Adriaan Engelbrecht

Dr. Adriaan Engelbrecht

Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville 7535, South Africa
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 September 2021 in South African Journal of Science
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Journal Article
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GAGraham J. Alexander
Graham J. Alexander
KTKrystal A. Tolley
Krystal A. Tolley
BMBryan Maritz
Bryan Maritz
AMAndrew McKechnie
Andrew McKechnie
PMPaul Manger
Paul Manger
GKGraham I.H. Kerley
Graham I.H. Kerley

9 September 2025 in Land
Verified
Journal Article
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NLNgoako Lucas Letsoalo
Ngoako Lucas Letsoalo
Igshaan SamuelsIgshaan Samuels
Igshaan Samuels
JTJulius Tlou Tjelele
Julius Tlou Tjelele
HPHosia Turupa Pule
Hosia Turupa Pule
CCClement Frederick Cupido
Clement Frederick Cupido
AEAdriaan Engelbrecht
Adriaan Engelbrecht
Climate change has intensified extreme weather events worldwide, such as droughts, which have severely affected South Africa’s rangelands by reducing productivity and increasing livestock mortality. This study aimed to investigate variability in grazing capacities and stocking rates with respect to land tenure, long-term grazing capacity norms, field surveys, and farmer perceptions during and post-drought conditions in the three biomes in South Africa. In-person interviews and field surveys were conducted with 85 farmers from the Grassland (n = 25), Savanna (n = 35), and Nama-Karoo (n = 30) biomes and vegetation condition was surveyed during or after the drought. Grazing capacity did not differ significantly across land tenure systems in the Savanna biomes (p > 0.05), but significant differences were found in the Grassland and Nama-Karoo biomes (p< 0.05). Over > 60% of farmers in the Nama-Karoo biome rated their rangeland condition as poor because of the drought, and field surveys showed that grazing capacities were four times lower than the national recommended grazing capacity norm. Considering the high inter-annual variability in vegetation productivity and differences in farmers’ perceptions based on local knowledge, it is recommended that the Department of Agriculture adopt flexible grazing capacity ranges in the regulations of the Conservation of Agricultural Resource Act 43 of 1983.

15 May 2020 in Zootaxa
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VRV. Ras
V. Ras
SNS. Neethling
S. Neethling
AEAdriaan Engelbrecht
Adriaan Engelbrecht
AMAndre Morandini
Andre Morandini
KBK.M. Bayha
K.M. Bayha
MGM.J. Gibbons
M.J. Gibbons
Chrysaora (Pèron & Lesueur 1810) is the most diverse genus within Discomedusae, and 15 valid species are currently recognised, with many others not formally described. Since Chrysaora fulgida (Reynaud 1830) was first recognised as occurring off the south west (SW) coast off South Africa, the species has been variously synonymised with Chrysaora hysoscella (Linnaeus 1767) and Chrysaora africana (Vanhöffen 1902). Using DNA evidence alongside multivariate tools to analyse quantitative morphometric and meristic data, as well as information from the cnidome, we unambiguously separate C. fulgida from C. hysoscella; we resurrect C. africana as a valid species and recognise a new species, Chrysaora agulhensis sp. nov. Full descriptions of C. fulgida, C. africana and C. agulhensis sp. nov. are provided. The species have different geographical patterns of distribution around the region, with restricted areas of overlap: C. agulhensis sp. nov. is found along the southern coast of South Africa and over the Agulhas Bank, C. fulgida extends from Cape Point in South Africa to southern Angola, and C. africana can be found from southern Namibia northwards to the Gulf of Guinea. The species can be readily separated in the field by a combination of tentacle/lappet number and shape, colour patterns and the form of the oral arms.

