De Hoop Nature Reserve Research Articles

Peptide mass fingerprinting as a tool to assess micromammal biodiversity in Pleistocene South Africa: The case of Klipdrift Shelter

Remains of small mammals from archaeological sites are often used as palaeoenvironmental proxies in the reconstruction of past environments. Yet, identification of micromammals to species-level based on morphological traits is often difficult due to fragmentation of diagnostic skeletal elements. Here we test the potential of Zooarchaeology by Mass Spectrometry (ZooMS) as a tool for the taxonomic identification of micromammal remains from Middle Stone Age (MSA) sequences in South Africa. ZooMS peptide markers are first established for 14 extant micromammal species present in the region. These novel peptide markers are then used to identify micromammal bone remains from the MSA levels of Klipdrift Shelter (c. 72–51 ka), De Hoop Nature Reserve, South Africa. Our study shows that collagen preservation in micromammal bones from MSA contexts is sufficient for successful ZooMS analysis. To our knowledge, these results represent the oldest material successfully analysed with ZooMS from an African context. The peptide markers developed as part of this study can be used to characterize a larger number of micromammal assemblages. This holds significant promise for the future application of ZooMS to prehistoric material in South Africa and elsewhere in the continent.

Multi-proxy speleothem-based reconstruction of mid-MIS 3 climate in South Africa

Abstract. The southern coast of South Africa displays a highly dynamical climate as it is at the convergence of the Atlantic and Indian oceans, and it is located near the subtropical/temperate zone boundary with seasonal influence of easterlies and westerlies. The region hosts some key archeological sites with records of significant cognitive, technological and social developments. Reconstructions of the state and variability of past climate and environmental conditions around sites of archeological significance can provide crucial context for understanding the evolution of early humans. Here we present a short but high-resolution record of hydroclimate and temperature in South Africa. Our reconstructions are based on trace elements, calcite and fluid inclusion stable isotopes, as well as fluid inclusion microthermometry, from a speleothem collected in Bloukrantz cave, in the De Hoop Nature Reserve in the southern Cape region of South Africa. Our record covers the time period from 48.3 to 45.2 ka during marine isotope stage 3. Both δ18Oc and δ13Cc show strong variability and covary with Sr/Ca. This correlation suggests that the control on these proxies originates from internal cave processes such as prior carbonate precipitation, which we infer to be related to precipitation amount. The hydroclimate indicators furthermore suggest a shift towards overall drier conditions after 46 ka, coincident with cooling in Antarctica and drier conditions in the eastern part of South Africa corresponding to the summer rainfall zone (SRZ). Fluid inclusion-based temperature reconstructions show good agreement between the oxygen isotope and microthermometry methods, and results from the latter display little variation throughout the record, with reconstructed temperatures close to the present-day cave temperature of 17.5 ∘C. Overall, the BL3 speleothem record thus suggests relatively stable temperature from 48.3 to 45.2 ka, whereas precipitation was variable with marked drier episodes on sub-millennial timescales.

 Gnathiapipinde sp. nov. (Crustacea, Isopoda, Gnathiidae), a temporary parasite of the pufferfish, Amblyrhynchoteshonckenii, from temperate southern Africa.

A new species, Gnathiapipinde sp. nov., is described from specimens taken from pufferfish, Amblyrhynchoteshonckenii, at Chintsa and De Hoop Nature Reserve on the southern Indian Ocean coast of South Africa. Gnathiapipinde sp. nov. is characterised by the straight frontal margin, presence of conical superior frontolateral process, a strong and bifid mediofrontal processes, pronounced and pointed supraocular lobes, mandible strongly curved with a dentate blade, and the claviform penes produced more than a third the length of the pereon. A summary and key to the males of all known species of the Gnathiidae from the Temperate Southern African marine realm is provided.

Mechanical loading of primate fingers on vertical rock surfaces

Mechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arboreal primates by dissipating forces and economising the recruitment of muscles during climbing. The recent discovery of extremely curved phalanges in a hominin, Homo naledi, is puzzling, for it suggests life in an arboreal milieu, or, alternatively, habitual climbing on vertical rock surfaces. The importance of climbing rock walls is attested by several populations of baboons, one of which uses a 7-m vertical surface to enter and exit Dronkvlei Cave, De Hoop Nature Reserve, South Africa. This rock surface is an attractive model for estimating the probability of extreme mechanical loading on the phalanges of rock-climbing primates. Here we use three-dimensional photogrammetry to show that 82–91% of the climbable surface would generate high forces on the flexor tendon pulley system and severely load the phalanges of baboons and H. naledi. If such proportions are representative of vertical rock surfaces elsewhere, it may be sufficient to induce stress-mitigating curvature in the phalanges of primates.Significance: We present the first three-dimensional photogrammetric analysis of a vertical rock surface climbed by a non-human primate, the chacma baboon (Papio ursinus). Our results show that a large proportion of a vertical rock wall would compel crimp and slope hand positions during climbing – grips that could explain the extraordinary phalangeal curvature expressed by a Middle Pleistocene hominin, Homo naledi.

