The R.C. Dening Collection
Introduction to Zambian Butterflies
by R.C. Dening F.R.E.S.
Species and Habitats - continued
WITHIN THE RAINFOREST BIOME
contrasts strongly with the surrounding deciduous or semi-deciduous forests that cover
much of Zambia. In general, it infiltrates from the main Congo rainforest zone across the
north of the country, in the form of riverine, evergreen wet forest, extending in some
places to swamp forest and somewhat larger evergreen stands.
forests have two main effects on the butterfly fauna. They provide specialised
microclimates and a different range of hostplants. Thus species which require the deep
shade of the forest floor proliferate in the forests near Kalene Hill, in the extreme
northwest, while plant families such as Lauraceae are hosts for such species as Papilio
Riverine evergreen habitats also exist to a limited extent in other
parts of the country, where butterfly species occur which prefer evergreen hostplants not
normally found in savanna habitats.
For instance, the preference of Charaxes
brutus is for the family Meliaceae, predominantly evergreen species associated with
fringing forest. It also occurs where these species have been planted as shade trees, as
in the centre of Lusaka, where population explosions are sometimes observed on the Trichilia
emetica trees in Cairo Road, with larvae and pupae scattered on the public benches.
In many of the northern riverine habitats, the occurrence of
rainforest fauna is patchy, with no great numbers of different species in any one place.
Thus along a small, shady stream, one may see the White Banded Swallowtail Papilio
echerioides homeyeri, the small riodinin Abisara rogersi and possibly the
Euthaline forest floor species Aterica galene and Catuna crithea pallidior.
One or more spectacular Charaxes may also occur, such as C.murphyi on the
South Mutundu River near Mufulira, or C.eudoxus mitchelli in small patches of wet
forest at Lake Kashiba (Mpongwe) near Ndola or again at the South Mutundu River, albeit
Wet, thickly forested places at the sources of
streams may also contain unusual species. Thus the source of the Zambezi, some miles north
of the MwinilungaIkelenge road, is home to deep shade species of the forest floor,
such as Bicyclus sebetus, B.trilophus and B.sophrosyne overlaeti. It has
also provided the only confirmed Zambian record of Charaxes acuminatus cottrelli.
Not far away, near the Ken Suckling Mission on the Luakela River, in April 1988, Blease
found the only known Zambian colony of the African Leaf Butterfly Kamilla ansorgei.
Similar habitats occur in the northern Luapula Province, for
instance along the Kalungwishi River, and in Northern Province, where they have become
known in association with popular waterfalls. Here Bicyclus sebetus also occurs,
together with unusual Charaxes, such as C.lucretius schofieldi and
Of all these habitats, the most notable is the
Isombo and Mudileji cluster of streams to the west of Kalene Hill in northwest Mwinilunga.
They flow into the Zambezi inside Angola, and are unconnected to the Congo rainforest to
the north. They appear to represent a relict fauna from the past pluvial period.
First noted in 1954, these relatively small
evergreen areas had been undisturbed throughout the colonial period, due to their
proximity to the Angolan border; by mutual agreement people could pass through them, but
not settle within them. They survived intact until the 1970's, but their status today is
not clear, due to pressure from an influx of refugees. It has been reported that the
Isombo forest itself has been cut down to make way for cassava fields. Thus an appreciable
number of species in the list may have ceased to occur within Zambia. On the other hand,
they may still survive in other relict patches in the same neighbourhood.
||A common Swallowtail
in these forests is the green Papilio phorcas congoanus (left), otherwise recorded
only from Mufulira and the Kalungwishi, and then as ssp.nyikanus, far to the east
in the Afro-Alpine forests on the Nyika Plateau. The sub-specific differences suggest an
absence of widespread interconnected gene flow since before the last northern glaciation,
and its contemporary arid period in Central Africa (possibly 22 000 BP). Other notable
Swallowtails are the large Papilio hesperus, and Graphium ridleyanus,
a remarkable reddish Acraea mimic.
Among the Pierids is the delicate,
translucent-winged Pseudopontia paradoxa in its own monotypic subfamily, and
two wet forest Leptosia spp., L.hybrida vansomereni and L.nupta.
The acraeine genus Bematistes of large forest species is
represented by B.epaea, B.macarista and B.umbra macaroides, while common
danaines are Amauris niavius and A.tartarea.
In deep shade occur the satyrines Gnophodes
betsimena parmeno and the previously mentioned Bicyclus species, plus B.mesogena,
B.mandanes and B.dubia.
