Experimental tests of the role of predation in the population dynamics of voles and lemmings

Abstract

1. Reasons for fluctuating populations of small mammals have been intensively investigated since the early days of modern ecology. Particular interest has been taken in vole populations exhibiting multiannual oscillations. Much empirical and theoretical work has been accomplished to find out the key factor(s) driving these population cycles and many reviews have been written about the results. 2. One of the most plausible processes for explaining regular fluctuations in small mammals is predation. Here I review the existing literature on the experimental studies of the role of predation in vole population dynamics in the hope that a critical examination of these studies will help researchers improve the design of future experiments. 3. Most predation manipulations have been done in exclosures, but there are also studies that have attempted to reduce or increase predator numbers in non-fenced areas, islands and enclosures. 4. As the number of experimental studies has increased, their quality in terms of replication, use of controls and realistic spatial and temporal scales has also improved. 5. Most studies have found population-level effects of predator manipulations on prey populations. The effects have varied from very weak to very strong, reflecting dissimilar experimental designs and the great variety of predator-prey interactions among different kinds of species in different landscapes. Most of these studies show that predation limits population growth of voles, and in some circumstances even regulate vole population fluctuations, but none of them clearly demonstrates that predation consistently changes fluctuation patterns of voles. 6. To be able to assess more reliably the true role of predation on (cyclic) population fluctuations of voles, more competent experiments are still needed not only over the geographical range of cyclic population dynamics, but also in areas of weakly or non-cyclic populations of voles. INTRODUCTIONThere is no doubt that predation is one of the most important forces affecting the behaviour, population dynamics and evolution of prey species. It is also likely that the role and the impact of predation vary between communities, species, populations and individuals, and that the effect of predation is not constant over time and space (Lima & Bednekoff, 1999). This review is focused on predation on small rodents as a well-studied model system.

Implications of scale-independent habitat specialization on persistence of a rare small mammal

“…Predation can be an extremely important influence on vole populations (Turchin and Hanski, 1997;Korpimaki et al, 2002;Sundell, 2006), and their habitat use patterns can vary according to predation intensity (Sundell et al, 2012). Although we did not formally collect data on predation, much of the evidence strongly suggests that habitat selection by the Amargosa vole is predator-mediated.…”

Birds help plants: a meta-analysis of top-down trophic cascades caused by avian predators

“…Many predator reduction experiments have already been undertaken with voles or lemmings and their predators (reviewed in Sundell 2006). However, the plant responses are often not reported at all.…”

Ecological factors influencing the breeding distribution and success of a nomadic, specialist predator

“…Finally, predation has an important role in shaping vole population dynamics and often can limit the population growth of voles (Sundell 2006). Steppes of north-Kazakhstan harbour a highly diverse predator guild preying potentially on small mammal species, including specialist (Pallid Harriers, Short-eared Owls Asio flammeus) and generalist predators (two fox species, mustelids and a diverse raptor community).…”