Lessons for conservation management: Monitoring temporal changes in genetic diversity of Cape mountain zebra (Equus zebra zebra).

The Cape mountain zebra (Equus zebra zebra) is a subspecies of mountain zebra endemic to South Africa. The Cape mountain zebra experienced near extinction in the early 1900’s and their numbers have since recovered to more than 4,800 individuals. However, there are still threats to their long-term persistence. A previous study reported that Cape mountain zebra had low genetic diversity in three relict populations and that urgent conservation management actions were needed to mitigate the risk of further loss. As these suggestions went largely unheeded, we undertook the present study, fifteen years later to determine the impact of management on genetic diversity in three key populations. Our results show a substantial loss of heterozygosity across the Cape mountain zebra populations studied. The most severe losses occurred at De Hoop Nature Reserve where expected heterozygosity reduced by 22.85% from 0.385 to 0.297. This is alarming, as the De Hoop Nature Reserve was previously identified as the most genetically diverse population owing to its founders originating from two of the three remaining relict stocks. Furthermore, we observed a complete loss of multiple private alleles from all populations, and a related reduction in genetic structure across the subspecies. These losses could lead to inbreeding depression and reduce the evolutionary potential of the Cape mountain zebra. We recommend immediate implementation of evidence-based genetic management and monitoring to prevent further losses, which could jeopardise the long term survival of Cape mountain zebra, especially in the face of habitat and climate change and emerging diseases.

Translocation a potential corridor for equine piroplasms in Cape mountain zebra (Equus zebra zebra).

Translocation of animals in fragmented habitats is an important means of dispersal and gene flow, however, the movement of animals has led to the spread of various diseases globally and wildlife are often the reservoirs of these diseases. Currently, Cape mountain zebra are translocated within South Africa as a management method for augmentation of isolated and fragmented populations. The movement of pathogens due to translocations in local regions have gone largely unchecked, particularly where there may still be isolated regions that can be negatively affected. Equine piroplasmosis is a tick-borne disease caused by Theilaria equi and/or Babesia caballi reported to occur in equids (Bhoora et al., 2010; Zweygarth et al., 2002). Here, the presence of T. equi and B. caballi was detected in 137 clinically healthy Cape mountain zebra from three South African reserves, Mountain Zebra National Park (MZNP), De Hoop Nature Reserve (DHNR) and Karoo National Park (KNP) using the multiplex EP real-time PCR (qPCR) assay. We observed 100% prevalence for T. equi and identified only one animal from MZNP with B. caballi. These results affirm that precautions should be taken prior to founding new populations of Cape mountain zebra and that potential farms and properties adjacent to prospective reserves should be screened for the presence of the organisms in order to mitigate risks of infection to domestic animals.

Extent of Solar Tracking Differs between Two Co-occurring Congeneric Geophytes That Differ in Leaf Shape

Premise of research. By adjusting leaf angles to orient toward or away from the sun, solar tracking modifies direct light interception, which consequently modifies leaf temperature. Leaf temperature is also influenced by leaf shape, due to its effect on heat transfer across boundary layers. Two co-occurring, closely related geophytic species of Pelargonium that differ dramatically in leaf shape were observed to exhibit differences in diurnal leaf movements. We asked whether leaf movements were consistent with solar tracking, whether they differed between the two species, and whether leaf shape and movement interacted to influence leaf temperature.Methodology. We measured solar tracking, leaf temperatures, stomatal conductance, and light interception across a diurnal time course in midwinter in the field at De Hoop Nature Reserve in South Africa.Pivotal results. Highly dissected leaves of P. triste moved to track the sun more closely than shallowly lobed leaves of P. lobatum. In contrast to predictions based on leaf energy budget calculations, average diurnal temperatures for both leaf shapes remained close to ambient, with the only significant deviation occurring early in the morning in P. triste. The best model predicting the extent of leaf temperature difference from ambient included leaf shape, leaf movement, and the proportion of the leaf surface receiving direct light, and, notably, the interaction between leaf shape and movement.Conclusions. Leaf three-dimensionality interacts with movement to dictate direct light absorption, and all are critical to fully understanding leaf thermal profiles of nonflat leaves under field conditions.