There are many more spectacular Nymphalidae, represented by Lachnoptera
anticlea; Kamilla cymodoce; several forest Neptis spp. (e.g. N.nemetes,
N.nicoteles), and the common Pseudoneptis bugandensis ianthe. The splendid
scarlet male of Cymothoe sangaris luluana may with luck be seen after the rains, or
C.herminia katshokwe in deep shade. These are matched by large Pseudacraeas,
such as P.kuenowi, P.boisduvali, P.lucretia protracta and the smaller green spotted
P.semire. Three forest floor Euriphenes (E.pallidior, E.incerta theodota
and E.saphirina trioculata) may sometimes be found in numbers, flying alongside Catuna
crithea pallidior and Aterica galene.
spectacular in the understorey are eight large purple, yellowish, orange and reddish Euphaedras,
such as E.overlaeti, E.herberti katanga, E.katangensis, E.cooksoni, and E.crawshayi
(left). These fly at shoulder height, while the four Bebearia species, particularly
the large and striking B.plistonax, tend to skim the ground.
Notable Lycaenids fluttering in the
shade are the white Oboronia guessfeldti and the delicate hairstreak Oxylides
faunus. Flying along the streams, the very large hesperiid Gamia shelleyi may
be seen, while in July, well into the dry season, the rare Artitropa cama appears.
However, the most spectacular species of all are the rainforest Charaxes
of the Tiridates group, notably C.numenes aequatorialis, C.tiridates
tiridatinus, C.imperialis lisomboensis, C.ameliae amelina and C.pythodoris.
Rainforest Charaxes of other groups include C.eudoxus (which occurs in
Zambia as three subspecies), C.lucretius (in two subspecies), C.anticlea
proadusta, C.hildebranti katangensis, and the black Charaxes etheocles carpenteri and
While virtually all of these species are found in the strips of
evergreen forest in the Kalene Hill pedicle, many also occur in other forest patches
across the north of Zambia. But the question arises as to why these other forest patches
are so much less species rich.
Williamson, in an orchid study, has drawn
attention to the occurrence of periodic natural disasters (Williamson,1982)
In May 1968, the worst frost in living memory blanketed the whole
country. In some upland woodlands, an estimated 20% of the epiphytes were destroyed; at
Solwezi hoar-frost on the trees gave the impression of a light snowfall, destroying almost
all the mosses and lichens and taking a very heavy toll of orchid species. Some relict
riparian forests were severely affected, even in Mwinilunga District where frost is very
infrequent. North of Mwinilunga on the Luakela River, some trees died, creating large gaps
in the riparian forest and subsequent breaking up of the river bank.
In the Northern Province, Raphia palms in the centre of
seepages were badly damaged or destroyed. The riparian forest above Kundalila Falls was
severely affected, causing an estimated loss of up to 20% of the epiphytes. In 1977,an
unusually high flood swept away the complete relict forest above the Falls.
An interesting observation is that the gallery
forest at the Zambezi Rapids near Kalene Hill has not been adversely affected in recent
times by flooding or frost.
In 1971/72, a severe drought was experienced over the whole country
except in Mwinilunga District. This drought caused many relict seepages to dry up. Fires
were more severe than usual, causing complete destruction of some bogs.
Thus it seems likely that the periodic incidence of frost, drought
and flooding has limited the occurrence of sensitive butterfly species to a small number
of well-favoured evergreen forest localities. But slow re-establishment into damaged
localities is likely to occur between disaster incidents, as we have seen with Kamilla
ansorgei on the Luakela River.
|This biome is
confined to small high altitude areas in the northeast of Zambia. The best known is a
small part of Malawi's Nyika Plateau, which extends into Zambia. Also included are the
tops of the Mafinga and Makutu Mts.
The Nyika element
comprises the small Chowo forest at the headwaters of a stream, together with associated
montane grassland. The altitude of this montane forest is around 2 000 metres. It is a
National Park. A book at the Rest House, in which entomologists have recorded their
captures, has provided a comprehensive list of the fauna. Other patches of montane forest
occur at similar altitudes in the Mafinga and Makutu Mountains. As with the patches of
rainforest across northern Zambia, the butterfly fauna of these areas is substantially
different to that of the surrounding savanna.
The Papilionidae are well represented in these
montane areas. Common savanna species occur, such as P.demodocus and Graphium
angolanus, as also species from the wetter savanna areas, such as P.ophidicephalus,
P.dardanus tibullus and Graphium policenes, though not in any great numbers.
Some rainforest species are represented by a montane subspecies, such as P.mackinnoni
isokae and P.phorcas nyikanus. Exclusively montane species are the green-banded
P.thuraui cyclopis, the white-banded P.jacksoni nyika and the large
Lauraceae feeding P.pelodurus vesper.
