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Analysis of spatiotemporal partitioning is pivotal to shed light on interspecific coexistence. Most research effort has involved large-sized carnivores and their prey, whereas little attention has been devoted to lagomorphs. We assessed spatiotemporal overlap among the European brown hare Lepus europaeus and its potential competitors and predators through camera-trapping in an area in Central Italy. We estimated the interspecific patterns of the spatiotemporal activity rhythms of brown hares, its potential predators (the red fox Vulpes vulpes, the pine marten Martes martes, the domestic cat Felis catus, and the domestic dog Canis familiaris), and a competitor, the roe deer Capreolus capreolus. Brown hare activity was studied in natural conditions as well as in a fenced area that excluded terrestrial predators and competitors. Free-ranging hares developed a more nocturnal behavior to avoid diurnal predators (i.e., domestic carnivores and martens). Although high temporal overlap was observed between free-ranging brown hares and both red foxes (82%) and roe deer (81%), hares avoided fox by being more active on darkest nights, as well as avoided roe deer through spatial partitioning. We suggest that hares may adapt their spatiotemporal behavior to avoid potential predators and competitors.

Foraging animals have several tools for managing the risk of predation, and the foraging games between them and their predators. Among these, time allocation is foremost, followed by vigilance and apprehension. Together, their use influences a forager's time allocation and giving-up density (GUD) in depletable resource patches. We examined Allenby's gerbils (Gerbilus andersoni allenbyi) exploiting seed resource patches in a large vivarium under varying moon phases in the presence of a red fox (Vulpes vulpes). We measured time allocated to foraging patches electronically and GUDs from seeds left behind in resource patches. From these, we estimated handling times, attack rates and quitting harvest rates (QHRs). Gerbils displayed greater vigilance (lower attack rates) at brighter moon phases (full < wane < wax < new). Similarly, they displayed higher GUDs at brighter moon phases (wax > full > new > wane). Finally, gerbils displayed higher QHRs at new and waxing moon phases. Differences across moon phases not only reflect changing time allocation and vigilance, but changes in the state of the foragers and their marginal value of energy. Early in the lunar cycle, gerbils rely on vigilance and sacrifice state to avoid risk; later they defend state at the cost of increased time allocation; finally their state can recover as safe opportunities expand. In the predator–prey foraging game, foxes may contribute to these patterns of behaviours by modulating their own activity in response to the opportunities presented in each moon phase.

Analyses of temporal partitioning and overlaps in activity rhythms are pivotal to shed light on interspecific coexistence between similar species or prey and predators. In this work, we assessed the overlap of activity rhythms between the Eurasian beaver Castor fiber and its potential competitors and predators through camera trapping in an area in Central Italy. Interspecific overlaps of temporal activity patterns were estimated for the beavers, potential predators (the red fox Vulpes vulpes and the grey wolf Canis lupus), and a potential competitor, the coypu Myocastor coypus. The beavers showed a mostly crepuscular behaviour. Although high temporal overlap was observed between the Eurasian beavers and the red foxes and grey wolves, the activity of the beavers did not overlap with that of the predators. Accordingly, the beavers were more active on the darkest nights, i.e., avoiding bright moonlight.

Rodents make foraging decisions by balancing demands to acquire energy and mates with the need to avoid predators. To identify variations in the risk of predation, nocturnal rodents may use moonlight as a cue of risk. Moonlight avoidance behaviors have been observed in many nocturnal rodent species and are widely generalized to small mammals. However, most prior studies have been limited to 1 species or 1 study site, or occurred in modified habitats. We evaluated desert rodent activity patterns in natural habitats from 1999 to 2006 at 62 study sites across the Great Basin Desert of western North America. Rodent activity was examined by livetrapping in open habitats, using the presence of the sand-obligate kangaroo mouse (Microdipodops) as a habitat indicator. Activity patterns were assessed on 69 nights with clear skies and compared to corresponding moonlight values (moon phase and brightness) to evaluate the frequency of moonlight avoidance. Analyses of total activity of all species in the rodent assemblage relative to moonlight showed a distinct nonrandom (triangular-shaped) pattern but no significant correlations. However, individual genera of desert rodents responded differently to moonlight. Only kangaroo rats (Dipodomys) displayed significant moonlight avoidance patterns; they were maximally active at significantly different moonlight levels and avoided bright moonlight to a greater extent than co-occurring rodents. Moonlight seemed to limit the activity of kangaroo rats most strongly on bright nights during waxing moon phases and summer seasons, but not significantly during the spring or fall seasons, or during waning moons. Rather than avoiding moonlight, the activity of deer mice (Peromyscus), pocket mice (Perognathus), and kangaroo mice may be governed by changes in competition with kangaroo rats. Differences in the body size, locomotion, and space use of kangaroo rats relative to other rodents may explain why different moonlight responses were detected, especially if these traits alter how rodents perceive risk from bright moonlight. These findings indicate that moonlight avoidance may be a specialized trait of kangaroo rats rather than a general behavior of nocturnal desert rodents in the Great Basin.

