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Mduduzi Ndlovu

University of the Free State, Zoology and Entomology, Faculty Member

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I am a professional zoologist intrigued by a wide range of theoretical and practical issues in African ecology and conservation. My broad research interests include ornithology, wildlife ecology and conservation biology.

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Tinotendashe Pori

Michael Yabsley

The University of Georgia

Instituto Leônidas e Maria Deane - Fiocruz

Adewole Adekola

University of Ibadan

Veronika Cottontail

Patricia Parker

University of Missouri - St. Louis

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Papers by Mduduzi Ndlovu

Influence of season and other factors on avian Trypanosoma spp. and microfilarial prevalence in the Lowveld, South Africa

South African Journal of Science

To comprehend the effects of emerging infectious diseases on both human and animal health, it is ... more To comprehend the effects of emerging infectious diseases on both human and animal health, it is necessary to understand the ecology of pathogens that have wildlife reservoirs. In this study, we determined the prevalence of the parasites Trypanosoma spp. and filarial nematodes in the bloodstream of birds in and around the Kruger National Park, South Africa, partly to test the hypothesis that season influences parasitaemia. Other factors considered were foraging habits, gregariousness or solitariness, and whether location might facilitate contact between birds and parasite vectors. Microscopy was used to screen stained blood smears prepared from 685 captured birds of 87 species. It was found that 3.9% of the birds were infected with filarial nematodes (as reflected by the presence of microfilariae) and 3.1% with Trypanosoma spp. No cases of coinfection with both types of parasite were encountered. Ground-foraging and solitary birds had the highest parasite prevalences compared to oth...

Comparative performance Data-MB Wardjomto et al.xlsx

This dataset includes information on starlings sampled in the Kruger National Park and details on... more

Peter Mundy1941–2023

African Journal of Wildlife Research

Responses of ground-dwelling arthropods to long-term prescribed fire regimes in a savanna protected area

Background Sound management of protected areas is crucial for biodiversity conservation. In savan... more Background Sound management of protected areas is crucial for biodiversity conservation. In savanna systems, fire is common, yet little is known on the direct and long-term effects of prescribed burns on arthropod abundance, richness, and diversity. Standardised pitfall traps and active searches were used to compare variation in abundance, richness and diversity of arthropods at various experimental burn plots in the Kruger National Park, a protected area in a savanna setting. Results Hymenopterans: Formicidae were the most abundant (76.4%), whilst Coleopterans, Araneae and Orthopterans constituted 18.6, 3 and 1% of the total arthropods collected respectively. Coleopterans were the most diverse group (30.2%) compared to Hymenopterans: Formicidae (24.6), Araneae (24.6) and Orthopterans (4%). Abundance, species richness and diversity of multi-taxa significantly differed between the treatment plots. Abundance and diversity of Formicidae were significantly lower, hence, species richness...

Integrating Nguni cattle into black rhino reserves: Could this be a novel rural community-based conservation model?

Academia Letters, 2021

Data for: Temperature fluctuations inside savanna termite mounds: do size and plant shade matter?

We measured diurnal external temperature, mound size (volume), amount of shade and mound internal... more We measured diurnal external temperature, mound size (volume), amount of shade and mound internal temperature over a 24-hour period. Internal mound temperature varied daily following the diurnal changes of external temperature. Active termite mounds maintained a higher internal temperature than inactive ones, and the magnitude of this difference increased with mound volume; active and inactive mounds were equally affected by shade amount and external temperature fluctuations. Large mounds maintained near optimal internal temperatures compared to smaller sized mounds.

Pulses Are Related to Foraging Guild and Food-Web Position

community to resourcepulses are related to foraging guild and food-web position

Association benefits between harvester termites (Trinervitermes trinervoides) and num-num plants (Carissa bispinosa) in a semi-arid savanna setting

