53 Works

Cross-continental analysis of coastal biodiversity change

Helmut Hillebrand, Gavin M. Rishworth, Janine B. Adams, Matthew S. Bird, Nicola K. Carrasco, Andreas Dänhardt, Jennifer Dannheim, Daniel A. Lemley, Pierre A. Pistorius & Gregor Scheiffarth
Whereas the anthropogenic impact on marine biodiversity is undebated, the quantification and prediction of this change is not trivial. Simple traditional measures of biodiversity (e.g., richness, diversity indices) do not capture the magnitude and direction of changes in species or functional composition. In this paper, we apply recently developed methods for measuring biodiversity turnover to time-series data of four broad taxonomic groups from two coastal regions: the southern North Sea (Germany) and the South African...

Data from: Leaf traits of African woody savanna species across climate and soil fertility gradients: evidence for conservative vs. acquisitive resource use strategies

Benjamin J. Wigley, Jasper A. Slingsby, Sandra Diaz, William J. Bond, Herve Fritz & Corli Coetsee
1. Establishing trade-offs among traits and the degree to which they co-vary along environmental gradients has become a key focal point in the effort to develop community ecology into a predictive science. While there is evidence for these relationships across global datasets, they are often too broad in scale, and do not consider the particularities of local to regional species pools. This decreases their usefulness for developing predictive models at scales relevant for conservation and...

Data from: Dietary studies in birds: testing a non-invasive method using digital photography in seabirds

Davide Gaglio, Timothée Cook, Maëlle Connan, Peter G. Ryan & Richard B. Sherley
Dietary studies give vital insights into foraging behaviour, with implications for understanding changing environmental conditions and the anthropogenic impacts on natural resources. Traditional diet sampling methods may be invasive or subject to biases, so developing non-invasive and unbiased methods applicable to a diversity of species is essential. We used digital photography to investigate the diet fed to chicks of a prey-carrying seabird and compared our approach (photo-sampling) to a traditional method (regurgitations) for the greater...

Data from: The conservation status and population decline of the African penguin deconstructed in space and time

Richard Sherley, Robert Crawford, Andrew De Blocq, Bruce Dyer, Deon Geldenhuys, Christina Hagen, Jessica Kemper, Azwianewi Makhado, Lorien Pichegru, Desmond Tom, Leshia Upfold, Johan Visagie, Lauren Waller & Henning Winker
Understanding changes in abundance is crucial for conservation, but population growth rates often vary over space and time. We use 40 years of count data (1979–2019) and Bayesian state-space models to assess the African penguin Spheniscus demersus population under IUCN Red List Criterion A. We deconstruct the overall decline in time and space to identify where urgent conservation action is needed. The global African penguin population met the threshold for Endangered with a high probability...

Climate change impacts on seabirds and marine mammals: the importance of study duration, thermal tolerance and generation time

Florian Orgeret, Andréa Thiebault, Kit M. Kovacs, Christian Lydersen, Mark A. Hindell, Sarah Ann Thompson, William J. Sydeman & Pierre A. Pistorius
Understanding climate change impacts on top predators is fundamental to marine biodiversity conservation, due to their increasingly threatened populations and their importance in marine ecosystems. We conducted a systematic review of the effects of climate change (prolonged, directional change) and climate variability on seabirds and marine mammals. We extracted data from 484 studies (4808 published studies were reviewed), comprising 2215 observations on demography, phenology, distribution, diet, behaviour, body condition and physiology. The likelihood of concluding...

Data from: Quantification of avian hazards to military aircraft and implications for wildlife management

Morgan B. Pfeiffer, Bradley F. Blackwell & Travis L. DeVault
Collisions between birds and military aircraft are common and can have catastrophic effects. Knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. Despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. We hypothesized that species relative hazard scores...