Urban areas not only provide wildlife with new ecological niches, in terms of food availability, human protection and den sites but also they increase the possibility of conflict with man. Despite being a protected species in Italy, the crested porcupine is considered as an agricultural pest, with a tasty meat, thus widely poached. We studied food selection and other ecological factors shaping the ranging behaviour of crested porcupines in a suburban area, where a high poaching pressure could be expected. We monitored radio-tagged adult, paired crested porcupines throughout 1 year. Over 70% of individually marked porcupines were poached. Despite the local absence of predators, but in presence of poaching pressure, porcupines avoided clear moonlight nights and daylight activity, establishing dens in thorny thickets. Deciduous woodlands and shrubwood were positively selected for feeding throughout the year, while farmlands and fallows were underused. Although the crested porcupine has been confirmed as a “generalist” species in terms of food selection, with adaptations to dig underground storage organs, a strong preference for fruits and epigeal parts of plants was detected in our study. Porcupines evolved in Asia and Africa with a number of competing grazing herbivores, as well as in presence of a heavy predation risk leading to development of quills. This might have confined them to exploit roots and rhizomes as food, as well as scrub habitats for protection. Our results suggest that porcupines can revert to the use of optimal food resources, when local selective forces allow it.

The hypothesis that fluorescence in scorpions functions in the detection of ultraviolet light was tested. We reduced the fluorescence of scorpions by prolonged exposure to ultraviolet light on a 16:8 h light:dark cycle and compared their activity levels and light environment choices to unmodified scorpions in simple arenas that were half in shadow and half exposed to light. Three different lighting conditions were tested: infrared (IR) light only, IR + ultraviolet light and IR + white light. Treatments were illuminated by infrared light for videotaping. Activity level was measured by the number of transitions from the exposed to shadowed regions, and choice was measured by the percentage of time spent in the shadowed portion of the arena. Under IR + ultraviolet light, fluorescent scorpions reduced their activity levels and the variance in habitat choice increased, compared with reduced-fluorescence scorpions. There were no differences between fluorescent and non-fluorescent scorpions in the IR only condition or in the IR + white light condition. This is interpreted as evidence that fluorescence aids in the detection of and response to ultraviolet light, and possible implications of this result in natural habitats are discussed. This is the first experimental demonstration of a possible function for scorpion fluorescence.

The foraging decisions of animals are often influenced by risk of predation and by the renewal of resources. For example, seed-eating gerbils on sand dunes in the Negev Desert of Israel prefer to forage in the bush microhabitat and during darker hours due to risk of predation. Also, daily renewal of seed resource patches and timing of nightly foraging activity in a depleting environment play important roles in species coexistence. How these factors influence the timing of gerbil foraging was investigated by quantifying foraging activity in seed resource patches that were experimentally renewed hourly during the night. Gerbils showed strong preference for the safe bush microhabitat and foraged less in response to high levels of illumination from natural moon light and from artificial sources. It is demonstrated here for the first time that gerbils also responded to temporal and spatial heterogeneity in predatory risk through their timing of activity over the course of each night. Typically, gerbils concentrated their activity early in the night, but this changed with moon phase and in response to added illumination. These results can be understood in terms of the nature of patch exploitation by gerbils and the role played by the marginal value of energy in determining the cost of predation. They further show the dynamic nature of gerbil foraging decisions, with animals altering foraging efforts in response to time, microhabitat, moon phase, illumination, and resource availability

In nature, animals are exposed to a broad range of threats imposed by predators, which may strongly influence the ecology of prey species directly or indirectly by affecting their behavior via fear of predation. Here, we studied wood mice behavioral and physiological responses to simulated predation risk. Risk avoidance was analyzed by live trapping with control traps and traps treated with feces of common genet (direct cue of risk) under new moon nights and following by simulated full moon conditions (indirect cue). The time devoted to foraging behavior and capture time were analyzed by video recording mice activity around traps. Food intake was calculated based on the amount of bait remaining in each trap. Fecal corticosterone metabolites (FCMs) were measured by enzyme-immunoassay as indicators of physiological stress responses. Fewer wood mice were captured during full moon, yet only non-breeding adult males clearly avoided common genet odor. Mice were captured sooner at night during the simulated full moon conditions and later in predator-treated traps. Foraging activity was lower when individuals faced predator's feces, but neither food intake nor FCM levels were affected by predation risk cues. Direct and indirect cues of predation risk selectively affected wood mice behavior, although behavioral responses seem to be modulated by different costs-benefit balances related to the individual's perception of risk. The lack of physiological responses to predation risk cues suggests that wood mice did not perceive them as reliable stressors or the response was too small or transient to be measured by FCM.