The Hoverfly (Pelloloma nigrifacies) by Werner Barkemeyer
On 19 January 1963 Dr. Brian and Dr. Pamela Stuckenberg made a trip to
the eastern slopes of the Naudesnek Pass where they collected insects for the
Natal Museum at Pietermaritzburg. Among the many interesting little creatures
they found at altitudes of 2350-2525 m, were three specimens of hoverfly which
they had never seen before.

A hoverfly is about the size of an ordinary housefly. It has a black face and
a flat and mostly yellow back. The eyes of two of the specimens were separated
but in the third specimen the eyes touched above the antennae. The
Stuckenberg’s concluded that they had caught one male and two females of an
insect that was unknown to science. The specimens were duly sent to Dr. Richard
J. Vockeroth in Ottawa, Canada. Vockeroth is one of the leading hoverfly
specialists in the world. The specimens had some very peculiar characteristics that
precluded them from being placed in existing hoverfly genera. Having studied the
flies from Naudesnek very carefully Vockeroth, concluded that these insects were
indeed a new species. A new genus was accordingly established for the hoverflies
from Naudesnek.

In 1973 Stuckenberg described each detail of the species in a scientific
journal where it was formally named as Pelloloma nigrifacies. The male and a
female specimen can be found in the collections of the Natal Museum in
Pietermaritzburg. The second female is in the Canadian National Collection of
Insects in Ottawa.

Up to now, Pelloloma nigrifacies has only been found at Naudesnek and
nowhere else in the world. It is a rare species but is still living in the area. Not
much is known about its life cycle however, it is most probable that the larvae feed
on little insects such as greenflies. The diet of the adult hoverfly is pollen and
nectar provided by a variety of plant species flowering in the area. Therefore the
adults can be found during the summer season only when they may be of some
importance as a pollinator. In 2000, the German entomologist Christian F.
Kassebeer published an article with the description of two more Pelloloma species
from Ruwenzori and from Mount Kenya. All the three Pelloloma species form a
group of hoverflies which only occur in Africa and which seem to be restricted to
areas at high altitude. For more information on hoverflies, see diptera/syrphidae/ There is an intimate
relationship between the insects and plants of the region and more information in
this regard can be found in the two publications mentioned below;
“Long-proboscid fly pollination of two orchids in the Cape Drakensberg mountains,
South Africa” by S. D. Johnson and K. E. Steiner
Large hovering flies with elongated nectar-feeding mouthparts play an important
role in the pollination of South African plants. Here we describe and illustrate the
pollination of two long-spurred orchids —Disa oreophila H. Bolus subsp.erecta
Linder and Brownleea macroceras Sond. — by the long-proboscid fly Prosoeca
ganglbaueri Lichtwardt (Nemestrinidae).
“Pollination by long-proboscid flies in the endangered African orchid Disa scullyi”
by S.D. Johnson, School of Biological and Conservation Sciences, University of
KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville, Pietermaritzburg
3209, South Africa
Flowers specialized for pollination by long-proboscid flies are particularly prevalent
in the southern African flora. Although many orchids in this region possess flowers
with traits that are consistent with long-proboscid fly pollination, evidence from field
observations is lacking for most of these species. Flowers of the critically
endangered orchid Disa scullyi Bolus (Orchidaceae) were observed to be
pollinated by the large nemestrinid fly species Prosoeca ganglbaueri Lichtwardt at
a remote site in the Cape Drakensberg Mountains, South Africa. The orchid's floral
spur contains copious amounts of dilute sucrose-rich nectar and its length (c. 42
mm) closely matches that of the fly proboscis (c. 40 mm). Flies caught on the
orchids carried pollinaria of D. scullyi on the basal portion of their proboscides.
Although flies were not common at the study site, they showed considerable fidelity
to D. scullyi, resulting in high levels of pollen removal and deposition in flowers in
the population. Habitat loss and trampling by cattle, rather than pollination failure,
appear to pose the greatest threat to the few remaining populations of this species.