Journal of Arid Environments, 2019

Few plant-insect interactions have been documented in semi-arid savannas. The reciprocal benefits... more Few plant-insect interactions have been documented in semi-arid savannas. The reciprocal benefits that termites derive from plants in the ecosystem remain poorly studied. We studied the association between Carissa bispinosa (thorny shrub), and Trinervitermes trinervoides, termite mounds in Nylsvley nature reserve, South Africa and further assessed whether the association changed in its importance in different seasons. We hypothesised that mounds provide nutrients for plants, hence trees establish better on mounds and, in return, plants protect the mounds from predation. We measured plants (height, canopy diameter, leaf appearance and fruiting) and mounds (height, diameter, damage and activity) and also evaluated soil nutrient properties from mounds with active colonies and the adjacent matrix. There was a significant benefit accrued to both organisms from the plant-insect association. Plants on mounds were larger (~3.3 times taller), greener and fruited more in the dry season compared to matrix plants. Mounds under plants were significantly less damaged compared to exposed mounds. Sodium, magnesium, potassium, sulphur and copper were enriched in mounds relative to the matrix. The nutrient further validates the high productivity of plants on mounds. Although the benefits of trees from termite mounds is well documented, our findings show that trees established on mounds can protect the mounds from damage and excessive erosion.

Elephants, termites and mound thermoregulation in a progressively warmer world

Landscape Ecology, 2018

Context With global change, microclimates become important refuges for temperature-sensitive, ran... more Context With global change, microclimates become important refuges for temperature-sensitive, rangerestricted organisms. In African savannas, woody vegetation on Macrotermes mounds create widelydispersed microclimates significantly cooler than the surrounding matrix, which buffer against elevated temperatures at the finer scale of mounds, allowing species to persist at the landscape scale. Termite colonies cultivate symbiotic fungi to digest lignin, but the fungi require temperatures between 29 and 32°C, which termites strive to maintain. Mound-associated vegetation is a hot-spot for elephant herbivory, so removal of woody species cover by elephants could influence mound-associated microclimates, impacting temperature regulation by termites. Objectives We explored the interaction between two prominent ecosystem engineers (termites and elephants) to ascertain whether elephant removal of mound woody cover affects (1) external moundassociated microclimate and (2) internal mound temperature. Methods We surveyed 44 mounds from three sites in Kruger National Park, South Africa, during an El Electronic supplementary material The online version of this article (

Temperature fluctuations inside savanna termite mounds: Do size and plant shade matter?

Journal of Thermal Biology, 2018

Mound building termites are key ecosystem engineers of subtropical savanna regions. Mounds allow ... more Mound building termites are key ecosystem engineers of subtropical savanna regions. Mounds allow termites to maintain suitable conditions for termite reproduction and food cultivation ('fungus gardens'). We studied how the internal mound temperature of Macrotermes natalensis, a dominant mound-building termite of the subtropical savanna of southern Africa, responds to a number of environmental variables. We used general additive mixed models (GAMM) to determine how external temperature, mound size (volume) and the amount of vegetation shade affects mound internal temperature over a 24-h period. Internal mound temperature varied daily following changes of the external temperature, although the range of variation was much smaller. Active termite mounds maintained a higher internal temperature than inactive ones, and mound activity reinforced the positive effect of mound size and moderated the negative effect of vegetation shade on internal temperatures. In turn, external temperature fluctuations equally affected active and inactive mounds. Large mounds maintained near optimal internal temperatures compared to smaller sized mounds. We therefore conclude that termite mound size is a stronger determinant of internal mound temperature stability compared to plant shade cover.

Body Mass and Pectoral Muscle Size Changes in African Waterfowl During Moult

African Journal of Wildlife Research, 2017

Body mass and organ size dynamics during flight-feather moult vary among waterfowl species. To be... more Body mass and organ size dynamics during flight-feather moult vary among waterfowl species. To better understand adaptations of the African waterfowl, we measured how body masses of Spur-winged Goose (Plectropterus gambensis), South African Shelduck (Tadorna cana), Yellow-billed Duck (Anas undulata), Red-billed Teal (Anas erythrorhyncha) and Southern Pochard (Netta erythrophthalma) change during flight-feather moult. We further assessed how pectoral muscle size of Spur-winged Goose and South African Shelduck varied during the same period of flight-feather moult. Our results indicate that Spur-winged Goose and South African Shelduck underwent atrophy and subsequent regeneration of the pectoral muscles, while their body mass decreased at the onset of moult and later stabilized from the time when flight feathers were two-thirds grown until moult was completed. Body mass of Yellow-billed Duck and Red-billed Teal decreased from the onset of moult until the mid-point but thereafter increased rapidly, returning to pre-moult levels by the time moult was completed. Southern Pochard gradually lost mass from the start of moult almost until moult completion, at which time mass increased slightly. We conclude that African waterfowl exhibit different fluctuations in body mass and pectoral muscle size during flight-feather moult. Taken together, these findings suggest that no single hypothesis can fully explain the interspecific differences in the moult strategies of African waterfowl as reflected in changes in body and pectoral muscle conditions.

