Nocturnal Activity Patterns Research Articles

Comparative study on the nocturnal activity of phlebotomine sand flies in a highland and lowland foci of visceral leishmaniasis in north-western Ethiopia with special reference to Phlebotomus orientalis

BackgroundLeishmania donovani, the causative agent of visceral leishmaniasis (VL), is most probably vectored by Phlebotomus orientalis in north-western Ethiopia. The aim of this study was to determine and compare the nocturnal activity patterns of Ph. orientalis in VL endemic foci of Libo-Kemkem (highland) and Metema (lowland) districts of north-western Ethiopia.MethodsSampling of sand flies was conducted bimonthly from January-May 2012 in the highland and from March-June 2013 in the lowland. Sand flies were sampled using two CDC light traps placed in compounds occupied by both cattle and humans. Sampling of sand flies started at 18:00 h and ended at 06:00 h. Every hour, a cage was replaced by another cage.ResultsIn total, 9479 nocturnally active sand flies were collected from both study areas. Six Phlebotomus species (Ph. orientalis, Ph. duboscqi, Ph. papatasi, Ph. bergeroti, Ph. rodhaini and Ph. martini) and several Sergentomyia spp. were identified. In both areas, of the six Phlebotomus spp., Ph. orientalis was the preponderate. In the highland, the hourly activity pattern of Ph. orientalis females was higher before midnight with a peak in density between 22:00–23:00 h, whereas in the lowland after midnight between 03:00–04:00 h.ConclusionsThe present study showed that Ph. orientalis females exhibited different nocturnal activity patterns with a peak in the early part of the night in the highland and in the latter part of the night in the lowland areas. As the risk of acquiring L. donovani infections vary in the two areas, appropriate control strategies should be developed according to the activity of Ph. orientalis in the respective areas.

Thermoconformity strategy in the freshwater turtle Hydromedusa tectifera (Testudines, Chelidae) in its southern distribution area

Ectotherm species are not capable of generating metabolic heat; therefore, they present different strategies for regulating their body temperatures, ranging from a precise degree of thermoregulation to a passive thermoconformity with ambient temperatures. In reptiles, aerial basking is the most common mechanism for gaining heat. However, among aquatic reptiles, such as freshwater turtles, aquatic basking is also frequent. Hydromedusa tectifera is a turtle of exclusively aquatic and nocturnal habits widely distributed in South America. We studied the relationship between body temperature (Tb) of H. tectifera and its habitat, and explored the effects of sex, life stage and body size and mass on Tb. Fieldwork was conducted in two streams of a mountain area of central Argentina. We recorded cloacal temperature, size and mass of 84 turtles. We also determined individuals’ sex and life stage (adult/juvenile). Regarding ambient temperatures, we measured water temperature on the surface (Tsurf) and at depth of turtle capture (Tdepth) and air temperature. Mean Tb was 18.58°C (Min = 10.20°C; Max = 25.70°C). Tsurf and Tdepth were highly correlated. Multi-model analysis using Akaike criterion indicated that Tb was strongly associated with water temperature, whereas air temperature and body size and mass did not show a significant effect. There was also no effect of turtle sex or life stage on Tb. Our results indicate that H. tectifera is a thermoconformer and eurythermal species. A nocturnal pattern of activity and a fully aquatic lifestyle are suggested as determinant factors.

Effects of light and microhabitat on activity pattern and behaviour of wild and hatchery-reared juveniles ofStichopuscf.horrens

Animals develop behavioural strategies throughout life to improve their survival in nature. Juvenile activity and behaviour of the commercial tropical sea cucumberStichopuscf.horrenswere examined considering factors that may influence survival at this critical developmental stage. Wild juveniles were observedin situto describe diel activity and movement. Wild and hatchery-reared juveniles were observed in the laboratory to evaluate the influence of different light-dark cycles and microhabitats on feeding and sheltering behaviour. All juveniles (4–54 g) displayed a distinct nocturnal activity pattern both in the field and laboratory. Nocturnal activity was strongly associated with feeding and locomotion. Wild and hatchery-reared juveniles were most active at night, displayed intermediate activity during twilight, and minimal to no activity during daytime. Movement rates of wild juvenilesin situwere significantly influenced by time and size to a lesser extent. Under constant light and constant dark for 48 h, juvenile feeding rhythm was endogenously controlled and strongly entrained to natural light-dark cycles. Sheltering was directly affected by light and linked to strong phototactic and thigmotactic reflexes. Juveniles preferred vegetation as shelter compared to coral, sand or open space, and showed equal preference for seagrass and macroalgae. Deviations in behaviour of hatchery-reared juveniles under laboratory conditions indicate some degree of acclimation to an artificial environment with minimal threats and a decreased sensitivity to light. The implications of nocturnal feeding, light-induced sheltering, shelter preferences and acclimation to artificial conditions are discussed in relation to juvenile survival in nature and potential restocking of the species.