Pierids on the other hand are poorly represented. Five widespread
savanna species are to be found: Catopsilia florella, Colias electo hecate, Nepheronia
argia mhondana, Eurema brigitta and Mylothris rueppellii. Another Eurema,
E.mandarinula, is found in Zambia only in the montane grasslands, while Mylothris
crawshayi and M.sagala dentatus are associated with the montane forests.
The wealth of Acraeine species in the savanna
areas of Zambia is not reflected at the higher altitudes, only nine species normally being
seen on the Nyika. Of these, three are common savanna species: Acraea natalica, A
eponina and A.ventura, the two latter being associated with damp grasslands. A.parei
orangica, in the anacreon group and only found on the Nyika, is the main
grassland species, sometimes occurring in great numbers. The small A.goetzei and
the delicate polymorphic A.acuta are found mainly near the forest edges. More
closely associated with the forest are the larger transparent-forewinged A.baxteri
on the Nyika, and A.insignis on the Mafingas, both rarely seen.
||The most unusual
forest species is Bematistes scalivittata (left), rather small and dusky for this
genus, which occurs in damp, shady places.
The Danainae are represented by the
ubiquitous Danaus chrysippus and two Amauris species, A.echeria serica and
A.ellioti junia, both subspecies of otherwise widespread taxa in Afro-montane
habitats. A.niavius occurs in the Mafinga Mts., as subspecies dominicanus
rather than the subspecies niavius of the evergreen forests of northern Zambia.
Surprisingly, a single specimen of Tirumula formosa has been recorded from the
The Satyrinae are poorly represented. The almost universal
palaeotropical Melanitis leda occurs even at the altitude of Chowo forest.
Otherwise three montane species occur: Aphysoneura pigmentaria, in association with
Arundinaria and various grasses, and Bicyclus simulacris and Henotesia
ubenica in more open areas.
Only eight representatives of the subfamily
Nymphalinae have been commonly recorded. Four are palaeotropical migrants; Hypolimnas
misippus, Cynthia cardui, Junonia orithya and J.hierta. The common savanna
species J.octavia and J.artaxia also occur. Two temperate
Afro-montane Admirals, Antanartia schaenia dubia and A.dimorphica are found
at the forest edges.
Of the ten Limenitine species, Eurytela hiarbas lita is an
Afro-montane representative from more temperate regions to the south, while the woodland Eurytela
dryope also occurs occasionally. The almost ubiquitous Byblia anvatara acheloia
is found along forest edges. Four Neptis species have been recorded, the widespread
N.laeta and the small N.nina (Makutu and Mafinga Mts. only), while the
commonest species is the Afro-montane N.aurivillii, and the rarest, the very
similar N.incongrua. Both of the latter prefer deep shade. There is a montane
white-banded Cymothoe, C.cottrelli, a deep shade species, and two Pseudacraeas,
the widespread woodland P.lucretia expansa and the unusual P.deludens.
The latter mimics the aforementioned Amauris echeria serica, and also prefers
shade. The only record for the tribe Euthaliini is of Bebearia orientis in May
Finally, the subfamily Charaxinae is
represented by at least nine common savanna species: C.varanes vologeses, C.candiope,
C.jasius saturnus, C.brutus, C.pollux geminus, C.druceanus proximans, C.achaemenes and
C.guderiana. Around bamboo thickets, C.macclounii is to be found. Four
specifically montane species occur: C.acuminatus nyika, the large blue C.xiphares
ludovici, the even rarer C.ansorgei levicki, and the black C.nyikensis.
A further black montane species, C.aubyni australis, has been recorded from the
Since most of the butterflies in the family Lycaenidae are
associated with grassland, it is uncertain which of the many species recorded from the
Malawi Nyika can be claimed for Zambia. Indeed, the Zambian border is not clearly defined
across the grassland. One certain occurrence is the Small Copper, Lycaena phlaeas
abbotti, which has been recorded in January, April and October. Lampides boeticus
is common during the rains. Several Uranothauma species have been recorded,
including U.crawshayi, U.cuneatum and U.williamsi. Other occurrences are Harpendyreus
juno, Actizera stellata and Euchrysops malathana. Cottrell recorded Lepidochrysops
nyika, L.pampolis and L.intermedia, mainly in November.
species are associated with grassland and are widespread in the rest of Zambia. However, Eagris
sabadius ochreana, Gorgyra bibulus and Chondrolepis telisignata (left) have
been recorded only on the Nyika.