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A note on the effect of the full moon on the activity of wild maned wolves, Chrysocyon brachyurus
Abstract
It is well established in the scientific literature that animal prey species reduce their activity at times of high predation risk. In the case of nocturnal animals this occurs when there is a full moon; however, the response of predators to the changes in their prey behaviour is relatively unknown. Two responses are possible: (1) increase in search effort to maintain food intake; or (2) decrease in distance travelled due to either: (a) an effort to conserve energy or (b) increased kill efficiency. Using GPS tracking collars we monitored the distances travelled (which is representative of search effort) by three maned wolves during the night of the full and new moon for five lunar cycles (during the dry season). A Wilcoxon matched-paired test showed that the maned wolves travelled significantly less during the full compared to the new moon (p < 0.05). On average, during the 10 h of darkness during a full moon maned wolves travelled 1.88 km less than on a new moon. These data suggest that maned wolves respond to temporally reduced prey availability by reducing their distance travelled.
... The behavior of predators is often driven by the behavior of prey species [15], therefore, as prey alter their activity around lunar phases, predators may adjust their behavior accordingly. In response to decreased activity of prey species, predators may respond by either increasing effort expended on searching for prey or reduce distance traveled to conserve energy and increase efficiency [16]. Red foxes (Vulpes vulpes) and maned wolves (Chrysocyon brachyurus) often reduce movement during full moons, likely to conserve energy during periods of less prey availability [16,17]. ...
... In response to decreased activity of prey species, predators may respond by either increasing effort expended on searching for prey or reduce distance traveled to conserve energy and increase efficiency [16]. Red foxes (Vulpes vulpes) and maned wolves (Chrysocyon brachyurus) often reduce movement during full moons, likely to conserve energy during periods of less prey availability [16,17]. Conversely, predators may also increase activity during new moons when visibility is lowest. ...
... Activity of ocelots and their prey species overlapped in relation to lunar phase and any differences in activity of prey were thought to relate to differences in visual ability of the species [14,51]. A similar pattern of reduced movement during full moons was observed in maned wolves, also attributed to temporal differences in prey availability [16]. Data on preferred prey within our study area were not collected during the duration of our study, however, we may expect similar overlap between ocelots and their prey species which may suggest greater activity during darker nights and explain the greater movement rate of ocelots during new moons. ...
Various landscape and environmental factors influence animal movement and habitat selection. Lunar illumination affects nocturnal visual perception of many species and, consequently, may influence animal activity and habitat selection. However, the effects of varying moon stage may differ across taxa. Prey species often reduce activity during highly visible periods of night while predators may increase activity or alter their habitat use. Ocelots (Leopardus pardalis) and bobcats (Lynx rufus), two nocturnal predatory felids that coexist in southern Texas, may also alter their behavior in response to the phase of the moon. To evaluate the effects of lunar phase on habitat selection of ocelots and bobcats, we executed a step selection analysis using high-frequency GPS-telemetry data collected on each species (ocelot, N = 8; bobcat, N = 13) in southern Texas during 2017–2021 and compared step length during new versus full moons. We predicted that ocelots would increase use of dense thornshrub to reduce their visibility during a full moon. However, as bobcats are habitat generalists and are more active during crepuscular periods, we predicted less influence of moon phase on activity. Ocelots did not alter habitat selection in response to lunar phase but moved shorter distances during full moon phases. Conversely, bobcats selected for greater vegetation cover during full moons, possibly to facilitate hunting during brighter periods, but exhibited no difference in movement across lunar phase. We provide, to our knowledge, the first example of habitat selection by predators in relation to lunar phase and show differences across new versus full moons by ocelots and bobcats such that ocelots alter step length but not habitat selection while bobcats altered habitat selection but not step length in response to shifting lunar phase. Further, we suggest the high potential for ocelot-vehicle collisions on darker nights due to increased movement by ocelots and poor visibility for drivers.
... Vasquez 1994;Brown & Kotler 2004;Griffin et al. 2005). As a consequence, predators are expected to be more active around the time of the full moon because of two opposing factors (but see Sábato et al. 2006): (1) they must search intensively for prey that is concealed and attentive, because on bright moonlit nights prey species shift to more apprehensive foraging strategies ) and/or are less active (Clarke 1983;Sábato et al. 2006;Berger-Tal et al. 2010) and (2) they benefit from higher light levels when seeking prey (Clarke 1983;Kotler et al. 1988), as predators are most lethal during moonlit hours of the night (Kotler et al. 2002). ...
... Vasquez 1994;Brown & Kotler 2004;Griffin et al. 2005). As a consequence, predators are expected to be more active around the time of the full moon because of two opposing factors (but see Sábato et al. 2006): (1) they must search intensively for prey that is concealed and attentive, because on bright moonlit nights prey species shift to more apprehensive foraging strategies ) and/or are less active (Clarke 1983;Sábato et al. 2006;Berger-Tal et al. 2010) and (2) they benefit from higher light levels when seeking prey (Clarke 1983;Kotler et al. 1988), as predators are most lethal during moonlit hours of the night (Kotler et al. 2002). ...
... seals versus sharks: Trillmich & Mohren 1981; deer mice and gerbils versus owls : Clarke 1983;Kotler et al. 1991;Schmidt 2006;Berger-Tal et al. 2010;bats versus owls: Law 1997; elk, Alces alces, versus wolves, Canis lupus: Creel et al. 2008; red fox, Vulpes vulpes, versus striped hyaenas, Hyaena hyaena: Mukherjee et al. 2009) and birds (e.g. auklets versus gulls : Nelson 1989; desert rodents versus owls: Price et al. 1984; petrels versus skuas: Mougeot & Bretagnolle 2000), less information is available on the response of predators to moonlight (but see Grassman et al. 2005;Di Bitetti et al. 2006;Sábato et al. 2006;Mukherjee et al. 2009). Study of the effects of moonlight on the behaviour of predators is important mainly because predator behaviour is not primarily driven by the ultimate risk of predation (especially in the case of top predators, which do not have intraguild predators; Lourenço et al. 2011); in addition, this topic has received little attention in behavioural ecology research. ...
The effects of moon phases on predator–prey relationships have so far been mainly investigated from the prey’s perspective. The response of a predator to moon phases may represent a complex trade-off between overcoming the antipredator strategies of its prey and balancing other needs/constraints (e.g. individual status and condition). We explored the year-round effects of the lunar cycle on radiotagged breeders and dispersers of an avian predator, the eagle owl, Bubo bubo, from the perspective of movement patterns, foraging effort and display intensity. In general, the movements of breeders suggested an increase in activity around the time of the full moon. This may be related to an increase in both the time needed to detect prey (on brighter nights prey are more concealed and wary) and the time the predator devotes to visual displays (the full moon increases the conspicuousness of signalling). However, hunting activity also peaked during dark nights, when prey might be harder to see. In contrast, the behaviour of dispersing owls was not affected by lunar cycles. Natal dispersal involves potentially dangerous crossings of unknown landscapes (which probably requires similar effort throughout the year), and because of the absence of reproductive constraints should not require greater activity when food profitability is low. The status of individuals may thus play a crucial role in cost–benefit considerations and behavioural decisions, by directly affecting the time and effort individuals need to allocate to various activities related to their most immediate needs (e.g. breeding successfully versus overcoming dispersal costs).
... Vasquez 1994; Brown and Kotler 2004; Griffin et al. 2005). Indeed, on bright moonlit nights: (1) prey shift to more apprehensive foraging strategies (Kotler et al. 2010), and/or (2) are less active (Clarke 1983; Sábato et al. 2006; Berger-Tal et al. 2010). Consequently, selection pressures likely exist on predators to be more active (but see Sábato et al. 2006), as they should search more intensively for prey (although this activity increase depends on the way predators search for their prey, and is ...
... Indeed, on bright moonlit nights: (1) prey shift to more apprehensive foraging strategies (Kotler et al. 2010), and/or (2) are less active (Clarke 1983; Sábato et al. 2006; Berger-Tal et al. 2010). Consequently, selection pressures likely exist on predators to be more active (but see Sábato et al. 2006), as they should search more intensively for prey (although this activity increase depends on the way predators search for their prey, and is ...
... Actually, predators are most lethal during the brightest hours of the night (Kotler et al. 2002). Despite the longterm interest in the influence of lunar phases on prey behaviour and antipredator strategies (reviewed in Penteriani et al. 2011), less information is available on the response of predators to moonlight (but see Grassman et al. 2005; Di Bitetti et al. 2006; Sábato et al. 2006; Mukherjee et al. 2009). In addition, the interest in the response of predators to moon phases is increased by the evidence that predators at the same trophic level can prey upon each other (with or without consumption; Polis and Holt 1992), a phenomenon that has paramount consequences (e.g. ...
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.
... Similarly, human activities may contribute to variations in movement patterns (Coman et al. 1991;Theuerkauf et al. 2001;Fox 2006;Gehrt et al. 2009) by providing alternative habitats with easily obtainable resources (Contesse et al. 2004;Atwood Introduction Moon phase and the associated differences in ambient light are known to alter the movement of nocturnal animals (Frid and Dill 2002;Chakraborty 2020;Mendes et al. 2020), but have only rarely been investigated as factors affecting mesopredator movement. Canids, although primarily dependent on olfactory senses, are considered active coursing hunters that may be dependent on visual cues (Loveridge and Macdonald 2003;Thererkauf et al. 2003;Rasmussen and Macdonald 2012), particularly during periods when olfactory cues are difficult to detect (e.g. during periods of high wind speeds; Ruzicka and Conover 2011). Canids should therefore take advantage of periods when the likelihood of visually detecting prey is increased, namely during brighter nights when prey are easier to detect (Wells and Lehner 1978;Ferguson et al. 1988;Melville et al. 2020). ...
... Improved prey detection during brighter nights should therefore result in reduced movement, as seen by Sábato et al. (2006) who noted that the reduced movement by maned wolves (Chrysocyon brachyurus) during brighter nights could be a result of increased hunting success that required less movement to maintain metabolic requirements. However, it was also noted that the observed decreased travel distance during full moon could be a result of reduced availability of rodents and supplemental feeding of everbearing fruits, which required less movement to obtain. ...
An animal’s ability to traverse a landscape and utilise available resources is vital for its survival. The movement patterns of an animal provide insight into space use, activity patterns and ecological requirements that are imperative for successful farming and wildlife management practices. Home ranges are often used as a measurement of space use, which provides a quantitative value of an animal’s movement patterns in relation to various biological factors. A factor that is often overlooked in the analysis of movement patterns is the effect of moon phase, despite its known impact on the activity and hunting success of nocturnal predators. We live-trapped, radio-collared and monitored five black-backed jackals (Canis mesomelas) in the Golden Gate Highlands National Park, South Africa, between 2018 and 2019 to determine the impact of various environmental factors on movement patterns. Annual home ranges varied between individuals, were larger in subadults and overlapped between three jackals. Space use and travel velocity suggested a crepuscular activity pattern with a reliance on nocturnal activity and limited diurnal activity. Individual space use suggested variation between moon phases, although overall variation was negligible. Jackals travelled farther during new moon, compared with full moon, with the most notable difference between 23:00 and 04:00. Our results suggest that jackal behaviour does not align with the predation risk hypothesis. Space use and travel velocities varied between seasons, possibly because of differences in activity during mating and pupping periods. Our study confirms the flexibility in jackal space use and suggests a possible relationship with moon phase. To properly understand movement patterns at an individual and population level, we encourage additional research about jackals and various environmental factors via multidisciplinary collaborations.