Microclimates mitigate against hot temperatures in dryland ecosystems: termite mounds as an example

Ecosphere, 2016

Microclimates mitigate against hot temperatures in dryland ecosystems: termite mounds as an example.

Geographic variation in factors that influence timing of moult and breeding in waterfowl

Zoology, 2017

Waterfowl flight-feather moult is expected to occur when energy is not needed for breeding and wh... more Waterfowl flight-feather moult is expected to occur when energy is not needed for breeding and when a suitable safe habitat is available. Flight-feather regrowth is an energetically costly stage in the annual cycle of waterfowls. In this study, we tested the hypothesis that moult will coincide with the time of year when food and aquatic habitats are most abundant. We investigated how the timing of rainfall relates to the timing of breeding and flight-feather moult in five common southern African waterfowl at two sites in South Africa with opposite rainfall regimes (one summer, one winter). We then incorporated published data to compare and contrast the relative timing of breeding and moult in southern hemisphere (southern African and Australian) waterfowl with northern hemisphere (European and North American) species. Our results showed that southern African waterfowl breed in the wet season and moult during the dry season. Tadorna cana was an exception, breeding in the dry season and moulting during the wet season in the summer-rainfall area. There was also a long lag period between peak breeding and peak moult in southern hemisphere waterfowl species, the longest lag being that of birds in the summer-rainfall area. By comparison, northern hemisphere waterfowl species breed and moult during the warm season, with a shorter lag period between peak breeding and peak moult compared to southern hemisphere species. We concluded that waterfowl in southern Africa (with the exception of T. cana), southeast Australia, Europe and North America time their breeding period to coincide with peaks in the availability of both food and breeding sites. Northern hemisphere species moult where chances of predation are low, when temperatures are warm, and before food and aquatic habitats approach their winter minima. By contrast, southern hemisphere waterfowl delay the onset of moult until the dry season, opting to moult when both food and aquatic moulting habitats are scarce.

Investigating Avian Influenza Infection Hotspots in Old-World Shorebirds

PLoS ONE, 2012

Heterogeneity in the transmission rates of pathogens across hosts or environments may produce dis... more Heterogeneity in the transmission rates of pathogens across hosts or environments may produce disease hotspots, which are defined as specific sites, times or species associations in which the infection rate is consistently elevated. Hotspots for avian influenza virus (AIV) in wild birds are largely unstudied and poorly understood. A striking feature is the existence of a unique but consistent AIV hotspot in shorebirds (Charadriiformes) associated with a single species at a specific location and time (ruddy turnstone Arenaria interpres at Delaware Bay, USA, in May). This unique case, though a valuable reference, limits our capacity to explore and understand the general properties of AIV hotspots in shorebirds. Unfortunately, relatively few shorebirds have been sampled outside Delaware Bay and they belong to only a few shorebird families; there also has been a lack of consistent oropharyngeal sampling as a complement to cloacal sampling. In this study we looked for AIV hotspots associated with other shorebird species and/or with some of the larger congregation sites of shorebirds in the old world. We assembled and analysed a regionally extensive dataset of AIV prevalence from 69 shorebird species sampled in 25 countries across Africa and Western Eurasia. Despite this diverse and extensive coverage we did not detect any new shorebird AIV hotspots. Neither large shorebird congregation sites nor the ruddy turnstone were consistently associated with AIV hotspots. We did, however, find a low but widespread circulation of AIV in shorebirds that contrast with the absence of AIV previously reported in shorebirds in Europe. A very high AIV antibody prevalence coupled to a low infection rate was found in both first-year and adult birds of two migratory sandpiper species, suggesting the potential existence of an AIV hotspot along their migratory flyway that is yet to be discovered.

