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Wildlife & Ecological Investments Field Research Programme 2014
Overview for Balule Game Reserve
Contributors - Tomos Avent, Caz Schiess, Henrietta Chilton & Elme Breytenbach
In 2012 Wildlife & Ecological Investments started a research and training programme in Struwig Eco
Reserve. Since then, over 800 students from more than 20 countries have joined our College,
Undergraduate and Masters training programmes in Savannah Ecology, Southern African
Conservation, and Bush-craft Training.
Our team on the ground have also helped restore and maintain the road network throughout OREC,
especially through rock packing and soil filling rill erosion, vegetation clearing, and continued work on
mitre drains and bolsters.
The purpose of this report is to introduce the ongoing research work on Struwig and present an
overview of the data collected so far in 2014. Due to the limited area of operation and traversing on
OREC, our research programme has thus far been limited to small-scale bird, invertebrate, habitat,
herbivore and predator monitoring projects. In the future we would like to expand our research focus
to help address larger questions pertinent to the conservation management of Balule Game Reserve.
The following report will be broken down into research themes, first outlining our survey approaches,
then summarizing our data and, if appropriate at this point, some research findings. At the end of
some sections I suggest some of the further work that would be possible if we are able to expand the
programme into a larger area. It is not the purpose of this overview to go into detailed methods and
justifications of our survey work, but copies of these can be obtained on request – please email
tom.avent@wei.org.za.
Report Themes
1. Habitat Assessment ………………………………………………………………………………………….……….. Page 2
2. Bird Surveying.………………………………………………………………………………………………….……….. Page 8
3. Predator Monitoring …………………………………………………………………………………………………. Page 12
4. Elephant Monitoring …………………………………………………………………………………………………. Page 22
5. Game Monitoring …………………………………………………………………………………………….……….. Page 23
6. Invertebrate Sampling ….…………………………………………………………………………………………… Page 25
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1. Habitat Assessment
Habitat Analyses have been conducted at 15 sites each winter since 2012 (sites mapped in Figure 1).
Figure 1. Habitat Assessment and Bird Point Count Survey Sites
At each habitat assessment site our teams record all woody vegetation over 1 metre tall, detailing
species name, height class, basal stem diameter, average stem diameter (for multi-stemmed bushes),
the width of the widest point of the canopy, and the extent of elephant and fire impact. A qualitative
and quantitative evaluation of elephant impact (and fire although the fire data is not featured in this
report) is graded according to the Walker scale as detailed below:
TYPE: CODE:
Pulled or kicked out A
Pushed over and dead or apparently dead B
Main trunk broken, is or appears to be dead C
Main trunk broken but re-sprouting or likely to re-sprout D
Pushed over but still alive E
Main trunk tusk-slashed F
Main trunk debarked (% of the circumference) *G
Roots exposed and eaten (% of the circumference) *H
Primary branches broken *J
Secondary and/or smaller branches broken *K
None: Z
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*Impact types G, H, J, K must be quantified according to the percentage classes given below. The percentage classes refer to the percentage of the total canopy volume (J & K) and are estimated. In the case of exposed roots and debarking of the main trunk (types G & H), the percentage of the root base or trunk's perimeter (i.e. a circle) affected must be estimated and coded accordingly.
1-10%
11-25%
26-50%
51-75%
76-90%
91-100%
Over the period 2012-2014, our research teams have identified 61 tree species in and around our
Habitat Assessment sites on OREC (Figure 2). The habitat assessments involved the surveying of
1864 trees over the three year period.
Abutilon angulatum Commiphora mollis Gymnosporia senegalensis
Acacia burkei Commiphora pyracanthoides Hippocratea longipetiolata
Acacia erubescens Crossopteryx febrifuga Karomia speciosa
Acacia exuvialis Croton megalobotrys Lannea schweinfurthii
Acacia gerrardii Dalbergia melanoxylon Lantana camara
Acacia grandicornuta Dichrostachys cinerea Mundulea sericea
Acacia karroo Diospyros mespiliformes Manilkara mochisia
Acacia nigescens Ehretia amoena Ozoroa paniculosa
Acacia Senegal Euclea divinorum Pappea capensis
Albizia harveyi Euclea natalensis Peltophorum africanum
Boscia albitrunca Euclea undulate Philenoptera violacea
Cassia abbreviate Grewia bicolor Schotia brachypetala
Cissus cornifolia Grewia caffra Sclerocarya birrea
Coddia rudis Grewia flava Spirostachys africana
Colophospermum mopane Grewia flavascens Terminalia prunioides
Combretum apiculatum Grewia hexamita Tricalysia junodii
Combretum collinum Grewia inaequilatera Tricalysia lanceolata
Combretum hereroense Grewia monticola Ximenia americana
Combretum imberbe Grewia villosa Ximenia caffra
Combretum mossambicense Grewia subspathulata (hybrid of G.monticola & G.bicolor))
Ziziphus mucronata
Commiphora Africana
Figure 2. A species list of trees identified on OREC over the period 2012-2014
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This initial analysis covers the following questions:
i) Are certain tree species more impacted by elephant?
ii) Are elephants having a greater impact on certain height categories of trees?
iii) Are there differences in the relative level of elephant impact between sites?