... Studies on activity patterns in vertebrates, both in captivity and in the wild, provide knowledge that helps establish the status of the circadian system and serve as tools to estimate animal welfare (Sutherland 1998). Different physiological and behavioral variables have been shown to exhibit daily rhythmicity; in particular, daily distribution of locomotor activity has been studied extensively in numerous species (Piccione et al. 2008a(Piccione et al. , 2008b(Piccione et al. , 2011a(Piccione et al. , 2011b(Piccione et al. , 2013a(Piccione et al. , 2013b(Piccione et al. , 2013cGiannetto et al. 2010Giannetto et al. , 2018Lanteri et al. 2016;Refinetti et al. 2016;Fries et al. 2017;Cerutti et al. 2018), but few studies have been conducted on the behavior of wild maned wolf (Sábato et al. 2006;Coelho et al. 2018). ...
... The loss of daily rhythmicity in the other two subjects can be attributed to the low value of robustness of rhythm of locomotor activity in this species, easily influenced by external noxae. There is evidence that the influence of different environmental synchronizers like social environment, human presence, interaction with competitors, food availability or time food uptake may lead to changes in the diurnal/nocturnal activity rhythm in maned wolves (Sábato et al. 2006; Barrera and Bentosela 2016;Coelho et al. 2018;Jones et al. 2018). Housing conditions and human presence have been showed to have an influence on the daily amount of activity in horse and sheep (Piccione et al. 2008c(Piccione et al. , 2011b. ...
The aim of this study was to evaluate the daily total locomotor activity in captive Chrysocyon brachyurus. Three maned wolves were housed individually under natural light–dark cycle and environmental conditions. In each animal, locomotor activity was monitoored for 30 days by means of an activity data logger (Actiwatch Cambridge©Neurotechnology, Cambridge, UK), applied on a neck collar. Locomotor activity was evaluated by visual inspection of actograms. The average amount of activity during light and dark phases and Cosine 20 Peak were calculated using Actiwatc Activity Analysis 5.06. Subject A was more active during the light phase, and subjects B and C were more active during the dark phase. The single cosinor method applied on the amount of activity recorded every hour showed a daily rhythm of locomotor activity only in subject B (2 years old). Acrophase was observed between 03:20 and 07:30, and robustness had a value between 37.00% and 63.40%. Only one subject due to their early withdrawal from its natural habitat, developed a manifest anthropic dependence, with a marked adaptation to the habitat of captivity presenting an anthropophilic behavior. This study would help to define more appropriate management and conservation strategies for this emblematic mammal of South America.
... Though the golden jackals were frequently seen around the burrows, their nocturnal activity significantly peaked between Bthird quarter^and Bnew moon^phase in KNP. Similarly, other canids have also shown this peak in activity, for, e.g., crab-eating fox (Yanosky and Mercolli 1990;Faria-Corrêa et al. 2009) and maned wolf in Brazil, wherein the latter traveled significantly more on nights of the new moon than compared to the full moon (Sábato et al. 2006). It is likely that the increased activity in the last quarter and new moon nights could be associated with a circumvention behavior including possible detection by prey and protection from predators (Yanosky and Mercolli 1990;Sábato et al. 2006). ...
... Similarly, other canids have also shown this peak in activity, for, e.g., crab-eating fox (Yanosky and Mercolli 1990;Faria-Corrêa et al. 2009) and maned wolf in Brazil, wherein the latter traveled significantly more on nights of the new moon than compared to the full moon (Sábato et al. 2006). It is likely that the increased activity in the last quarter and new moon nights could be associated with a circumvention behavior including possible detection by prey and protection from predators (Yanosky and Mercolli 1990;Sábato et al. 2006). ...
Availability and use of a natal burrow site is a prerequisite for survival, propagation, and breeding success for many burrow-dependent species. Among mammals, canids typically use existing burrows of other animals during the breeding season. The study describes the factors influencing the golden jackal (Canis aureus) in selecting appropriate burrows in Keoladeo National Park (KNP), India, including a description of site-specific habitat characteristics, microhabitat conditions, and the burrow-specific activities. Jackals had occupied 11 of the 47 recorded burrows and had chosen the area with more wood cover. The occupied burrows were found active throughout the day. The mean detections per day were significantly highest in the month of May for “rearing pups.” The nocturnal activity was associated with the lunar phase, with a significant peak between the “third quarter” to “new moon” phase. The intensity of the activity of adults and pups were analyzed across 6 weeks (April–May), wherein feeding, grooming, playing, and guarding significantly occurred between fourth and sixth weeks. The pups suckled every 8 h, and at about 3 weeks old, regurgitated food also became part of their diet. Jackal pups and adults spent an average of 103.60 and 36.13 min per day playing and guarding the burrows, respectively. Increased temperature with the day’s progression significantly reduced jackal’s activities and they retreated around 1200 h. Guarding of the burrows by adults significantly increased during night hours (0030–0500 h), when the pups are more susceptible to predation. Both the sexes participated in parental care activities, taking turns to guard the burrow, grooming, and playing with the pups. The study thus provides insights on the golden jackal’s natal site selection, observances, and use of sub-surface earthen refuges in semi-arid condition.
... Pesquisas envolvendo pequenos mamíferos já relacionaram fatores como fases lunares, pluviosidade, umidade relativa do ar com a atividade dos mesmos (Halle e Stenseth, 2000;Everts et al., 2004;Esbérard, 2007) e estudos envolvendo mamíferos de médio porte como Leopardus pardalis (Emmons et al., 1989), Chrysocyon brachyurus (Sábato et al., 2006) e Aotus azarai (Fernandez-Duque, 2004) constataram o efeito de diferentes fases lunares no período de atividade. O graxaim (Cerdocyon thous) é um canídeo com ampla distribuição na América do Sul, sendo encontrado desde o Uruguai e norte da Argentina até a Colômbia, ocupando diversos ambientes, sendo que no Brasil ocorre tanto em áreas de floresta como de campo (Berta, 1982;Nowak, 1999) e com exceção da Amazônia é encontrado em todos os biomas (Cerrado, Caatinga, Pantanal, Floresta Atlântica e Campos Sulinos) (Fonseca et al., 1996;Emmons e Feer, 1999;Reis et al., 2006). ...
... Entre as fases lunares, não ocorreu nenhuma relação com a atividade do graxaim, sendo que as duas fases com maior número de registros, a fase de lua nova e fase de lua cheia são antagônicas em relação à luminosidade. Sábato et al. (2006) constatou para outra espécie de canídeo neotropical (Chrysocyon brachyurus) alterações no período de atividade em diferentes fases lunares. É importante salientar que alguns fatores podem influenciar na luminosidade causada pela lua no ambiente, como a copa das árvores e principalmente dias com céu nublado. ...
http://dx.doi.org/10.5007/2175-7925.2009v22n4p147
Estudou-se o período de atividade do graxaim (Cerdocyon thous) no vale do Rio Itajaí, Santa Catarina, sul do Brasil através de armadilhas fotográficas durante um período de 15 meses e a relação desta atividade com os fatores abióticos (pluviosidade, temperatura e fases lunares). Foi constatado que sua atividade é basicamente noturna (54%) e crepuscular (25%), sendo classificada como catemeral. Não houve nenhuma relação do período de atividade com os fatores abióticos avaliados.
... However, utility of this method is hard to assess, since our knowledge of the vocal behavior of wild maned wolves is still sparse. Sábato et al. (2006) reported reduction of nocturnal activity by wild maned wolves during periods of full moon compared to periods of new moon, but it is currently unknown if lunar phases correlate with vocalization rates. To the best of our knowledge, no study has tested the effect of abiotic factors on vocal activity of maned wolves. ...
... Further studies are needed to confirm this hypothesis. Sábato et al. (2006) reported a decrease in the activity of maned wolves during nights of full moon when compared to new moon, possibly due to increased kill efficiency during moonlit nights, and consequently a reduced necessity to travel long distances. Therefore, these animals would have more time to vocally defend their territories, presenting a lunar-philic vocal behavior as our results showed. ...
Acoustic communication is favored at times of day and under weather conditions that allow the most effective sound transmission. Changes in vocal activity due to temporal and environmental factors can add significant information about the function of animals’ calls by providing clues about behavioral patterns. Estimating the temporal variation of vocal activity also can be important for conservation when calls are used to infer a species’ presence and abundance. The maned wolf (Chrysocyon brachyurus) is a near-threatened species and its conservation efforts could benefit from information gathered using passive acoustic monitoring (PAM), but their vocal behavior pattern in the wild is currently unknown. We investigated the nocturnal pattern of roar-bark sequences by maned wolves in Serra da Canastra National Park (Minas Gerais, Brazil) during 4 months of the breeding season and measured the influence of period of night, weather conditions, and lunar phase on their vocal activity. Roar-barks were more frequently emitted in the first 3 h of the night, suggesting an important social function for these long-distance calls in the beginning of the period of greatest activity of maned wolves. The occurrence of sequences was negatively related to mean wind speed, which suggests that wolves are avoiding moments of poor sound transmission. No sequence was detected when wind speed was above 5.4 m/s, probably due to equipment limitation, masking by wind noise, or absence of vocal activity. Maned wolves also vocalized more during moonlit nights. A better understanding of seasonal variation in vocal activity of maned wolves is required, but our study shows that it is possible to detect behavioral patterns of wild populations of this species only by sound, validating PAM as a tool for the conservation of this threatened carnivore.
... They can modify foraging patterns, intensity of intraspecific interactions, and overall daily activity when the weather changes (Stokes et al. 2001). Variation in rodent activity may strongly affect other species, e.g., their predators (Lindström and Hörnfeldt 1994;LaHaye et al. 2004;Sábato et al. 2006) or prey (Vander Wall et al. 2005Perea et al. 2011). Understanding behavioral patterns of rodents can help explaining changes in activity of other species in the community. ...
... Precipitation may reduce prey detectability as well as decrease small mammal activity, which negatively influences reproduction and survival of species preying on rodents, such as owls (Vickery and Bider 1981;LaHaye et al. 2004) and mammalian predators (Sábato et al. 2006). Thus, weather conditions may indirectly influence the hunting effectiveness of predators, highly limiting their populations, especially during breeding season. ...
Rodents constitute a crucial part of food chains in many ecosystems, thus changes in their activity might influence many other species in the community. Moreover, daily variations in activity appear to be an important adaptation, helping rodents to cope with fluctuating intensity of predation pressure and food availability. We investigated how night activity of yellow-necked mouse (Apodemus flavicollis) and bank vole (Myodes glareolus) changes with weather conditions. Increased cloud cover enhanced activity of mice, but this effect tended to be weaker during the full moon. In turn, the activity of bank voles was positively influenced by moon phase regardless of cloud cover. Temperature had negative effect on activity of both species. Rainfall positively influenced A. flavicollis capture numbers, but tended to decrease activity of M. glareolus. Therefore, while the activity of both mice and voles was under a strong influence of weather variables, their responses to weather were largely species-specific.