Linking avian communities and avian influenza ecology in southern Africa using epidemiological functional groups

Veterinary Research, 2012

The ecology of pathogens, and particularly their emergence in multi-host systems, is complex. New... more The ecology of pathogens, and particularly their emergence in multi-host systems, is complex. New approaches are needed to reduce superficial complexities to a level that still allows scientists to analyse underlying and more fundamental processes. One promising approach for simplification is to use an epidemiological-function classification to describe ecological diversity in a way that relates directly to pathogen dynamics. In this article, we develop and apply the epidemiological functional group (EFG) concept to explore the relationships between wild bird communities and avian influenza virus (AIV) in three ecosystems in southern Africa. Using a two year dataset that combined bird counts and bimonthly sampling for AIV, we allocated each bird species to a set of EFGs that captured two overarching epidemiological functions: the capacity of species to maintain AIV in the system, and their potential to introduce the virus. Comparing AIV prevalence between EFGs suggested that the hypothesis that anseriforms (ducks) and charadriiforms (waders) drive AIV epidemiology cannot entirely explain the high prevalence observed in some EFGs. If anseriforms do play an important role in AIV dynamics in each of the three ecosystems, the role of other species in the local maintenance of AIV cannot be ruled out. The EFG concept thus helped us to identify gaps in knowledge and to highlight understudied bird groups that might play a role in AIV epidemiology. In general, the use of EFGs has potential for generating a range of valuable insights in epidemiology, just as functional group approaches have done in ecology.

Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa

Proceedings of the Royal Society B: Biological Sciences, 2011

Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), em... more Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non- Anas species even when we account for differences in their foraging behaviour (primarily dabbli...

Host associations, biogeography, and phylogenetics of avian malaria in southern African waterfowl

Parasitology, 2012

SUMMARYThe relevance of spatial variation in the environment and host communities for parasite co... more SUMMARYThe relevance of spatial variation in the environment and host communities for parasite community composition is poorly documented, creating a need for additional case studies from which general principles can be developed. Avian malaria in southern African waterfowl has not previously been studied. As a first step towards documenting and understanding its biogeography, we used PCR and molecular sequencing techniques to analyse 454 blood samples from Afrotropical ducks from 5 different locations (spread around the subregion) for avian malaria. Fifty-five blood samples were positive for one or more genera of haematozoa. The regional infection rate across all sites and sampling periods was 12·1%. Nine individuals carried dual infections containing multiple haematozoa. Fifteen different cytochromebhaplotypes among 52 positives (3 samples failed to sequence) and 61 total sequences were found. Eleven haplotypes closely matchedPlasmodium, whereas 4 were more similar toHaemoproteus....

The Ecology of Influenza A Viruses in Wild Birds in Southern Africa

EcoHealth, 2011

Data from: Water for African elephants (Loxodonta Africana): faecal microbial loads affect use of artificial waterholes

In semi-arid protected areas artificial waterholes ensure that water is locally available to anim... more In semi-arid protected areas artificial waterholes ensure that water is locally available to animals for extended periods. However, artificial waterholes may limit animal movement, which contributes towards habitat deterioration. Challenges of artificial water provisioning worsen in the presence of ecosystem engineers like African elephants Loxodonta africana, capable of transforming environments. Camera traps were used to monitor elephant visitation at 21 artificial waterholes in the Kruger National Park, South Africa. We also assessed if water quality parameters influenced elephant preference for certain waterholes. There were no significant correlations between elephant abundance and water physicochemical properties. However, there was a strong negative correlation between elephant abundance and levels of Escherichia coli in water. Our findings suggest that elephants avoid drinking water with high levels of faecal microbial loads. Whereas most studies addressing animal management in protected areas consider waterholes as homogeneous units, we posit that water quality could also determine local landscape use and movement patterns of key species like elephants, a finding with relevant implications in reserve management practices

Use of Artificial Waterholes by Animals in the Southern Region of the Kruger National Park, South Africa

African Journal of Wildlife Research, 2018

Artificial waterholes are a widely used, yet contested wildlife management practice in semi-arid ... more Artificial waterholes are a widely used, yet contested wildlife management practice in semi-arid environments. We evaluated wildlife water provisioning at four artificial waterholes in the southern region of the Kruger National Park. We documented daily waterhole visitation patterns of mammals during the wet and dry seasons using camera-traps. We recorded 26 mammal species at the waterholes, with African elephants (Loxodonta africana) and impalas (Aepyceros melampus) being the most abundant. We used generalized linear mixed models (GLMM) to determine which variables (season, time of day, water quality, and the presence of carnivores or elephants) would affect animal visitation. Waterhole visitation patterns differed according to time of day, but this effect remained relatively constant between seasons. More animals visited waterholes in the dry season compared to the wet season. Carnivore presence negatively affected impala abundance. Elephant presence did not affect impala and white rhinoceros (Ceratotherium simum) visits to waterholes. Water quality also appeared to play a role in determining animal abundance. Based on our results, though obtained from a limited sample size, we suggest some management practices to be considered when deciding which waterholes should be closed down or left open.