To calculate the proportion of trees impacted relative to their abundance, ‘impact scores’ were
generated. Firstly, a tree was classified as ‘impacted’ if it had been recorded in any of the impact
categories (excluding the ‘Z’ no impact category). If the only impact to the tree was in categories G,
H, J or K, the tree was only classed as ‘impacted’ if one or more of the associated percentages was
over 50%. More rigorous impact scores have been calculated using the Walker Scale for other WEI
projects but we were aiming to create a quick and easily repeatable method to assess the data for
OREC.
To create an impact score for each tree species we first calculated the percentage of trees impacted
within each species and then calculated:
- the percentage of total trees impacted for each species ( % Impacted = (no. of trees of the
species impacted / total no. of trees impacted ) x 100)
- the percentage of total trees for each species (% availability = (no. of trees of species / total
no. of trees) x 100)
- an impact score for each species (Impact Score = % impacted / % availability)
This method of creating impact scores was then repeated for enquiries ii) and iii), using the relevant
categories – i.e. height categories (ii) and survey site locations (iii) rather than species.
The differences between impact scores for each category were evaluated for independence using
Chi-squared tests. An impact score of above 1.0 will demonstrate ‘selection’ for that species, where
as an impact score of below 1.0 will demonstrate a lack of selection. We therefore assume that
species showing some level of impact but not ‘selected for’, are chosen by elephants due to their
high availability rather than a preference by the elephants.
Again, this analysis is designed as a quick and easy method to identify patterns and indications of
associations. Further analysis and behavioural observation would be required to confirm the
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selectivity behaviour of elephants in the OREC area. The analysis in this report only includes the 2013
data, a summary of which is illustrated in Table 1.
Number of Sites Surveyed 17 (two additional sites were selected)
Number of Trees Surveyed 771
Number of Trees Impacted 97
% of Trees Impacted 12.58
Number of Tree Species 38
Number of Tree Species Impacted 17
% of Tree Species Impacted 44.74
Table 1. A table summarising the research effort and results from the Habitat Assessments in 2013. The no. of species listed here is lower than those stated in Fig 2. as Fig 2. includes different sites assessed in 2012.
i) Tree species impact selectivity by elephant The 2013 data indicated that 13 of the 17 species impacted by elephants were selected for by the
elephants (impact score >1.0) (Figure 3). There was a statistically significant difference between
species, with Sclerocarya birrea and Peltiphorum African displaying the highest impact scores of
7.95.
Figure 3. The analytical variables describing species impacted by elephants in 2013. The % availability illustrates the relative abundance of each species in the survey sites. The % impact illustrates the percentage of
total impacted tree of each species. Impact scores <1.0 indicate impact is due to abundance of the species rather than selection by elephants.
0.10
1.00
10.00
100.00
Tree species selection by Elephants in 2013
% Impact
% Availability
Impact Score
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ii) Elephant impact in different tree height classes
The highest impact scores were seen by trees in the largest height category (10m-20m) with over 30
% of trees in that category displaying impact (Figure 4). Although there is only a low percentage of
total trees impacted in this group (Figure 5), this is more likely to be a reflection of the low number of
individuals in this height category. Further analysis of tree species most impacted within this group
alone would be useful to highlight the more vulnerable mature trees of the larger species. 25% of trees
between 4m-6m were impacted by elephant (Figure 5), the group also displaying a high impact score.
Around 18% of all impacted trees fall in this category (Figure 4). The height category with the greatest
percentage of total trees impacted was between 2m-4m (Figure 5), and the impact score of over 1.5
highlights the need to investigate species specific trends in this group, especially to find out if these
are trees at maturity in this height category, or less-mature trees. This would potentially provide
insights into elephant impact on recruitment and establishment rates of larger species in the region.
Figure 4. Tree impact scores and % of trees impacted within each height category
Figure 5. Tree impact scores and % of total trees impacted
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iii) Elephant impact levels at WEI Survey sites
There was a notable difference in the levels of impact at different sites (Figure 6) suggesting a need
for an investigation into other factors affecting impact on habitat. The difference may be purely to
do with tree composition, but other spatial and environmental factors are certainly worth
investigating. The main purpose of this graph was so that we could assign sites a coarse ‘High’,
‘Medium’, or ‘Low’ category for our bird guild analysis in Section Two of this report.