The Bamboo Sylph (Metisella syrinx)
This butterfly is so rare they don’t have a
photo of it! The Bamboo Sylph (Metisella syrinx) is a butterfly of the Hesperiidae
family. It is a rare and highly localised species which is only known from the
Eastern Cape, through southern Lesotho to the extreme south of KwaZulu-Natal.
The wingspan is 32–34 mm for males and 32–37 for females. Adults are on wing
from January to February. There is one generation per year. The larvae feed on
Thamnocalamus tessellatus. Drakensberg bamboo, Berg bamboo or Drakensbergbamboes.
Woodhall, S. Field Guide to Butterflies of South Africa, Struik Publishers, 2005.

The region does not have a very wide variety of wild animals however, there are
some very special animals such as the Slogget’s ice rat and the Grey rhebuck

Slogget’s ice rat
Slogget’s ice rat (Otomys sloggetti) is a species of rodent that lives at higher
altitudes than any other mammal in Southern Africa. There is a resident population
on the peak at Mont-aux-sources (3282m)! It can be seen alongside the roads and
tracks on the plateaus and escarpment in the vicinity of Rhodes. According to “The
Complete Book of Southern African Mammals”, it does not occur below 2500m
above sea-level. This quaint little rodent was named after Lieutenant-General Sir
Arthur Sloggett RA, MC (1857 – 1929) who submitted a collection to the British
Museum on his return to the United Kingdom after the Anglo-Boer War.

Grey rhebuck currently occur in mountainous terrain. The past distribution of the
grey rhebuck is likely to have been slightly more extensive than at present and
they are currently found in grassland, on hills and mountains at high altitudes,
1900 to 3300 m above sea level and favour plateaux and slopes of 20 degrees and
less. Warmer, north-facing slopes are preferred. Grey rhebuck feed very
selectively, almost entirely on forbs. They favour short, burnt veld for feeding and
long grass for cover. Grey rhebuck occur either as single males, or in small groups
of up to 10 animals, comprising one adult male, adult females, and young. Herd
males are territorial and occupy home ranges/territories of about 70 ha in the
Drakensberg Yearling males leave the herd or may be evicted just prior to the
onset of calving in November. Reproduction is seasonal: mating takes place from
March to May and most young are born between November and January.
Expansion of grey rhebuck populations is limited, owing to their specific habitat
requirements. On some private properties, and the periphery of some protected
areas, grey rhebuck are poached, or harassed and killed by uncontrolled dogs.
The grey rhebuck is sought after by hunters.

The Cape grysbok (Raphicerus melanotis) is a secretive and solitary animal,
which is partial to the shoots and leaves of vines, and steals out under cover of
darkness to feast on this rich food. They are found as far west as the Cedarberg
Mountains and as far east as the Eastern Cape. They are relatively more active at
night than during the day, and are predominantly browsers. Grysbok lack the grace
and proud posture of the steenbok: the grysbok has a thickset body, and fragile,
short legs. The forelegs are a little shorter than the hind legs, causing its back to
slope. The grysbok spends a lot of time washing and grooming its thick, wiry coat.
If it feels threatened, it may lie flat on the ground and then speed away, keeping its
head low. Grysbok have small territories and can usually be seen on their own, in
pairs during the mating season, or in small family groups. A single lamb is born,
usually in spring. The lamb is born with a darker coat than its parents and is kept
hidden for the first few months until it can fend for itself.

More than 230 bird species have been identified in the Barkly East district, of
which, some of the most sought after by “twitchers” are the following two species;
Lammergeier, Lammergeyer, or Bearded Vulture, (Gypaetus barbatus)
("Bearded Vulture-Eagle"), is the only member of the genus Gypaetus. The name
stems from the belief (misperception) that it attacked lambs. Traditionally
considered an Old World vulture, it actually forms a minor lineage of Accipitridae
together with the Egyptian Vulture (Neophron percnopterus), its closest living
relative. They are not much more closely related to the Old World vultures proper
than to, for example, hawks, and differ from the former by their feathered neck. Although
quite dissimilar, Egyptian and Bearded Vulture both have a lozenge-shaped tail that is
unusual among birds of prey. It eats mainly carrion and lives and breeds on crags in high
mountains in southern Europe, North Africa, Southern Africa, the Indian Subcontinent, and
Tibet, laying one or two eggs in mid-winter which hatch at the beginning of spring. Populations
are resident.