Influence of season and other factors on avian Trypanosoma spp. and microfilarial prevalence in the Lowveld, South Africa

South African Journal of Science

To comprehend the effects of emerging infectious diseases on both human and animal health, it is ... more To comprehend the effects of emerging infectious diseases on both human and animal health, it is necessary to understand the ecology of pathogens that have wildlife reservoirs. In this study, we determined the prevalence of the parasites Trypanosoma spp. and filarial nematodes in the bloodstream of birds in and around the Kruger National Park, South Africa, partly to test the hypothesis that season influences parasitaemia. Other factors considered were foraging habits, gregariousness or solitariness, and whether location might facilitate contact between birds and parasite vectors. Microscopy was used to screen stained blood smears prepared from 685 captured birds of 87 species. It was found that 3.9% of the birds were infected with filarial nematodes (as reflected by the presence of microfilariae) and 3.1% with Trypanosoma spp. No cases of coinfection with both types of parasite were encountered. Ground-foraging and solitary birds had the highest parasite prevalences compared to oth...

Comparative performance Data-MB Wardjomto et al.xlsx

This dataset includes information on starlings sampled in the Kruger National Park and details on... more

Peter Mundy1941–2023

African Journal of Wildlife Research

Responses of ground-dwelling arthropods to long-term prescribed fire regimes in a savanna protected area

Background Sound management of protected areas is crucial for biodiversity conservation. In savan... more Background Sound management of protected areas is crucial for biodiversity conservation. In savanna systems, fire is common, yet little is known on the direct and long-term effects of prescribed burns on arthropod abundance, richness, and diversity. Standardised pitfall traps and active searches were used to compare variation in abundance, richness and diversity of arthropods at various experimental burn plots in the Kruger National Park, a protected area in a savanna setting. Results Hymenopterans: Formicidae were the most abundant (76.4%), whilst Coleopterans, Araneae and Orthopterans constituted 18.6, 3 and 1% of the total arthropods collected respectively. Coleopterans were the most diverse group (30.2%) compared to Hymenopterans: Formicidae (24.6), Araneae (24.6) and Orthopterans (4%). Abundance, species richness and diversity of multi-taxa significantly differed between the treatment plots. Abundance and diversity of Formicidae were significantly lower, hence, species richness...

Integrating Nguni cattle into black rhino reserves: Could this be a novel rural community-based conservation model?

Academia Letters, 2021

Data for: Temperature fluctuations inside savanna termite mounds: do size and plant shade matter?

We measured diurnal external temperature, mound size (volume), amount of shade and mound internal... more We measured diurnal external temperature, mound size (volume), amount of shade and mound internal temperature over a 24-hour period. Internal mound temperature varied daily following the diurnal changes of external temperature. Active termite mounds maintained a higher internal temperature than inactive ones, and the magnitude of this difference increased with mound volume; active and inactive mounds were equally affected by shade amount and external temperature fluctuations. Large mounds maintained near optimal internal temperatures compared to smaller sized mounds.

Pulses Are Related to Foraging Guild and Food-Web Position

community to resourcepulses are related to foraging guild and food-web position

Association benefits between harvester termites (Trinervitermes trinervoides) and num-num plants (Carissa bispinosa) in a semi-arid savanna setting

Journal of Arid Environments, 2019

Few plant-insect interactions have been documented in semi-arid savannas. The reciprocal benefits... more Few plant-insect interactions have been documented in semi-arid savannas. The reciprocal benefits that termites derive from plants in the ecosystem remain poorly studied. We studied the association between Carissa bispinosa (thorny shrub), and Trinervitermes trinervoides, termite mounds in Nylsvley nature reserve, South Africa and further assessed whether the association changed in its importance in different seasons. We hypothesised that mounds provide nutrients for plants, hence trees establish better on mounds and, in return, plants protect the mounds from predation. We measured plants (height, canopy diameter, leaf appearance and fruiting) and mounds (height, diameter, damage and activity) and also evaluated soil nutrient properties from mounds with active colonies and the adjacent matrix. There was a significant benefit accrued to both organisms from the plant-insect association. Plants on mounds were larger (~3.3 times taller), greener and fruited more in the dry season compared to matrix plants. Mounds under plants were significantly less damaged compared to exposed mounds. Sodium, magnesium, potassium, sulphur and copper were enriched in mounds relative to the matrix. The nutrient further validates the high productivity of plants on mounds. Although the benefits of trees from termite mounds is well documented, our findings show that trees established on mounds can protect the mounds from damage and excessive erosion.