... The circadian clock is an evolutionary-conserved feature that allows organisms to anticipate time of the day and season, thus enabling them to adapt their biochemical, physiological, and behavioral processes to outside changes (Pittendrigh, 1993; Yerushalmi & Green, 2009). A crucial characteristic of these endogenous circadian oscillators is their capacity to entrain the rhythms with such environmental cues (zeitgebers) as light, temperature , and food availability (Carneiro & Araujo, 2009; Jud et al., 2005; Pittendrigh, 1993; Sábato et al., 2006; Stephan, 2002). ...
... Studies also reported on the influence of the moonlight on the nocturnal activity and the occurrence of certain behavioral patterns in ungulates (Wronski et al., 2006). The moonlight was actually recognized as an important factor in reducing the activity levels of nocturnal prey species (Sábato et al., 2006) in response to the presence of natural predators that tend to adjust their temporal hunting patterns to the times when preys are most vulnerable (Theuerkauf et al., 2003). Theuerkauf et al. (2003) argued that a dim light, as it occurs at dawn, dusk, and during moonlit nights, provides the best hunting conditions for wolves (Canis lupus), as preys are more easily detectable. ...
We investigated the activity patterns of a European roe deer (Capreolus capreolus) population living in a forested Apennine area in central Italy, in order to shed light on the environmental and biological factors that were expected to account for the observed activity patterns on daily and yearly bases. Daily and seasonal activity patterns of 31 radio-collared roe deer were assessed through sessions of radio tracking for a total period of 18 consecutive months. Roe deer showed bimodal activity patterns throughout the year, with the two highest peaks of activity recorded at dawn and dusk. Activity patterns of males and females differed during the territorial period (from early spring to late summer), whereas they did not during the nonterritorial period. Most likely, behavioral thermoregulation can be held responsible for variation of daily activity patterns in different seasons. In winter, for instance, activity during the dawn period was significantly higher than in other seasons and daylight activity was significantly higher than at night. Nocturnal activity was highest in summer and lowest in winter. During the hunting season, moreover, roe deer showed lower activity levels than during the rest of the year. The prediction that roe deer would show lower activity levels during full moon nights, when the predation risk was assumed to be higher, was not confirmed by our data. Activity rhythms in roe deer were thus subjected to both endogenous and environmental factors, the latter working as exogenous synchronization cues. Accordingly, in changing environmental and ecological conditions, a circadian cycle of activity could be seen as the result of complex interactions among daily behavioral rhythm, digestive physiology, and external modifying factors.
... Although it should be considered that nocturnal movements in risky environments, such as steep terrains and rocky slopes, can be safer and more efficient during brighter nights, our results pointed out that the nocturnal activity of ibex was more pronounced in the area where the predator was present, suggesting a role of predation risk in this choice. Most ungulate species exhibit higher nocturnal activity during brighter nights [50], despite moonlight also improving the hunting success of most of their predators [18,[51][52][53][54]. It is worth noting that in the specific case of ibex-wolf system the former is a diurnal mammal whereas the latter is a nocturnal one, so the benefit of a bright night is comparatively higher for the prey than for the predator. ...
Flexibility in activity timing may enable organisms to quickly adapt to environmental changes. Under global warming, diurnally adapted endotherms may achieve a better energy balance by shifting their activity towards cooler nocturnal hours. However, this shift may expose animals to new or increased environmental challenges (e.g. increased predation risk, reduced foraging efficiency). We analysed a large dataset of activity data from 47 ibex (Capra ibex) in two protected areas, characterized by varying levels of predation risk (presence versus absence of the wolf—Canis lupus). We found that ibex increased nocturnal activity following warmer days and during brighter nights. Despite the considerable sexual dimorphism typical of this species and the consequent different predation-risk perception, males and females demonstrated consistent responses to heat in both predator-present and predator-absent areas. This supports the hypothesis that shifting activity towards nighttime may be a common strategy adopted by diurnal endotherms in response to global warming. As nowadays different pressures are pushing mammals towards nocturnality, our findings emphasize the urgent need to integrate knowledge of temporal behavioural modifications into management and conservation planning.
... Most insects have a 24-h rhythm either to capture their prey or to escape a predator. The antlion larvae also possess a 24-h rhythm, and they maintain this rhythm to get their prey in the proper phase of the potential prey activity (Sabato et al. 2006;Van Laerhoven et al. 2003). It is very important for their feeding behavior because most of the species of antlion larvae are sit-and-wait predators, and they completely depend on the arrival of the prey according to their 24-h rhythm. ...
Temperature influences the survival, growth, and development of insects including the antlion. In the present study, we examined the 24-h rhythm in the pit-building behavior of the antlion larvae at three different temperature conditions, high (37°C), low (17°C), and room temperature (Control: 25.9 ± 0.2°C). We recorded pit-building activities by monitoring two variables: the Time Lag for the Initiation of Pit Reconstruction (TLIPR) after the demolition of the pit, and the Total Time for Pit Construction (TTPC). We monitored TLIPR and TTPC at four different time points with equidistant intervals (i.e. 08:00-10:00 h, 14:00-16:00 h, 20:00-22:00 h, and 02:00-04:00 h) each day over three consecutive days. We employed single Cosinor rhythmometry to evaluate the characteristics of 24-h rhythm in TLIPR and TTPC. We used one-way ANOVA to find out the effects of the temperature on TLIPR and TTPC. We detected a statistically significant 24-h rhythm in TLIPR at the group level, irrespective of the temperature conditions. 24-h rhythm in TTPC was abolished at high and low temperatures. Temperature significantly affected TLIPR and TTPC in general. It also significantly affected the mesor of the rhythms in both variables as well as the amplitude of TTPC. Finally, we noted that although high and low temperatures affected the pit-building behavior in general, the thermal conditions did not lead to a complete cessation of pit-building activities. The 24-h rhythmic pattern associated with TTPC is more susceptible to the effects of thermal regimes (17°C or 37°C) unlike that associated with TLIPR.
... Within this contextualization and specifically concerning the specific influence of environmental light on social behavior, an increase in the social communication and/or interaction between congeners in dim light conditions for some mammal and bird species is reported [72][73][74][75][76]. This, in turn, might enforce social cohesion both at a horizontal and vertical level. Similarly, the activity in mammals [77][78][79][80], birds [81,82], reptiles [83,84], urodeles [85], and invertebrates [86][87][88] is positively correlated with decreasing moonlight. During a full moon, animals' visual skills may be better and move at lesser proportions since they can identify both surrounding resources and potential threats more easily, but they are also more exposed to predators in these bright light conditions. ...
Given energy costs for gestating and caring for male offspring are higher than those of female newborns, external environmental conditions might be regarded as likely to affect the timing of delivery processes differentially depending on the sex of the newborn calf to be delivered. The aim of the present paper is to evaluate the association between environmental stressors such as the moon phase and weather-related factors and the onset of labor in female dromedaries. A binary logistic regression model was developed to find the most parsimonious set of variables that are most effective in predicting the probability for a gravid female dromedary to give birth to a male or a female calf, assuming that higher gestational costs and longer labor times are ascribed to the production of a male offspring. Although the differences in the quantitative distribution of spontaneous onset of labor across lunar phases and the mean climate per onset event along the whole study period were deemed nonsignificant (p > 0.05), a non-negligible prediction effect of a new moon, mean wind speed and maximum wind gust was present. At slightly brighter nights and lower mean wind speeds, a calf is more likely to be male. This microevolutionary response to the external environment may have been driven by physiological and behavioral adaptation of metabolic economy and social ecology to give birth to cooperative groups with the best possible reduction of thermoregulatory demands. Model performance indexes then highlighted the heterothermic character of camels to greatly minimize the impact of the external environment. The overall results will also enrich the general knowledge of the interplay between homeostasis and arid and semi-arid environments.
... These shifts in predator and scavenger abundance match previously observed results (see Davies et al. 22 ). Our results run counter to observations seen with changing natural light levels where increased natural light decreases predator activity, 14,35 thus reaffirming that the night-light niche is a novel behavior in response to artificial light that can influence the patterns of nocturnal predators. These results also run counter to the findings of Davies et al. which suggest that artificial lights may shift diurnal arthropod communities. ...
While recent studies explore the negative impacts of light pollution on arthropods, few studies investigated community-level responses to artificial light. Using an array of landscaping lights and pitfall traps, we track community composition over 15 consecutive days and nights, including a five-night pre-light period, a five-night during-light period, and a five-night post-light period. Our results highlight a trophic-level response to artificial nighttime lighting with shifts in the presence and abundance of predators, scavengers, parasites, and herbivores. We show that associated trophic shifts occurred immediately upon the introduction of artificial light at night and are limited to nocturnal communities. Lastly, trophic levels reverted to their pre-light state, suggesting many short-term changes in communities are likely the result of behavioral shifts. These trophic shifts may become common as light pollution increases, implicating artificial light as a cause of global arthropod community change and highlighting light pollution’s role in global herbivorous arthropod decline.
... Higher activity levels on more moonlit nights have been recorded for wolves 21 , African wild dogs 23 , and coyotes 24,25 . The opposite trend (i.e., lower activity on more moonlit nights) has been observed in wild maned wolves 26 and black-backed jackals 27 . Research on jackals suggest that the activity response to moonlight is variable and dependent on resource availability 28 . ...
There are limited studies investigating the combined effects of biological, environmental, and human factors on the activity of the domestic dog. Sled dogs offer a unique opportunity to examine these factors due to their close relationship with handlers and exposure to the outdoors. Here, we used accelerometers to measure the activity of 52 sled dogs over 30 days from two locations in Canada. The two locations differ in the working demands of dogs, therefore we used linear mixed effects models to assess how different factors impact daytime and nighttime activity of working versus nonworking dogs. During the daytime, we found that males were more active than females among nonworking dogs and younger dogs were more active than older dogs among working dogs. Alaskan huskies had higher activity levels than non-Alaskan husky breeds in working sled dogs during the day. Nonworking dogs were slightly more active during colder weather, but temperature had no effect on working dogs’ activity. The strongest predictor of daytime activity in working dogs was work schedule. These results indicate that the influence of biological factors on activity varied depending on dogs’ physical demands and human activity was the most powerful driver of activity in working dogs.
... Por ejemplo, en la competencia interespecífica las especies dominantes influyen en la actividad temporal de las especies subordinadas, es decir que estás especies evitaran estar activas durante los picos de actividad de las especies dominantes para disminuir los encuentros , Vanak et al. 2013. Las especies presa concentran su actividad de forrajeo durante las horas que sus depredadores son menos activos, ya que esto les permite disminuir su riesgo de depredación , Lima Sábato et al. 2006. ...