The activity patterns of two sympatric shrew species from the Eastern Cape Province, South Africa

AbstractThe locomotor activity patterns of two species of shrew were investigated under both standard laboratory conditions and in their natural environment. Trapping, using live traps, was undertaken on a seasonal basis to determine the predominant periods of activity for each species in their natural habitat. We assessed if there was a seasonal variation to the locomotor activity in the shrews. In the laboratory, locomotor activity patterns were investigated under the following lighting conditions, in sequence; 12L:12D (2 weeks), constant darkness (3 weeks), 12L:12D (2 weeks), 12D:12L an inverted light cycle (2 weeks) followed by 6 weeks at 16L:8D and 8L:16D for each species. Temperature was maintained at a constant temperature of 25 ± 1°C. Foraging behaviour and body mass changes were recorded throughout the study. Both species exhibited predominantly nocturnal locomotory activity patterns under laboratory conditions. In the field the forest shrew, Myosorex varius, altered its predominant activity period depending on the season, displayed polyphasic activity patterns and was caught throughout the year; it neither gained nor lost body mass. The greater red musk shrew, Crocidura flavescens, was strictly nocturnal in the field, more so than under laboratory conditions, gained body mass readily in the laboratory and was very rarely captured during winter. Therefore, each species displayed slightly different behavioural adaptations when exposed to the same conditions. These findings emphasize the similarities and differences in activity amongst co‐occurring small mammal species in light of possible competition avoidance mechanisms.

Spatial and temporal response of wildlife to recreational activities in the San Francisco Bay ecoregion

Non-motorized human recreation may displace animals from otherwise suitable habitat; in addition, animals may alter their activity patterns to reduce (or increase) interactions with recreationists. We investigated how hiking, mountain biking, equestrians, and recreationists with domestic dogs affected habitat use and diel activity patterns of ten species of medium and large-sized mammals in the San Francisco Bay ecoregion. We used camera traps to quantify habitat use and activity patterns of wild mammals and human recreationists at 241 locations in 87 protected areas. We modeled habitat use with a multi-species occupancy model. Species habitat use was most closely associated with environmental covariates such as landcover, precipitation, and elevation. Although recreation had less influence on habitat use, the presence of domestic dogs was negatively associated with habitat use of mountain lions and Virginia opossum. We also compared diel activity patterns of species at sites with no observed recreation to the activity patterns of species at sites with high (≥eight per day) levels of non-motorized recreation. Coyotes were more active at night and less active during the day in areas with high levels of recreation. Striped skunks were slightly more active later into the morning in areas that allowed human recreation. Smaller carnivores with nocturnal activity patterns may not be directly affected by recreational activities that are limited to daylight hours. We suggest that by maintaining habitat free of domestic dogs, and creating trail-free buffers, land managers can manage recreation in a way that minimizes impacts to wildlife habitat and preserves the value of protected areas to people and wildlife.

Deletion of Gpr55 Results in Subtle Effects on Energy Metabolism, Motor Activity and Thermal Pain Sensation.

