Lynx Activity Research Articles

Reduced human disturbance increases diurnal activity in wolves, but not Eurasian lynx

Wildlife in the Anthropocene is increasingly spatially and temporally constrained by lethal and non-lethal human disturbance. For large carnivores with extensive space requirements, like wolves and Eurasian lynx, avoiding human disturbance in European landscapes is challenging when sufficient space with low disturbance is rarely available. Consequently, investigating behavioural adjustments to human presence is critical to understanding the capacity to adapt to human disturbance. We hypothesised that under low human disturbance conditions, large carnivores would adjust their temporal behaviours to make use of daytime, and when daytime human disturbance is high, they would opt for nocturnality. Using camera trap data from nine European study sites along a gradient in human disturbance, we analysed wolf and Eurasian lynx activity patterns. Our data spanned multiple years, 2014 – 2022, and we focused our analysis on September until April, when most large carnivore monitoring takes place. For wolves, our analysis revealed i) increased nocturnal behaviour, ii) decreased diurnal overlap with increasing human activity, and iii) a significant association between a higher probability of nocturnal activity and increasing human disturbance. For Eurasian lynx, we found iv) consistently nocturnal behaviours across all study sites, regardless of human disturbance, and v) no association between human disturbance and increased probability of being active during the night. Our results show that wolves can adjust to diurnal or cathemeral behaviours under low human disturbance, but shift to nocturnality when human disturbance increases. Eurasian lynx, however, consistently maintain their nocturnal behaviour, which we attribute to their principal hunting strategy of stalk and ambush. If human disturbance constrains large carnivore activity to nighttime, it could influence their interactions with prey, leading to cascading effects in the ecosystem. On the other hand, maintaining nocturnal behaviours in human-dominated landscapes may benefit large carnivore conservation, by decreasing negative interactions with humans thereby contributing to a landscape of coexistence.

When death comes: linking predator-prey activity patterns to timing of mortality to understand predation risk.

The assumption that activity and foraging are risky for prey underlies many predator-prey theories and has led to the use of predator-prey activity overlap as a proxy of predation risk. However, the simultaneous measures of prey and predator activity along with timing of predation required to test this assumption have not been available. Here, we used accelerometry data on snowshoe hares (Lepus americanus) and Canada lynx (Lynx canadensis) to determine activity patterns of prey and predators and match these to precise timing of predation. Surprisingly we found that lynx kills of hares were as likely to occur during the day when hares were inactive as at night when hares were active. We also found that activity rates of hares were not related to the chance of predation at daily and weekly scales, whereas lynx activity rates positively affected the diel pattern of lynx predation on hares and their weekly kill rates of hares. Our findings suggest that predator-prey diel activity overlap may not always be a good proxy of predation risk, and highlight a need for examining the link between predation and spatio-temporal behaviour of predator and prey to improve our understanding of how predator-prey behavioural interactions drive predation risk.

Hares, Humans, and Lynx activity rhythms: Who avoids whom?

Hares, Humans, and Lynx activity rhythms: Who avoids whom?

European Roe Deer Increase Vigilance When Faced with Immediate Predation Risk by Eurasian Lynx

AbstractPrey animals must balance antipredatory behaviour with foraging behaviour. According to the risk allocation hypothesis, prey increase antipredatory behaviour and reduce foraging activity during pulses of high risk, but with continuous risk, other activities must continue and antipredatory behaviour decreases despite the risk. We studied the impact of lynx presence on the vigilance behaviour of wild roe deer under conditions of (i) a pulsed elevated risk by experimentally spreading lynx urine as an olfactory cue, and (ii) continuous risk by comparing an area where lynx was eradicated 160 years ago to an area where lynx has been re‐introduced 30 years ago. Roe deer were extremely vigilant in response to the predator olfactory cue; however, roe deer vigilance did not differ measurably among areas with or without potential lynx presence. Deer were more vigilant before sunset than during the night at both study areas, probably due to long‐term adaptation of roe deer to human hunting during daytime. Vigilance decreased from August to September even though activity of lynx increases in autumn, which may be a result either of increased foraging due to decrease in food quality in autumn, or of changes in social organization of the deer. Our results suggested that the degree of vigilance depends on environmental cues. We found that roe deer respond to lynx urine despite a long absence of lynx in the ecosystem. Our results support the risk allocation hypothesis for responses to pulses of high risk but not for responses to continuous elevated levels of risk.

Activity patterns of Eurasian lynx are modulated by light regime and individual traits over a wide latitudinal range.