Figure 6. A graph to show the percentage of trees impacted at each survey site in 2013
Grass Biomass
To estimate winter grass biomass, the mean of the disk pasture meter readings from all sites was
calculated. To estimate grass biomass, we applied this value to the Kruger DPM calibration set out in
Zambatis et al 2006 which, for readings such as ours under 26cm is as follows:
kg ha−1 = [31.7176 (0.32181/x) x0.2834]2
Our sites are not laid out perfectly to estimate grass biomass as we cover much larger areas than
standard Veld Condition Assessments and do naturally survey some areas of bare ground in the region.
If calculated including all bare ground (to present an estimate for the entire area) we have calculated
a grass biomass of 947 kg ha-1 but if we exclude all readings of zero (bare ground) then we reach a
figure of 1439 kg ha-1. This may provide a better estimate of grass biomass in the more vegetated
areas around OREC.
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20
30
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2 2b 3 12 13 10 15 16 7 9 4 11 6 14 17 5 8
Perecentage of trees impacted at the survey sites in 2013
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2. Bird Surveying There is an ever growing need to monitor changes in biodiversity. Gathering biodiversity data over a
number of years allows patterns in communities to be identified and correlated to changes in habitat,
climate and management. However, it is probably impossible to identify the total diversity of all taxa
(everything from slime moulds to bacteria to vertebrates) in an area of one hectare, let alone an entire
reserve the size of Balule. Therefore, it is often necessary to use certain indicator groups for
monitoring. Our study focuses on surveying birds to assess biodiversity as they are widely accepted to
be one of the best indicator groups of ecosystem health. This is because they;
are reasonably diverse (not overly so such as many invertebrate groups, or have restricted
diversity such as small mammals);
can be identified in the field (as opposed to many other taxa that require removal of samples);
have existing well tested survey methods for estimating bird densities in a range of habitats;
have known habitat requirements for many species.
Populations of individual bird species however will naturally vary from year to year and such variation
may mask underlying trends. To prevent annual fluctuations in bird abundances disrupting overall
picture of ecosystem health, bird species have been grouped into feeding guilds (e.g. insectivores,
granivores etc.), the diversity of which have been shown to give a clearer picture of ecological
responses over time. Grouping species into guilds also mitigates the effects of accidental
misidentification of related species, as they are likely to belong to similar guilds. To study bird diversity
we conducted 10 minute bird point counts every month at 15 sites (same sites as Habitat Assessment
sites (see Figure 1)) inside the reserve. We increase the frequency of these surveys every winter, when
we have larger research teams available. During this time, we will replicate each survey site assessed
three times within a period of six weeks. Birds present at a survey site during the winter months are
likely to be there pre-dominantly for feeding so will minimise the influence of other guild factors (e.g.
nesting).
So far in 2014 our teams have recorded 185 different species during bird point counts in OREC, with
over 5000 individual records entered into our database this year so far. A complete species list with
common names in alphabetical order is shown in Figure 7 below. It must be remembered that this
certainly does not claim to be a comprehensive species list of the area, as some species are more likely
to be recorded than others when using the point count method. This does however give an indication
of avifaunal utilization of certain areas on the reserve which can be used for further analysis.
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Acacia Pied Barbet Crowned Lapwing Pied Kingfisher
African Firefinch Dark-capped Bulbul Purple Roller
African Fish-Eagle Diderick Cuckoo Rattling Cisticola
African Goshawk Double-banded Sandgrouse Red billed Buffalo-Weaver
African Green-pigeon Dusky Indigobird Red-backed Shrike
African Grey Hornbill Egyptian Goose Red-billed Buffalo-Weaver
African Harrier-Hawk Emerald-spotted Wood-Dove Red-billed Firefinch
African Hoopoe Eurasian Hobby Red-billed Hornbill
African Palm-Swift European Bee-eater Red-billed Oxpecker
African Paradise-Flycatcher European Roller Red-billed Quelea
African Pied Wagtail Fiscal Flycatcher Red-crested Korhaan
African Pipit Fork-tailed Drongo Red-eyed Dove
African Reed-Warbler Giant Kingfisher Red-faced Cisticola
African Spoonbill Glossy Ibis Red-faced Mousebird
Amethyst Sunbird Golden-breasted Bunting Reed Cormorant
Amur Falcon Golden-tailed Woodpecker Retz's Hemet-shrike
Arrow-marked Babbler Greater Blue-eared Starling Rufous-naped Lark
Ashy Flycatcher Greater Honeyguide Sabota Lark
Barn Swallow Greater Striped Swallow Sombre Greenbul
Bateleur Green Wood-Hoopoe Southern Black Flycatcher
Bearded Scrub-Robin Green-backed Camaroptera Southern Black Tit