La actividad espacio-temporal de los mamíferos silvestres está regulada por ritmos endógenos como, su historia evolutiva, edad, sexo, estado fisiológico, así como exógenos relacionados con la luz-oscuridad, precipitación, temperatura ambiental, disponibilidad de alimento, disponibilidad de agua, estación del año, fase lunar y por las interacciones inter e intraespecíficas. Las especies simpátricas presentan mecanismos para coexistir en un mismo espacio. Una de sus estrategias es la segregación en alguna de las tres dimensiones principales de su nicho ecológico: alimento, espacio o tiempo. El presente trabajo se enfocó en evaluar la actividad espacio-temporal del ensamblaje de mamíferos medianos y grandes que habitan en el bosque tropical seco de la Reserva de la Biosfera Tehuacán-Cuicalán. Se utilizó el foto-trampeo para el registro de las especies y se realizó durante un año (2012-2013). El ensamblaje estuvo compuesto por 17 especies de mamíferos medianos y grandes, y también se registraron 5 especies domésticas (perros, gatos, vacas, asnos y cabras). El uso espacial fue analizado por medio de modelos de ocupación para dos especies y se encontró que en general las especies silvestres simpátricas, los depredadores y sus presas potenciales, así como las especies silvestres y las domésticas co-ocurren de forma independiente (Capítulo 2). Mientras que el lince (Lynx rufus) y el conejo (Sylvilagus floridanus) presentaron agregación espacial (Capítulo 2). Sin embargo, la mayoría de las especies analizadas presentaron diferencias significativas en sus horarios de actividad (Capítulo 3). Los resultados sugieren que la estrategia principal dentro del ensamblaje es la segregación temporal, ya que las especies hacen uso de los mismos sitios para realizar sus actividades pero en diferente horario. También es posible que existan otras estrategias, no evaluadas en este estudio, como diferencias en el eje trófico. Se recomienda realizar estudios relacionados con la dieta y parámetros poblacionales para conocer cómo la dimensión trófica del nicho, permite entender la coexistencia y las posibles consecuencias en la dinámica poblacional de las especies que conforman el ensamblaje.
... The low value of robustness of rhythm of locomotor activity predisposes to an easily influence by external stimuli. There is evidence that the influence of different environmental synchronizers such as social environment, human presence, interaction with competitors, food availability, or time food uptake may lead to changes in the diurnal/nocturnal activity rhythm in maned wolves (Sábato et al., 2006;Barrera and Bentosela, 2016;Coelho et al., 2018;Jones et al., 2018). The temporary captivity condition was not able to influence the behavior of maned wolves that maintained a nocturnal daily rhythm. ...
The aim of the study was to extend the knowledge about to the total locomotor activity behavior in maned wolves (Chrysocyon brachyurus) through the comparison with domestic dogs (Canis familiaris). Five maned wolves housed individually in 4 m² dens with nest boxes, and runs allowing them to move in outdoors area of 250 m² with natural vegetation; and five Beagles dogs living individually in a 12 m² box with an outside area of 50 m², were subjected to natural light-dark (L/D) cycle (maned wolves: 15L/9D; dogs 14L/10D) and environmental conditions (maned wolves: 22-26°C, 64Rh%; dogs 17-23°C, 65Rh%). In each animal the monitoring of locomotor activity was performed for 2 days by means of an activity data logger (Actiwatch Cambridge Neurotechnology, Cambridge, UK), applied on a neck collar. Data were analyzed by the single Cosinor method. At the obtained rhythmic parameters two-way analysis of variance (ANOVA) was applied to verify differences due to day of monitoring and species. Maned wolves showed a nocturnal daily rhythm of locomotor activity. Dogs showed a diurnal daily rhythm of locomotor activity. The diurnality index was 0.29 and 0.93, respectively for maned wolves and dogs. The two studied species showed statistically difference in mesor and amplitude of rhythm, higher in maned wolves (mesor:3256.64±364.87 arbitrary unit; amplitude:3726.32±327.50 arbitrary unit) than dogs (mesor:414.06±9.68 arbitrary unit; amplitude:502.35±18.78 arbitrary unit).
We can claim that maned wolves, housed in captivity is more active than dogs and showed an oppose daily rhythm of locomotor activity.
... It has been shown that predator avoidance is amongst the main determinants of mammalian spatial behaviour (Lima and Dill 1990;Monterroso et al. 2013). Nocturnal carnivores are adapted to hunting in darkness, but most of them increase their hunting success during bright moonlight nights or by hunting in open or semi-open habitats (Cozzi et al. 2012;Prugh and Golden 2014;Sábato et al. 2006). ...
Assessing carnivores and prey temporal activity patterns as well as their overlap provides valuable insights into behavioural mitigations of competition. Moon phases may also play an important role in shaping wild mammals’ activity rhythms with prey showing peaks of activity in darkest nights. Camera trapping has enriched the possibility to conduct systematic studies of activity patterns and temporal niche overlap on mammalian guilds. In this study, we used camera traps to investigate intra-guild interactions and temporal partitioning among three meso-carnivores and their common prey in two Mongolian areas characterized, respectively, by a grassland and a forest–alpine meadow. We detected a moderate–high interspecific overlap in red foxes, pikas and tolai hares. We found a moderate overlap of temporal activity patterns among nocturnal carnivores as well as among nocturnal prey species. Interestingly, we observed a moderate overlap between hares and meso-carnivores. Amongst nocturnal species, the red fox and the stoat had a peak in activity in the brightest nights, the stone marten and the Mongolian silver vole preferred to range in dark nights, whereas activity of the tolai hare was not dependent on moon phases. Our work provides some first insights of temporal pattern interactions within a small- and meso-mammal assemblage in Central Asia. Our results indicate that meso-carnivores and their potential prey can co-occur in Central Mongolia by means of temporal partitioning.
... The high transmission costs and the technical impossibility of simultaneous diurnal and nocturnal recording schemes prevented us from programming all loggers for intensive ACC recording every night. We discarded rainy or very windy days, and avoided cloudy, rainy or very windy nights, to prevent bad weather or clouds on moonlit nights interfering with our study (Martin, 1990;S abato, Bandeira de Meloa, Vaz Magnia, Young, & Mendes Coelho, 2006). ...
The importance of nocturnal display in diurnal birds has been neglected for a long time, owing to the difficulties in recording behaviour by night. Using loggers with an accelerometer (ACC) we studied nocturnal display in male African houbara bustards, Chlamydotis undulata, ssp. fuertaventurae. Diurnal display of male houbaras consists of a visual component, the display run, and an acoustic component, the boom. Nocturnal display runs were only recorded twice, both on full moon nights. Nocturnal booming intensity was highest on full moon nights when it reached similar levels to those during peak diurnal display at dawn. The more favourable physical conditions for sound transmission and the reduced acoustic competition with wind and other birds at night have been proposed to explain nocturnal vocalizing. Minimizing copulation disruptions, a frequent intramale competition mechanism in bustards, could be an additional advantage of nocturnal display. However, these factors do not explain why vocal activity is highest on full moon nights. We suggest that moonlight may help displaying males to detect predators, as well as to communicate visually with approaching females. Moonlight also allows males to combine booms with visual signals produced by the white neck feathers exposed during booming into more efficient multimodal signals. Moonlight would thus ultimately lead to males achieving nocturnal copulations, which indeed might be more frequent than previously thought, according to rates of nocturnal ACC-recorded precopulatory movements. Finally, nocturnal booming sequences had almost twice as many booms as diurnal ones, which suggests that nocturnal vocalizations transmit higher-quality information about signalling males than diurnal vocalizations. Nocturnal booming significantly increased the total display time of male houbara bustards; thus, future studies should investigate whether nocturnal vocal activity represents an important contribution to individual fitness in this and other nocturnally vocalizing diurnal species.
... Shorteared owls (Asio flammeus) are more successful at hunting deermice (Peromyscus maniculatus) when illumination is high (Clarke 1983). In turn, antipredator avoidance behaviours are heightened by some prey species during periods of high nocturnal illumination (Clarke 1983;Sábato et al. 2006;Harmsen et al. 2011). Snowshoe hares' (Lepus americanus) nocturnal movements decreased and they favoured foraging in dense vegetation when illumination was high (Griffin et al. 2005;Gigliotti and Diefenbach 2018). ...
Moon phase and variation in ambient light conditions can influence predator and prey behaviour. Nocturnal predators locate prey visually, and prey may adjust their activity to minimise their predation risk. Understanding how native mammals in Australia respond to varying phases of the moon and cloud cover (light) enhances knowledge of factors affecting species’ survival and inference regarding ecological and population survey data. Over a two-year period within a fenced conservation reserve, in south-eastern Australia, with reintroduced native marsupial predator and prey species (eastern barred bandicoot, southern brown bandicoot, long-nosed potoroo, rufous bettong, Tasmanian pademelon, brush-tailed rock-wallaby, red-necked wallaby, eastern quoll, spotted-tailed quoll, and naturally occurring swamp wallaby, common brushtail possum, common ringtail possum), we conducted monthly spotlight surveys during different moon phases (full, half and new moon). We found an interaction between cloud cover and moon phase, and an interaction of the two depending on the mammal size and class. Increased activity of prey species corresponded with periods of increasing cloud cover. Predators and medium-sized herbivores were more active during times of low illumination. Our findings suggest that moon phase affects the nocturnal activity of mammal species and that, for prey species, there might be trade-offs between predation risk and foraging. Our findings have implications for: ecological survey design and interpretation of results for mammal populations across moon phases, understanding predator and prey behaviour and interactions in natural and modified (artificial lighting) ecosystems, and potential nocturnal niche partitioning of species.
... Furthermore, because many nocturnal mammalian predators rely on vision during the final stages of the hunt, moonlight may be important (Kavanau and Ramos 1975). However, to date, only few studies have addressed the impact of moonlight on the activity of canid predators (Sábato et al. 2006). In our study, moonlit nights did not induce any changes in space-use patterns of Close jackals suggesting a change in their foraging behavior strategy. ...
We studied the influence of agricultural villages on space-use patterns of golden jackals (Canis aureus Linnaeus) in the Mediterranean region of Israel. Villages in our research area attract jackals due to poor sanitation conditions in and around villages. As resources in these villages are abundant and predictable, we expected that space-use patterns of jackals near those villages, including home-range characteristics and movement paths, would differ from those of jackals inhabiting more natural areas. Using radio-locations from 16 individuals (8 near villages and 8 from more natural areas), we found that mean home-range size of jackals close to villages was 6.6 AE 4.5 km 2 , smaller than mean home-range size of jackals in more natural areas (21.2 AE 9.3 km 2 , P ¼ 0.001). Similarly, core area size of jackals near villages was 1.2 AE 0.92 km 2 , compared to 3.5 AE 1.6 km 2 for individuals inhabiting more natural areas (P ¼ 0.004). The core area/home-range ratio was greater for jackals near villages than for those occupying more natural areas (0.122 AE 0.045 vs. 0.095 AE 0.037, respectively, P ¼ 0.004). Jackals moved little during the day, with day ranges smaller for jackals near villages than away from them (1.65 AE 0.67 vs. 7.5 AE 5.6 km 2 , respectively, P ¼ 0.028). However, jackals near villages moved as much at night as did jackals in more natural areas, although movement was in a less directional manner. Changes in distribution and predictability of resources due to anthropogenic activity affect not only the home-range size of jackals, but also how they utilize and move through space. ß 2011 The Wildlife Society.
... These information in urban areas are needed both for increasing our basic understanding of the ecology of many tropical organisms and for understanding impacts of human activity on the behavior of them (Blake et al. 2012). The behavior and activity pattern of mammals can be influenced by intrinsic factors, such as: sex, age (Fernandez-Duque 2004), reproductive period (Halle & Stenseth 2000), and extrinsic factors, like as lunar phases (Sábato et al. 2006), photoperiod (Everts et al. 2004), temperature (Ferraz et al. 2010), precipitation and relative humidity (Carvalho et al. 2011). Temperature, relative humidity, precipitation and solar radiation can have effects on animal behavior, as these factors are directly related to thermoregulation, energy expenditure and animal wellbeing (Takahashi et al. 2009). ...