The G-protein coupled receptor 55 (GPR55) is activated by cannabinoids and non-cannabinoid molecules and has been speculated to play a modulatory role in a large variety of physiological and pathological processes, including in metabolically perturbed states. We therefore generated male mice deficient in the gene coding for the cannabinoid/lysophosphatidylinositol (LPI) receptor Gpr55 and characterized them under normal dietary conditions as well as during high energy dense diet feeding followed by challenge with the CB1 receptor antagonist/GPR55 agonist rimonabant. Gpr55 deficient male mice (Gpr55 KO) were phenotypically indistinguishable from their wild type (WT) siblings for the most part. However, Gpr55 KO animals displayed an intriguing nocturnal pattern of motor activity and energy expenditure (EE). During the initial 6 hours of the night, motor activity was significantly elevated without any significant effect observed in EE. Interestingly, during the last 6 hours of the night motor activity was similar but EE was significantly decreased in the Gpr55 KO mice. No significant difference in motor activity was detected during daytime, but EE was lower in the Gpr55 KO compared to WT mice. The aforementioned patterns were not associated with alterations in energy intake, daytime core body temperature, body weight (BW) or composition, although a non-significant tendency to increased adiposity was seen in Gpr55 KO compared to WT mice. Detailed analyses of daytime activity in the Open Field paradigm unveiled lower horizontal activity and rearing time for the Gpr55 KO mice. Moreover, the Gpr55 KO mice displayed significantly faster reaction time in the tail flick test, indicative of thermal hyperalgesia. The BW-decreasing effect of rimonabant in mice on long-term cafeteria diet did not differ between Gpr55 KO and WT mice. In conclusion, Gpr55 deficiency is associated with subtle effects on diurnal/nocturnal EE and motor activity behaviours but does not appear per se critically required for overall metabolism or behaviours.

Seasonal expression of migratory behavior in a facultative migrant, the pine siskin

The vast majority of what is known about migration comes from studies of obligate migration—regular and predictable “to-and-fro” seasonal movements. Much less is known about facultative migration, which occurs less predictably in space and time. Here, we use pine siskins (Spinus pinus), nomadic and irruptive finches, as a captive model to advance our understanding of facultative migration. Building on approaches used to study obligate migration, we investigate whether pine siskins exhibit migratory restlessness in captivity, similar to obligate migrants, and whether pine siskins express a seasonal pattern of migratory behavior. Pine siskins exhibited nocturnal migratory restlessness that was remarkably similar to that in obligate migrants; it was characterized by jumping and wing whirring behavior that was preceded by a period of quiescence. This behavior was expressed seasonally, peaking in the spring, when free-living pine siskins frequently migrate. As in many obligate migrants, migratory restlessness in pine siskins coincided with elevated body condition and showed minimal overlap with body molt. Although pine siskins are both nocturnal and diurnal migrants, patterns of diurnal activity did not mirror patterns of nocturnal activity and were more difficult to interpret. Free-living pine siskins frequently migrate in the fall, but in captivity showed no clear pattern of fall migratory restlessness. We suggest that this could reflect a relatively predictable and programmed spring migration and a more facultative fall migration. Migrations are undertaken by a diverse array of animals and are important to the functioning of many ecosystems. The goal of this study was to shed light on an important, but understudied form of migration: facultative migration. Facultative migrations occur less predictably than the better-studied “to-and-fro” seasonal migrations of obligate migrants. Using a songbird, the pine siskin, as a model, we sought to determine if pine siskins express a migratory state in captivity and whether pine siskins exhibit a seasonal pattern of migratory behavior. We found that pine siskins showed behavioral and physiological changes associated with a migratory state, which were remarkably similar to those in obligate migrants. Pine siskins showed seasonal changes in migratory behavior in the study that suggest that this species has a predictable and programmed spring migratory period and a much more flexible fall migration.

Quantifying the effect of body mass index, age, and depression severity on 24-h activity patterns in persons with a lifetime history of affective disorders.