Data from: At sea vocal repertoire of a foraging seabird

Andréa Thiebault, Isabelle Charrier, Pierre Pistorius & Thierry Aubin
Seabirds spend most of their time at sea, yet our knowledge of their activities and behaviour is limited due to difficulties of in-situ data collection. In particular, we know virtually nothing about their acoustic communication when at sea. We benefited from the recent development of miniaturised audio-recording devices to deployacoustic recorders on breeding Cape gannets Morus capensis to study their vocal activity while foraging. Call sequences were recorded on 1718 occasions, from which acoustic variables...

Loss of an apex predator in the wild induces physiological changes in prey

Neil Hammerschlag, Chris Fallows, Michael Meyer, Simon Seakamela, Samantha Orndorff, Stephen Kirkman, Deon Kotze & Scott Creel
Predators can impact prey via predation or risk effects, which can initiate trophic cascades. Given widespread population declines of apex predators, understanding and predicting the associated ecological consequences is a priority. When predation risk is relatively unpredictable or uncontrollable by prey, the loss of predators is hypothesized to release prey from stress; however, there are few tests of this hypothesis in the wild. A well-studied predator-prey system between white sharks (Carcharodon carcharias) and Cape fur...

Data from: Sex-specific and individual preferences for hunting strategies in white sharks

Alison V. Towner, Vianey Leos-Barajas, Roland Langrock, Robert S. Schick, Malcolm J. Smale, Tami Kaschke, Oliver J.D. Jewell, Yannis P. Papastamatiou & Oliver J. D. Jewell
Fine-scale predator movements may be driven by many factors including sex, habitat, and distribution of resources. There may also be individual preferences for certain movement strategies within a population which can be hard to quantify. Within top predators, movements are also going to be directly related to the mode of hunting; for example sit-and-wait or actively searching for prey. Although there is mounting evidence that different hunting modes can cause opposing trophic cascades, there has...

Data from: Compensatory life history responses of a mesopredator may undermine carnivore management efforts

Liaan Minnie, Angela Gaylard & Graham I. H. Kerley
Lethal carnivore management, aimed at reducing carnivore impacts, is a global phenomenon threatening the persistence of many carnivores. Black-backed jackals Canis mesomelas, the dominant cause of livestock predation in southern Africa, are widely hunted to reduce livestock predation. Despite centuries of lethal management, jackals persist. Smaller canids, like jackals, are highly adaptable and display variable responses to mortality sources, which may affect management outcomes. The effects of killing carnivores will depend on their behaviour, social...

Data from: Phylogenetic relationships in the southern African genus Drosanthemum (Ruschioideae, Aizoaceae)

Sigrid Liede-Schumann, Nicolai M. Nürk, Guido W. Grimm, Alastair J. Potts & Ulrich Ulrich
Background. Drosanthemum, the only genus of the tribe Drosanthemeae, is widespread over the Greater Cape Floristic Region in southern Africa. With 114 recognized species, Drosanthemum together with the highly succulent and species-rich tribe Ruschieae constitute the ‘core ruschioids’ in Aizoaceae. Within Drosanthemum, nine subgenera have been described based on flower and fruit morphology. Their phylogenetic relationships, however, have not yet been investigated, hampering understanding of monophyletic entities and patterns of geographic distribution. Methods. Using chloroplast...

Data from: Group foraging increases foraging efficiency in a piscivorous diver, the African penguin

Alistair M. McInnes, Cuan McGeorge, Samuel Ginsberg, Lorien Pichegru & Pierre A. Pistorius
Marine piscivores have evolved a variety of morphological and behavioural adaptations, including group foraging, to optimize foraging efficiency when targeting shoaling fish. For penguins that are known to associate at sea and feed on these prey resources, there is nonetheless a lack of empirical evidence to support improved foraging efficiency when foraging with conspecifics. We examined the hunting strategies and foraging performance of breeding African penguins equipped with animal-borne video recorders. Individuals pursued both solitary...

Data from: Sacrificial males: the potential role of copulation and predation in contributing to copepod sex-skewed ratios

Ryan J. Wasserman, Mark Weston, Olaf L.F. Weyl, P. William Froneman, Rebecca J. Welch, Tim J.F. Vink, Tatenda Dalu & Tim J. F. Vink
Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator-prey dynamics between notonectid predators (backswimmers) and...

