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The degree of prey sociality reflects trade-offs between predation risk, and competition for mates and resources. Consequently, the degree of sociality is predicted to differ spatiotemporally. Variations in nychthemeral sociality are, however, understudied. We assessed the activity of solitary, territorial black wildebeest bulls (Connochaetes gnou) over rutting and non-rutting seasons. We predicted that solitary bulls would reduce their nocturnal use of territorial stands and join herds to reduce predation risk from nocturnally hunting lions (Panthera leo), but that these responses would differ across rutting and non-rutting seasons. We used camera trap data and modelled solitary bull and herd activity over 24-hour daily cycles, across rutting and non-rutting seasons. We calculated the proportion of images with solitary bulls and herds across nocturnal and diurnal periods, across both seasons. We show that solitary bulls are predominantly diurnal across both seasons, but the probability of nocturnal detection is higher in the rutting than in the non-rutting season. Furthermore, we recorded a lower proportion of solitary bulls to herds at night in the non-rutting relative to the rutting season. Thus, wildebeest bulls may trade-off predation risk for mate acquisition during the rutting season but reduce risky solitary behaviour during the non-rutting season. [ABSTRACT FROM AUTHOR]

Circadian rhythms are timekeeping mechanisms responsible for an array of biological processes. Disruption of such cycles can detrimentally affect animal health. Circadian rhythms are critical in the co-evolution of host–parasite systems, as synchronization of parasite rhythms to the host can influence infection dynamics and transmission potential. This study examines the circadian rhythms in behaviour and activity of a model fish species (Poecilia reticulata) in isolation and in shoals, both when uninfected and infected with an ectoparasite (Gyrodactylus turnbulli). Additionally, the rhythmical variance of parasite activity under different light conditions as well as rhythmical variance in parasite transmissibility was explored. Overall, infection alters the circadian rhythm of fish, causing nocturnal restlessness. Increased activity of gyrodactylids on the host's skin at night could potentially contribute to this elevated host activity. Whilst migration of gyrodactylids across the host's skin may have caused irritation to the host resulting in nocturnal restlessness, the disruption in guppy activity rhythm caused by the expression of host innate immunity cannot be excluded. We discuss the wider repercussions such behavioural responses to infection have for host health, the implications for animal behaviour studies of diurnal species as well as the application of chronotherapeutic approaches to aquaculture.

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive insect pest that has caused significant economic losses in a myriad of agricultural crops in Europe and the USA. The communication as well as the control of this pest largely rely on semiochemicals (e.g., pheromones) and semiophysicals (e.g., substrate‐borne vibrations). Nevertheless, the nocturnal activity of H. halys is still largely unknown. In the present study, the diel vibrational communication of H. halys was investigated in controlled laboratory and semi‐field conditions. Moreover, the relevance of this ecological trait for integrated pest management (IPM) strategies was assessed by extending playback periods of bimodal (i.e., pheromones + vibrational playbacks) traps to 24 h, and comparing it to the current trap model (solar panel, about 12 h of playback) and a control (no playback, only pheromone). We found that H. halys did not exhibit discernible differences of vibrational activity between photophase and scotophase, with the exception of signal type 2 that in laboratory conditions was predominately emitted within nocturnal and morning hours (i.e., 20:00–12:00). Additionally, the calling activity was negatively affected by warmer (>32 °C) and windier (>7 m s−1) conditions in semi‐field settings. Bimodal traps that were power‐supplied for 24 h captured significantly more males than the other groups, and more females than the control group. Results suggest that the nocturnal vibrational activity of H. halys should be accounted for within IPM strategies by activating the bimodal traps also during the scotophase. [ABSTRACT FROM AUTHOR]

Activity patterns in animals are often species-specific, and can be generally categorized as diurnal, crepuscular, or nocturnal. Understanding these patterns provides insight into ecological adaptations and behaviors. The common grass snake (Natrix natrix), one of the most common and widespread European snake species, is traditionally considered diurnal, with scarce evidence of its crepuscular and nocturnal activity. We aimed to document the distribution, environmental conditions, and potential phenotype associations of nighttime activity in N. natrix. We used citizen science data from iNaturalist (1992-2022), Observation.org (2012-2022), together with personal field observations (2010-2023) to collect 127 crepuscular and nocturnal activity records. Most observations occurred between May and August, coinciding with the peak activity period of grass snakes across their distribution range. Statistical analyses revealed no significant difference in mean daily temperatures between crepuscular and nocturnal observations. However, striped individuals displayed nocturnal activity at higher temperatures, consistent with their distribution in warmer regions, but failed to register any difference when tested on a geographic subsample, that accounted for sympatry of the phenotypes. Surprisingly, we found no significant impact of moon presence or moonlight on nighttime activity or age class, contrary to expectations based on other snake species' responses. While our study reveals that nocturnal activity in the common grass snake is geographically widespread, further research is warranted to understand its drivers and ecological implications. This study highlights the value of citizen science platforms for biological and ecological research, offering unparalleled spatial and temporal coverage by their users. In conclusion, our work extends the knowledge of nocturnal behavior in N. natrix and underlines the critical role of citizen science in discovering behavioral aspects of common and widespread species. [ABSTRACT FROM AUTHOR]