BackgroundPatients with affective disorders of different ages have been found to present weight changes and different circadian activity patterns. This study assessed the effects of age, Body Mass Index (BMI) and depression severity on the activity-rest cycle in persons with affective disorders using a novel multifactorial 24-h analysis method.MethodsTwo hundred and thirty-six participants aged between 14 and 85 years underwent 5 to 22 days of actigraphy monitoring (mean duration = 14 days). BMI was also recorded and symptom severity was assessed with the Hamilton Depression Rating Scale (HDRS). Participants were divided into two groups: healthy controls (n = 68) and participants with a lifetime diagnosis of affective disorders (n = 168). First, the multiple regression method was employed to formulate the circadian activity pattern in term of the factors age, BMI and HDRS. For each group, the functional linear analysis method was applied to assess the relative effects of the factors. Finally, Wald-tests were used to assess the contribution of each factor on the circadian activity pattern.ResultsIn the affective disorders group, higher BMI was associated with higher activity levels from 3 am until 5.30 am and with lower activity levels from 10 am until 10.30 pm. Older age was associated with less activity across the day, evening, and night - from 11 am until 5.30 am. Higher HDRS scores were associated with higher activity around 1:30 am. In healthy controls, the effects of BMI and age on activity patterns were less pronounced and affected a narrower portion of the 24-h period.ConclusionThese findings suggest that older age and higher BMI are linked to lower daytime activity levels. Higher BMI and worse symptom severity were also associated with nocturnal activity patterns suggestive of sleep disturbances. The influence of age and BMI on 24-h activity profiles appear to be especially pronounced in people with affective disorders.

Changing winter conditions in the boreal forest: the effects of fluctuating temperature and predation risk on activity and physiological stress level in bank voles

Due to global climate change, the winter conditions in the North are predicted to change, as the time with an intact insulating snow cover gets shorter or disappears altogether. For small mammals, this could cause exposure to strong temperature fluctuations and increased predation risk, inducing severe stress and leading to alterations in the physical condition and behavior. To test this, we exposed bank voles (Myodes glareolus) to different temperature regimes and cues of predator threat under laboratory conditions. The test animals experienced either a stable but cool temperature regime resembling the stable conditions under snow cover, or an unstable temperature regime with cold nights and warmer days simulating the climate change scenario with unstable winter. After 3 weeks, the animals were additionally exposed to owl calls or sounds of non-predatory bird species. Stress levels, activity, food consumption, and body mass were monitored. We observed that the voles exposed to unstable temperatures adjusted their normal, mostly nocturnal, and circadian activity pattern towards a more diurnal rhythm without any significant responses in their stress level. Introducing the sound manipulation elevated the stress levels in females but not in males. The sound-induced stress levels did not differ between the temperature treatments. However, the temperature regime tended to affect anti-predator behavior as individuals experiencing unstable temperatures and a threatening sound decreased their overall activity, unlike individuals under stable temperature treatments. It seems that behavioral plasticity in bank voles may diminish the risk of accumulation of stress in cases of multiple simultaneous stressors. The future course of many ecosystems in the northern hemisphere has raised many questions as climate change is predicted to have notable consequences especially in these regions due to alterations in winter conditions. Our results suggest that these environmental changes could alter the circadian activity pattern and possibly, even the anti-predator behavior of bank voles. However, the adaptability and behavioral plasticity in this species may diminish the risk of pathological accumulation of stress effects.

Terrestrial medium and large-sized mammal’s diversity and activity patterns from Tamá National Natural Park and buffer zone, Colombia

The eastern mountain range of Andes in Colombia is one of the least studied areas for mammals in the country, yet, potentially one of the most diverse. Here we present the first survey of medium and large-sized mammals for Tama National Natural Park (NNP) and La Carpa and La Rochela buffer areas, as basic information for the conservation and management of the NNP, including the potential inclusion of these buffer zones as part of the NNP. We used different complementary survey techniques (i. e., camera-traps, transects and interviews) to assess the diversity of these mammals in a 216 km2 area of the park; our effort included 72 linear transects of 1.8 Km, opportunistic sampling sessions, 16,714 camera trap-days, 39 structured interviews and indirect records and direct observation of animals. We recorded 21 species of mammals classified in 8 orders and 16 families distributed in four conservation categories. Complementary methods significantly improved the results. We found a dominant nocturnal activity pattern for the assemblage and low activity overlapping among most species. This is the first assessment of medium and large-sized mammal’s diversity for Tama NNP and for most North-eastern Andes in the country. Our results highlight the presence of large threatened species such as Tremarctos ornatus, Puma concolor and Mazama rufina. Our results could serve as basis for the conservation planning and management of the protected area and its buffer zones, and the potential expansion of the park.

