Joris Cromsigt

Joris Cromsigt
Large parts of our planet are currently facing a dramatic and rapid loss of the world’s last wild megafauna (mammalian herbivores and carnivores > 40kgs). If this so-called defaunation continues, near future mammal communities will consist of few species of smaller body size. In contrast, parts of particularly the northern hemisphere experience a megafaunal rewilding and see populations of large carnivores and herbivores increase. Defaunation and rewilding may both have huge consequences for the sustainable functioning of socio-ecological systems. In my unit, Megafauna & Sustainability (MegaSus), we investigate the patterns and processes of defaunation and rewilding and the consequences for sustainable functioning of ecosystems as well as human society. Our main study systems include African savannas and European boreal and temperate forests.


I teach in a variety of courses and topics at both MSc and PhD level, including adaptive wildlife management, trophic ecology, megafaunal ecology, conservation biology and experimental design.


Defaunation & Ecosystem Sustainability
We study the effects of so-called megaherbivores, such as white rhino and elephant, on the functioning of South African ecosystems. Megaherbivores (> 1,000 kgs as adult) are said to have disproportionate effects on ecosystems because their populations are not controlled by predation. Current rampant poaching of rhino and elephant is threatening the survival of these last remaining megaherbivores. We explore a broad diversity of the consequences of their loss ranging from biogeochemistry, to fire regimes, and climate-vegetation feedbacks.

As part of this theme I lead the HOTSPOT program, 2017-2022, which focuses on the white rhino poaching crisis in Hluhluwe-iMfolozi Park, South Africa. The program has two main objectives: (1) increasing our understanding of white rhino movement patterns and population ecology and (2) investigating the ecological effects of losing white rhino. The team currently includes one PhD, one Postdoc and one field technician.

Rewilding & Ecosystem Sustainability
In contrast to large parts of the world, Europe is experiencing a revival of several larger mammal species, including large carnivore such as wolf, ungulates, and larger bird species. This rewilding occurs passively or through active (re)introductions of large mammals. The aim of active rewilding is to mitigate effects of global change (such as biodiversity loss) and restore top-down trophic interactions and associated ecosystem structure and functioning. In a variety of projects across Europe, we study the consequences of rewilding, including the effects of introductions of European bison and red deer in the Netherlands and the consequences of the large carnivore comeback in Europe.

Within this latter theme, I currently also lead the major research program, BEYOND MOOSE, which studies the consequences of strong increases in several European deer species with a focus on the ecology and management of multispecies ungulate communities in Sweden. The program currently includes 3 PhD students and several senior scientists.

I am also work package leader in the SCANDCAM project that investigates the use of camera traps for the long-term monitoring of wildlife in Scandinavia. This project includes a postdoc that falls under my supervision.


2011-ongoing, Dept. Wildlife, Fish & Environmental Sciences, SLU, Umeå

2009-2011, Marie Curie Intra-European postdoctoral fellow, Center for Ecological and Evolutionary Synthesis, University of Oslo, Norway

2008-2009, Marie Curie postdoctoral fellow, Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland

2006-2007, Postdoctoral researcher, University of Groningen, the Netherlands

2001-2006, PhD, University of Groningen, the Netherlands

1999-2000, MSc, Wageningen University, the Netherlands


Graduated PhD students

Dr. Liza le Roux, The Role of Apex Predators in Ecosystem Function: Fear Triggered Cascades Regulated by Differential Prey Vulnerability, 2017, main supervisor, Nelson Mandela University, South Africa

Dr. Nokubonga Mgqatsa, Tree-toppling by Elephants and its Consequences in the Thicket Mosaic Vegetation of Addo Elephant National Park, 2017, co-supervisor, Nelson Mandela University, South Africa

Dr. Ellinor Sahlén, Indirect Effects of Predation in Human-Modified Landscapes, 2016, co-supervisor, SLU, Umeå

Dr. Cleo Gosling, Biotic Determinants of Heterogeneity in a South African Savanna, 2014,  co- supervisor, University of Groningen, the Netherlands

Dr. Ruth Nichols, Bite DNA: Fine-Scale Resource Partitioning in Temperate Ungulates, 2013, co- supervisor, SLU, Umeå

PhD students still to graduate (with year of expected graduation)

Anna Widén, Interacting land uses and impacts of ungulate communities in Sweden, 2022, main supervisor, SLU

Olli Hyvärinen, Ecological cascading effects of white rhino poaching, 2022, main supervisor, SLU