The activity patterns of most terrestrial animals are regarded as being primarily influenced by light, although other factors, such as sexual cycle and climatic conditions, can modify the underlying patterns. However, most activity studies have been limited to a single study area, which in turn limit the variability of light conditions and other factors. Here we considered a range of variables that might potentially influence the activity of a large carnivore, the Eurasian lynx, in a network of studies conducted with identical methodology in different areas spanning latitudes from 49°7′N in central Europe to 70°00′N in northern Scandinavia. The variables considered both light conditions, ranging from a day with a complete day–night cycle to polar night and polar day, as well as individual traits of the animals. We analysed activity data of 38 individual free-ranging lynx equipped with GPS-collars with acceleration sensors, covering more than 11,000 lynx days. Mixed linear additive models revealed that the lynx activity level was not influenced by the daily daylight duration and the activity pattern was bimodal, even during polar night and polar day. The duration of the active phase of the activity cycle varied with the widening and narrowing of the photoperiod. Activity varied significantly with moonlight. Among adults, males were more active than females, and subadult lynx were more active than adults. In polar regions, the amplitude of the lynx daily activity pattern was low, likely as a result of the polycyclic activity pattern of their main prey, reindeer. At lower latitudes, the basic lynx activity pattern peaked during twilight, corresponding to the crepuscular activity pattern of the main prey, roe deer. Our results indicated that the basic activity of lynx is independent of light conditions, but is modified by both individual traits and the activity pattern of the locally most important prey.

Canada Lynx (<em>Lynx canadensis</em>) detection and behaviour using remote cameras during the breeding season

The efficacy of surveys in detecting Canada Lynx (Lynx canadensis) can vary considerably by geographic area. We conducted surveys using digital passive infrared trail video-cameras from January to April 2013, during the breeding season of the Canada Lynx, in the John Prince Research Forest in central British Columbia. We used snow-track surveys to test the efficacy of our camera surveys. We measured trail camera detection rates by survey week and location and we noted Canada Lynx activity and behaviours recorded by the cameras. The detection rate increased between January and April, reaching a peak of 8 Canada Lynx/100 camera-days in early April. Canada Lynx spent more time at camera sites displaying behaviours such as scent-marking and cheek-rubbing in late March. The combination of both snow-track and trail camera surveys was especially effective, with Canada Lynx detected at 77% of all monitored sites. Depending on survey objectives, it may be beneficial to conduct camera as well as other non-invasive survey methods for Canada Lynx during the breeding season, when survey efficacy and detection rates are maximized.

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

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.

Seasonal and daily activity patterns of free‐living Eurasian lynx Lynx lynx in relation to availability of kills

Activity patterns of predators are influenced by several factors including season and temperature as well as the availability of prey species. We investigated the activity of six free‐living Eurasian lynx Lynx lynx (four males and two females without kittens) in the Bohemian Forest along the border between Germany and the Czech Republic. The lynx were tagged with GPS‐collars with acceleration sensors in 2005, 2010 and 2011. Activity was measured every 5 minutes on 1,360 days (403,467 measurements) to detect circadian activity patterns. All lynx were predominantly crepuscular, with an average activity of 8.9 hours/day and with the lowest activity at midday. The activity patterns of male and female lynx did not differ significantly. With each 10°C increase in the mean air temperature per day, the lynx decreased their daily activity by 30 minutes. In winter, activity was concentrated at dusk. We also investigated whether lynx activity was influenced by the availability of freshly killed roe deer Capreolus capreolus, red deer Cervus elaphus or European hare Lepus europaeus. We compared the activity data of 357 days with a kill (109 recorded kills) and 316 days without a kill and calculated generalised additive mixed models. On days with a kill, the lynx were 3.3 hours/ day less active than on days without a kill. The activity on consecutive days with a killed prey did not differ. The pattern of activity on days with a kill differed little from the pattern of activity on days without a kill.

Influence of tourism and traffic on the Eurasian lynx hunting activity and daily movements

Human presence influences survival of large carnivores in several ways and even outdoor activities can be a source of disturbance. As ungulate prey provide the Eurasian lynx (Lynx lynx) with food for several nights and the pattern of lynx activity is mainly shaped by searching for and consuming large prey, the need to move decreases strongly while the prey is eaten. However, during the day, human activity may drive lynx to move to safe shelters and habitat features such as dense vegetation may increase tolerance. In the Bohemian Forest (Czech Republic), we found 116 prey killed by five GPS–collared lynxes. We tested whether the kill sites were located farther from roads or tourist trails than a set of randomly generated locations and whether presence of roads or tourist trails and habitat structure influenced the distance ‘kill site to daytime resting sites’. At night, with low human activity, lynxes did not avoid roads and even selected the surroundings of tourist trails. The distance ‘kill site to daytime resting sites’ correlated negatively with presence of habitat concealment and distance to tourist trails, suggesting that outdoor activities may have to be considered in lynx management plans.

Circadian Activity Patterns of Canada Lynx in Western Montana

Abstract: We recorded activity data for 6 male and 5 female lynx in winter and 3 male and 6 female lynx during summer in western Montana, USA, using motion‐sensitive radiocollars. Lynx diel activity appeared to vary by sex, season, and reproductive status. During summer, male lynx exhibited a crepuscular activity pattern, whereas females with kittens remained active throughout the photoperiod. During winter, lynx of both sexes were most active during the afternoon and early evening. Although we observed no evidence that predation risk drove lynx activity patterns, such patterns may be a function of kitten‐rearing activity, thermoregulatory strategies, and foraging behavior.

