Predicting the potential demographic impact of predators on their prey: a comparative analysis of two carnivore-ungulate systems in Scandinavia

• Published in: The Journal of animal ecology Vol. 81; no. 2; pp. 443 - 454
• Main Authors: Gervasi, Vincenzo, Nilsen, Erlend B., Sand, Håkan, Panzacchi, Manuela, Rauset, Geir R., Pedersen, Hans C., Kindberg, Jonas, Wabakken, Petter, Zimmermann, Barbara, Odden, John, Liberg, Olof, Swenson, Jon E., Linnell, John D. C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing 01.03.2012; Blackwell Publishing Ltd; Blackwell
• Subjects: Age; Age composition; Age Distribution; age structure; Alces alces; Animal and plant ecology; animal communities; Animal ecology; Animal populations; Animal, plant and microbial ecology; Animals; Bears; Biological and medical sciences; Boreal forests; Brown bears; Canis lupus; Capreolus capreolus; Carnivora; Carnivora - physiology; Carnivores; Community ecology; Comparative analysis; courser; Deer; Demography; Ecological research; Ecosystem; Environmental Sciences related to Agriculture and Land-use; Female; Food Chain; Forest ecosystems; Forests; Foxes; Fundamental and applied biological sciences. Psychology; General aspects; Harvesting; kill rate; life history; Lynx; Lynx lynx; Male; Mammalia; Mammals; Miljö- och naturvårdsvetenskap; Models, Biological; Norway; physiology; Population Dynamics; Population ecology; Predation; Predator-prey interactions; predator-prey relationships; Predators; Predatory Behavior; Prey; Scandinavia; Seasons; Simulation; Species Specificity; stalker; Sweden; Ursus arctos; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Vulpes vulpes; Wildlife ecology; Wolves; Scandinavia; Europe; Norway; Sweden; Predator prey relation; Fissipedia; Carnivora; Life history; Demography; stalker; Alces alces; Ursus anctos; Lynx lynx; Carnivorous animal; Scandinavia; courser; Capreolus capreolus; Vertebrata; Mammalia; kill rate; Artiodactyla; Canis lupus; Ungulata; Vulpes vulpes
• ISSN: 0021-8790; 1365-2656; 1365-2656
• DOI: 10.1111/j.1365-2656.2011.01928.x

1. Understanding the role of predation in shaping the dynamics of animal communities is a fundamental issue in ecological research. Nevertheless, the complex nature of predator-prey interactions often prevents researchers from modelling them explicitly. 2. By using periodic Leslie-Usher matrices and a simulation approach together with parameters obtained from long-term field projects, we reconstructed the underlying mechanisms of predator-prey demographic interactions and compared the dynamics of the roe deer-red fox-Eurasian lynx-human harvest system with those of the moose-brown beargray wolf-human harvest system in the boreal forest ecosystem of the southern Scandinavian Peninsula. 3. The functional relationship of both roe deer and moose λ to changes in predation rates from the four predators was remarkably different. Lynx had the strongest impact among the four predators, whereas predation rates by wolves, red foxes, or brown bears generated minor variations in prey population λ. Elasticity values of lynx, wolf, fox and bear predation rates were -0157, -0.056, -0.031 and -0.006, respectively, but varied with both predator and prey densities. 4. Differences in predation impact were only partially related to differences in kill or predation rates, but were rather a result of different distribution of predation events among prey age classes. Therefore, the age composition of killed individuals emerged as the main underlying factor determining the overall per capita impact of predation. 5. Our results confirm the complex nature of predator-prey interactions in large terrestrial mammals, by showing that different carnivores preying on the same prey species can exert a dramatically different demographic impact, even in the same ecological context, as a direct consequence of their prédation patterns. Similar applications of this analytical framework in other geographical and ecological contexts are needed, but a more general evaluation of the subject is also required, aimed to assess, on a broader systematic and ecological range, what specific traits of a carnivore are most related to its potential impact on prey species.