Flight patterns and sex ratio of beetles of the subfamily Dynastinae (Coleoptera, Melolonthidae)

Dynastinae is one of the most representative subfamilies of Melolonthidae (Scarabaeoidea) and has considerable ecological importance due mainly to interactions with plants of the families Araceae and Annonaceae. This relationship has led to the evolution of nocturnal activity patterns, which are influenced by environmental conditions. In the present study, abiotic factors were investigated to comprehend the influence on the flight patterns and identify the sex ratio of beetles from this subfamily. A study was conducted at Campo de Instrução Marechal Newton Cavalcanti in northeastern Brazil between December 2010 and November 2011. Thirteen species of Dynastinae were identified, most of which were from the genus Cyclocephala. Abundance and richness were greater in the dry season. Six species exhibited peak flight activity at specific periods of the night. More females than males were recorded for Cyclocephala distincta and C. paraguayensis. The present findings suggest that rainfall reduces the flight activity of these beetles and different time schedules may be related to mating behavior, foraging behavior and the avoidance of interspecific resource competition.

Lion proximity, not moon phase, affects the nocturnal movement behaviour of zebra and wildebeest

AbstractMoon phase affects nocturnal activity patterns in mammals. Among ungulates, a number of studies have found animals to be more active over full moon nights. This may be because increased luminosity provides increased opportunity to forage and/or increased ability to detect predators; known as the visual acuity hypothesis. Here, we use GPS‐derived movement data to test for the influence of moon phase on plains zebra Equus quagga and blue wildebeest Connochaetes taurinus activity in Kruger National Park, South Africa. We compare animal movement (rate and displacement) over full and new moon nights, and consider the effect of lion proximity. We found that lion proximity largely determined the nocturnal movements of zebra and wildebeest, not moon phase. When lions were >1 km away, there was no difference in the nocturnal movement activity of prey animals over full and new moon conditions, contradicting previous findings. When lions were within 1 km of these animals, however, the movement of zebra and wildebeest greatly increased over the new moon, the relatively dark period when lion were most likely hunting. Although we could not explicitly test for predator detection here, our findings suggest that the visual acuity hypothesis does not hold for zebra and wildebeest in Kruger National Park (KNP) given that there is no evidence for increased foraging activity over the full moon. The influence of moon phase on the nocturnal activity of African ungulates may be more complicated than anticipated, and we suggest that this cannot be estimated unless predator proximity is accounted for.

Seasonal Dynamics of Phlebotomine Sand Fly Species Proven Vectors of Mediterranean Leishmaniasis Caused by Leishmania infantum.

BackgroundThe recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011–2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported.Methods/Principal FindingsA common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am.ConclusionsDespite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories.

Diurnality as an energy-saving strategy: energetic consequences of temporal niche switching in small mammals.

Endogenous daily (circadian) rhythms allow organisms to anticipate daily changes in the environment. Most mammals are specialized to be active during the night (nocturnal) or day (diurnal). However, typically nocturnal mammals become diurnal when energetically challenged by cold or hunger. The circadian thermo-energetics (CTE) hypothesis predicts that diurnal activity patterns reduce daily energy expenditure (DEE) compared with nocturnal activity patterns. Here, we tested the CTE hypothesis by quantifying the energetic consequences of relevant environmental factors in mice. Under natural conditions, diurnality reduces DEE by 6-10% in energetically challenged mice. Combined with night-time torpor, as observed in mice under prolonged food scarcity, DEE can be reduced by ∼20%. The dominant factor determining the energetic benefit of diurnality is thermal buffering provided by a sheltered resting location. Compared with nocturnal animals, diurnal animals encounter higher ambient temperatures during both day and night, leading to reduced thermogenesis costs in temperate climates. Analysis of weather station data shows that diurnality is energetically beneficial on almost all days of the year in a temperate climate region. Furthermore, diurnality provides energetic benefits at all investigated geographical locations on European longitudinal and latitudinal transects. The reduction of DEE by diurnality provides an ultimate explanation for temporal niche switching observed in typically nocturnal small mammals under energetically challenging conditions. Diurnality allows mammals to compensate for reductions in food availability and temperature as it reduces energetic needs. The optimal circadian organization of an animal ultimately depends on the balance between energetic consequences and other fitness consequences of the selected temporal niche.