The capybara, Hydrochoerus hydrochaeris (Rodentia, Caviidae), is a species adapted to diverse environments, including urbanized areas, where its populations can reach high densities. In this study, we searched the behavioral pattern of capybaras in urban areas, and investigated the effect of temperature and relative humidity in its activity pattern. The study was conducted in an urban area of the Aquidauana municipality in the state of Mato Grosso do Sul, Brazil. Observations occurred between June 2014 and March 2015, using the scan sampling method. We found that capybaras spent most of your time in aquatic activities and rest. Temperature was positively correlated with the percentage of individuals engaged in aquatic activities. Relative humidity was negatively correlated with the percentage of individuals at rest and positively correlated with aquatic activities. Capybaras exhibit behavioral thermoregulation, which explains the large amount of time spent on aquatic activities with the increase in temperature and relative humidity.
... Number of publications that tested the effect of human disturbances and their findings 5 research papers included in this review found that moonlight had an effect on activity patterns, but the influence of the moonlight suppressed activity in some species and enhanced activity in othersSábato et al. 2006). ...
... This result gives us direct insight of mouse decision-making and the behavioural response elicited when a trade-off between predation risk and feeding is presented (see predation risk allocation hypothesis [43]). According to this theory, individuals would increase feeding effort during new moon phases when the perceived predation risk is low, since moonlight can increase prey detectability and hence, hunting success for predators [44,45]. Thus, darker nights caused mice to feel safer, allowing individuals to spend energy in the device. ...
Animals making foraging decisions must balance the energy gained, the time invested, and the influence of key environmental factors. In our work, we examined the effect of predation risk cues and experience on feeding efforts when a novel food resource was made available. To achieve this, we live-trapped wood mouse Apodemus sylvaticus in Monte de Valdelatas (Madrid), where 80 Sherman traps were set in four plots. Traps were subjected to two food-access difficulties in treatments consisting of three consecutive nights: open plastic bottles (easy) and closed bottles (difficult), both using corn as bait. To simulate predation risk, we set fox faeces in half of the traps in each plot. We also considered moonlight (medium/low) as an indirect predation risk cue. We analysed whether bottles had been bitten by mice and the gnawed area of each bottle was measured. Our results indicated that food access difficulty, experience, and predation risk determined mice feeding decisions and efforts. The ability of mice to adapt feeding effort when a new food source is available was demonstrated because a higher proportion of closed bottles exhibited bite marks and the gnawed area was bigger. Moreover, mouse experience was determinant in the use of this new resource since recaptured mice gnawed broader orifices in the bottles and the gnawed area increased each time an individual was recaptured. Additionally, direct predation risk cues prompted mice to bite the bottles whereas the effect of different moon phases varied among the food access treatments. This study provides direct evidence of formidable efficacy of wild mice to exploit a new nutrient resource while considering crucial environmental factors that shape the decision-making procedure.
... For example, prey species such as the kangaroo rat (Dipodomys spectabilis; Daly et al. 1992) and snowshoe hare (Lepus americanus; Griffin et al. 2005) reduce nocturnal activity during brightly illuminated nights, caused by the full moon, in an effort to decrease predation risk (Lima andDill 1990, Sabato et al. 2006). Similarly, reduced prey availability has been found to decrease predator activity in the maned wolf (Chrysocyon brachyurus ;Sabato 2006) and white-throated round-eared bat (Lophostoma silvicolum; Lang et al. 2006). Although lunar phase and illumination impact daily activity patterns of many species, lunar phase also appears to influence activity in relation to key life history events. ...
... Furthermore, the lowest movement in our study occurred during the full moon, supporting the assumption that prey changes their spatial distribution to avoid visual predators benefitting from lunar illumination (Longland & Price, 1991). For example, to avoid predation risks during their return to refuges (Riou & Hamer, 2008), prey species stayed hidden (Kotler, Brown, & Hasson, 1991;Price, Waser, & Bass, 1984) or showed lower movement activity (Morrison, 1978), which was followed by reduced activity of aquatic (Horký, Slavík, Bartoš, Kolářová, & Randák, 2006) or terrestrial predators (Sábato, de Melo, Magni, Young, & Coelho, 2006). However, increases in the activity of predators have rarely been observed within the lunar cycle. ...
The movement of individuals within preferred areas is reduced by a high availability of food and information about its distribution, while high number of competitors promotes increased movement. Experienced animals use information about social and physical environment to improve resources exploitation, tended to maintain positions within the preferred areas and reuse the environment that is often referred to as site fidelity. In this study, radio‐telemetry was used to observe the movements of 98 adult brown trout, Salmo trutta, in oligotrophic streams with different population densities; to determine subpopulation site fidelity, 5,195 conspecifics from 14 subpopulations were individually tagged during spring and autumn. During a 7‐year‐long field study, we tested the hypothesis that brown trout individuals from subpopulations with high site fidelity would display lower movement. The hypothesis was supported, and reduced movement was further related to high subpopulation density in association with high slope indicating the physical environment‐influenced movement. The probability of contact between individuals increased with subpopulation site fidelity and subpopulation density. No influence of food abundance on brown trout movement was found. Furthermore, increased body size predicted higher movement (and vice versa). The least movement occurred during the day and during the full moons. Our study tended to show that individuals reused preferred areas and needed less movement to exploit available resources.
... In the tropical forests of Central America, the activity of P. concolor and Leopardus pardalis (Linnaeus, 1758) was not affected by lunar phases, even with the change in the availability of some prey (Harmsen et al., 2011). For predators, however, little is known about their behavioral responses to the lunar cycle (Sábato et al., 2006). ...
Predator-prey systems are regulated by a behavioral response race, in which the predator develops adaptations that enhance its hunting success and its prey adopt anti-predator strategies. In the present study, we analyzed the activity patterns, the influence of moonlight, and the habitat use of Leopardus pardalis and Puma concolor in comparison with their potential prey, Dasypus novemcinctus, Mazama gouazoubira, Pecari tajacu, Sapajus libidinosus, Kerodon rupestris, Cuniculus paca and Dasyprocta prymnolopha, in the Serra das Almas Nature Reserve in northeastern Brazil. Leopardus pardalis was predominantly nocturnal, while P. concolor presented a cathemeral pattern, however, the overlap coefficient between these species was high. The activity of L. pardalis overlapped strongly with three typical nocturnal prey (D. novemcinctus, K. rupestris and C. paca). While P. concolor had considerable temporal overlap with all prey. Both predators were habitat generalists, in contrast, most prey species exhibited a significant association with a specific type of habitat. The phases of the moon did not influence the activity patterns of the different species, except for K. rupestris, which was more active on moonlit nights. Our findings indicate that the predators maximize the efficiency of their foraging behavior by using habitats and the circadian cycle in a more generalist manner.
... An increase in stress hormones is expected in these situations, because the animals need to cope with the new stressors (predator, prey, or conspecific;Blanchard, McKittrick, & Blanchard, 2001;Fowler, 1986). On the other hand, walking and foraging are behaviors normally regularly expressed by wild maned wolves without any specific stimulus being present (Bandeira de Melo et al., 2007;Coelho et al., 2008Coelho et al., , 2011Sábato, de Melo, Magni, Young, & Coelho, 2006). Vasconcellos, Adania, and Ades (2012) showed that captive maned wolves express contrafreeloading, suggesting that it was due to the necessity to express natural behaviors in captive environments (but see Young & Lawrence, 2003). ...
Environmental enrichment is a technique that may reduce the stress of nonhuman animals in captivity. Stress may interfere with normal behavioral expression and affect cognitive decision making. Noninvasive hormonal studies can provide important information about the stress statuses of animals. This study evaluated the effectiveness of different environmental enrichment treatments in the diminution of fecal glucocorticoid metabolites (stress indicators) of three captive maned wolves (Chrysocyon brachyurus). Correlations of the fecal glucocorticoid metabolite levels with expressed behaviors were also determined. Results showed that environmental enrichment reduced fecal glucocorticoid metabolite levels. Furthermore, interspecific and foraging enrichment items were most effective in reducing stress in two of the three wolves. No definite pattern was found between behavioral and physiological responses to stress. In conclusion, these behavioral and physiological data showed that maned wolves responded positively from an animal well being perspective to the enrichment items presented.
... In fact, predation influences the ecology and evolution of mammalian species through direct mortality and behavioural responses to the threat of death (Creel, 2011), with the prey being often one step ahead of predators in the "arms race" (for a synthesis: Krebs and Davies, 1978). Although adapted to find prey in darkness, some nocturnal carnivores improve their hunting success in bright moonlit nights (e.g Lima Sàbato et al., 2006;Cozzi et al., 2012; but see 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. ...
... In addition to extrinsic pressures, intrinsic factors such as sex and body size have also been shown to be important determinants of home-range size in ungulates (Kjellander et al. 2004) and of movement distance in some canids (e.g., maned wolf, Chrysocyon brachyurus-Lima Sabato et al. 2006). In some species, social factors may also affect home-range size: homerange size increases with pack size in Ethiopian wolves (Canis simensis- Ashenafi et al. 2005), while pack size accounts for 87% of variation in range size in coyotes (Canis latrans- Bowen 1981), though this relationship is not apparent in some canids (e.g., African wild dogs, Lycaon pictus- Mills and Gorman 1997;Creel and Creel 2002). ...
Extinction risk in African wild dogs (Lycaon pictus) has been linked to their wide-ranging movement behavior.
However, drivers of variability in African wild dog ranging are not well understood. This study examines the
effects of intrinsic and extrinsic factors on ranging patterns and describes scale-dependent and intra-annual
variation in the ranging of 5 packs of African wild dogs in the Okavango Delta from 2007 to 2010. 95% fixed
kernel home ranges (X = 739 ± 81 km2) and daily step lengths (X = 8.5 ± 0.5 km) in this study are larger than
have generally been reported for African wild dogs elsewhere. Little seasonal variation in daily ranging distances
was observed despite home-range contractions during denning to 27% of packs’ ranges outside the denning
period. During nondenning periods, litter size was the most influential driver of ranging patterns, with large
litters associated with reduced pack movements and smaller home ranges at all temporal scales. Pack size was
also a significant driver of home-range size (but not daily distance travelled) at weekly timescales, where larger
packs utilized smaller ranges. Daily temperatures were inversely related to home-range size and step length at
short timescales, while higher flood levels were related to reduced ranging distances at intermediate timescales.
Our results indicate that extrinsic drivers of African wild dog ranging behavior tend to be scale dependent, while
intrinsic factors may be more influential for ranging patterns than previously reported.
... Hence, during bright moonlit nights, hunting effectiveness of canids is greater (e.g. Lima Sàbato et al., 2006;Kotler et al., 2010), including red foxes (Molsher, Gifford & McIlroy, 2000) and wolves (Theuerkauf et al., 2003), potential predators of the crested porcupine . In particular, red foxes can shift prey selection when the lunar phase changes (Molsher et al., 2000). ...