The ‘strength of weak ties’ among female baboons: fitness-related benefits of social bonds

Studies across a range of species have shown that sociability has positive fitness consequences. Among baboons, both increased infant survival and adult longevity have been associated with the maintenance of strong, equitable and durable social bonds. However, not all baboon populations show these patterns of bonding. South African chacma baboons, Papio ursinus, in the Drakensberg Mountains and De Hoop Nature Reserve show cyclical variation in social relations across time, with strong bonds formed only during certain times of the year. Using long-term data from the De Hoop baboons, we tested whether social relations influence female reproductive success in our study group in a manner similar to other baboon populations. Our results show that the number of strong bonds a female maintained predicted birth rate, and that the number of weak bonds a female possessed predicted infant 12-month survival and infant longevity. Fitness-related benefits of sociability were, however, independent of female dominance rank, and there was no relationship between the number of weak and strong bonds a female maintained. One possible explanation for the influence of weak as well as strong bonds in our study group may be that variation in demographic and ecological conditions across populations may favour the use of different social strategies by females. In our sample, weak bonds as well as strong bonds appear to be instrumental to achieving fitness-related benefits.

A cost-benefit analysis of using Rooikrans as biomass feedstock for electricity generation: A case study of the De Hoop nature reserve, South Africa

Invasive alien plants (IAPs) like Rooikrans (Acacia Cyclops) have several undesirable effects on both the natural environment and the social, economic and cultural wellness of society in the De Hoop nature reserve of the Western Cape Province. A few of these negative effects are: the change in coastal sediment dynamics, the change in seed dispersal dynamics, and the fact that it is overtaking native plants. However, Rooikrans can also potentially be used as biomass feedstock for electricity generation. Following a system dynamics modelling approach, the feasibility of using woody biomass from Rooikrans was investigated. The RE-model used data obtained from the Department of Environmental Affairs’ (DEA) Natural Resource Management (NRM) division, consulted with experts and conducted literature reviews with respect to the subject matter. Three scenarios were tested and the RE-model results showed that all scenarios have a positive cumulative Net Present Values (NPVs), with the exception of the baseline case scenario. This study shows that the production of electricity using Rooikrans woody biomass is a viable and feasible option in comparison with electricity production by diesel generators.

Two dung beetle species that disperse mimetic seeds both feed on eland dung

Scarabaeus spretus zur Strassen was observed to roll and bury Ceratocaryum argenteum (Restionaceae) seeds in the sandplain fynbos of the Potberg area of the De Hoop Nature Reserve, South Africa. This species is the second dung beetle species found to be deceived by the faecal mimicry of C. argenteum seeds – the first species being Epirinus flagellatus. An isotopic analysis suggests that both these dung beetle species most likely feed on eland (Taurotragus oryx), not bontebok (Damaliscus pygargus pygargus), dung. Thus the model in this mimicry is eland dung; this interaction suggests large herbivores are an integral part of this fynbos. 
 Supplementary Video: A Scarabaeus spretus dung beetle burying seeds of Ceratocaryum argenteum: https://youtu.be/C_VFlAcsx10

Klipdrift Shelter, southern Cape, South Africa: preliminary report on the Howiesons Poort layers

Surveys for archaeological sites in the De Hoop Nature Reserve, southern Cape, South Africa resulted in the discovery of a cave complex comprising two locations, Klipdrift Cave and Klipdrift Shelter. Excavations commenced in 2010 with Later Stone Age deposits initially being recovered at the former site and Middle Stone Age deposits at the latter. The lithic component at Klipdrift Shelter is consistent with the Howiesons Poort, a technological complex recorded at a number of archaeological sites in southern Africa. The age for these deposits at Klipdrift Shelter, obtained by single grain optically stimulated luminescence, spans the period 65.5 ± 4.8 ka to 59.4 ± 4.6 ka. Controlled and accurate excavations of the discrete layers have resulted in the recovery of a hominin molar, marine shells, terrestrial fauna, floral remains, organic materials, hearths, lithics, ochre, and ostrich eggshell. More than 95 pieces of the latter, distributed across the layers, are engraved with diverse, abstract patterns. The preliminary results from Klipdrift Shelter presented in this report provide new insights into the Howiesons Poort in this sub-region and contribute further to ongoing knowledge about the complex behaviours of early Homo sapiens in southern Africa. Excavations at the Klipdrift Complex will continue in the future.