Food reward without a timing component does not alter the timing of activity under positive energy balance

Circadian clocks drive daily rhythms in physiology and behavior which allow organisms to anticipate predictable daily changes in the environment. In most mammals, circadian rhythms result in nocturnal activity patterns although plasticity of the circadian system allows activity patterns to shift to different times of day. Such plasticity is seen when food access is restricted to a few hours during the resting (light) phase resulting in food anticipatory activity (FAA) in the hours preceding food availability. The mechanisms underlying FAA are unknown but data suggest the involvement of the reward system and homeostatic regulation of metabolism. We previously demonstrated the isolated effect of metabolism by inducing diurnality in response to energetic challenges. Here the importance of reward timing in inducing daytime activity is assessed.The daily activity distribution of mice earning palatable chocolate at their preferred time by working in a running wheel was compared with that of mice receiving a timed palatable meal at noon. Mice working for chocolate (WFC) without being energetically challenged increased their total daily activity but this did not result in a shift to diurnality. Providing a chocolate meal at noon each day increased daytime activity, identifying food timing as a factor capable of altering the daily distribution of activity and rest. These results show that timing of food reward and energetic challenges are both independently sufficient to induce diurnality in nocturnal mammals. FAA observed following timed food restriction is likely the result of an additive effect of distinct regulatory pathways activated by energetic challenges and food reward.

Beaver (Castor fiber) activity patterns in a predator-free landscape. What is keeping them in the dark?

Activity patterns play an important role in the fitness of animals. Energy conservation, physiological adaptations, prey availability, competition, and predation caused by predators and humans are all important parameters influencing when, and where, animals are active. Over time, however, a change in such external factors can lead to a shift in optimal activity patterns. In this paper, we use camera traps to study the daily activity patterns of Eurasian beavers (Castor fiber) reintroduced into an atypical, predator-free landscape. We explore if and how beavers have adjusted their activity patterns in the absence of predators, and whether this varies with day length and moonshine. Our results reveal that beavers in our study area have a mainly crepuscular and nocturnal activity pattern, similar to animals in more natural landscapes with predators. Changes in day length had only a limited effect on the duration of beavers’ activity, but, contrary to our expectations, beaver activity increased during bright moonlight. Activity patterns were also clearly bimodal during nights with bright moonlight, but unimodal during dark nights. The shape of their activity pattern did change throughout the year. These results suggest that beavers can alter their activity patterns in response to external cues, but that the current absence of predators has not resulted in a relaxation of their nocturnal activity patterns. We discuss our results in light of historical human persecution and suggest that beaver activity patterns continue to be influenced by ghosts of predators past.

Wooing during Day or Night is not the Same: an Experimental Study in the Wolf Spider Schizocosa malitiosa

AbstractDiurnal and nocturnal activity patterns shown by different species will strongly determine the characteristics of signals as well as the sensory channels used during sexual interactions. Despite this, few studies have experimentally tested the effects of lighting and time of day on courtship characteristics in arthropods. Previous studies have shown that the wolf spider Schizocosa malitiosa can be active during the day or at night. We tested whether the period of the day affects the sexual behavior of S. malitiosa, by pairing males and females under diurnal or nocturnal conditions. We carried out mating trials in diurnal and nocturnal conditions in arenas containing female refuges. In diurnal conditions, male leg shaking behavior occurred at higher rates and consisted of greater leg raising angles relatively to nocturnal conditions. We did not find differences in mounts and mount latency between both experimental groups. In nocturnal conditions, female attacks and emergence from refuges were higher. Also, although mount occurrence did not differ between the two treatments, mounts inside the refuge were more frequent in diurnal conditions. Results suggest behavioral flexibility in male courtship and female receptivity responses relative to the time of the day.