19 February 2021 in Zootaxa
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MBMichael Brown
Michael Brown
SSSimonetta Scorrano
Simonetta Scorrano
ZKZafrir Kuplik
Zafrir Kuplik
DKDrikus Kuyper
Drikus Kuyper
VRVerena Ras
Verena Ras
MGMark J Gibbons
Mark J Gibbons
A new species of the cosmopolitan jellyfish genus Aurelia is described from the coastal waters of Mozambique using a combination of morphological, meristic and genetic information (COI and 18S). The species can be separated from congeners that have been recently described by a combination of bell shape, number of canal origins and anastomoses, and the shape of the manubrium and oral arms. Three types of nematocysts are present in the tissues of both the bell margin and oral arms, and this description of the cnidome will allow for future comparison. Pairwise genetic comparisons showed a mean COI divergence of 4.8% within the group, and a mean divergence ranging between 15% and 22% with all other species of Aurelia.

1 July 2024 in Zootaxa
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MGMikhaila Leigh Gordon
Mikhaila Leigh Gordon
JCJonathan F. Colville
Jonathan F. Colville
AEAdriaan Engelbrecht
Adriaan Engelbrecht
VCVanessa Couldridge
Vanessa Couldridge
The genus Bullacris in the family Pneumoridae was most recently revised by Dirsh in 1965 based on morphological comparisons between species. However, since that time, new information about the genus and the family has come to light, necessitating a revision of the genus. In addition, the species B. boschimana was originally described based on a single female specimen. Here we present and describe the male of the species for the first time. The aim of this study was to update the current species descriptions by including additional specimens and incorporating additional methods for a more comprehensive comparison. Analyses consisted of morphometric measurements from high-quality images of type specimens, existing South African museum specimens, as well as personally collected specimens. Acoustic signals are also presented and compared between species. In addition, phylogenetic analyses were conducted on the barcoding mitochondrial gene COI and two nuclear genes, namely ITS and 18S. Results show that according to morphological, acoustic and genetic data, B. discolor and B. serrata as well as B. intermedia and B. membracioides share notable similarities. Bullacris discolor and B. serrata share similar phenotypic traits, in which B. discolor can either appear uniform in colour or have a speckled variation that is very similar in appearance to B. serrata. Bullacris intermedia and B. membracioides have a 5% mitochondrial DNA pairwise distance, suggesting that they may have not be fully diverged; however, morphological analysis shows that these species are morphologically distinguishable. It is suggested that these species may have undergone spatial separation at one point; however, further investigation is required. Additional sampling across a wider geographic range is essential to clarify the relationships between B. discolor and B. serrata, as well as between B. intermedia and B. membracioides.

9 July 2022 in African Entomology
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RSRekha Sathyan
Rekha Sathyan
VCVanessa Couldridge
Vanessa Couldridge
AEAdriaan Engelbrecht
Adriaan Engelbrecht
Host-associated genetic differentiation in grasshoppers has received limited attention, due to a lack of information on grasshopper-plant associations. The bladder grasshopper, Bullacris unicolor (Linnaeus, 1758) (Orthoptera: Pneumoridae), is a phytophagous species that can occur on at least six host plants within its geographic range. However, the relationship between host plant association and genetic variation of bladder grasshoppers has not been studied before. In light of this, the present study examined host plant-related genetic [mitochondrial cytochrome oxidase 1 (CO1) and the internal transcribed spacer (ITS) gene regions] and morphological (antennal length, body length, head width, abdomen width, femur length, tibia length and pronotum length) divergence within a population of B. unicolor. We used two plant species, belonging to different families, namely Didelta spinosa (L.fil.) Aiton (Asteraceae) and Roepera morgsana (L.) Beier & Thulin (Zygophyllaceae), to evaluate variation between individuals collected on these two sympatric host plants at a single locality in the Northern Cape, South Africa. The results demonstrated non-significant host related genetic variation with very low values of FST, indicating a low level of variation. The phylogram strongly indicated that there are no host-associated genetic differences in B. unicolor by displaying limited genomic clustering, whereas some differentiation was observed between the morphological measurements of males and females among host plants. Further studies using microsatellite molecular markers may help to discern population genetic structure. In addition, significant host-associated morphological divergence highlights the need to examine the mechanisms by which host utilization affects morphological features.