The impact of native large herbivores and fire on the vegetation dynamics in the Cape renosterveld shrublands of South Africa: insights from a six‐yr field experiment

AbstractQuestionRenosterveld – a vegetation complex within the Fynbos Biome of South Africa – occurs in multiple structural states, including shrublands and various types of grasslands, lawns and herb‐lands. Uncertainty exists over whether the present unpalatable shrubland state might have replaced a historical grassland state. Settled agriculture characterized by fixed burning cycles and overgrazing by livestock has been blamed for this putative change. However, the disappearance of native large herbivores has also been implicated. Understanding the drivers responsible for putative state changes is of importance for conservation of this critically endangered vegetation type.LocationRenosterveld shrublands and grasslands of the De Hoop Nature Reserve, Western Cape Province, South Africa.MethodsThree structural states of renosterveld (grazing lawn, tussock grassland and shrubland) were subjected to an experiment involving fire (burned/unburned) and herbivory (grazed/ungrazed by native mesoherbivores). Using animal exclosures and experimental burning, we measured the responses of the biomass of major plant functional types over 6 yrs to test whether switches between states occur in order to discern the drivers of these changes. The data were analysed using permutational manova, Fisher's exact contingency tests and NMDS.ResultsHerbivory (but not fire) had significant effects on lawn and tussock grassland biomass. Palatable shrubs proliferated in tussock grassland protected from herbivory. Unpalatable shrubs invaded burned lawn habitats exposed to herbivory. The vegetation composition of the shrubland state was affected by fire, herbivory and by the interaction between the two. Burned and grazed shrubland reverted to a dense canopy unpalatable state, while shrubland plots protected from grazing became palatable shrubland with a grass understorey. Palatable shrub species increased in the unburned and ungrazed shrubland plots, while the biomass of unpalatable shrubs declined in both the unburned grazed and exclosure plots.ConclusionWe found no evidence supporting the hypothesis that the disappearance of native large herbivores led to the conversion of tussock grassland into unpalatable shrubland. Instead, the removal of native browsers caused palatable shrubs to dominate tussock grassland areas. Unpalatable shrubland is retained through a combination of fire and herbivory, but how this state established and persisted historically remains undetermined. Temporary relief from large herbivore grazing after unpalatable shrubland has been burned is recommended if a more open grassland state is the desired target.

Ontogenetic Scaling of Fore- and Hind Limb Posture in Wild Chacma Baboons (Papio hamadryas ursinus)

Large-scale interspecific studies of mammals ranging between 0.04–280 kg have shown that larger animals walk with more extended limb joints. Within a taxon or clade, however, the relationship between body size and joint posture is less straightforward. Factors that may affect the lack of congruence between broad and narrow phylogenetic analyses of limb kinematics include limited sampling of (1) ranges of body size, and/or (2) numbers of individuals. Unfortunately, both issues are inherent in laboratory-based or zoo locomotion research. In this study, we examined the relationship between body mass and elbow and knee joint angles (our proxies of fore- and hind limb posture, respectively) in a cross-sectional ontogenetic sample of wild chacma baboons (Papio hamadryas ursinus) habituated in the De Hoop Nature Reserve, South Africa. Videos were obtained from 33 individuals of known age (12 to ≥108 months) and body mass (2–29.5 kg) during walking trials. Results show that older, heavier baboons walk with significantly more extended knee joints but not elbow joints. This pattern is consistent when examining only males, but not within the female sample. Heavier, older baboons also display significantly less variation in their hind limb posture compared to lighter, young animals. Thus, within this ontogenetic sample of a single primate species spanning an order of magnitude in body mass, hind limb posture exhibited a postural scaling phenomenon while the forelimbs did not. These findings may further help explain 1) why younger mammals (including baboons) tend to have relatively stronger bones than adults, and 2) why humeri appear relatively weaker than femora (in at least baboons). Finally, this study demonstrates how field-acquired kinematics can help answer fundamental biomechanical questions usually addressed only in animal gait laboratories.