Bearded Woodpecker Green-capped Eremomela Southern Boubou
Bennett's Woodpecker Green-winged Pytilia Southern Grey-headed Sparrow
Black Crake Grey Go-Away-Bird Southern Ground-Hornbill
Black Cuckoo Grey Heron Southern Masked-Weaver
Black Cuckooshrike Grey Heron Southern White-crowned Shrike
Black Stork Grey Hornbill Southern Yellow-billed Hornbill
Black-backed Puffback Grey Penduline Tit Speckled Mousebird
Black-chested Snake-Eagle Grey Tit-Flycatcher Spotted Flycatcher
Black-collared Barbet Grey-headed Bush-Shrike Stierling's Wren-Warbler
Black-crowned Tchagra Grey-headed Sparrow Streaky-headed Seedeater
Black-headed Oriole Hadeda Ibis Swainson's Spurfowl
Black-shouldered Kite Hamerkop Swee Waxbill
Blacksmith Lapwing Helmeted Guineafowl Tawny Eagle
Black-winged Stilt Hooded Vulture Tawny-flanked Prinia
Blue Waxbill House Sparrow Terrestrial Brownbul
Booted Eagle Indigobird Three-banded Plover
Bronze Mannikin Jacobin Cuckoo Trumpeter Hornbill
Brown hooded Kingfisher Jameson's Firefinch Verreaux's Eagle Owl
Brown Snake-Eagle Klaas's Cuckoo Village Indigobird
Brown-crowned Tchagra Kurrichane Thrush Violet-backed Starling
Brown-hooded Kingfisher Laughing Dove Wahlberg's Eagle
Brown-throated Martin Lesser Striped Swallow Water Thick-knee
Brubru Lilac-breasted Roller White-backed Vulture
Burchell's Coucal Little Bee-eater White-bellied Sunbird
Burchell's Starling Little Rush-Warbler White-breasted Cormorant
Burnt-Necked Eremomela Little Swift White-browed Robin Chat
Cape Glossy Starling Long-billed Crombec White-browed Scrub-Robin
Cape Turtle-Dove Long-tailed Paradise-Whydah White-crested Helmet-Shrike
Cape White-eye Magpie Shrike White-crowned Lapwing
Cardinal Woodpecker Marabou Stork White-crowned Shrike
Cattle Egret Marico Sunbird Southern White-faced Scops Owl
Chinspot Batis Monotonous Lark Woodland Kingfisher
Cinnamon-breasted Bunting Natal Spurfowl Yellow-bellied Eremomela
Cloud Cisticola Neddicky Yellow-bellied Greenbul
Collared Sunbird Orange-breasted Bush-Shrike Yellow-billed Oxpecker
Common Scimitarbill Pale Flycatcher Yellow-breasted Apalis
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Common Swift Pearl-spotted Owlet Yellow-fronted Canary
Crested Barbet Pel's Fishing-Owl Yellow-throated Petronia
Crested Francolin Peregrine Falcon Zitting Cisticola
Croaking Cisticola Pied Crow
Figure 7. All birds recorded by sight or sound in 10 minute bird point counts in 2014 (Figure continued from previous page)
To get an understanding of the knock-on effect that elephant impact to habitat has on bird guild
diversity, the survey sites were split up into ‘High’, ‘Medium’, and ‘Low’ impact groups. Each bird
species was then assigned to a feeding guild, and the proportion of individuals within each guild was
compared between sites with different levels of elephant impact (see Figure 8).
There was statistically significant difference in bird guild composition in sites with different levels of
elephant impact. This was largely due to the significant decrease in frugivorous (fruit eating)
individuals and a significant increase in insectivores with higher impact levels. A decrease in in
frugivores may be explained by the selective preference of elephants for impacting larger trees in the
area (see section 1, Figure 4), as many fruit producing trees must reach maturity before they fruit. The
increase in insectivorous birds could be explained by an increase in damaged or dead vegetation
creating food sources and habitat for increased insect populations. It would be interesting to further
break-down the insectivore guild into two separate guilds, one for flying insects and another for
ground insects. The most interesting outputs from this study will come when we are able to assess
annual trends in levels of elephant impact and investigate and associated changes in bird guild
diversity.
The bird point count data provides a lot of opportunity for future analysis as we continue surveying
over a number of years, but we currently garner very little information from so few sites in such a
small area. We would like to significantly increase the number of survey sites throughout Balule so
that we can start to develop species distribution maps for the wider area and map species diversity
across the Reserve using predictive species distribution modelling. Figure 9 is a predictive species
diversity model that WEI created for Welgevonden Game Reserve using bird point data from just six
weeks of surveying at 40 sites over the 37,500 ha game reserve. These kinds of outputs would be
relatively easy to achieve if we are able to survey a greater number of sites across a wider area.
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Figure 8. Bird guild composition in low, medium, and high impact sites in OREC
Figure 9. WEI predictive species richness map of Welgevonden Game Reserve from a six week survey.
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3. Predator monitoring
Survey teams conduct opportunistic predator searches most mornings throughout the year. All fresh
tracks and signs, along with actual sightings, are recorded onto a customised cybertracker database.
This is an attempt to gain a better understanding of predator movements through the area and
territories held.
