32 Works

Data from: Population connectivity and phylogeography of a coastal fish, Atractoscion aequidens (Sciaenidae), across the Benguela Current region: evidence of an ancient vicariant event.

Romina Henriques, Warren M. Potts, Carmen V. Santos, Warwick H. H. Sauer & Paul W. Shaw
Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of...

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: Forest degradation and invasive species synergistically impact Mimusops andongensis (Sapotaceae) in Lama Forest Reserve, Benin

Gisele K.S. Sinasson, Charlie M. Shackleton, Romain L. Glèlè Kakaï & Brice Sinsin
Harvesting of Non-Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density...

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...

Sperm competition risk affects ejaculate strategy in terms of sperm number but not sperm size in squid

Yoko Iwata, Noriyosi Sato, Noritaka Hirohashi, Yoshiro Watanabe, Warwick Sauer & Paul Shaw
In polygamous species, the mode of sperm storage in females influences evolution of sperm quantitative and qualitative traits because it provides the arena for sperm competition, cryptic female choice and fertilization processes. In this study, we compared ejaculate traits of two squid species, Heterololigo bleekeri and Loligo reynaudii. Both species show dimorphic sperm traits associated with alternative reproductive tactics where consort and sneaker males transfer sperm to different storage sites within a female (on the...

Secondary contacts and genetic admixture shape colonisation by an amphiatlantic epibenthic invertebrate

Jamie Hudson, Kerstin Johannesson, Christopher McQuaid & Marc Rius
Research on the genetics of invasive species often focuses on patterns of genetic diversity and population structure within the introduced range. However, a growing body of literature is demonstrating the need to study the native range, and how native genotypes affect both ecological and evolutionary mechanisms within the introduced range. Here we used genotyping-by-sequencing to study both native and introduced ranges [based on 1,653 single nucleotide polymorphisms (SNPs)] of the amphiatlantic marine invertebrate Ciona intestinalis....

Data from: Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

Brian Helmuth, Francis Choi, Allison Matzelle, Jessica L. Torossian, Scott L. Morella, K. A. S. Mislan, Lauren Yamane, Denise Strickland, P. Lauren Szathmary, Sarah Gilman, Alyson Tockstein, Thomas J. Hilbish, Michael T. Burrows, Anne Marie Power, Elizabeth Gosling, Nova Mieszkowska, Christopher D. G. Harley, Michael Nishizaki, Emily Carrington, Bruce Menge, Laura Petes, Melissa M. Foley, Angela Johnson, Megan Poole, Mae M. Noble … & Gerardo Zardi
At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10–30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements...

Data from: Spatio-temporal genetic structure and the effects of long-term fishing in two partially sympatric offshore demersal fishes

Romina Henriques, Sophie Von Der Heyden, Marek R. Lipinski, Nina Du Toit, Paulus Kainge, Paulette Bloomer & Conrad A. Matthee
Environmental gradients have been shown to disrupt gene flow in marine species, yet their influence in structuring populations at depth remains poorly understood. The Cape hakes (Merluccius paradoxus and M. capensis) are demersal species co-occurring in the Benguela Current system, where decades of intense fishing resulted in severely depleted stocks in the past. Previous studies identified conflicting mtDNA genetic substructuring patterns and thus contrasting evolutionary trajectories for both species. Using 10 microsatellite loci, the control...

Raw data used for analysis of parental care from video footage of breeding Cape Rockjumpers (Chaetops frenatus), from the Western Cape of South Africa

Krista Oswald
Demonstrated negative effects of increased temperatures on avian reproductive success suggest a mechanism by which climate change may impact species persistence. High temperatures can result in reduced parental care and reduced nestling condition in passerines with dependent young, resulting in lowered fledging success and population recruitment. We examined provisioning rate and nestling condition in a South African mountain endemic, the Cape Rockjumper Chaetops frenatus, whose population declines correlate with warming habitat. Our aim was to...

Trait strengthening in mussels

Laurent Seuront, Katy Nicastro, Christopher McQuaid & Gerardo Zardi
Plastic pollution is ubiquitous with increasing recognition of its direct effects on species’ fitness. Little is known, however, about its more subtle effects, including the influence of plastic pollution on the morphological, functional and behavioural traits of organisms that are central to their ability to withstand disturbances. Among the least obvious but most pernicious forms of plastic-associated pollution are the chemicals that leach from microplastics. Here, we investigate how such leachates influence species’ traits by...

Scope for growth data

Aldwin Ndhlovu
This data set was used to calculate the energy budget and to calculate scope for growth for ecological engineers (intertidal mussels) comparing those that are affected by endolithic cyanobacterial parasites and clean intertidal mussels. It has data for growth, both whole body and shell biomineralization, and the reproductive potential of infested individuals. There is also data for components of scope for growth, feeding rates, ammonium exctretion, standard metabolic rates and lethal temperature measurements data.