South African kelp moving eastwards: the discovery of Ecklonia maxima (Osbeck) Papenfuss at De Hoop Nature Reserve on the south coast of South Africa

Historical and recent evidence is documented to demonstrate that the eastern limit of the major kelp-bed forming seaweed Ecklonia maxima has moved c. 73 km eastward along the south coast of South Africa since 2006, after remaining unchanged for almost 70 years. A significant population has established at Koppie Alleen, De Hoop Nature Reserve, which has been monitored from 2008 to 2011. It is hypothesised that the eastward spread is limited by aspects of the inshore water temperature regime, and recent evidence suggests that gradual cooling along this coast may have caused the change in distribution. It seems likely that if a cooling trend continues along the South African south coast, kelp beds and their associated species will move farther eastward in future decades, affecting the ecology and livelihoods along this coast.

Resolving management conflicts: could agricultural land provide the answer for an endangered species in a habitat classified as a World Heritage Site?

SUMMARYThe short-interval fires required to promote grazing for large herbivores within the Cape Floristic Region World Heritage Site are detrimental to plant diversity. At the same time, longer interval fires significantly reduce graze quality. Conservation managers thus face an enormous challenge when the herbivores are also a conservation priority, since the competing conservation objectives are difficult to reconcile. Population growth rates of genetically important populations of endangered Cape mountain zebra (Equus zebra zebra) are low or declining following management focused on their fynbos habitat. Investigation of spatial and temporal habitat use and the diet of Cape mountain zebra, focusing on the use of land historically converted to agricultural grassland within fynbos in De Hoop Nature Reserve (South Africa), determined factors limiting populations and facilitated development of management strategies. Zebras selected grassland over other habitat types, despite grassland accounting for only a small proportion of the reserve. Grasses also made up the greatest proportion of diet for zebras throughout the year. Time spent on grasslands increased with grass height and was likely to have been influenced by grass protein levels. It is likely that grazing resources are a limiting factor for zebra, and so options for improving and/or increasing grassland at De Hoop should be considered. Translocation of surplus males to other conservation areas, reductions in other herbivore populations and targeted burns to increase grassland availability all offer short-term solutions. However, the acquisition of agricultural grassland adjacent to reserves is likely to be a viable long-term management strategy for this and other genetically important Cape mountain zebra populations. Low conservation priority habitats, such as farmland, should be considered for other management conflicts, as they have the potential to play a vital role in conservation.

Heterogeneity in shore flies – the case of Glenanthe Haliday (Diptera: Ephydridae) in the Old World

Old World species of the genus Glenanthe are treated comprehensively with an emphasis on the unusually diverse morphological heterogeneity discovered in structures of the male terminalia. As perspective for this treatment, the tribe Lipochaetini, in which Glenanthe is placed, is characterized and discussed, and an annotated key to the four included genera is provided to facilitate their identification. Glenanthe is demonstrated to be a monophyletic lineage within Lipochaetini. Seven Old World species of Glenanthe are now known, including two new Afrotropical species as follows (type locality in parenthesis): G. namibia n. sp. (Namibia. Mukwe: Divuju: Okavango River [18°04’04”S, 21°28’51”E] and G. danielssoni n. sp. (Republic of South Africa. Cape Province: De Hoop Nature Reserve [34°27’S, 28°25’E]. The identity of G. fuscinervis Becker, revised status (raised from synonymy with G. ripicola (Haliday)), is clarified, and found to be conspecific with Hydrina ochracea Oldenberg, which is recognized as a junior synonym. Papp’s synonymy of Glenanthe fasciventris Becker with Hydrellia (Glenanthe) ripicola Haliday is confirmed, and herein we relegate G. iranica Canzoneri & Rampini also as junior synonym of G. ripicola. The remarkable diverse structures of the male terminalia of all included species are described and illustrated and distribution maps are also provided.

Ectoparasite Diversity on Rodents at De Hoop Nature Reserve, Western Cape Province

Fleas, lice, mites and ticks were collected from 41 Rhabdomys pumilio and seven Otomys irroratus at De Hoop Nature Reserve in the Western Cape Province of South Africa. The aims of the study were firstly to quantify parasite abundance and to record the species richness on the rodents. Secondly to record the parasite species that were shared between R. pumilio and O. irroratus and thirdly to compare the parasite abundance on R. pumilio between localities of varying antelope activity. Each rodent was individually examined under a stereoscopic microscope and its parasites were removed, counted and identified to species level. The parasite species included seven flea, one louse, nine mite and 10 tick species. Three undescribed mite species were also recovered and new locality records were obtained for six flea, two lice, two mite and one tick species. Several flea, mite and tick species were shared between R. pumilio and O. irroratus. Both the mean abundance of the total ectoparasite burdens and the mean tick abundance were significantly higher on R. pumilio individuals that were trapped in habitats preferred and occupied by large antelope species compared to habitats in which antelope were absent or rarely present.

