Responses of a top and a meso predator and their prey to moon phases

Abstract

We compared movement patterns and rhythms of activity of a top predator, the Iberian lynx Lynx pardinus, a mesopredator, the red fox Vulpes vulpes, and their shared principal prey, the rabbit Oryctolagus cuniculus, in relation to moon phases. Because the three species are mostly nocturnal and crepuscular, we hypothesized that the shared prey would reduce its activity at most risky moon phases (i.e. during the brightest nights), but that fox, an intraguild prey of lynx, would avoid lynx activity peaks at the same time. Rabbits generally moved further from their core areas on darkest nights (i.e. new moon), using direct movements which minimize predation risk. Though rabbits responded to the increased predation risk by reducing their activity during the full moon, this response may require several days, and the moon effect we observed on the rabbits had, therefore, a temporal gap. Lynx activity patterns may be at least partially mirroring rabbit activity: around new moons, when rabbits moved furthest and were more active, lynxes reduced their travelling distances and their movements were concentrated in the core areas of their home ranges, which generally correspond to areas of high density of rabbits. Red foxes were more active during the darkest nights, when both the conditions for rabbit hunting were the best and lynxes moved less. On the one hand, foxes increased their activity when rabbits were further from their core areas and moved with more discrete displacements; on the other hand, fox activity in relation to the moon seemed to reduce dangerous encounters with its intraguild predator.

Nocturnal activity of a “diurnal” species, the northern chamois, in a predator-free Alpine area

“…Nocturnal activity of ungulates changes significantly with the period of the year, probably because of seasonal shifts in foraging strategies and rumination/energy requirements (Cederlund, 1989). Different from what one might expect from a potential prey species (Penteriani et al, 2013;Mori et al, 2014a), nocturnal movements of chamois in PNP were mostly concentrated on bright moonlight nights, thus confirming prediction (ii). The chamois is a species which uses vision as its main sensory system (Raveh et al, 2012), thus it may not be unlikely that this is the primary reason why it is active mainly in moonlit nights (Prugh and Golden, 2014).…”

“…As a response, prey species decrease predator efficiency by concentrating their movements in what we perceive as total darkness (e.g. Penteriani et al, 2013;Mori et al, 2014) and/or dense vegetation cover and shrub canopies (Mandelik et al, 2003;Prugh and Golden, 2014). Antipredatory tactics of potential prey should primarily involve avoidance of predators, e.g.…”

“…shifting activity to times when the probability of meeting predators is the lowest (e.g. Fenn and MacDonald, 1995;Penteriani et al, 2013;Bischof et al, 2014), with females with offspring being particularly careful to avoid encounters with potential predators (e.g. Romeo and Lovari, 1996).…”

Hunting behaviour and breeding performance of northern goshawks Accipiter gentilis, in relation to resource availability, sex, age and morphology

“…Our analysis of radio-tracking data for both range size and distances travelled within ranges (e.g. from the nest and between locations) highlights the importance of considering a combination of different spatio-temporal factors and individual-level processes when studying animals' ranging behaviour Penteriani et al 2013). The findings agree with those of recent studies that ascribed intraspecific variation in home range behaviour to both differences among individuals and resource availability (Börger et al 2006;Saïd et al 2009;Arlettaz et al 2010;van Beest et al 2011).…”

Dodging the moon: The moon effect on activity allocation of prey in the presence of predators

“…Moonlight is an important abiotic determinant of the activity of nocturnal species (Kotler, Brown, & Hasson, ; Penteriani et al., ). Moon brightness varies between different phases and times of the night because the moon transit (when the moon is on the zenith and thus, apart from new moon, when there is greater nocturnal illumination) is different in each moon phase.…”