Data from: Multiple mating, paternity and complex fertilisation patterns in the chokka squid Loligo reynaudi

Marie-Jose Naud, Warwick H. H. Sauer, Niall J. McKeown, Paul W. Shaw & Marie-Jose Naud
Polyandry is widespread and influences patterns of sexual selection, with implications for sexual conflict over mating. Assessing sperm precedence patterns is a first step towards understanding sperm competition within a female and elucidating the roles of male- and female-controlled factors. In this study behavioural field data and genetic data were combined to investigate polyandry in the chokka squid Loligo reynaudii. Microsatellite DNA-based paternity analysis revealed multiple paternity to be the norm, with 79% of broods...

Data from: Secondary contact and asymmetrical gene flow in a cosmopolitan marine fish across the Benguela upwelling zone

Kerry Reid, Thierry B. Hoareau, John E. Graves, Warren M. Potts, Sandrina M. R. Do Santos, Arrie W. Klopper & Paulette Bloomer
The combination of oceanographic barriers and habitat heterogeneity are known to reduce connectivity and leave specific genetic signatures in the demographic history of marine species. However, barriers to gene flow in the marine environment are almost never impermeable which inevitably allows secondary contact to occur. In this study eight sampling sites (five along the South African coastline, one each in Angola, Senegal and Portugal) were chosen to examine the population genetic structure and phylogeographic history...

Data from: C4 anatomy can evolve via a single developmental change

Marjorie R. Lundgren, Luke T. Dunning, Jill K. Olofsson, Jose J. Moreno Villena, Jacques W. Bouvier, Tammy L. Sage, Roxana Khosravesh, Stefanie Sultmanis, Matt Stata, Brad S. Ripley, Maria S. Vorontsova, Guillaume Besnard, Claire Adams, Nicholas Cuff, Anthony Mapaura, Matheus E. Bianconi, Christine M. Long, Pascal-Antoine Christin, Colin P. Osborne, Roxana Khoshravesh & Jose J. Moreno-Villena
C4 photosynthesis boosts productivity in warm environments. Paradoxically, this complex physiological process evolved independently in numerous plant lineages, despite requiring specialized leaf anatomy. The anatomical modifications underlying C4 evolution have previously been evaluated through interspecific comparisons, which capture numerous changes besides those needed for C4 functionality. Here, we quantify the anatomical changes accompanying the transition between non-C4 and C4 phenotypes by sampling widely across the continuum of leaf anatomical traits in the grass Alloteropsis semialata....

Historical and contemporary records of the invasive mussel Mytilus galloprovincialis in southern Africa

Kevin C. K. Ma, Molline N. C. Gusha, Gerardo I. Zardi, Katy R. Nicastro, Jonathan R. Monsinjon & Christopher D. McQuaid
This dataset contains data described in the paper entitled "Biogeographic drivers of distribution and abundance in an alien ecosystem engineer: Transboundary range expansion, barriers to spread, and spatial structure". Data include: (1) historical and contemporary records of the invasive mussel Mytilus galloprovincialis to re-construct its invasion history and patterns of spread across biogeographic regions of southern Africa; (2) densities of M. galloprovincialis at different shore heights measured from multiple sites across South Africa; (3) semi-quantitative...

Data from: Influence of intra- and interspecific variation in predator-prey body size ratios on trophic interaction strengths

Ross N. Cuthbert, Ryan J. Wasserman, Tatenda Dalu, Horst Kaiser, Olaf L. F. Weyl, Jaimie T. A. Dick, Arnaud Sentis, Mike W. McCoy & Mhairi E. Alexander
1. Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra- and interspecific variation in predator-prey body size ratios are lacking. 2. We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass towards three scaled size...

Data from: Determinants of flammability in savanna grass species

Kimberley J. Simpson, Brad S. Ripley, Pascal-Antione Christin, Claire M. Belcher, Caroline E. R. Lehmann, Gavin H. Thomas, Colin P. Osborne & Pascal-Antoine Christin
1. Tropical grasses fuel the majority of fires on Earth. In fire-prone landscapes, enhanced flammability may be adaptive for grasses via the maintenance of an open canopy and an increase in spatiotemporal opportunities for recruitment and regeneration. In addition, by burning intensely but briefly, high flammability may protect resprouting buds from lethal temperatures. Despite these potential benefits of high flammability to fire-prone grasses, variation in flammability among grass species, and how trait differences underpin this...

Data from: The contribution of land tenure diversity to the spatial resilience of protected area networks

Alta De Vos & Graeme S. Cumming
1. The relationship between diversity and resilience is relatively well-established for ecological systems, but remains much less explored for socioeconomic systems. Institutional diversity may have particular relevance for protected areas, whose managerial responses to environmental change depend on their legal basis, ability to make and enforce rules, and socio-political acceptance and endorsement. 2. Protected area expansion strategies are increasingly turning to private land conservation to increase the configuration and connectivity of national protected area networks....