Data from: Diet shifts by adult flightless dung beetles Circellium bacchus, revealed using DNA metabarcoding, reflect complex life histories

Graham I. H. Kerley, Marietjie Landman, Gentile F. Ficetola, Frédéric Boyer, Aurélie Bonin, Delphine Rioux, Pierre Taberlet & Eric Coissac
Life history changes may change resource use. Such shifts are not well understood in the dung beetles, despite recognized differences in larval and adult feeding ability. We use the flightless dung beetle Circellium bacchus to explore such shifts, identifying dung sources of adults using DNA metabarcoding, and comparing these with published accounts of larval dung sources. C. bacchus is traditionally considered to specialise on the dung of large herbivores for both larval and adult feeding....

Data from: Behaviourally mediated predation avoidance in penguin prey: in situ evidence from animal-borne camera loggers

Jonathan M. Handley, Andréa Thiebault, Andrew Stanworth, David Schutt & Pierre Pistorius
Predator dietary studies often assume that diet is reflective of the diversity and relative abundance of their prey. This interpretation ignores species-specific behavioural adaptations in prey that could influence prey capture. Here, we develop and describe a scalable biologging protocol, using animal-borne camera loggers, to elucidate the factors influencing prey capture by a seabird, the gentoo penguin (Pygoscelis papua). From the video evidence, we show, for the first time, that aggressive behavioural defence mechanisms by...

CPR dataset for: Testing Bergmann's Rule in Marine Copepods

Max D. Campbell, David S. Schoeman, William Venables, Rana Abu-Alhaija, Sonia D. Batten, Sanae Chiba, Frank Coman, Claire H. Davies, Martin Edwards, Ruth Eriksen, Jason D. Everett, Yutaka Fukai, Mitsuo Fukuchi, Octavio Esquivel Garrote, Graham Hosie, Jenny Huggett, David G. Johns, John A. Kitchener, Philippe Koubbi, Felicity R. McEnnulty, Erik Muxagata, Clare Ostle, Karen V. Robinson, Anita Slotwinski, Kerrie M. Swadling … & Anthony J. Richardson
This is the global dataset used for the Campbell et al. (2021) paper “Testing Bergmann’s Rule in marine copepods”. The dataset includes the mean length of copepods weighted by abundance found in 97,830 continuous plankton recorder (CPR) samples. Further, it contains satellite observations for sea surface temperature, chlorophyll-a, and dissolved oxygen (see paper for details). It was a massive collaborative effort to get this dataset assembled by the Global Alliance of CPR Surveys (GACS 2011,...

Dispersal and coastal geomorphology limit potential for mangrove range expansion under climate change

Jacqueline Raw
Latitudinal range limits for mangroves on high-energy, wave-dominated coasts are controlled by geomorphological features and estuarine dynamics. Mangroves reach a southern global range limit along the South African coastline, but the distribution is patchy, with stands occurring in only 16% of the estuaries in the region. Yet, the persistence of forests planted >50 years ago beyond the natural distribution limit suggests that additional estuaries could support mangroves. Understanding regional drivers is necessary to inform global...

Data from: Phantoms of the forest: legacy risk effects of a regionally extinct large carnivore

Ellinor Sahlén, Sonja Noell, Christopher S. DePerno, Jonas Kindberg, Göran Spong, Joris P. G. M. Cromsigt & Joris P.G.M. Cromsigt
The increased abundance of large carnivores in Europe is a conservation success, but the impact on the behavior and population dynamics of prey species is generally unknown. In Europe, the recolonization of large carnivores often occurs in areas where humans have greatly modified the landscape through forestry or agriculture. Currently, we poorly understand the effects of recolonizing large carnivores on extant prey species in anthropogenic landscapes. Here, we investigated if ungulate prey species showed innate...