A novel citizen science approach for large-scale standardised monitoring of bat activity and distribution, evaluated in eastern England

In many countries, bats have high conservation prioritisation owing to their trophic position, habitat associations and threat level, and many have dedicated management plans. However, poor knowledge of species' ecology, identification issues and surveying challenges mean that large-scale monitoring to produce required distribution and abundance information is less developed than for some other taxa. Static detectors deployed to record bats throughout whole nights have been recommended for standardised acoustic monitoring but to date their cost has prohibited wide uptake. Here we describe an extensive survey approach in which members of the public borrowed detectors to participate in a large-scale monitoring and mapping project. Covering a 15% sample of the study area over two years, the survey generated over 600,000 bat recordings. We describe a semi-automated step-wise method for processing this large volume of recordings to assign identity to species or genus level with low error rates. Twelve species were recorded during the survey, ranging from the near ubiquitous Common Pipistrelle Pipistrellus pipistrellus to the locally scarce Leisler's bat Nyctalus leisleri. We show pronounced patterns of seasonality consistent with post-breeding dispersal and new information on nocturnal activity patterns. Using regression trees we generate new maps of standardised variation in activity which is likely to reflect underlying spatial variation in relative abundance. These reveal hitherto unknown patterns for species of superficially similar status. We conclude that with logistical support and centralised automated species identification it is now possible for the public to contribute to acoustic bat monitoring at an unprecedented scale.

Behavioral and physiological responses of American black bears to landscape features within an agricultural region

Human activities and variation in habitat quality and configuration have been shown to influence space use patterns in many species, but few studies have documented the physiological responses of free‐ranging animals to these factors. We combined remote biologger technology, capturing continuous heart rate values, with locational data from GPS collars to investigate the behavioral and physiological reactions of American black bears (Ursus americanus) to a landscape dominated by agriculture (52.5% areal cover). Our study occurred at the edge of the range of this species, with small, scattered patches of forest within a mosaic of crop fields and an extensive road network. However, only ~2–4% of the area contained crops that bears consumed (corn, sunflowers, oats). We used GPS locations to identify the habitat that bears occupied, and to estimate their rates of travel. Heart rates increased with movement rates, rising by over 30% from resting rate to their fastest travel speeds. We used a modeling approach to distinguish among factors that influenced heart rates independent of movement rates. Bears commonly crossed agricultural areas that provided no food or cover and their heart rates, elevated beyond what was expected from their movement rate, were indicative of a stress response. However, when bears entered agricultural areas composed of edible crops, many individuals showed reduced movement and slower heart rates, suggesting that bears foraging there felt at ease or crops allow bears to more easily forage due to their dense spatial arrangements. Unexpectedly, female bears elicited lower heart rates and lower levels of activity in the most fragmented patches of natural habitat, possibly a sign of human‐avoidance behavior or a reaction related to crossing roads. During fall, as bears prepared for hibernation, their heart rates declined two weeks before their movements slackened, evidence that metabolism slowed to enhance fat accumulation; they also shifted to a nocturnal activity pattern, likely to reduce exertion during the heat of the day. The use of a physiological monitor provided new insights on bear biology and ecology that would not have otherwise been apparent.

Habitat use and relative abundance of the Spotted Paca Cuniculus paca (Linnaeus, 1766) (Rodentia: Cuniculidae) and the Red-rumped Agouti Dasyprocta leporina (Linnaeus, 1758) (Rodentia: Dasyproctidae) in Guatopo National Park, Venezuela

The Spotted Paca Cuniculus paca and the Red-rumped Agouti Dasyprocta leporina are affected by habitat loss and hunting. In Venezuela, their conservation status is unknown, even within protected areas. The objective of this study was to estimate the relative abundance, activity patterns, habitat use, and effect of human activities on these species in Venezuela. To achieve this, 26 camera-trap stations (20.8km 2 ) were established in Guatopo National Park between February and April 2011, characterization of the habitat was undertaken and occupancy models were created. The relative abundance of the Spotted Paca was 1.62 captures/100trap-nights, with a fully nocturnal activity pattern. The relative abundance of the Red-rumped Agouti was 2.32 captures/100trap-nights, with a pronounced diurnal activity pattern. The occupation probability of the Red-rumped Agouti (0.61 SE 0.02) was higher than that of the Spotted Paca (0.27 SE 0.02). Spotted Pacas were mainly found in areas with mature forest and high tree density, whereas the Red-rumped Agoutis were most frequently found in valleys with little disturbed forest. A positive correlation was found between illegal hunting activities and areas occupied by the Spotted Paca. It is important to strengthen the park control measurements to reduce illegal hunting of Spotted Pacas.