Leopard
Eight individuals have been identified within the OREC and surrounding borders. Three males, three
females, and two of unknown sex. Photographic indentikits have been created for each of these
individuals (see Figure 11) and we have named the individuals as follows:
Matimba: Adult male new to the area since mid-June 2014. His tracks are distinctive; the
centre lobe of his left back foot protrudes out backwards behind the side lobes.
Mala: Adult Female first spotted on Mala road when she had an interaction with a hyena
whilst protecting a kill. She is a very large female with a characteristic ‘J’ above her eye, making her
easily identifiable. She has been seen with Matimba on the river banks behind camp and may produce
cubs in early November 2014.
Sabi: Very relaxed individual. Generally regarded to be the dominant male in the area but may
have this dominance threatened by Matimba. Sabi has often been seen in the western section of
OREC.
Rue: Adult Female, name short for Rusermi as she was first spotted just off main road and
was later she was seen in Oewer Camp killing a warthog 20 meters from the swimming pool and staff.
She has only been seen on two occasions, we cannot confirm if she is resident or nomadic.
Ntombi: Adult female, named for her pretty and feminine features. She is has been spotted
around Dundee Dam area but is also extremely shy, so sightings of her are fleeting. It has been a while
since she was last spotted and the team is not sure if she is still in the area.
Dinidza: Adult male, named after the area. Was originally found lying with an impala kill under
a jackalberry, on the railway line. He has only been seen once. There are reports coming in from the
reserve manager on Dinidza that a new large male has been spotted regularly at his camp, as well as
a collared female around Dinidza camp through to Mafunyane Camp.
Nyala: Adult of unknown sex, was seen once up in the branches of a nyala tree, but made a
quick escape. Nyala is a large individual but has the face of a female. Staff at Struwig have seen this
same striking green eyed individual a number of times in that immediate area but could never sex it.
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Dundee: Adult of unknown sex, seen many times around Dundee dam in 2012 and 13, but not
seen in 2014. Has a characteristic eye patch over its right eye.
From general observations our teams have noted that Matimba, Mala & Sabi seem to be the more
dominant Individuals so far. Matimba is a new to the area with tracks and sightings suggesting he is
traversing the whole OREC region. Matimba has been seen with a female and we expect some cubs in
early Nov 2014. Judging from the frequency of sightings, it had been assumed that Sabi is dominant,
but it will be interesting to see how the introduction of Matimba to the area will affect the population
dynamics in this regard.
A map of monthly recordings is shown in Figure 10. Each recorded point shown on the map represents
an individual day when either a sighting or a fresh track has been recorded onto our Cybertracker
Database.
Figure 10. Monthly recordings map of leopard in WEI’s area of operation on OREC. Each point represents a day
when a sighting or fresh track has been recorded.
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Figure 11. Photographic ID Database of individuals recorded by WEI in OREC (This Figure covers Pages 14, 15 & 16)
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Lion
The only data recorded on the lion populations is from the predator searches and incidental sightings.
However, our team has also built up a good understanding of the lion populations in the region (Figure
12) and the following is an anecdotal report form WEI Field Technician, Caz Schiess:
“Up until May 2013 it was thought from the lion movements that Klasserie lions dominated the east
of the reserve. Very seldom were any lions from the west (Balule) seen and when seen, they were very
skittish. The Pride from the West is large with a coalition comprising three males and between eight
and ten other individuals, with cubs ranging from six to ten months. These cubs were very light in colour
compared to the Klasserie lions in the east, which is made up of a coalition of three males, two females,
and a group of six cubs ranging between approximately 10-24 months old. Two of the older cubs were
confirmed male.
In the early months of 2013, we started noticing tracks from the Western Pride males were growing
more in frequency. Tragically in May this year we discovered the dying body of one of the lioness from
the Eastern Pride. Her injuries suggest that she was attacked by another lion, as she was bitten on her
neck severing her jugular, with further injuries to her hind leg and side. The rest of the pride were
present and calling for her. It is important to also mention that there were no hyenas in the area. Since
this incident this pride has not been seen and the Western Pride dominates the region.
Having said this, the lion dynamics are still changing, and we have recently spotted three young
individuals; two females and one male, along the Olifants River between the Bush Camp and Struwig
Main Camp. These individuals are approximately 22-26months of age and very light in colour - blonde
like the western pride. We have also sighted two young (22-26 month old) males on the
Krabia/Klasserie side. Whether or not these are the youngsters from the two established prides is
unknown.
There are also suspicions of a 3rd pride now frequenting the reserve, but further investigation is needed
is needed to establish if they are part of the larger 2 prides.”
A map of monthly lion sightings is shown in Figure 12.
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Figure 12. Monthly recordings map of lion in WEI’s area of operation on OREC. Each point represents a day
when a sighting or fresh track has been recorded.
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Spotted Hyena
Our teams suspect that there is a clan of eight individuals covering the entire OREC region, although
there is a high frequency of other individuals or clans coming through the area. In April 2014 three
cubs were spotted near a den site on Mitsi Road. A monthly recordings map is shown below (Figure
13).