Elephants, termites and mound thermoregulation in a progressively warmer world

Landscape Ecology, 2018

Context With global change, microclimates become important refuges for temperature-sensitive, ran... more Context With global change, microclimates become important refuges for temperature-sensitive, rangerestricted organisms. In African savannas, woody vegetation on Macrotermes mounds create widelydispersed microclimates significantly cooler than the surrounding matrix, which buffer against elevated temperatures at the finer scale of mounds, allowing species to persist at the landscape scale. Termite colonies cultivate symbiotic fungi to digest lignin, but the fungi require temperatures between 29 and 32°C, which termites strive to maintain. Mound-associated vegetation is a hot-spot for elephant herbivory, so removal of woody species cover by elephants could influence mound-associated microclimates, impacting temperature regulation by termites. Objectives We explored the interaction between two prominent ecosystem engineers (termites and elephants) to ascertain whether elephant removal of mound woody cover affects (1) external moundassociated microclimate and (2) internal mound temperature. Methods We surveyed 44 mounds from three sites in Kruger National Park, South Africa, during an El Electronic supplementary material The online version of this article (

Temperature fluctuations inside savanna termite mounds: Do size and plant shade matter?

Journal of Thermal Biology, 2018

Mound building termites are key ecosystem engineers of subtropical savanna regions. Mounds allow ... more Mound building termites are key ecosystem engineers of subtropical savanna regions. Mounds allow termites to maintain suitable conditions for termite reproduction and food cultivation ('fungus gardens'). We studied how the internal mound temperature of Macrotermes natalensis, a dominant mound-building termite of the subtropical savanna of southern Africa, responds to a number of environmental variables. We used general additive mixed models (GAMM) to determine how external temperature, mound size (volume) and the amount of vegetation shade affects mound internal temperature over a 24-h period. Internal mound temperature varied daily following changes of the external temperature, although the range of variation was much smaller. Active termite mounds maintained a higher internal temperature than inactive ones, and mound activity reinforced the positive effect of mound size and moderated the negative effect of vegetation shade on internal temperatures. In turn, external temperature fluctuations equally affected active and inactive mounds. Large mounds maintained near optimal internal temperatures compared to smaller sized mounds. We therefore conclude that termite mound size is a stronger determinant of internal mound temperature stability compared to plant shade cover.

Body Mass and Pectoral Muscle Size Changes in African Waterfowl During Moult

African Journal of Wildlife Research, 2017

Body mass and organ size dynamics during flight-feather moult vary among waterfowl species. To be... more Body mass and organ size dynamics during flight-feather moult vary among waterfowl species. To better understand adaptations of the African waterfowl, we measured how body masses of Spur-winged Goose (Plectropterus gambensis), South African Shelduck (Tadorna cana), Yellow-billed Duck (Anas undulata), Red-billed Teal (Anas erythrorhyncha) and Southern Pochard (Netta erythrophthalma) change during flight-feather moult. We further assessed how pectoral muscle size of Spur-winged Goose and South African Shelduck varied during the same period of flight-feather moult. Our results indicate that Spur-winged Goose and South African Shelduck underwent atrophy and subsequent regeneration of the pectoral muscles, while their body mass decreased at the onset of moult and later stabilized from the time when flight feathers were two-thirds grown until moult was completed. Body mass of Yellow-billed Duck and Red-billed Teal decreased from the onset of moult until the mid-point but thereafter increased rapidly, returning to pre-moult levels by the time moult was completed. Southern Pochard gradually lost mass from the start of moult almost until moult completion, at which time mass increased slightly. We conclude that African waterfowl exhibit different fluctuations in body mass and pectoral muscle size during flight-feather moult. Taken together, these findings suggest that no single hypothesis can fully explain the interspecific differences in the moult strategies of African waterfowl as reflected in changes in body and pectoral muscle conditions.