The functional ecology of bat pollination in the African sausage tree Kigelia africana (Bignoniaceae)

Ethan Newman, Keeveshnee Govender, Sandy Van Niekerk & Steven D. Johnson
Plants often interact with a wide range of animal floral visitors that can vary in their pollination effectiveness. Flowers of the African sausage tree Kigelia africana are be visited by bats and bush babies during the night and by birds during the day. We studied floral traits (phenophases, scent, colour and nectar chemistry) and the visitation frequency and pollination effectiveness of different flower visitors to determine if K. africana is functionally specialized for bat-pollination. We...

Field-based ecological studies to assess prospective biological control agents for invasive alien plants: an example from giant rat’s tail grass

Guy Sutton, Kim Canavan, Michael Day & Iain Paterson
1. Biological control (biocontrol) of invasive alien plants is a widely utilised weed management tool. Prospective biocontrol agents are typically assessed through host-specificity testing and pre-release efficacy studies performed in quarantine. However, rearing of the potential biocontrol agents and/or test plants is often difficult or impossible under quarantine conditions. Moreover, practitioners may attain laboratory-artefacts in quarantine, which may result in the potential agent being needlessly rejected. Field-based studies in the weed’s indigenous distribution could overcome...

Prey and predator density-dependent interactions under different water volumes

Ross Cuthbert, Tatenda Dalu, Ryan Wasserman, Arnaud Sentis, Olaf Weyl, William Froneman, Amanda Callaghan & Jaimie Dick
Predation is a critical ecological process that directly and indirectly mediates population stabilities, as well as ecosystem structure and function. The strength of interactions between predators and prey may be mediated by multiple density-dependences concerning numbers of predators and prey. In temporary wetland ecosystems in particular, fluctuating water volumes may alter predation rates through differing search space and prey encounters rates. Using a functional response approach, we examined the influence of predator and prey densities...

Data from: Density-dependent and species-specific effects on self-organization modulate the resistance of mussel bed ecosystems to hydrodynamic stress

Katy Nicastro & Gerardo Zardi
Mussels self-organize to form large regularly-patterned biogenic structures that modify the biotic and abiotic environment and provide numerous ecosystem functions and services. We used two mussel species which form mono-specific and mixed beds to investigate how species-specific behaviour affects self-organization and resistance to wave stress. For these results, the laboratory dataset was used. Perna perna has strong attachment, but low motility, while Mytilus galloprovincialis shows the reverse. At low density the less motile P. perna...

Distribution and abundance of intertidal sea urchins in South Africa

Kevin C. K. Ma, Suzanne Redelinghuys, Molline N. C. Gusha, Siphelele B. Dyantyi, Christopher D. McQuaid & Francesca Porri
This dataset contains data described in the paper entitled "Intertidal estimates of sea urchin abundance reveal congruence in spatial structure for a guild of consumers". Data include: (1) counts of intertidal sea urchins (Diadema cf. savignyi, Echinometra mathaei, Parechinus angulosus, Stomopneustes variolaris, and Tripneustes gratilla) made from 164 visits to 116 rocky shore sites across South Africa by six different observers; (2) GPS co-ordinates determined for every 1-km distance interval of the South African coastline...

Data from: Ecosystem-scale impacts of non-timber forest product harvesting: effects on soil nutrients

Sheunesu Ruwanza & Charlie M. Shackleton
1. The harvesting of non-timber forest products (NTFPs) is a global phenomenon, the sustainability of which has been studied for many species at the individual and population level. However, the broader scale impacts of NTFP harvesting have been acknowledged but rarely examined. 2. We assessed plant size and the soil attributes undercanopy and in the open, in replicate, paired harvested and non-harvested sites for three NTFPs differing in the extent of biomass removed, i.e. timber...

Data from: The mayfly nymph Austrophlebioides pusillus Harker defies common osmoregulatory assumptions

Renee Dowse, Carolyn G. Palmer, Kasey Hills, Fraser Torpy & Ben J. Kefford
Osmoregulation is a key physiological function, critical for homeostasis. The basic physiological mechanisms of osmoregulation are thought to be well established. However, through a series of experiments exposing the freshwater mayfly nymph Austrophlebioides pusillus (Ephemeroptera) to increasing salinities, we present research that challenges the extent of current understanding of the relationship between osmoregulation and mortality. A. pusillus had modelled 96 h LC10, LC50 and LC99 of 2.4, 4.8 and 10 g l−1 added synthetic marine...

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Resource Types

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Affiliations

  • Rhodes University
    32
  • University of Pretoria
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  • South African Institute for Aquatic Biodiversity
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