Graham I. H. Kerley

Graham I. H. Kerley
Nelson Mandela University | NMMU · Centre for African Conservation Ecology & Department of Zoology

PhD

About

335
Publications
138,616
Reads
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11,069
Citations
Citations since 2016
115 Research Items
6110 Citations
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201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
Additional affiliations
January 2012 - March 2013
Victoria University of Wellington
Position
  • Research Associate
January 2005 - December 2012
Nelson Mandela University
March 1991 - October 1991
New Mexico State University
Position
  • PostDoc Position

Publications

Publications (335)
Article
Full-text available
Paradoxically, despite the growth in protected areas globally, many species remain threatened and continue to decline. Attempts to conserve species in suboptimal habitats (i.e., as refugee species) may in part explain this Protected Area Paradox. Refugee species yield poor conservation outcomes as they suffer lower densities and fitness. We suggest...
Article
Full-text available
Human activities have affected animals’ behaviour, distribution and population structure and this effect is predicted to increase in the future. Considerable effort is therefore being focussed on understanding and predicting such future changes in response to anthropogenic pressures, this to better conserve and restore populations and species. Howe...
Article
Full-text available
Measuring and comparing activity patterns provide key insights into the behavio-ral trade-offs that result in animal activity and their extrinsic and intrinsic drivers. Camera traps are a recently emerged source of data for sampling animal activity used to estimate activity patterns. However, nearly 70% of studies using such data to estimate activi...
Article
Full-text available
Optimally foraging animals should minimise time spent foraging in order to perform other fitness-enhancing activities. The ruminants’ more efficient digestive system, requiring lower volumes of forage, is predicted to provide an advantage over hindgut fermenters with respect to foraging effort, but this may be offset by their need for higher qualit...
Article
Full-text available
Ecological niche differences are necessary for stable species coexistence but are often dif- ficult 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 toward food plant species identity. Empirical support f...
Preprint
Full-text available
Traditional prey preference models use a coarse species-specific prey body mass of three-quarters of adult female body mass, assumed to reflect the average mass across the prey population. This ignores demographic-specific prey preferences, potentially biasing estimates of preferred prey sizes. We refined prey selection models for two model predato...
Article
There have been few attempts to assess how members of the herbivore guilds (e.g. grazers, browsers, mixed-feeders, frugivores) vary in their preferences for these diet resources as dietary resources vary. We used fecal microhistology to assess grass consumption in relation to grass availability for five populations of the plains zebra Equus quagga,...
Data
This file provides the data used to estimate zebra diet and plant growth form cover for the paper: Potgieter, T-L. & Kerley, G.I.H. 2022. The zebra as a grazer: selectivity for grass consumption differs as grass availability varies. African Journal of Ecology 00.00-00
Article
Human-wildlife conflicts may be unintended consequences of conservation successes and rewilding, and could be exacerbated where baselines around biodiversity have shifted. Mediating conflict is a conservation priority due to its socio-economic impacts and the consequences negative perceptions have for conservation outcomes. We document locally nove...
Article
Large (>15 kg) carnivores, namely lions (Panthera leo ), leopards (Panthera pardus ), cheetahs (Acinonyx jubatus), African wild dogs (Lycaon pictus ), spotted (Crocuta crocuta) and brown hyaenas (Parahyaena brunnea ), have been reintroduced to 16 private- and state-owned reserves in the Eastern Cape Province, South Africa. Objectives behind these r...
Article
Full-text available
Megaherbivores (adult body mass > 1000 kg) are suggested to disproportionately shape ecosystem and Earth system functioning. We systematically reviewed the empirical basis for this general thesis and for the more specific hypotheses that 1) megaherbivores have disproportionately larger effects on Earth system functioning than their smaller counterp...
Article
en Competition occurs between species for shared resources and the subordinate species can reduce this by avoiding competitors, either proactively or reactively. Cheetah are subordinate members of the African large carnivore guild, vulnerable to losing resources or being killed by larger carnivores. We directly investigate how cheetah space and hab...
Article
Full-text available
The single listed blue antelope held in an SA museum has now been confirmed as not representing this species. This means that despite the species having been (prior to its extinction) endemic to South Africa, we do not have any direct (i.e. not fossil or archaeological) specimens of this species. There is an urgency to reassess the various fossil o...
Article
Invertebrate communities occupying hypolithic habitats at the rock-soil interface are diverse and can contribute significantly to ecosystem functioning, especially in arid environments. However, these communities are poorly understood. We tested three hypotheses of processes that may structure these communities, these reflecting species-area relati...
Article
Chacma baboons (Papio ursinus) intentionally overturn rocks to feed on the invertebrates beneath. However, baboons do not move all the rocks they encounter, with this presumably reflecting cost–benefit (or effort–reward) trade-offs in their foraging behavior. We ask, how do “clever baboons” choose rock sizes and shapes and move these rocks? Using o...
Article