Microclimates mitigate against hot temperatures in dryland ecosystems: termite mounds as an example

Ecosphere, 2016

Microclimates mitigate against hot temperatures in dryland ecosystems: termite mounds as an example.

Geographic variation in factors that influence timing of moult and breeding in waterfowl

Zoology, 2017

Waterfowl flight-feather moult is expected to occur when energy is not needed for breeding and wh... more Waterfowl flight-feather moult is expected to occur when energy is not needed for breeding and when a suitable safe habitat is available. Flight-feather regrowth is an energetically costly stage in the annual cycle of waterfowls. In this study, we tested the hypothesis that moult will coincide with the time of year when food and aquatic habitats are most abundant. We investigated how the timing of rainfall relates to the timing of breeding and flight-feather moult in five common southern African waterfowl at two sites in South Africa with opposite rainfall regimes (one summer, one winter). We then incorporated published data to compare and contrast the relative timing of breeding and moult in southern hemisphere (southern African and Australian) waterfowl with northern hemisphere (European and North American) species. Our results showed that southern African waterfowl breed in the wet season and moult during the dry season. Tadorna cana was an exception, breeding in the dry season and moulting during the wet season in the summer-rainfall area. There was also a long lag period between peak breeding and peak moult in southern hemisphere waterfowl species, the longest lag being that of birds in the summer-rainfall area. By comparison, northern hemisphere waterfowl species breed and moult during the warm season, with a shorter lag period between peak breeding and peak moult compared to southern hemisphere species. We concluded that waterfowl in southern Africa (with the exception of T. cana), southeast Australia, Europe and North America time their breeding period to coincide with peaks in the availability of both food and breeding sites. Northern hemisphere species moult where chances of predation are low, when temperatures are warm, and before food and aquatic habitats approach their winter minima. By contrast, southern hemisphere waterfowl delay the onset of moult until the dry season, opting to moult when both food and aquatic moulting habitats are scarce.

Investigating Avian Influenza Infection Hotspots in Old-World Shorebirds

PLoS ONE, 2012

Heterogeneity in the transmission rates of pathogens across hosts or environments may produce dis... more Heterogeneity in the transmission rates of pathogens across hosts or environments may produce disease hotspots, which are defined as specific sites, times or species associations in which the infection rate is consistently elevated. Hotspots for avian influenza virus (AIV) in wild birds are largely unstudied and poorly understood. A striking feature is the existence of a unique but consistent AIV hotspot in shorebirds (Charadriiformes) associated with a single species at a specific location and time (ruddy turnstone Arenaria interpres at Delaware Bay, USA, in May). This unique case, though a valuable reference, limits our capacity to explore and understand the general properties of AIV hotspots in shorebirds. Unfortunately, relatively few shorebirds have been sampled outside Delaware Bay and they belong to only a few shorebird families; there also has been a lack of consistent oropharyngeal sampling as a complement to cloacal sampling. In this study we looked for AIV hotspots associated with other shorebird species and/or with some of the larger congregation sites of shorebirds in the old world. We assembled and analysed a regionally extensive dataset of AIV prevalence from 69 shorebird species sampled in 25 countries across Africa and Western Eurasia. Despite this diverse and extensive coverage we did not detect any new shorebird AIV hotspots. Neither large shorebird congregation sites nor the ruddy turnstone were consistently associated with AIV hotspots. We did, however, find a low but widespread circulation of AIV in shorebirds that contrast with the absence of AIV previously reported in shorebirds in Europe. A very high AIV antibody prevalence coupled to a low infection rate was found in both first-year and adult birds of two migratory sandpiper species, suggesting the potential existence of an AIV hotspot along their migratory flyway that is yet to be discovered.

Linking avian communities and avian influenza ecology in southern Africa using epidemiological functional groups