Figure 13. Monthly recordings map of spotted hyena in WEI’s area of operation on OREC. Each point
represents a day when a sighting or fresh track has been recorded.
Wild dog
Tracks, signs and sightings are more frequent during the drier months. Our teams previously recorded
a pack of 14 dogs but over time the pack size coming through the area has reduced, first to 12, then
to 10, to 4 and now just 2. The team is developing a manual Indentikit database. The dominant pack
that move through OREC have been denning in Klaserie for the last few years (G Beverly 2014, pers
comm). Since Dec 2013 our teams have only observed the alpha female and three others moving
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through the OREC region. These dogs were also seen in the Klaserie and Timbavati at the end of 2013
(G Beverly 2014, pers comm), and at the Balule Gate at the beginning of 2014.
In May 2013 four other dogs were spotted on Krabia. One of these was collared, and confirmed as
members of the ‘Investec Pack, a group collared in 2012 near Skukuza but have since split up (pers
comm - Grant Beverly).
Our team have noted that the dogs seem to follow a relatively fixed route through the reserve and
are easily picked up on when in the area. The two 2014 sightings in OREC are shown in Figure 14.
Figure 14. A recordings map of black-backed jackal, African wild cat, Caracal and African wild dog in WEI’s area of operation on OREC in 2014. Each point represents a day when a sighting or fresh track has been recorded.
Cheetah
There has only been one cheetah sighting on the OREC region during WEI’s tenure in the area.
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Caracal
There have been very few sightings of caracal, with only two, possibly three, individuals recorded.
Serval
Our teams have not seen signs of serval to date in the OREC region.
African wild cat
Four different individuals have been seen on the OREC region.
And the most interesting predation event of the year so far….
Our team has twice observed a gutsy honey badger predating upon porcupine in the region in 2014.
This was featured on the Go Southern Africa Blog (go-southernafrica.com/) under the title of ‘Quills &
Claws’.
Photo Credit – Caz Schiess & Anna Nagel
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4. Elephant monitoring
All elephant sightings, tracks and signs are recorded by our survey teams throughout the year.
Although herd size seems relatively consistent between the wet and dry season, trends suggest that
elephant spend more time in the OREC region during the dry winter months (see Figures 15 and 16).
Figure 15. Graph to show the monthly changes in the number of elephant sightings (in blue) and total number
of individuals recorded (orange) during WEI Game Transects in 2014.
Fig 16. Seasonal representation of elephant sightings from WEI Game Transects in 2014.
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5. Game Monitoring
WEI conducts at least two replicates of two separate vehicle-based game transects each month.
Transect A is 12km long and Transect B is 19km long. These transects collect data on species, age
classes, sex classes, and interspecific associations.
We have used vehicle-based game transects to very successfully estimate population numbers in
larger closed systems in the past (see Figure 17 – from WEI’s Welgevonden Game Reserve research
programme). Unfortunately, our limited area of operation in OREC prevents enough data collection
to support this same modelling approach using DISTANCE© sampling software. It would also be useful
to access habitat/vegetation maps for Balule as DISTANCE© modelling gives the most accurate
estimates when you can create detection functions for each habitat type and then model the
populations based on the proportion of the total area covered by that habitat type. However, even
with fantastic habitat maps, we would still not be able to create realistic estimates in such a small
area.
Greater traversing would allow us to create population estimates for the wider Balule region, and
could save the reserve substantial sums of money through substituting aerial censuses with free WEI
Game Transects if our population estimates are shown to be accurate over time.
Figure 17. Graph from WEI’s work in Welgevonden showing the actual numbers of animals counted for each
species during aerial censuses in 2010 and 2011 (dark bars) and the population estimates of each species from
modelling vehicle-based game transect data from the months around the aerial censuses during the same
years (light bars).
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The WEI game transects do however provide some interesting trends. An example of this is seen with
the changing proportion of age classes in Impala in Figure 18. Again, only a few species provide enough
data to support meaningful conclusions in this small area.
Figure 18. Monthly changes in age-class composition from WEI vehicle-based game transects on OREC
The survey team have been surprised at the number of Sharp’s grysbok sightings in the region.
Although not threatened, these species are infrequently seen and so our teams are very fortunate to
get such a great opportunity to get such great sightings. A map of recordings from our game transect
data is shown in Figure 19.
Fig 19. Recordings of Sharp’s Grysbok during WEI Game Transects on OREC in 2014
0
20
40
60
80
Jan Feb Mar Apr May Jun Jul Aug Sep
Per
cen
tage
of
reco
rdin
gs
ImpalaAdult Sub-A Juve
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6. Invertebrate Sampling
Each winter we are joined by Elme Breytenbach, an entomologist formally of the Agricultural Research
Council, who teaches students invertebrate sampling techniques and collects some baseline data for
the region. Each week, for six weeks, we have a consistent survey effort at two sites in the Struwig
Camp; one in an open grassland area and the other in thicker ‘bush’ vegetation. At each of these sites,
for 24 hours the following are set out:
- Three pit-fall traps; one control, one meat bait, one fermenting fruit bait;
- 24 pan traps; 8 red bowls, 8 yellow bowls, 8 white bowls;
- One Malaisse trap;
- Two Butterfly traps.