Nannet Fabri, Role of different deer species in spread of tick-borne diseases, 2022, main supervisor, SLU & Utrecht University

Bjorn Mols, Large carnivores in anthropogenic landscapes: how landscapes of fear created by humans and large carnivores affect deer behaviour and structure ecosystems, 2022, co-supervisor, University of Groningen

Anne Loosen, Trade-offs in a managed landscape: spatio-temporal moose foraging and spatial predation risk, 2022, co-supervisor, Inland Norway University of Applied Sciences

Robert Spitzer, Resource Utilization Patterns of European Ungulates along Land Use and Species Richness Gradients, 2019, main supervisor, SLU, Umeå

Sabine Pfeffer, Understanding Wildlife-Human Conflicts in Species-rich European Ungulate communities, 2020, co- supervisor, SLU, Umeå

Karin Larsson, Grazing and fire – key processes for tree and flowering plant succession, 2022, co- supervisor, SLU


Dr. Liza le Roux, 2017-2019, Nelson Mandela University, South Africa

Dr. Tim Hofmeester, 2017–2019, SLU

Dr. Sheila Holmes, 2019–2021, SLU

Publikationer i urval


Veldhuis MP, Kihwele ES, Cromsigt JPGM, Ogutu JO, Hopcraft JGC, Owen-Smith N and Olff H. 2019. Large herbivore assemblages in a changing climate: incorporating water dependence and thermoregulation. Ecology Letters. In press.

Chamaillé‐Jammes S, Valeix M & Cromsigt JPGM. 2019. Predator Effects on Herbivore Dynamics and Behavior: What Mechanisms Lead to Trophic Cascades in Savannas? In: Savanna Woody Plants and Large Herbivores (eds, PF Scogins & M Sankaran), pp. 279-308, Wiley, UK.

van Beeck Calkoen STS, Leigh-Moy K, Cromsigt JPGM, Spong G, Lebeau LC, Heurich M. The Blame Game: Using eDNA to identify species-specific tree browsing by red deer (Cervus elaphus) and roe deer (Capreolus capreolus) in a temperate forest. 2019. Forest Ecology and Management 451: 117483.

Flezar U, le Roux E, Kerley GIH, Kuijper D, te Beest M, Druce DJ, Prinsloo D and Cromsigt JPGM. 2019. Simulated elephant-induced habitat changes can create dynamic landscapes of fear. Biological Conservation 237: 267-279.

Kuijper DPJ, Churski M, Trouwborst A, Heurich M, Smit C, Kerley GIH & Cromsigt JPGM. 2019. Keep the wolf from the door: How to conserve wolves in Europe's human-dominated landscapes? Biological Conservation 235: 102-111.

Landman M, Mgqatsa N, Cromsigt JPGM and Kerley GIH. 2019. Elephant effects on treefall and logfall highlight the absence of megaherbivores in coarse woody debris conceptual frameworks. Forest Ecology and Management 438: 57-62.

le Roux E, Marneweck D, Clinning G, Druce DJ, Kerley GIH and Cromsigt JPGM. 2019. Top-down limits on prey populations may be more severe in larger prey species, despite having fewer predators. Ecography 42: 1115-1123.

Spitzer R, Churski M, Felton A, Heurich M, Kuijper DPJ, Landman M, Rodriguez E, Singh NJ, Taberlet P, van Beeck Calkoen S, Widemo F & Cromsigt JPGM. 2019. Doubting dung: eDNA reveals high rates of misidentification in diverse European ungulate communities. European Journal of Wildlife Research 65: 28.

Hofmeester TR, Cromsigt JPGM, Odden J, Andrén H, Kindberg J and Linnell JDC. 2019. Framing pictures: a conceptual framework to identify and correct for biases in detection probability of camera traps enabling multi-species comparison. Ecology and Evolution 9: 2320-2336.

Fayolle A, Swaine MD, Aleman J, Azihou AF, Bauman D, te Beest M, Chidumayo EN, Cromsigt JPGM, Finck M, Gonçalves FMP, Gillet J-F, Gorel A, Hick A, Holdo R, Kirunda B, Mahy G, McNicol I, Ryan CM, Revermann R, Plumptre A, Pritchard R, Nieto-Quintano P, Schmitt CB, Seghieri J, Swemmer T, Talila H, Woollen E. 2019. A sharp floristic discontinuity revealed by the biogeographic regionalization of African savannas. Journal of Biogeography. Online early.



Cromsigt JPGM, te Beest M, Kerley GIH, Landman M, le Roux E and Smith FA. 2018. Trophic rewilding as a climate change mitigation strategy? Philosophical Transactions of the Royal Society B.