Veterinary Research, 2012

The ecology of pathogens, and particularly their emergence in multi-host systems, is complex. New... more The ecology of pathogens, and particularly their emergence in multi-host systems, is complex. New approaches are needed to reduce superficial complexities to a level that still allows scientists to analyse underlying and more fundamental processes. One promising approach for simplification is to use an epidemiological-function classification to describe ecological diversity in a way that relates directly to pathogen dynamics. In this article, we develop and apply the epidemiological functional group (EFG) concept to explore the relationships between wild bird communities and avian influenza virus (AIV) in three ecosystems in southern Africa. Using a two year dataset that combined bird counts and bimonthly sampling for AIV, we allocated each bird species to a set of EFGs that captured two overarching epidemiological functions: the capacity of species to maintain AIV in the system, and their potential to introduce the virus. Comparing AIV prevalence between EFGs suggested that the hypothesis that anseriforms (ducks) and charadriiforms (waders) drive AIV epidemiology cannot entirely explain the high prevalence observed in some EFGs. If anseriforms do play an important role in AIV dynamics in each of the three ecosystems, the role of other species in the local maintenance of AIV cannot be ruled out. The EFG concept thus helped us to identify gaps in knowledge and to highlight understudied bird groups that might play a role in AIV epidemiology. In general, the use of EFGs has potential for generating a range of valuable insights in epidemiology, just as functional group approaches have done in ecology.

Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa

Proceedings of the Royal Society B: Biological Sciences, 2011

Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), em... more Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non- Anas species even when we account for differences in their foraging behaviour (primarily dabbli...

Host associations, biogeography, and phylogenetics of avian malaria in southern African waterfowl

Parasitology, 2012

SUMMARYThe relevance of spatial variation in the environment and host communities for parasite co... more SUMMARYThe relevance of spatial variation in the environment and host communities for parasite community composition is poorly documented, creating a need for additional case studies from which general principles can be developed. Avian malaria in southern African waterfowl has not previously been studied. As a first step towards documenting and understanding its biogeography, we used PCR and molecular sequencing techniques to analyse 454 blood samples from Afrotropical ducks from 5 different locations (spread around the subregion) for avian malaria. Fifty-five blood samples were positive for one or more genera of haematozoa. The regional infection rate across all sites and sampling periods was 12·1%. Nine individuals carried dual infections containing multiple haematozoa. Fifteen different cytochromebhaplotypes among 52 positives (3 samples failed to sequence) and 61 total sequences were found. Eleven haplotypes closely matchedPlasmodium, whereas 4 were more similar toHaemoproteus....

The Ecology of Influenza A Viruses in Wild Birds in Southern Africa

EcoHealth, 2011

Data from: Water for African elephants (Loxodonta Africana): faecal microbial loads affect use of artificial waterholes

In semi-arid protected areas artificial waterholes ensure that water is locally available to anim... more In semi-arid protected areas artificial waterholes ensure that water is locally available to animals for extended periods. However, artificial waterholes may limit animal movement, which contributes towards habitat deterioration. Challenges of artificial water provisioning worsen in the presence of ecosystem engineers like African elephants Loxodonta africana, capable of transforming environments. Camera traps were used to monitor elephant visitation at 21 artificial waterholes in the Kruger National Park, South Africa. We also assessed if water quality parameters influenced elephant preference for certain waterholes. There were no significant correlations between elephant abundance and water physicochemical properties. However, there was a strong negative correlation between elephant abundance and levels of Escherichia coli in water. Our findings suggest that elephants avoid drinking water with high levels of faecal microbial loads. Whereas most studies addressing animal management in protected areas consider waterholes as homogeneous units, we posit that water quality could also determine local landscape use and movement patterns of key species like elephants, a finding with relevant implications in reserve management practices

Use of Artificial Waterholes by Animals in the Southern Region of the Kruger National Park, South Africa

African Journal of Wildlife Research, 2018

Artificial waterholes are a widely used, yet contested wildlife management practice in semi-arid ... more Artificial waterholes are a widely used, yet contested wildlife management practice in semi-arid environments. We evaluated wildlife water provisioning at four artificial waterholes in the southern region of the Kruger National Park. We documented daily waterhole visitation patterns of mammals during the wet and dry seasons using camera-traps. We recorded 26 mammal species at the waterholes, with African elephants (Loxodonta africana) and impalas (Aepyceros melampus) being the most abundant. We used generalized linear mixed models (GLMM) to determine which variables (season, time of day, water quality, and the presence of carnivores or elephants) would affect animal visitation. Waterhole visitation patterns differed according to time of day, but this effect remained relatively constant between seasons. More animals visited waterholes in the dry season compared to the wet season. Carnivore presence negatively affected impala abundance. Elephant presence did not affect impala and white rhinoceros (Ceratotherium simum) visits to waterholes. Water quality also appeared to play a role in determining animal abundance. Based on our results, though obtained from a limited sample size, we suggest some management practices to be considered when deciding which waterholes should be closed down or left open.