Significance Herbivores influence nutrient cycling by depositing feces across the landscape. Where herbivores go in the landscape is governed by factors such as food requirements and vulnerability to predation, traits that are related to body size. We show that mammals that differ in body size not only use the landscape differently but also differ...
Article
Scent‐marking is an important form of communication for solitary species, as the information remains for the receiver after the sender has left the area. Individuals of different demographic or dominance classes (ranks) need to provide different information to conspecifics. Therefore, the use of scent‐marking sites is of particular value for solita...
Article
Both interference and exploitative competition for prey occurs between carnivore species, which can be exacerbated if the carnivore species are of similar body size, meaning that they select for similar prey species. Studies on competition within the large carnivore guild in Africa have mainly focused on the interactions between the larger dominant...
Article
Optimal foraging theory predicts less diverse predator diets with a greater availability of preferred prey. This narrow diet niche should then be dominated by preferred prey, with implications for predator–prey dynamics and prey population ecology. We investigated lion (Panthera leo) diets in Hluhluwe–iMfolozi Park (HiP), South Africa, to assess wh...
Article
Full-text available
Scent-marking is a way for individuals to indirectly communicate; however, the information is not exclusive to a single species and can be informative to a whole community. Prey or competitively inferior species can use scent-marks from predators/dominant species to avoid interactions. Cheetahs are a subordinate member of the large carnivore guild...
Article
Full-text available
Setting appropriate conservation measures to halt the loss of biodiversity requires a good understanding of species' habitat requirements and potential distribution. Recent (past few decades) ecological data are typically used to estimate and understand species’ ecological niches. However, historical local extinctions may have truncated species–env...
Article
Arid Thicket transformation by domestic meso-herbivores is purported to follow a state-and-transition model. Our study represents a first attempt to verify this hypothesis in Pruim-Spekboomveld, a variation of Arid Thicket. We correlate structural and compositional attributes of thicket bush clumps to distance from artificial watering points in fou...
Conference Paper
Introducing consumptive and non-consumptive effects into food webs can have profound effects on individuals, populations and communities. Consequently, the deliberate use of predation and/or fear of predation is an emerging technique for controlling wildlife. Many now advocate for the intentional use of large carnivores and livestock guardian dogs...
Technical Report
Full-text available
A compilation of research gaps and priorities extracted from PredSA ""Livestock predation and its management in South Africa: a scientific assessment"
Article
Full-text available
Apex predators are crucial for maintaining ecological patterns and processes, yet humans hinder their ability to fulfil this role by displacing them from the landscape. Many apex predator species such as African lions (Panthera leo) are experiencing catastrophic declines as a result of competition with growing human populations. Increasing our unde...
Article
Landscapes of fear have become widely studied in the northern hemisphere, but are still largely understudied in the more complex, diverse carnivore-prey communities of Africa. Habitat changes brought about by a mega-herbivore, the African elephant (Loxodonta africana), can modify the perceived landscape of fear by predation vulnerable prey species...
Chapter
Conservation assessment for the Cape mountain zebra
Article
Full-text available
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationis...
Article
The recolonization of wolves in European human-dominated landscapes poses a conservation challenge to protect this species and manage conflicts. The question of how humans can co-exist with large carnivores often triggers strong emotions. Here we provide an objective, science-based discussion on possible management approaches. Using existing knowle...
Article
Full-text available
Understanding and identifying drivers of local population declines are important in mitigating future risks and optimising conservation efforts. The Knysna elephants have, after being afforded protection since the early 1900s, declined to near extinction today. We propose three hypotheses as to why the Knysna elephant population declined. The refug...
Preprint
Full-text available
Setting appropriate conservation measures to halt the loss of biodiversity requires a good understanding of species' habitat requirements and potential distribution. Recent (past few decades) ecological data are typically used to estimate and understand species' ecological niche. However, historical local extinctions may have truncated species-envi...
Article
Introducing consumptive and non-consumptive effects into food webs can have profound effects on individuals, populations and communities. This knowledge has led to the deliberate use of predation and/or fear of predation as an emerging technique for controlling wildlife. Many now advocate for the intentional use of large carnivores and livestock gu...
Article
Despite the importance of coarse woody debris (CWD) in woody ecosystems, conceptual frameworks of its dynamics currently exclude the role of the megaherbivores, focusing instead on the role of insects, disease, fire, wind and droughts. However, recognizing the ecological roles of the megaherbivores is one of the most urgent contemporary issues, par...
Article
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 becaus...
Article
Conservation agencies rely on accurate wildlife population estimates to inform management practices. The importance of accuracy increases with smaller, threatened populations, but so too does the challenge in achieving it, especially for evasive species in low-visibility terrain. Non-invasive survey techniques have been successfully applied in such...
