Living on the edge - circadian habitat usage in pre-weaning European hares (Lepus europaeus) in an intensively used agricultural area

Abstract

Over the last decades, the European hare (Lepus europaeus) has become the subject of many interdisciplinary studies due to the sharp Europe-wide population decline. In European hares, the first stage of life until weaning and the subsequent dispersal have been sparsely studied, in particular, habitat selection, movements and survival rate, as juveniles´ precocial lifestyle is dominated by concealment, motionlessness and inconspicuousness. In this study, free-living juvenile European hares (leverets) were detected systematically by thermography (n = 394), radio-tagged or marked (n = 122) from birth until the fifth week of life to research their habitat usage and pre-dispersal movements. The day-resting places and night locations, as well as the distance moved by leverets with aging, were evaluated by generalized linear mixed effect models. In addition, the habitat preference was assessed by a conservative use-availability analysis. Up to the fifth week of life, 30.5% of all leverets used cultivated areas in the daytime. In contrast, the remaining 69.4% animals inhabitated linear or small planar structures in the daytime, with the edges of field tracks, hedges and some ruderal structures clearly being preferred. At nighttime, 93% of all juveniles, which occupied linear structures in the daytime, used the adjoining fields up to 20 m away from the next linear structure. Nocturnal distances of more than 60 m to the next edge rarely occurred before the end of the pre-weaning phase. The time of day and age have a significant influence on the distance moved by juvenile hares. With increasing age, leverets moved less during the day and roamed further at night. The results are largely consistent with the behavioral patterns found in the few previous studies on pre-weaning European hares and show the importance of hiding places for leverets in early life stages. This study should contribute to a better understanding of behavior in juvenile life-history stages of European hares that may help to identify vulnerable phases in their lifecycle. In addition, the findings can refine existing population models and improve conservation efforts.

Survival rates on pre-weaning European hares (Lepus europaeus) in an intensively used agricultural area

“…This can be explained by the fact that leverets of the genus Lepus leave their birth area between the second and fourth day of life to find their own daily hiding place (Broekhuizen and Maaskamp 1976;O'Donoghue and Bergman 1992;Rongstad and Tester 1971). In this study, almost all animals of the age class up to 4 days were found on bare soil or in fields with a low vegetation height (Voigt and Siebert 2019). Taken together, the change of place from the area of birth and the low coverage can lead to a rise in mortality rate due to an increased conspicuousness and visibility for predators.…”

“…A recent study has shown that leverets performed a pronounced change in habitat between daytime and nighttime (Voigt and Siebert 2019), which is related to nursing behaviour. This fact was taken into account in the analysis.…”

“…Although the overall loss rate of pre-weaning hares is quite high, there does not seem to be any specific endangered points in time for this period, and mortality affects all age groups equally. During the day, leverets hide at a variable distance from the suckling site (Broekhuizen and Maaskamp 1976), preferably at the margins of field paths and ditches or hedges (Voigt and Siebert 2019), and leave this place only for a short period of time to be suckled. During the nursing period, which usually lasts 4 to 5 weeks (Broekhuizen and Maaskamp 1980), leverets start to feed on green fodder during the second week of life (Martinet and Demarne 1984).…”

“…Indeed, only in recent years have broader research efforts led to a better understanding of these interrelationships (e.g. Hummel et al 2017;Jensen 2009;Meichtry-Stier et al 2014;Schai-Braun et al 2015;Smith et al 2005;Voigt and Siebert 2019;Zellweger-Fischer et al 2011).…”

The Health and Future of the Six Hare Species in Europe: A Closer Look at the Iberian Hare

“…This mortality is due to, among other factors, agricultural landing, diseases, and predation [11]. Juvenile mortality of the European hare may reach 90% [36]. Data on the Iberian hare suggest that nearly 60% of the young die, corresponding to an increase of 40% in the population numbers [14].…”