be called black (https://www.mirror.co.uk/news/world-news/oh-deer-huge-python-spends-6367197 and https://www.alamy.com/stock-photo-a-steenbok-looking-camera-while-it-eats-leaves-off-tree-kgalagadi-40211532.html and https://fineartamerica.com/featured/portrait-of-a-steenbok-john-haldane.html).
September 28, 2022
A working approach to subspecies distinctions in the steenbok, Raphicerus campestris
@alanhorstmann @tonyrebelo @jakob @jeremygilmore @ludwig_muller @jwidness @colin25 @geichhorn @henrydelange @koosretief @michalsloviak @alexdreyer @chewitt1 @oviscanadensis_connerties @capracornelius @tandala
The subspecies of the steenbok (Raphicerus campestris, https://www.inaturalist.org/taxa/42375-Raphicerus-campestris) were revised by Groves and Grubb (2011, Ungulate Taxonomy). However, please see https://www.zoochat.com/community/threads/ungulate-taxonomy-revisited-the-evidence-for-the-splits-of-g-g.467230/page-3.
The treatment of Groves and Grubb largely follows that of Roberts A (1951, The Mammals of South Africa).
Until now, iNaturalist has avoided the problem of subspecies, by simply distinguishing the widely disjunct East African form, neumanni, from the nominate form of southern Africa.
The current approach, in iNaturalist, does not do justice to the subspecific distinctions in R. campestris. This is because
- the East African form does not look particularly distinctive, despite its geographical disjunction,
- the southwesternmost form, of Western Cape, is obviously distinctive despite grading continuously with other forms to the north and to the east, and
- the form penetrating the edges of the Namib desert is so ecologically extreme that it should be assumed to belong to an arid-adapted subspecies, unless proven otherwise.
Therefore, what seems most plausible is some compromise between the current 'lumped' approach, of only two subspecies, and the old, 'split' approach in which seven subspecies are recognised, viz.
- campestris (southwestern parts of South Africa)
- fulvorubescens (Eastern Cape and adjacent areas)
- natalensis (eastern parts of South Africa, as far north as Gauteng and the high-lying parts of Mpumalanga)
- zuluensis (Zululand and the low-lying parts of Mpumalanga)
- capricornis (Limpopo province through Zinbabwe to the Zambezi valley)
- steinhardti (Namibia, southern Angola, northwestern South Africa, and presumably southern Angola)
- neumanni (Kenya and Tanzania).
On the basis of photographic evidence, the main, obvious distinction is between the dark form of the southwesternmost part of South Africa, and the rest of the species-distribution. There seems no doubt that the nominate form, i.e. subspecies campestris, deserves recognition. This is true notwithstanding the uncertainty of its northern and eastern limits, where it intergrades with adjacent forms.
It also remains fair to assume that the disjunct form of East Africa, namely neumanni, is a valid subspecies. This is notwithstanding the surprising fact that, based on photos, it looks hardly different from the form in eastern South Africa.
This brings us to the arid-adapted, western form, the main distinctive feature of which, based on photos, is the extreme enlargement of the ear pinnae, at least in some individuals.
On one hand, it is possible that the western populations are merely an ecotype, as opposed to a subspecies. This is because the colouration is similar to eastern forms, apart from the usual tendency to pallor, that is so familiar in animals living in semi-deserts.
On the other hand, we should bear in mind that the western populations are globally unique, in ecological terms.
There is no ungulate, worldwide, of body mass less than 15 kg, that penetrates the edge of desert, other than R. campestris (https://www.inaturalist.org/observations/11048622).
A remarkable fact is that R. campestris lives both at the edge of the barren Namib, in Namibia, and under a mesic, equatorial climate in west-central Kenya.
So, it seems reasonable to recognise the subspecies steinhardti, the type location of which (https://en.wikipedia.org/wiki/Fransfontein) is in northwestern Namibia.
This leaves us with the mesic regions of southern Africa, from Eastern Cape through Free State and Kwazulu-Natal to Mozambique, Mpumalanga and Limpopo, and northwards through southeastern and western Zimbabwe to northeastern Botswana and western Zambia.
According to Roberts (1951), subspecies capricornis, of western Zimbabwe, is distinctive in nearly lacking the dark, V-shaped marking on the crown, that is normal in other subspecies (https://www.inaturalist.org/observations/136478014).
In support of a subspecific distinction, it is obvious from photos that the ears are, at least in some individuals, extremely small in Kruger National Park, in Limpopo province of South Africa.
However, it is easy to show that the dark, V-shaped marking on the crown does remain, at least faintly, even in
- the northern part of Kruger National Park (https://www.inaturalist.org/observations/105445728), and
- northeastern Botswana (https://www.inaturalist.org/observations/101364919).
This seems to contradict Roberts (1951).
Given the doubtful distinctions among the various eastern populations, perhaps we should choose whichever name takes chronological priority.
The choices are
- fulvorubescens 1822, 'Caffraria', Eastern Cape
- natalensis 1907, 'Drakensberg, Natal'
- zuluensis 1946, Umfolozi, now in northern Kwazulu-Natal
- capricornis 1906, Klein Letaba, now in Kruger National Park.
It seems likely that the populations in Eastern Cape represent intergradation with the nominate subspecies.
The name 'natalensis' seems to be invalid, i.e. a nomen nudum (see comment below).
Therefore, it resolves to a choice among the remaining two, and capricornis takes priority.
On this basis, I suggest that we provisionally recognise Raphicerus campestris capricornis (Thomas & Schwann, 1906).
In summary, I propose that we adopt the following subspecific names in iNaturalist:
- campestris (Western Cape and adjacent parts of Northern Cape and Eastern Cape)
- capricornis (northern Kwazulu-Natal, Mpumalanga, Limpopo, Gauteng, Mozambique, Zimbabwe, Zambia, easternmost Botswana, northeasternmost parts of both Namibia and Botswana)
- steinhardti (Namibia, Angola, most of Botswana, most of Northern Cape)
- neumanni (Kenya, Tanzania).
In all other regions, just identify to species-level, owing to the likelihood of intergradation. This includes the whole of Free State and North West (https://en.wikipedia.org/wiki/North_West_(South_African_province)), the eastern half of Eastern Cape, and eastern Botswana adjacent to Zimbabwe.
I leave readers with a few, carefully selected photos, illustrating the range of variation in the appearance of R. campestris.
The following shows how dark the nominate subspecies can be (https://www.inaturalist.org/observations/11241069). There is considerable individual variation in R. campestris, but no individual of any other subspecies is anywhere near as dark as this.
The following show the extreme variation in the size of the ear pinnae within R. campestris (https://www.shutterstock.com/image-photo/sharpes-grysbok-standing-shade-1917779507 vs http://www.rupavadodaria.com/my-first-veganniversary/).
The following show the variation in the dark marking in the rostrum, adjacent to the rhinarium. This is absent in some individuals of R. c. steinhardti (https://www.inaturalist.org/observations/6611664), whereas it reaches to between the eyes in some individuals of R. c. capricornis (https://www.alamy.com/male-steenbok-raphicerus-campestris-kruger-national-park-south-africa-image68361886.html?imageid=7C5898AA-9B45-4447-98EF-CB92AEA025CF&p=196821&pn=1&searchId=81afea0714a7b7094a750bf43216e26d&searchtype=0).
The following show how different the conspicuousness of the ear pinnae can be in R. campestris, depending on direction of illumination and whether the pale hair-curtains are open or closed (https://www.shutterstock.com/image-photo/steenbok-spotted-namibian-desert-710362444 vs https://stock.adobe.com/search?k=steenbok&asset_id=83926648).
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