Article
The loss of megafauna at the terminal Pleistocene has been linked to a wide range of Earth-system-level changes, such as altered greenhouse gas budgets, fire regimes and biome-level vegetation changes. Given these influences and feedbacks, might part of the solution for mitigating anthropogenic climate change lie in the restoration of extant megafa...
Chapter
Full-text available
This summary provides a narrative overview on Livestock Predation and its Management in South Africa, highlighting policy relevant aspects in a non-technical fashion. The assessment was undertaken by a team of experts, led by the authors of this summary, and provides extensive details, and a knowledge base of the diverse fields relevant to livestoc...
Chapter
Full-text available
Livestock predation and its management in South Africa: a scientific assessment (Eds Kerley, G.I.H., Wilson, S.L. & Balfour, D.). Centre for African Conservation Ecology, Nelson Mandela University, Port Elizabeth,
Article
Full-text available
1.Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., lowland habitats on fertile soils, coastal zones), land is often privately owned and state‐owned PAs tend to be under‐represented. Despite the potentially disproportionate contribution t...
Article
Animals sculpt landforms by physically altering the substrate. Many digging and burrowing animals are then considered zoogeomorphic agents. While the significance of soil disturbing species is well established, geomorphic impacts are rarely quantified for rock transporting species. The chacma baboon (Papio ursinus), a widespread and abundant primat...
Conference Paper
Full-text available
Lethal carnivore management, aimed at reducing carnivore impacts, is a global phenomenon threatening the persistence of many carnivores. In South Africa, carnivore persecution escalated during the expansion of pastoralism and the introduction of modern technology. Consequently most large carnivores have been extirpated from much of their historic r...
Article
Full-text available
Life history changes may change resource use. Such shifts are not well understood in the dung beetles, despite recognised 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 account...
Raw Data
Data from: Accessibility maps as a tool to predict sampling bias in historical biodiversity occurrence records. – Figshare Digital Repository, <https://figshare.com/s/bd9df619e915c4d19f57>.
Article
The loss of apex consumers (large mammals at the top of their food chain) is a major driver of global change [1]. Yet, research on the two main apex consumer guilds, large carnivores [2] and megaherbivores [3], has developed independently, overlooking any potential interactions. Large carnivores provoke behavioral responses in prey [1, 4], driving...
Article
Long-term biodiversity occurrence records are key to quantify long-term biodiversity patterns and trends and inform the conservation of threatened species, but they are strongly biased in terms of the species represented. This taxonomic bias, and its correlation to societal preferences, is well-identified in modern biodiversity datasets. However, i...
Article
Full-text available
Historical biodiversity occurrence records are often discarded in spatial modeling analyses because of a lack of a method to quantify their sampling bias. Here we propose a new approach for predicting sampling bias in historical written records of occurrence, using a South African example as proof of concept. We modelled and mapped accessibility of...
Article
Full-text available
Maintaining key ecological processes is a strong argument for conserving biodiversity, and this should extend to preventing the local extinction of keystone species that are otherwise common. Seed dispersal is such a process and chacma baboons (Papio ursinus ursinus) may facilitate seed dispersal, but currently suffer range contractions in South Af...
Article
Full-text available
Lethal carnivore management is a prevailing strategy to reduce livestock predation. Intensity of lethal management varies according to land-use, where carnivores are more intensively hunted on farms relative to reserves. Variations in hunting intensity may result in the formation of a source–sink system where carnivores disperse from high-density t...
Article
Apex predators can have considerable impacts on meso-carnivore diets, through competition or facilitation. Facilitation occurs when smaller predators consume carrion created by larger predators, especially large-bodied prey species normally inaccessible to meso-carnivores. In contrast, apex predators can also negatively affect meso-carnivore consum...
Article
Full-text available
Despite extensive evidence that African buffalo Syncerus caffer are grazers, De Graaff et al. using rumen content analysis of animals that had starved to death proposed that buffalo in grass-limited Eastern Cape thicket should be considered browsers. Although these anomalous findings were initially accepted, but later challenged, the browse-dominat...
Article
Full-text available
The Australian Rhino Project (www.theaustralianrhinoproject.org) proposes importing 80 rhinos from South Africa to Australia by 2019 at a cost of over $US4 million, and the first six due to have been moved in 2016. This project has high profile supporters in the private sector, zoos and both governments, and is gaining major publicity through assoc...
Article
Full-text available
Na de uitroeiing van de wisent in het wild aan het begin van de twintigste eeuw keerde de soort terug door middel van het fokken in gevangenschap en vervolgens een herintroductie in bosgebieden in Oost-Europa. Een van de belangrijkste problemen bij de instandhouding van de wisent is het beheer dat is gebaseerd op meningen en minder op wetenschappel...
Article
Adaptive governance and network governance theory provide a useful conceptual framework to guide the conservation of threatened species in complex multi-actor, multijurisdictional social ecological systems. We use principles from this theory to assess strengths and weaknesses in (1) national legislation, and (2) the Convention on International Trad...