Space use by Eurasian lynx in relation to reindeer migration

Semi-domesticated reindeer ( Rangifer tarandus tarandus (L., 1758)) is the primary prey of Eurasian lynx ( Lynx lynx (L., 1758)) in northern Sweden. The reindeer migrate between winter range in the forest and summer range in the mountains, a distance of 100–150 km. We studied space use by Eurasian lynx in relation to seasonal fluctuations of their primary prey in northern Sweden. The seasonal activity range sizes for males and single females were not significantly different between the three periods of the year (December–April, May–July, and August–November). The activity range size for family groups (i.e., female with kittens) was significantly smaller during summer than during autumn and winter. The mean distance between the centre of an individual lynx's activity range in one season to the centre of the activity range in the season immediately following did not differ significantly between seasons; mean distances were 6.6 km for males, 7.3 km for single females, and 8.4 km for family groups. This is about one order of magnitude shorter than the distance between summer and winter ranges for reindeer (100–150 km). The grand mean overlap between a lynx's activity range in one season and the next season was more than 40%. Hence, Eurasian lynx in northern Sweden do not appear to move with the migrating semi-domesticated reindeer.

Variation in daily activity of the free‐living Eurasian lynx (Lynx lynx) in Białowieża Primeval Forest, Poland

AbstractThe pattern of daily activity of the Eurasian lynx Lynx lynx L. was studied by radio‐telemetry in the Białowieża Primeval Forest (eastern Poland). Radio‐tracking of 18 lynx was done by 24‐h continuous observations and by sampling on a daily basis. Lynx were active mostly at night. There was generally one peak of activity between 15:00 and 07:00 which, however, decreased slightly between 20:00 and 22:00. On average, lynx were moving for 6.5 h/day. In males, 73% of locomotory activity occurred at night, whereas females were active as long during the daylight as during the night. Movement bouts of females were shorter than those of males (1.1 h vs 2.1 h) but more frequent (4.2 vs 3.0 bouts/day). General patterns of activity of females with and without kittens were similar. However, females with kittens were active twice as long per day than non‐reproducing females. In May–August (intensive care for kittens), reproducing females were active 26% longer than in September–April. Non‐reproducing females showed the opposite pattern; they were active 60% less in May–August compared with September–April. Locomotory activity of adult males was 30–70% longer in January–March (mating season) than in other seasons. The pattern of lynx activity was shaped predominantly by searching for and consuming large prey. The lynx were active for the longest time during the days when they searched for prey but made no kill (12.5 h/day on average) and for the shortest time on the first day after killing a deer (1.6 h/day). Their moving activity increased steadily in the following days, reaching 6.8 h/day on the fourth day of consuming a killed deer. Ambient temperatures and rainfall did not significantly affect lynx activity, but there was little movement most of the time in heavy rain, and all day when the temperature was above 30 °C.

The situation of the lynx ( Lynx lynx ) in Austria

Nine wild lynx were translocated from the Carpathian Mountains to Styria between 1977 and I979 in order to reintroduce this species into the Austrian Alps. Field projects continued until 1982, when monitoring of the released animals ceased. After five years the lynx had spread as far as 120 km from the site of rc-introduction, but observations wwc few and scldom confirmed. On- ly in the district of Carinthia, where lynx activity was strongest, did the hunters' association gathcr data by means of observation report forms. Lynx reports became scarce during the 1980s, and re-in- troduction seemed to have failed. when in 19x9 a series of sheep kills by lynx in Carinthia re-acti- vated the interest of the public in the lynx, and more observations were reported. The Carinthian Ilunters' Association formed a lynx group to verify these reports. More intensive training of the men- bers of the group since 1992 has revealed that much of the information collected was not valid proof of lynx presence. There is no established lynx population in the Austrian Alps a1 present. The moat rcgiilar and reliable observations come from the original region of the releases and from wuthern Carinthia, whcrc lynx immigrating from Slovcnia may sustain the Austrian population.

Environmental Determinants of Circadian Activity of Free-Ranging Iberian Lynxes

From February 1983 to May 1985, 12 Iberian lynxes ( Lynx pardinus ) (six adults and six juveniles) were radiotracked at hourly intervals for 114 24-h periods at Donana National Park, southwestern Spain. Nine environmental factors were related, by season and age class, to 12 indices of daily activity of lynxes derived from movement rates and pulses of the motion sensor in the transmitters. Coefficients of determination were higher in winter and summer than in spring. Juvenile lynxes appeared more sensitive to environmental factors than adults. Photoperiod had a major influence ( R 2 = 29%) on circadian activity pattern throughout the year. Environmental factors significantly related to activity of lynxes during winter were maximum temperature, pressure changes, evaporation, and moonphase. In summer, important variables were maximum temperature, moonphase, hours with moonlight, and high pressures. In spring, only rainfall and temperature (minimum and maximum) showed a slight but significant influence on activity of lynxes. Although some climatological factors may have a direct effect on the circadian activity of Iberian lynx, others (e.g., moonlight) may act indirectly by influencing the activity of the Mediterranean rabbit, the lynx's main prey.