Unlike most vultures, the Lammergeier does not have a bald head. This huge bird is 95–
125 cm (37–49 in) long with a wingspan of 275–308 cm (108– 121 in) (10 feet), and is quite
unlike most other vultures in flight due to its large, narrow wings and long, wedge-shaped
tail feathers. It weighs 4.8–7.2kg (11–16 lb). The adult has a buff-yellow body and head, the latter with the black moustaches which give this species its alternative name. It may rub mud over its chin, breast and leg feathers, giving these areas a rust-coloured appearance. The tail feathers and wings are grey. The juvenile bird is dark all over, and takes five years to reach full maturity. The

Lammergeier is silent, apart from shrill whistles at the breeding crags, and can live
up to 40 years in captivity.

Like other vultures it is a scavenger, feeding mostly from carcasses of dead
animals. It usually disdains the rotting meat, however, and lives on a diet that is
90% bone marrow. The Lammergeier can swallow whole bones up to the size of a
lamb's femur and its powerful digestive system quickly dissolves even large
pieces. The Lammergeier has learned to crack bones too large to be swallowed by
carrying them up to a height and then dropping them onto rocks below, smashing
them into smaller pieces and exposing the nutritious marrow. This learned skill
requires extensive practice by immature birds and takes up to seven years to
master.[ Its old name of Ossifrage ("bone breaker") relates to this habit. Live
tortoises are also dropped in similar fashion to crack them open. Although dropping
bones is a regular habit, the Lammergeier also obtains food by other means and
has been known to seize and carry off live prey such as a two foot monitor lizard.

The acid concentration of the Lammergeier stomach has been estimated to be of
pH about 1 and large bones will be digested in about 24 hours, aided by slow
mixing/churning of the stomach content. The high fat content of bone marrow
makes the net energy value of bone almost as good as that of muscle, even if
bone is less completely digested. A skeleton left on a mountain will dehydrate and
become protected from bacterial degradation and the Lammergeier can return to
consume the remainder of a carcass even months after the soft parts have been
consumed by other animals, larvae and bacteria.

The habitat is exclusively mountainous terrain (500–4,000 m/1,600–13,000 ft). An
individual has been seen at 24,000 feet (7,300 m). The bird breeds from mid-
December to mid-February, laying 1 to 2 eggs which hatch between 53 and 58 days.
After hatching the young spend 106 to 130 days in the nest before fledging.
Typically, the Lammergeier nests in caves and on ledges and rock outcrops.

The Drakensberg Rockjumper or Orange-breasted Rock-jumper (Chaetops
aurantius) is a medium-sized insectivorous passerine bird endemic to the
mountain fynbos of the Drakensberg Mountains of south-eastern South Africa. This
rock-jumper is 23–25 cm long with a long black tail and strong legs. The male has
a dark grey head with a thin white supercilium and a broad white moustache. The
back and wings are dark grey. The underparts are orange and the rump is rufous
red. The female and juvenile have a paler grey head, upperparts and wings, a
duller head pattern, an orange rump, and buff underparts. The call is a loud
wheeoo. This is a ground-nesting species which forages on rocky slopes and
scree. It frequently perches on rocks. The Rufous Rock-jumper uses one or two
additional individuals, usually a pair's offspring of the preceding breeding season,
to assist the parents in territorial defence and alarm calling, and in the feeding of
nestlingsand fledglings. Given the great similarities between the species, it is likely
that Drakensberg Rockjumper uses a similar strategy.