Le Roux E, Kerley GIH and Cromsigt JPGM. 2018. Megaherbivores modify trophic cascades triggered by fear of predation in an African savanna ecosystem. Current Biology 28: 2493-2499.

Valdés-Correcher E, Rodriguez E, Kemp YJ, Wassen MJ and Cromsigt JPGM. 2018. Comparing the impact of a grazing regime with European bison versus one with free-ranging cattle on coastal dune vegetation in the Netherlands. Mammal Research, 1-12.

Cromsigt JPGM, Kemp YJM, Rodriguez E and Kivit H. 2018. Rewilding Europe’s large grazer community: how functionally diverse are the diets of European bison, cattle and horse? Restoration Ecology 26: 891-899,

van Beeck Calkoen ST, Kuijper DPJ, Sand H, Singh NJ, van Wieren SE and Cromsigt JPGM. 2018. Does wolf presence reduce moose browsing intensity in young forest plantations? Ecography 41: 1776-1787.

Pfeffer SE, Spitzer R, Allen AM, Hofmeester TR, Widemo F, Singh NJ and Cromsigt JPGM. 2018. Pictures or Pellets? Comparing camera trapping and dung counts as methods for estimating population densities of ungulates. Remote Sensing in Ecology and Conservation 4: 173-183.



Cromsigt JPGM, Archibald S and Owen-Smith N (editors). 2017. Conserving Africa’s Mega-Diversity in the Anthropocene: the Hluhluwe-iMfolozi Park story. Ecology, Biodiversity and Conservation Series, Cambridge University Press.

Owen-Smith N, Cromsigt JPGM and Le Roux E. 2017. Smaller ungulates are first to incur imminent extirpation from an African protected area. Biological Conservation 216:108-114.

Rozen-Rechels D, te Beest M, Dew LA, le Roux E, Druce DJ and Cromsigt JPGM. 2017. Contrasting impacts of an alien invasive shrub on mammalian savanna herbivores revealed on a landscape scale. Diversity and Distributions 23:656-666.

Dew LA, Rozen-Rechels D, le Roux E, Cromsigt JPGM and te Beest M. 2017. Evaluating the efficacy of invasive plant control in response to ecological factors. South African Journal of Botany 109:203-213.

Felton AM, Felton A, Cromsigt JPGM, Edenius L, Malmsten J and Wam HK. 2017. Interactions between ungulates, forests and supplementary feeding: the role of nutritional balancing in determining outcomes. Mammal Research 62:1-7.

Churski M, Bubnicki JW, Jedrzejewska B, Kuijper DPJ and Cromsigt JPGM. 2017. Brown world forests:  increased ungulate browsing keeps temperate trees in recruitment bottlenecks in resource hotspots. New Phytologist 214:158-168.

Veldhuis MP, le Roux E, Cromsigt JPGM, Berg MP and Olff H. 2017. Determinants of patchiness of woody vegetation in an African savanna. Journal of Vegetation Science 28:93-104.



Gosling CM, Schrama M, Erk A, Olff H & Cromsigt JPGM. 2016. Mammalian herbivores, grass height and rainfall drive termite activity at different spatial scales in an African savanna. Biotropica 48: 656-666.

Kuijper DPJ, Bubnicki JW, Churski M and Cromsigt JPGM. 2016. Multi-trophic interactions in anthropogenic landscapes: the devil is in the detail. Proceedings of the Royal Society of London B 283:20152375.

van der Plas F, Howison RA, Mpanza N, Cromsigt JPGM and Olff H. 2016. Different‐sized grazers have distinctive effects on plant functional composition of an African savannah. Journal of Ecology 104:864-875.

Sahlén E, Noell S, DePerno CS, Kindberg J, Spong G and Cromsigt JPGM. 2016. Phantoms of the forest: Legacy risk effects of a regionally extinct large carnivore. Ecology and Evolution 6: 791-799.



Nichols RN, Cromsigt JPGM and Spong G. 2015. Using eDNA to experimentally test ungulate browsing preferences. SpringerPlus 4:489.

Fox HV, Bonnet O, Cromsigt JPGM, Fritz H and Shrader AM. 2015. Legacy effects of different land-use histories interact with current grazing patterns to determine grazing lawn soil properties. Ecosystems 18:720-733.

Nichols RN, Cromsigt JPGM and Spong G. 2015. DNA left on browsed twigs uncovers bite-scale resource use patterns in European ungulates. Oecologia 178:275-284.