The species diversity at each site for 2014 is shown in Figure 20.
Figure 20. Total insect morphospecies diversity from WEI sampling in Struwig Camp in winter 2014
The winter programme has also been supported by a three day survey in March each year for the last
three years. In total WEI have identified 63 different butterfly species, which are listed in Figure 21,
with a photograph of a selection of the samples shown in Figure 22.
0
20
40
60
80
100
1 2 3 4 5 6
No
of
Sp
ecie
s
Weeks
Struwig Insect Diversity 2014
(Bush)
(Grass)
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ID Common Name Scientific Name Family Sub-family ID Source & Page Comments
1 Common Orange Tip Colotis evenina evenina Pieridae Pierinae Woodhall - 328
2 Zebra White Pinacopteryx eriphia eriphia Pieridae Pierinae Woodhall - 318
3 Speckled Sulphur Tip Colotis agoye Pieridae Pierinae Woodhall - 332
4 Small Orange Tip Colotis evagore antigone Pieridae Pierinae Woodhall - 332
5 Guineafowl Hamanumida daedalus Nymphalidae Limenitinae Woodhall - 118
6 Common Diadem Hypolimnas misippus Nymphalidae Nymphalinae Woodhall - 128 Female mimics African Monarch
7 Club-tailed Emperor Charaxes zoolina zoolina Nymphalidae Charaxinae Woodhall - 108
8 Pearl Emperor Charaxes varanes varanes Nymphalidae Charaxinae Woodhall - 102
9 Green veined Emperor Charaxes candippe Nymphalidae Charaxinae Woodhall - 102
10 African Monarch Danaus chryssipus aegypticus Nymphalidae Danainae Woodhall - 36
11 African Veined White Belenois gidica abyssinica Pieridae Pierinae Woodhall - 336
12 Evening Brown or Twilight Brown Melanitis leda helena Nymphalidae Satyrinae Woodhall - 40
13 Yellow Pansy Junonia hierta cebrene Nymphalidae Nymphalinae Woodhall - 136
14 Golden Piper Eurytela dryope angulata Nymphalidae Nymphalinae Woodhall - 128
15 Forest White Belenois zochalia zochalia Pieridae Pierinae Woodhall - 334
16 Brown-veined White Belenois aurota aurota Pieridae Pierinae Woodhall - 336 Binoculars
17 Broad-bordered Grass Yellow Eurema brigitta brigitta Pieridae Coliadinae Woodhall - 348 Yellow pan trap
18 Two-pip Policeman Coeliades pisistratus Hesperiidae Coeliadinae Woodhall - 360 Poorly-developed wings. Fruit trap
19 Angled Grass Yellow Eurema desjardinsii marshalli Pieridae Coliadinae Woodhall - 348 Red pan trap
20 Red Tip Colotis antivippe gavisa Pieridae Pierinae Woodhall - 328 Red pan trap
21 Orange-and-Lemon Butterfly Eronia leda Pieridae Pierinae Woodhall - 320
22 Wandering Donkey Acraea Acraea neobule neobule Nymphalidae Heliconiinae Woodhall - 82 On road
23 Small Elfin Sarangesa phidile Hesperiidae Pyrginae Woodhall - 366 Binoculars
24 African Common White Belenois creona severina Pieridae Pierinae Woodhall - 336 Garden
25 Babault's Blue Leptotes babaulti Lycaenidae Lycaeninae Woodhall - 262
26 ? Delagoa Sandman ? Spalia delagoae Hesperiidae Pyrginae Woodhall - 372 ID to be confirmed
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27 Bushveld Orange Tip Colotis pallene Pieridae Pierinae Woodhall - 330
28 Common Nephele (Moth) Nephele comma Sphingidae Picker - 350
29 Mafa Sandman Spalia mafa mafa Nymphalidae Satyrinae Woodhall - 376
30 Eyed Bush Brown or March Patroller Henotesia perspicua perspicua Nymphalidae Satyrinae Woodhall - 44 Butterfly trap
31 Spotted Joker Byblia ilithyia Nymphalidae Biblidinae Woodhall - 126
32 Blue Pansy Junonia aenone Nymphalidae Nymphalinae Woodhall - 136
33 Small Orange Acraea (Dancing Acraea) Hyalites eponina Acraea Picker - 372
34 Window Acraea Acraea oncraea Nymphalidae Heliconiinae Woodhall - 86 Pitfall trap
35 Bushveld Purple Tip or Common Purple Tip Colotis ione Pieridae Pierinae Woodhall - 326 Red pan trap
36 Lemon Traveller Colotis subfasciatus subfasciatus Pieridae Pierinae Woodhall - 334
37 Suphur Orange Tip Colotis auxo Pieridae Pierinae Woodhall - 328 Red pan trap
38 Satyr Emperor Charaxes ethalion ethalion Nymphalidae Charaxinae Woodhall - 112 Butterfly trap
39 Banded Hopper Platylesches picanini Hesperiidae Hesperiinae Woodhall - 404