Predation avoidance is one of the main factors determining nocturnal activity of mammals, which has been shaped by evolution in relation to local environmental variables. The nocturnal activity of 16 female and 11 male radio-tagged adult crested porcupines Hystrix cristata was studied in four study sites of Southern Tuscany (Central Italy), with different environmental features. The activity patterns of porcupines, monitored for 16–23 h per week per individual, were correlated to lunar phases, in open/closed habitat types, throughout the year. The median duration of nocturnal activity was 7 h and 38 min, with no significant seasonal variation. Moonlight avoidance was shown in all our study sites, throughout the year, especially in open habitats. Full moon, irrespective of its visibility, always inhibited activity of this large rodent. Old World porcupines originated 5 million years ago in the forests of Asia and Africa, where a number of large carnivores must have preyed – and still prey – on them. Most likely, moonlight avoidance evolved as an antipredatory behaviour. In areas with no or little predation risk for example our study sites, moonlight avoidance could have been kept in the repertoire of porcupines because of its non-maladaptive nature.
... Patterns of activity in animals throughout the daily 24 h cycle are commonly related to season ( Hill et al., 2003), food availability and access ( Donati et al., 2007), and predation risk ( Lang et al., 2006). Less understood are animal activities related to ambient light conditions resulting from either seasonal variation, lunar phase or atmospheric condition ( Beltran & Delibes, 1994;Barnes et al., 2006;Dixon et al., 2006;Lang et al., 2006;Sabato et al., 2006;Grant, Chadwick & Halliday, 2009;Grant, Halliday & Chadwick, 2013). The only published study on elephant behaviour in relation to lunar cycles is that of Barnes et al. (2006) in the Kakum Conservation Area (KCA) in Southern Ghana, West Africa. ...
Abstract Long-term solutions to crop raiding by elephants (Loxodonta africana) should be based on an understanding of their behaviour and ecology. The real and perceived risks from humans have been shown to affect elephant behaviour. This is evidenced by elephants predominantly raiding crops at night, avoiding the height of human activity. If such human avoidance behaviours are apparent, it might also be expected that elephants avoid risks associated with higher visibility and increased human activity as may occur during the full moon. However, elephant nocturnal crop-raiding behaviour in relation to lunar cycles has largely been a neglected factor in studies of human-elephant interactions. In this study around Mikumi National Park, Tanzania, we apply circular statistics in this context for the first time to show a significant decrease in crop raiding during the full moon and apply this method retrospectively to data from another site in West Africa with similar results. Additionally, a greater proportion of farms raided was guarded during the full moon than any other moon phase. Our results indicate that variations in crop raiding with lunar phase could be a general feature of elephant behaviour and thus could be used to design and time mitigation efforts.
... The low value of robustness of rhythm of locomotor activity predisposes to an easily influence by external stimuli. There is evidence that the influence of different environmental synchronizers such as social environment, human presence, interaction with competitors, food availability, or time food uptake may lead to changes in the diurnal/nocturnal activity rhythm in maned wolves (Sábato et al., 2006;Barrera and Bentosela, 2016;Coelho et al., 2018;Jones et al., 2018). The temporary captivity condition was not able to influence the behavior of maned wolves that maintained a nocturnal daily rhythm. ...
In this study the authors evaluated the influence of physical activity on the daily rhythm of rectal temperature and total locomotor activity in untrained and trained horses. Rectal temperature and locomotor activity of 12 Italian saddle horses, 6 untrained (group A) and 6 trained (group B), was recorded for 48 h. Rectal temperature was recorded every 4 h with a rectal probe. Animals were equipped with actigraphy-based data loggers, Actiwatch-Mini® to record total activity. The application of two-way ANOVA showed a highly significant effect of time and exercise on rectal temperature in untrained and trained horses in both days of monitoring. A significant effect of time on locomotor activity was observed, but there was no effect of exercise. Cosinor analysis identified the periodic parameters and their acrophases during the 2 days of monitoring. For all rhythmic parameters of rectal temperature except amplitude, no statistically significant differences were observed between the two groups. Statistically significant differences for the rhythmic parameters of locomotor activity, except robustness, between untrained and trained horses were found. In conclusion, rectal temperature circadian pattern was similar in untrained and trained horses, indicating that the endogenous nature of its rhythm was not influenced by external stimuli such as physical exercise.
... Predator avoidance is purported to be an important factor driving such differences. In fact, in a study that did not measure wild-rodent activity, Lima Sábato et al. (2006) attributed the reduction in movements of a predator -wild maned wolves (Chrysocyon brachyurus (Illiger, 1815))during full-moon periods to ''reduced rodent activity because in all tested rodent species to date the same response to a full moon was observed'', although the quote is something of an overstatement. Kikkawa (1964) observed in the United Kingdom that Apodemus sylvaticus (L., 1758) were less active on clear nights with a full moon, presumably resulting in their being less trappable on those nights. ...
In Colima, Mexico, we conducted 8-night markrecapture grid studies of southern pygmy mice (Baiomys musculus (Merriam, 1892)) in January 20032007 in dry deciduous and tropical moist forests. For 40000 trap-nights, 436 individuals were captured 764 times (comprising 18.6% of small mammals). The male:female ratio was 1:1.37, 82.9% were adults, 51.4% of females were pregnant or lactating, and coastal animals, on average, were heavier than those inland. Females moved farther than males. Baiomys was on 17 of 25 grids (densities 1.82106.24 individuals/ha). Moon illumination did not affect capture or recapture probabilities, but trap-night did (overall, probability increased 1.66%/night). Grids with Baiomys had less bare ground and a more open canopy. Capture sites had more grass, less dead wood and bare ground, a more open and lower canopy, and greater distance to trees. Logistic regression indicated coastal capture sites had more forbs, grasses, and woody plants, and thicker vegetation at 1m height with trees being relatively distant. Variables differed somewhat for northern sites, and the equation for all grids included 10 of 14 environmental variables. Baiomys frequented edge of an unimproved road traversing one grid. Baiomys musculus, widespread in Colima, exhibited preference for habitats with relatively dense ground cover and at least a partially open canopy.
... Furthermore, because many nocturnal mammalian predators rely on vision during the final stages of the hunt, moonlight may be important (Kavanau and Ramos 1975). However, to date, only few studies have addressed the impact of moonlight on the activity of canid predators (Sábato et al. 2006). In our study, moonlit nights did not induce any changes in space-use patterns of Close jackals suggesting a change in their foraging behavior strategy. ...
We studied the influence of agricultural villages on space-use patterns of golden jackals (Canis aureus Linnaeus) in the Mediterranean region of Israel. Villages in our research area attract jackals due to poor sanitation conditions in and around villages. As resources in these villages are abundant and predictable, we expected that space-use patterns of jackals near those villages, including home-range characteristics and movement paths, would differ from those of jackals inhabiting more natural areas. Using radio-locations from 16 individuals (8 near villages and 8 from more natural areas), we found that mean home-range size of jackals close to villages was 6.6 ± 4.5 km2, smaller than mean home-range size of jackals in more natural areas (21.2 ± 9.3 km2, P = 0.001). Similarly, core area size of jackals near villages was 1.2 ± 0.92 km2, compared to 3.5 ± 1.6 km2 for individuals inhabiting more natural areas (P = 0.004). The core area/home-range ratio was greater for jackals near villages than for those occupying more natural areas (0.122 ± 0.045 vs. 0.095 ± 0.037, respectively, P = 0.004). Jackals moved little during the day, with day ranges smaller for jackals near villages than away from them (1.65 ± 0.67 vs. 7.5 ± 5.6 km2, respectively, P = 0.028). However, jackals near villages moved as much at night as did jackals in more natural areas, although movement was in a less directional manner. Changes in distribution and predictability of resources due to anthropogenic activity affect not only the home-range size of jackals, but also how they utilize and move through space. © 2011 The Wildlife Society.
... However, the factors behind these behavioural differences are not known. It is possible that antlion larvae adjust the timing of their hunting activity to that of their prey, a common behavioural trait of numerous other predators (e.g. Sabato et al. 2006 ). A previous study supports such possible adaptation, since antlion larvae are known to adjust their thermal activity range to that of their potential prey (Marsh 1987 ). ...
Pit-building antlion larvae are small sit-and-wait arthropod predators that dig conical pits in sandy soils. We investigated the effect of exposure to constant light versus constant dark conditions on antlion behaviour. Antlions tended to relocate less often, construct pits more frequently and construct larger pits in constant light. We interpret this as an indication of dichotomous behaviour under light versus dark conditions such that antlion larvae hunt during the day and modify their positions at night. Antlion larvae immediately responded to the complete switch in this illumination treatment and adapted their behaviour to fit the new conditions. Prey capture success did not differ between the constant light and constant dark conditions. When provided with a choice between light and dark conditions, the vast majority of larvae preferred the former. Those that preferred constant dark, however, were on average larger than those that preferred constant light. We thus suggest that since larger antlion larvae possess larger fat reserves, they can afford reductions in foraging activity (possibly to increase safety). An examination of the antlion trade-off between their preference for light and their preference for sand depth (which may affect their ability to evade predators) showed that their response to illumination was much more prominent, irrespective of the sand depth. Finally, combining light with other factors such as temperature and density may further elucidate microhabitat selection in pit-building antlion larvae.
The maned wolf Chrysocyon brachyurus (Illiger 1815) is considered the largest canid in South America, it has crepuscular nocturnal behavior, solitary and skittish habits. Its vocalization has different classifications, one of them called roar-barks, which helps in long-distance communication, being ideal for passive acoustic monitoring. For the study of the vocalizations of C. brachyurus in the Ecological Station of Itirapina in Brazil, were implanted 6 autonomous recorders called EcoPods. The locations of the station with the highest detection of vocalizations, their characteristics, temporal distribution in relation to sunset and moon phases were studied. The point with the highest concentration of roar-barks is the same as the point with the litter’s vocalization, indicating the importance of vocalizations in parental care. Passive acoustic monitoring allows a less invasive study and helps to understand the behavior of the maned wolf for its preservation.
In recent decades, the golden jackal Canis aureus has experienced a population increase in many European countries, including Croatia. As a result, human-jackal conflicts (e.g., damage to livestock and wildlife, general nuisance in (sub)urban areas) have increased dramatically, and there is an urgent need to develop and use a range of mitigation tools that also aim to control population growth. Hunting is one of the well-known tools for population control, therefore the aim of this study was to determine the effects of habitat type and weather conditions on jackal hunting success. From 2019 to 2023, a total of 217 jackals were culled during 106 hunting events in an approximately 10,500 ha lowland habitat along the Sava River in central Croatia. All jackals (56% males and 44% females) were culled using small calibre rifle (222 Remington) with night vision scope. Based on age structure, 16% juveniles and 84% adults were shot, and the average catch per unit effort (CPUE) was 2.0 animals/day. The best hunting success was obtained by attracting jackals with a calling method, i.e., by playing the sound of a wounded hare. Regarding the type of habitat, 56% of the culls were in cultivated, non-forested areas. It was confirmed that weather conditions, i.e., daily temperature and precipitation, influence hunting success, especially for males. Hunting success of adult males was lower on days with higher temperatures and on days with more precipitation. We can state that individual hunting with using calling method is an effective tool for successful golden jackals harvesting; moreover, jackal hunting can minimize the conflict with gamekeepers and farmers, and would help to improve public perception of jackals.