Ectoparasite diversity on rodents at De Hoop Nature Reserve, Western Cape Province

Fleas, lice, mites and ticks were collected from 41 Rhabdomys pumilio and seven Otomys irroratus at De Hoop Nature Reserve in the Western Cape Province of South Africa. The aims of the study were firstly to quantify parasite abundance and to record the species richness on the rodents. Secondly to record the parasite species that were shared between R. pumilio and O. irroratus and thirdly to compare the parasite abundance on R. pumilio between localities of varying antelope activity. Each rodent was individually examined under a stereoscopic microscope and its parasites were removed, counted and identified to species level. The parasite species included seven flea, one louse, nine mite and 10 tick species. Three undescribed mite species were also recovered and new locality records were obtained for six flea, two lice, two mite and one tick species. Several flea, mite and tick species were shared between R. pumilio and O. irroratus. Both the mean abundance of the total ectoparasite burdens and the mean tick abundance were significantly higher on R. pumilio individuals that were trapped in habitats preferred and occupied by large antelope species compared to habitats in which antelope were absent or rarely present.

Strontium isotope analyses of large herbivore habitat use in the Cape Fynbos region of South Africa

The Cape Fynbos region of South Africa, a global biodiversity hotspot, hosted a diverse large mammal fauna till shortly after permanent European settlement (1652). How these animals survived in this exceptionally nutrient-poor environment is puzzling and it is generally believed that they restricted their movements to the more fertile shale areas. We tested the hypothesis that large herbivores avoid nutrient-poor limestone and sandstone fynbos shrublands in favour of shale-derived renosterveld vegetation using strontium (Sr) isotope analysis. If this technique could reconstruct the preferred feeding habitats of the contemporary fauna, it might also be useful for reconstructing the preferred feeding grounds of an extinct fauna. Using the assumption that small rodents have spatially restricted foraging activities, we determined the (87)Sr/(86)Sr isotope ratios of rodent teeth to establish the isotopic signal characteristic of the different geological substrates in the area. We then analysed (87)Sr/(86)Sr isotope ratios in the bones of a number of different large herbivores found in De Hoop Nature Reserve using laser ablation multi-collector inductively coupled plasma mass spectrometry. These values were compared to the bioavailable (rodent) values on the respective geological substrates. The technique identified differences in feeding substrate selection between different species and groups of the same species. The results also showed that shale renosterveld shrubland is not the exclusive source of nutrition for the large herbivores. Strikingly different isotope ratios among individuals in some populations pointed to significant dispersal events from distant sources. However, we were unable to pinpoint the exact feeding areas using Sr isotope analysis probably because some animals use a combination of substrates for feeding and because the geology of the study area is complex with graded isotope signals. We suggest that this technique is a valuable additional tool for exploring large mammal foraging behaviour on habitats associated with contrasting and less complex geology.

Evaluation of Maternal Features as Indicators of Asynchronous Embryonic Development inMiniopterus natalensis

The timing of early reproductive events for the Natal long-fingered bat, Miniopterus natalensis, was examined during its breeding season (August to December) in its maternity roost at the De Hoop Nature Reserve (South Africa). This migrating species is monoestrous with copulation occurring around April in South African populations. Embryonic development is stalled during hibernation by delayed implantation of the blastocyst. As a result, limb bud stage embryos (CS13) are first noted in other South African populations in mid-September. The timing of these reproductive events for the De Hoop population is similar with bats arriving at the maternity roosts in September and embryos at the limb bud stage (CS13) being noted in this month. Pregnancy was not synchronous in the population with bats dissected on the same day exhibiting differences in the stage of development of their young (CS11 to CS21 being the largest range). Maternal features (progesterone concentration, body mass and abdominal distension) were analysed to determine if they provided a reliable estimate of embryonic stage. The progesterone concentrations of pregnant bats showed a similar profile to the Kwa-Zulu Natal and the Eastern Cape populations. Though progesterone concentration did increase as pregnancy progressed, it was not an accurate predictor of embryonic stage. Maternal body mass did not correlate with the stage of embryonic development. However, abdominal distension determined by palpation is an accurate field based predictor of the stages of pregnancy: no abdominal distension, small to medium abdominal distension and large abdominal distension distinguished between non-pregnant bats and those carrying either early (CS11–CS15) or mid-developmental stages (CS16–CS21), respectively.