Data from: Insect outbreaks alter nutrient dynamics in a southern African savanna: patchy defoliation of Colophospermum mopane savanna by Imbrasia belina larvae

Donovan B. De Swardt, Corli Wigley-Coetsee & Tim G. O’Connor
Severe defoliation is expected to affect nutrient cycling of an impacted system. Outbreaks of the lepidopteran Imbrasia belina (mopane worm) affect discrete patches of Colophospermum mopane trees in semi-arid savanna; larvae may completely defoliate trees for up to six weeks during each of the early and late growing seasons. We studied the impact of mopane worm outbreaks on the availability of nitrogen, phosphorus and potassium within mopane savanna by comparing defoliated with non-defoliated savanna patches....

Foraging in a dynamic environment: response of four sympatric sub-Antarctic albatross species to interannual environmental variability

Tegan Carpenter-Kling, Ryan Reisinger, Florian Orgeret, Maelle Connan, Kim Stevens, Peter Ryan, Azwianewi Makhado & Pierre Pistorius
Seasonal and annual climate variations are linked to fluctuations in the abundance and distribution of resources, posing a significant challenge to animals that need to adjust their foraging behaviour accordingly. Particularly during adverse conditions, and while energetically constrained when breeding, animals ideally need to be flexible in their foraging behaviour. Such behavioural plasticity may separate ‘winners’ from ‘losers’ in light of rapid environmental changes due to climate change. Here, the foraging behaviour of four sub-Antarctic...

Data from: Top–down limits on prey populations may be more severe in larger prey species, despite having fewer predators

Elizabeth Le Roux, David G. Marneweck, Geoff Clinning, Dave J. Druce, Graham I.H. Kerley & Joris P.G.M. Cromsigt
Variation in the vulnerability of herbivore prey to predation is linked to body size, yet whether this relationship is size‐nested or size‐partitioned remains debated. If size‐partitioned, predators would be focused on prey within their preferred prey size range. If size‐nested, smaller prey species should become increasingly more vulnerable because increasingly more predators are capable of catching them. Yet, whether either of these strategies manifests in top‐down prey population limitation would depend both on the number...

The generality of cryptic dietary niche differences in diverse large-herbivore assemblages

Robert Pringle, Johan Pansu, Matthew Hutchinson, T. Michael Anderson, Mariska Te Beest, Colleen Begg, Keith Begg, Aurelie Bonin, Lackson Chama, Simon Chamaillé-Jammes, Eric Coissac, Joris Cromsigt, Margaret Demmel, Jason Donaldson, Jennifer Guyton, Christina Hansen, Christopher Imakando, Azwad Iqbal, Davis Kalima, Graham Kerley, Samson Kurukura, Marietjie Landman, Ryan Long, Isaack Munuo, Ciara Nutter … & Tyler Kartzinel
Ecological niche differences are necessary for stable species coexistence but are often difficult to discern. Models of dietary niche differentiation in large mammalian herbivores invoke the quality, quantity, and spatiotemporal distribution of plant tissues and growth-forms but are agnostic towards food-plant species identity. Empirical support for these models is variable, suggesting that additional mechanisms of resource partitioning may be important in sustaining large-herbivore diversity in African savannas. We used DNA metabarcoding to conduct a taxonomically...

Helm ichnology locality data.xlsx

Charles William Helm
Locality database for 326 vertebrate ichnosites on the Cape south coast of South Africa.

photo database

Charles William Helm
Photo database from 326 Pleistocene Cape south coast ichnosites

photo database

Charles William Helm
Photo database from 326 Pleistocene Cape south coast ichnosites

Registration Year

  • 2023
  • 2022
  • 2021
  • 2020
  • 2019
  • 2018
  • 2017
  • 2016
  • 2015
  • 2013

Resource Types

  • Dataset


  • Nelson Mandela University
  • University of Cape Town
  • Swedish University of Agricultural Sciences
  • University of Tasmania
  • French National Centre for Scientific Research
  • Department of Agriculture, Forestry and Fisheries
  • University of Exeter
  • Massachusetts General Hospital
  • University of Glasgow
  • Rhodes University