An increase of nocturnal activity of ungulate species may represent a compensatory opportunity for energy intake, when activity in daylight is hindered by some disturbance events (e.g. hunting or predation). Therefore, mostly-diurnal and crepus-cular species may be active in bright moonlight nights whereas others may shift their diurnal activity towards darkest nights to limit their exposure to predators. In natural and undisturbed conditions, the wild boar may be active both during the day and the night, with alternating periods of activity and resting. In this work, we tested whether activity patterns of wild boar, a species with poor visive abilities, were dependent on moon phases and environmental lightening. We aimed to assess if nocturnal activity could be better explained by variations of the lunar cycle or by the variations of environmental lightening conditions, evaluated by means of different measures of night brightness. Data were collected through camera-trapping in Central Italy in 2019-2020. Despite the poor visive abilities of the wild boar, we observed that this ungulate significantly reduced their activity by avoiding the brightest nights. In our study area, the wild boar has to cope with both human pressure (i.e. mostly hunters and poachers) and predation by the grey wolf. Furthermore, the nocturnal activity of wild boar peaked in mid-Autumn, i.e. when hunting pressure is the highest and when leaf fall may bring wild boar to range for long distances to find suitable resting sites for diurnal hours.
Moonlight plays a significant role in prey–predator relationships. At full moon, predators' hunting success and activity rates generally increase. Even though the analysis of facultative carnivore movement patterns can improve our knowledge of how moonlight can change the behaviour of such a group of species with diverse ecological needs, few studies have been conducted with facultative carnivores and none with telemetric data. Here, we studied whether moonlight influences brown bear, Ursus arctos, movement behaviours. By analysing data collected from 2002 to 2014 for 71 collared individuals inhabiting Finland and Russian Karelia, we found that some internal and external factors are influencing brown bear movement patterns. In particular, this facultative carnivore moves more slowly and over shorter distances during hyperphagia periods than during the mating season. However, moonlight does not affect brown bear movements. Although brown bears are large carnivores, they are opportunistic omnivores with a high fruit diet and, therefore, the prey–predator relationships that are behind the dependence of carnivores on moonlight seem to be weaker than in obligate carnivores.
For millennia, people have associated the Moon with human behaviour. The concept of lunacy is derived from a presumed destabilising effect on the mind, although there is limited evidence of such causation. Recent sleep research has renewed interest in lunar influence, showing qualitative and quantitative changes in sleep at full moon. This brief review of studies measuring sleep in relation to the lunar cycle discusses possible impact on mental health and presents implications for further study.
The illumination and the gravitational pull of the moon on the earth are not same in all the prominent position of the moon during the lunar month, i.e. new moon (NM), first quarter (FQ), full moon (FM) and third quarter (TQ), and the amplitude of ocean tides also varies among those lunar phases. A huge number of investigations have shown the relation of lunar phases with the different activity of living organisms, like the activity pattern of marine and other animals, birds, insects and humans. These alterations of activity pattern may be due to the changes of lunar gravitational force on the earth surface and changes of “biological tide” or the alteration of electromagnetic field of the earth and lunar illumination. The altered autonomic neural activity and cardiovascular activity of higher vertebrates and light/dark cycle in different lunar phases are probably the fundamental causes of the changes of activity of other living organisms.
It is assumed that the response of the regulatory system of mammal activity, depends on the changes in light intensity throughout the 24-h cycle. The aim of this study was to determine whether the moon luminosity cycle exerts an effect on the locomotor activity of the Mexican wolf (C.lupus baileyi). Data collection was carried out with the actimetry, of 11 individuals were analyzed using ANOVA to determine the effect of the lunar cycle. Significant differences were encountered between moon phases (p = 0.001), with a decrement of activity during new and full moon. However, effects were dependent also on the age of the individuals and the daylight period. On the other hand, it is a possible regulation of the activity pattern by the effect of lunar periodicity. This periodicity needs a more detailed examination to determine its adaptive function.
We present here a compilation of the mammal species associated with the Reserva Particular do Patrimônio Natural (RPPN) Santuário do Caraça. From records confirmed by captures, visual observations, and indirect evidence we list 70 species of mammals, including Alouatta guariba, Chrysocyon brachyurus, Leopardus pardalis, Leopardus wiedii, Pecari tajacu, Puma concolor, Tapirus terrestris and Trinomys moojeni that are considered to be threatened species according to the Red Lists (Minas Gerais, Brazil, IUCN) and nine species endemic to the Atlantic Forest. Our findings reaffirm the importance of the reserve for the conservation of mammals, but also identify areas in need of further investigation, particularly regarding the threatened species.
The study of animal personality has important implications in conservation programs. When reintroduction is used for the preservation of a species, the survival ratio of reintroduced animals needs to be high. The determination of animal personality helps choosing the right animals, therefore increasing their survival chances and also increasing the reintroduction success. Three captive, male maned wolves were chosen for personality evaluation. Two personality tests were carried out and compared: The boldness score test estimated the level of boldness from a series of behaviors divided into bold, shy and fear categories; and questionnaires showed how zookeepers perceived the personality of the same three animals, while they were working with them. According to the boldness score calculation, Maned Wolf Two (MW2) was the boldest, followed, in order, by MW1 and MW3. According to the questionnaires, MW1 was the boldest, followed by MW2 and by MW3. Reasons for these contradictory results and variables that should be considered in both tests for increasing their accuracy are discussed. Used together, these tests showed to be helpful tools for choosing among individuals to be released in the wild.
This study aimed to verify the hypothesis that the lunar cycle influences the number of pediatric psychiatric emergency department (ED) visits.
Pediatric psychiatric ED visits between 2009 and 2011 were obtained retrospectively. Patients aged between 4 and 21 years presenting to Miami Children's Hospital ED with a primary psychiatric complaint were included in the study. Patients with a concomitant psychiatric problem and a secondary medical condition were excluded. The number of psychiatric visits was retrieved for the full moon dates, control dates as well as the day before and after the full moon when the moon appears full to the naked eye (full moon effect). A comparison was made using the 2-sample independent t test.
Between 2009 and 2011, 36 dates were considered as the true full moon dates and 108 dates as the "full moon effect." A total of 559 patients were included in the study. The 2-sample independent t tests were performed between the actual full moon date and control dates, as well as between the "full moon effect" dates and control dates. Our results failed to show a statistical significance when comparing the number of pediatric psychiatric patients presenting to a children's hospital ED during a full moon and a non-full moon date.
Our study's results are in agreement with those involving adult patients. The full moon does not affect psychiatric visits in a children's hospital.
Most studies in chronobiology focus on solar cycles (daily and annual). Moonlight and the lunar cycle received considerably less attention by chronobiologists. An exception are rhythms in intertidal species. Terrestrial ecologists long ago acknowledged the effects of moonlight on predation success, and consequently on predation risk, foraging behaviour and habitat use, while marine biologists have focused more on the behaviour and mainly on reproduction synchronization with relation to the Moon phase. Lately, several studies in different animal taxa addressed the role of moonlight in determining activity and studied the underlying mechanisms. In this paper, we review the ecological and behavioural evidence showing the effect of moonlight on activity, discuss the adaptive value of these changes, and describe possible mechanisms underlying this effect. We will also refer to other sources of night-time light ('light pollution') and highlight open questions that demand further studies.
Animals should use habitats that increase their chances of survival and reproductive output; thus, information on habitat use can be useful both from an ecological and a conservation perspective. Using global positioning system tracking collars, we studied habitat use by a pair of Chrysocyon brachyurus (maned wolves) living in a cerrado-Atlantic forest transition zone in Brazil. During our study, the female had a litter of pups, and we were able to evaluate how reproduction affected habitat use. To investigate habitat use, we mapped our telemetry fixes onto vegetational and geographical data obtained from satellite images of our study site. We investigated habitat use by maned wolves in relation to vegetation and land cover, proximity to buildings, proximity to roads, elevation, and distance to water sources. Maned wolves showed a strong preference for rocky fields, which are a subhabitat of cerrado, and a strong avoidance of Atlantic rain forest. Maned wolves also were associated significantly and positively with buildings and roads at night, likely because of supplemental feeding and ease of locomotion. Elevation was confounded with habitat type and the location of supplemental feeding; therefore, no firm conclusions could be drawn about this factor. The female remained <= 250 m from water when she was lactating. Although maned wolves can be behaviorally flexible in terms of habitat use, they show a strong preference for open habitats such as cerrado that is especially pronounced during a reproductive phase.
Procedures that increase foraging and exploratory behaviours are generally accepted as effective at improving welfare and reducing stereotypies in captive animals. To determine the effect of food and toy enrichment on the behaviour and hormonal levels of maned wolves (Chrysocyon brachyurus), 11 wolves were submitted to a baseline-enrichment-baseline schedule with four enrichment conditions: food scattering, toy presentation, edible toy presentation, and a combination of food and toy conditions. Behaviour and glucocorticoid metabolite concentrations (GCM) were assessed throughout the experiment. Our hypotheses were that enrichment procedures would lead to an increase in activity in the short and long term, a decrease in pacing, and a reduction in GCM concentrations. We also hypothesised that the concentrations of GCM would show a correlation with behaviour. Enrichment conditions increased immediate locomotion but did not produce long-term changes of activity nor reduced pacing. The procedures had a clear effect on individual behaviour and induced, under food enrichment conditions, an increased interest in food. Enrichment did not lead to decreased GCM concentration in the group as a whole, but there was a tendency for male and female animals to differ in hormonal reactions to environmental change. A positive correlation between GCM concentrations and pacing behaviour and a negative correlation between GCM concentrations and social behaviour were found. Results suggest that food scattering as an enrichment procedure may be used with maned wolves to enhance welfare, whilst also revealing the importance of taking individual and gender differences into account when planning enrichment techniques.
Predation has long been implicated as a major selective force in the evolution of several morphological and behavioral characteristics of animals. The importance of predation during evolutionary time is clear, but growing evidence suggests that animals also have the ability to assess and behaviorally influence their risk of being preyed upon in ecological time (i.e., during their lifetime). We develop an abstraction of the predation process in which several components of predation risk are identified. A review of the literature indicates that an animal's ability to assess and behaviorally control one or more of these components strongly influences decision making in feeding animals, as well as in animals deciding when and how to escape predators, when and how to be social, or even, for fishes, when and how to breathe air. This review also reveals that such decision making reflects apparent trade-offs between the risk of predation and the benefits to be gained from engaging in a given activity. Despite this body of evidence, several areas in the study of animal behavior have received little or no attention from a predation perspective. We identify several such areas, the most important of which is that dealing with animal reproduction. Much work also remains regarding the precise nature of the risk of predation and how it is actually perceived by animals, and the extent to which they can behaviorally control their risk of predation. Mathematical models will likely play a major role in future work, and we suggest that modelers strive to consider the potential complexity in behavioral responses to predation risk. Overall, since virtually every animal is potential prey for others, research that seriously considers the influence of predation risk will provide significant insight into the nature of animal behavior.
were active 45.2% 6 0.9 SE of the time and traveled 0.92 6 0.05 km/h. The mean length of activity bouts was 0.76 6 0.05 h, whereas inactivity bouts averaged 1.02 6 0.07 h. Wolves were active throughout the day, but their activity peaked at dawn and dusk, which coincided with periods when they killed most prey. Periods of reproduction and high tem- peratures had less pronounced effects on activity patterns. Human activity and other factors did not significantly affect the wolves' daily activity patterns. The influence of humans may be indirect if hunting of ungulates by humans modifies activity patterns of the wolves' prey. We conclude that the daily activity patterns of wolves in our study area were mainly shaped by their pattern of hunting prey.