40 Olive-haired Swift Borbo borbonica borbonica Hesperiidae Hesperiinae Woodhall - 410
41 White-cloaked Skipper Leucochitonea leubu Hesperiidae Pyrginae Woodhall - 370
42 Scarlet Tip Colotis danaea annae Pieridae Pierinae Woodhall - 326
43 Black-veined White Dixeia doxo parva Pieridae Pierinae Woodhall - 338
44 Dwarf blue Oraidium barberae Lycaenidae Lycaeninae Woodhall - 312
45 Clover Blue Zizina antanossa Lycaenidae Lycaeninae Woodhall - 312
46 Van Son's Emperor Charaxes vansoni Nymphalidae Charaxinae Woodhall - 114 Butterfly trap
47 Banded Gold Tip Colotis eris eris Pieridae Perinae Woodhall - 332
48 Veined Orange or Veined Tip Colotis vesta argillaceus Pieridae Pierinae Woodhall - 324 Red pan trap
49 Common Sandman Spialia diomus ferax (cf) Hesperiidae Pyrginae Woodhall - 378
50 Wallengren's Ranger or Skipper Kedestes wallengrenii wallengrenii Hesperiidae Hesperiinae Woodhall - 392 Pitfall trap
51 Small Marbled Elf Eretis umbra umbra Hesperiidae Pyrginae Woodhall - 366 Red pan trap
52 White-barred Emperor Charaxes brutus natalensis Nymphalidae Charaxinae Woodhall - 104 Butterfly trap
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Figure 21. Butterfly species lists. Elme Bretenbach (WEI). Reference books: – Woodhall, S., 2005. Field Guide to Butterflies of Southern Africa. Struik. – Picker et. al, Field Guide to Insects of South Africa. Struik.
53 Foxy Emperor Charaxes jasius saturnus Nymphalidae Charaxinae Woodhall - 104 Butterfly trap
54 Smokey Orange Tip Colotis euippe omphale Pieridae Pierinae Woodhall - 330 Butterfly trap
55 Lemon Traveller Colotis subfasciatus subfasciatus Pieridae Pierinae Woodhall - 334 White pan trap
56 Common Dotted Border Mylothris agathina agathina Pieridae Pierinae Woodhall - 344 Camp butterfly net
57 Common Grass Yellow Eurema hecabe solifera Pieridae Coliadinae Woodhall - 348 Camp butterfly net
58 Queen Purple Tip Colotis regina Pieridae Pierinae Woodhall - 326 Camp butterfly net
59 African Migrant/ Common Vagrant Catopsilia florella Pieridae Coliadinae Woodhall - 346 Butterfly trap
60 Squinting Bush Brown Bicyclus anynana anynana Nymphalidae Satyrinae Woodhall - 42 Butterfly trap
61 Batling Glider Cymothoe alcimedes Nymphalidae Charaxinae Woodhall - 116 Camp butterfly net
62 Apricot Playboy Deodorix dinochares Lycaenidae Lycaeninae Woodhall - 180 Camp butterfly net
63 Darker Commodore Precis antilope Nymphalidae Nymphalinae Woodhall - 132 Camp butterfly net
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Figure 22. A sample of butterfly specimens recorded on Struwig Eco Reserve
The invertebrate sampling programme has yielded some interesting specimens on Struwig, but none more so
than a single individual from the primitive Archaeognatha order. Amazingly enough this specimen was spotted
by our entomologist, Elme Breytenbach, whilst she was a passenger on a student training drive. Elme’s eye
caught a very small movement of what she originally thought was a bristletail or silverfish. Thinking it didn’t
look quite right, she collected the 5-6mm creature next to the dry grass on the verge of the road.
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On closer inspection it was seen to belong to the most primitive order of Archaeognatha. They closely resemble
silverfish (Thysanura) but are distinguished by arched thorax and compound eyes that meet in the middle of
the head. The central abdominal appendage is also much longer than the lateral ones. When disturbed they
jump high in the air by snapping the abdomen forward, which was how Elme spotted the specimen. Most are
found in leaf litter or under bark and rocks in moist habitats.
What makes this group so special is that they are the least-most evolutionarily changed insects, dating back
around 419.2 million years ago. They are one of the most poorly studied orders of insects in the World.
The Archaeognatha specimen found on Struwig. Photo credit Mike Haas
A MASSIVE THANK YOU TO OUR PARTNERS WHO MAKE ALL OF THIS POSSIBLE!
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