Animals are exposed to many conflicting ecological pressures, and the effect of one may often obscure that of another. A likely example of this is the so-called ‘‘lunar phobia’’ or reduced activity of bats during full moon. The main reason for lunar phobia was thought to be that bats adjust their activity to avoid predators. However, bats can be prey, but many are carnivorous and therefore predators themselves. Thus, they are likely to be influenced by prey availability as well as predation risk. We investigated the activity patterns of the perchhunting Lophostoma silvicolum and one of its main types of prey, katydids, to assess the influence of the former during different phases of the lunar cycle on a gleaning
insectivorous bat. To avoid sampling bias, we used sound recordings and two different capture methods for the katydids, as well as video monitoring and radiotelemetry for the bats. Both, bats and katydids were
significantly more active during the dark periods associated with new moon compared to bright periods around the full moon. We conclude that foraging activity of L. silvicolum is probably influenced by prey availability to a large extent and argue that generally the causes of lunar phobia are species-specific.
Optimal behavior theory suggests that prey animals will reduce activity during intermittent periods when elevated predation risk outweighs the fitness benefits of activity. Specifically, the predation risk allocation hypothesis predicts that prey activity should decrease dramatically at times of high predation risk if there is high temporal variation in predation risk but should remain relatively uniform when temporal variation in predation risk is low. To test these predictions we examined the seasonably variable response of snowshoe hares to moonlight and predation risk. Unlike studies finding uniform avoidance of moonlight in small mammals, we find that moonlight avoidance is seasonal and corresponds to seasonal variation in moonlight intensity. We radio-collared 177 wild snowshoe hares to estimate predation rates as a measure of risk and used movement distances from a sample of those animals as a measure of activity. In the snowy season, 5-day periods around full moons had 2.5 times more predation than around new moons, but that ratio of the increased predation rate was only 1.8 in the snow-free season. There was no significant increase in use of habitats with more hiding cover during full moons. Snowshoe hares' nightly movement distances decreased during high-risk full-moon periods in the snowy season but did not change according to moon phase in the snow-free season. These results are consistent with the predation risk allocation hypothesis. Copyright 2005.
In our study of the development of diving in Galápagos fur seals, we analysed changes in diving activity and body mass trends over the lunar cycle. Based on previously observed lunar cycles in colony attendance patterns, we hypothesized a greater impact of prey migrations of deep scattering layer organisms on younger fur seals. Using electronic dive recorders, we determined that seals dived less and deeper on moonlit nights than at new moon, and incurred body mass losses. These changes in foraging over the lunar cycle correlate with the suppression of the vertical migration of prey by lunar light. All effects were more pronounced in juveniles than adult females, with greater relative mass loss during full moon, which must (i) negatively affect long-term juvenile growth rates, (ii) lengthen periods of maternal dependence, and (iii) contribute to the lowest reproductive rate reported for seals. This underlines the importance of studying ontogeny in order to understand life histories, and for determining the susceptibility of animal populations to fluctuations in food availability.
Variations in predation risk affect the costs of foraging and may therefore warrant different foraging decisions. One class of models ("higher requisite profit") predicts that foragers should become more selective when predation risk increases, as low-profitability items that do not cover the increased costs are dropped from the diet. An alternative class of models ("reduced finickiness") predicts that foragers should become less selective when predation risk increases, because selectivity requires more extensive assessment and/or search behaviour, prolonging exposure to risk. We assessed the selectivity of foraging heteromyid rodents (Merriam's kangaroo rats, Dipodomys merriami, and pocket mice, Chaetodipus spp.) by comparing differences in "giving up densities" (GUD: the quantity of cryptic food left in a patch by animals for whom the diminishing marginal gains from foraging have dropped below the threshold for continued search) for foods of different value as a measure of selectivity in patches varying in predation risk. Data collected over two field seasons revealed that heteromyids were more selective when predation risk was highest; away from the protective cover of shrubs during the full moon. These findings support the predictions of higher requisite profit models.
The daily pattern of surface activity of banner-tailed kangaroo rats was measured by recording visits to automated feeders, which provided small quantities of millet. From November through March the activity pattern was nocturnal, with an early-evening peak and less activity during moon-up than moon-down. However, as a record drought developed and nights shortened in the spring, moonlight-avoidance ceased and nocturnal activity increased, with small amounts of daylight activity in May. Daylight activity increased during summer, becoming equal to night activity, then began to return to the usual nocturnal pattern at the same time as new vegetation appeared in response to summer rain.
Our primary study objective was to test the accuracy and reliability of consumer-grade GPS receivers in a variety of landscape settings. We established three measurement testing courses in open sky, young forest, and closed canopy settings within a conifer-dominated forest in western Oregon and rigorously tested the positional accuracy of six different GPS. All units were produced by established GPS manufacturers. We found that performance varied, in some cases considerably, among units and appeared to be influenced by canopy cover and satellite availability. Among the top GPS performers, we determined that users could expect positional accuracies within approximately 5 m of true position in open sky settings, 7 m in young forest conditions, and 10 m under closed canopies.
Analysis of 141 scats of maned wolf Chrysocyon brachyurus collected in a region of upland forest and meadows of south-eastern Brazil yielded 351 food items in the wet season (60 scats) and 407 in the dry season (81 scats). Scarabaeidae and rodents were the most frequent animal food in both seasons, complemented by birds in the wet season and unidentified mammals in the dry season. Seeds revealed Solanum lycocarpum to be the most frequent plant food in the dry season and an Annonaceae and a Cactaceae the most frequent in the wet season. A total of 33 seed morphospecies were retrieved. Although our results reveal some shared and some divergent trends from dietary studies undertaken in savanna (‘cerrado’) areas, we found a very high frequency of potentially harmful tourists' garbage. This highlights the necessity for better environmental education and confirms that the maned wolf is a generalist and opportunist omnivore.
The maned wolf Chrysocyon brachyurus is the largest canid inhabiting South America. Its geographic distribution includes the open fields of Brazil's central area, which is currently undergoing agricultural expansion. The diet of the maned wolf and its seasonal variation was determined on a dairy cattle ranch (São Luís farm, 566 ha) in the State of Minas Gerais, Brazil. From January to December faeces of the maned wolf were collected monthly (n= 150 scats; 397 food item occurrences). Twenty-nine taxa were identified from scats, 18 of animal origin (46% or 183 occurrences) and 11 of plants (54% or 214 occurrences). The fruits of Solanum lycocarpum were the dominant food item in our study (29%). Mammals contributed 13%, arthropods 12%, birds 11% and reptiles 2% of the food items. Arthropods and fruits were prevalent in the rainy season and mammals in the dry season. As expected for a heavily farmed region, frugivory results were at the lower end of the diversity scale (9–33 species) and included four old garden species. No previous study of the diet of maned wolf has registered as many species of Solanaceae as this one. Although dietary richness was lower, the main food items (wolf fruit, armadillos, rodents, birds) were the same as study sites in ‘cerrado’ and upland meadows. In this region, the open habitats occupied by the maned wolf were previously covered by Atlantic forest, suggesting that landscape modification such as cattle ranching has opened new frontiers for distribution expansion of the maned wolf. The impact of loss of dietary richness and the increase in Solanaceae on the survival of the maned wolf need to be evaluated.
The maned wolf Chrysocyon brachyurus is a nocturnal and shy species, which has proven difficult to study in the field; consequently, data about its behavioural biology are almost absent from the scientific literature. However, recent advances in global positioning system (GPS) technology mean that it is now possible to study the socio-spatial dynamics of this species in the field. In the present study three related maned wolves (an adult pair and their juvenile female offspring) were monitored by GPS tracking collars for a 6-month period, which included the birth of a litter of pups to the adult pair. The three GPS collars were programmed to record the position of the wearer every 2 h (simultaneously for all three individuals). Analyses of the data from the three individuals showed that the female had the largest home range, then the male and finally the juvenile. Furthermore, there was considerable overlap in home-range use by all three individuals. The home ranges of the adult pair also varied in relation to the birth of pups (decreasing dramatically and then showing a slow increase). During the night, which is the normal period of activity for this species, the three individuals avoided contact with each other. However, during the day, the adult pair usually slept together and their juvenile slept within a few hundred metres of their location. The distance travelled at night was greatest for the female, then the male and finally the juvenile. These data suggest that (1) the social bond between the male and female is strong, (2) maned wolves are highly tolerant of their juvenile offspring, even in the case of new pups being born, and (3) that maned wolves do not hunt together and, in fact, avoid each other when hunting.
Male treefrogs, Smilisca sila (Hylidae), produce calls of varying complexity and demonstrate a remarkable ability to synchronize their calls with those of neighbors. The bat Trachops cirrhosus eats frogs and uses the frogs' advertisement calls as locational cues. The bats are less likely to respond to synchronous calls than to asynchronous calls, and when given a choice prefer complex calls to simple calls.Experiments with bat models indicate that, like other frogs, S. sila probably uses visual cues to detect hunting bats. In response to bat models the frogs decreased both the number and the complexity of their calls. The calling behavior of the frogs was sampled in the field during periods with and without artificial illumination. The frogs produced fewer and less complex calls, and they tended to call from more concealed sites, during the period without illumination, when presumably it would have been more difficult for the frogs to detect hunting bats.
S. sila tended to call from sites with higher ambient noise level, the noise primarily originating from waterfalls. The frequencies of the dominant energies in the waterfall sounds completely overlapped the frequency range of the S. sila call; thus waterfalls might mask the frog calls. When given a choice between calls produced near and away from waterfall sounds, bats preferred the latter.
The temporal and spatial distribution of above-ground activith in Merriam's kangaroo rats, Dipodomys merriami, radio-tracked during 10 winters varied in relation to phases of the moon. At the full moon, animals were more likely to be found in their day burrows at scheduled hourly radio fixes, and when they emerged, they stayed closer to home. At partial moon phases, above-ground activity was preferentially allocated to hours when the moon was down. As predicted from an extension of Rosenzweig's (1974, J. Mammal., 55, 193–199) model of optimal above-ground activity, the suppression of nocturnal activity at the full moon was partially offset by relatively great activity at dusk and dawn, and losses to nocturnal versus diurnal predators were distributed differently over the lunar cycle. Gross predation rates did not differ significantly among moon phases, but the kangaroo rats' relatively crepuscular activity pattern at the full moon both reduced their vulnerability to nocturnal predators, as compared with the new moon phase, and raised their vulnerability to diurnal shrikes.
The effects of lunar light on the activity of old-field mice, Peromyscas polionotus, were determined by tracking in outdoor enclosures. Surface activity was inhibited by about 70% in full moon, 56% in three-quarter moon, 32% in half moon and 23% in quarter moon. The mice shifted their activity from the open area to cover during moonlit periods, thus inhibition in open areas was greater than indicated above. Activity patterns were not related to proximate foraging requirements, as food was provided ad libitum in the centre of the enclosures.
Thesis (Ph. D.)--Michigan State University. Dept. of Zoology, 1981. Includes bibliographical references (leaves 175-185). Microfilm. s
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Behavioural modulation of predation risk: moonlight avoidance and crepuscular com-pensation in a nocturnal desert rodent, Dipodmys merriami The secret lives of maned wolves Chrysocyon brachyurus Illiger 1815: as revealed by GPS tracking collars
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Activity levels of bats and katydids in relation to the lunar cycle
- Lang