A greater knowledge of the intrinsic and extrinsic factors of animal home range (HR) formation can help us to understand the fundamental biological issues underlying, for instance, movement patterns, habitat selection and survival. However, very little is known about the HRs of birds of prey fledglings, even though the post-fledging phase is recognised as crucial due to the high mortality of juvenile birds. We radio-tracked 138 Tengmalm's owl (Aegolius funereus) fledglings from 43 broods to determine their HRs during the post-fledging dependence period and to investigate the factors affecting their sizes. The study was conducted during four breeding seasons in Czechia and two seasons in Finland. The mean fledglings' HR size calculated according to the 95% IID Kernel Density Estimation method was 63.7 ± 43.9 ha (± SD; n = 71) during nocturnal activity and 52.0 ± 46.1 ha (n = 63) during diurnal roosting. The sizes of both nocturnal activity and diurnal roosting HRs increased with the longer individual duration of the post-fledging dependence period and also the higher rank of hatching within a brood. Diurnal roosting HRs were two times smaller in the Czech site, probably because of the very limited number of dense forest patches suitable for roosting as a legacy of the air pollution calamity in the 1970s, during which most coniferous stands died out. There was no difference in the size of nocturnal activity HR between the two study areas, although they differed markedly in terms of night length, altitude, weather, and forest age, structure and composition. This suggests that environmental factors are not decisive in determining the size of nocturnal activity HRs of Tengmalm's owl fledglings. Since the diurnal HRs always occurred within the area of the nocturnal HRs, we suggest that conservation of the densest and preferably oldest forest stands within the areas of the study species occurrence may offer straightforward conservation tasks for protecting Tengmalm's owl fledglings and also other species. [ABSTRACT FROM AUTHOR]

Background: Sleep disturbances frequently occur in patients with chronic neck pain. In these patients, upper trapezius muscle dysfunction is observed during sleep. This study aimed to evaluate the trapezius muscle activity during sleep among patients with chronic neck pain and sleep disturbances for comparison with healthy subjects. Study design: Cross-sectional study. Methods: Patients with chronic neck pain and healthy subjects participated in the study. Two overnight polysomnography recordings were conducted for each subject. Surface electromyography was utilized to record the nocturnal activity of the right and left upper trapezius muscles throughout the night. The nocturnal upper trapezius activity recording was divided into the following parts: wakefulness, rapid eye movement sleep (REM), and non-rapid eye movement sleep (NREM). The nocturnal activity during NREM sleep was further divided into three parts (stage I NREM sleep, stage II NREM, and stage III NREM. Normalization of EMG signals was performed. The normalized value of nocturnal activity was derived for analysis. Results: Among 15 patients with chronic neck pain and 15 healthy subjects, statistically significant differences were observed in the nocturnal activity of the upper trapezius. Compared to healthy subjects, the nocturnal activity of the upper trapezius was significantly higher during wakefulness, REM sleep, and NREM II and III sleep in patients with chronic neck pain and sleep disturbances. Conclusion: There was higher nocturnal upper trapezius activity in patients with chronic neck pain compared to healthy controls. The findings suggest a possible pathophysiological mechanism that may relate to chronic neck pain. Trial registration: CTRI/2019/09/021028. [ABSTRACT FROM AUTHOR]

An important, yet overlooked form of anthropogenic pollution is sensory pollution, and one of the most pervasive forms of sensory pollution is artificial light at night (ALAN). Despite the growing use of ALAN across the globe, limited research has examined the impacts of ALAN on coral reef fish. This study aims to further our understanding of the behavioural impacts of light pollution on fish by exposing the humbug damselfish (Dascyllus aruanus) to ALAN (∼15–25 lux, white LED light) over a period of 14 days, in situ. We assessed nocturnal activity, and diurnal shelter use and emergence time following a simulated threat in natural (control) and ALAN conditions. D. aruanus colonies exposed to ALAN were active at night and were lacking cryptic colouration observed in control fish, however this altered nocturnal activity did not appear to impact the diurnal behaviours we measured. Our findings provide critical insight into the impact of ALAN exposure to nocturnal behaviour of a diurnal fish and highlight the potential for increased risk of nocturnal predation under ALAN. Further studies with a longer ALAN exposure time will help illuminate the extent of behavioural changes and implications caused by ALAN in shallow coral reef systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Sand flies (Diptera: Psychodidae) are significant medical vectors of pathogens that cause illness in humans and animals. The most significant of these is the genus Leishmania (Kinetoplastida: Trypanosomatidae). Leishmaniasis is an important vector-borne disease. They are spread throughout the Old and New Worlds by the bites of female phlebotomine sand flies. Despite this importance, certain provinces where autochthonous leishmaniasis has historically existed and is re-emerging are lacking current data regarding their sand fly fauna. To provide a current update on the local sand fly fauna, a comprehensive entomological survey encompassing eight provinces was conducted subsequent to an analysis of past data regarding the species composition and distribution of sand flies in the area. Thus, the purpose of this study was to ascertain the species composition in various locations across eight provinces spread across four regions in Thailand. In order to gather information about the distribution of the phlebotomine sand fly, researchers used modified Centers for Disease Control and Prevention light traps between February 2021 and February 2022. At these 30 trappings in each province, we conducted 240 trapping nights in total. Collected sand flies were morphologically identified. The adult sand flies collected in this study were 8314 and represented 24 species of four genera, including 16 of Sergentomyia, 6 of Phlebotomus, 1 of Idiophlebotomus, and 1 of Chinius. Among these species, Sergentomyia anodontis had the largest population (25.71%), and population peaks were observed in Uthaithani province (51.81%). The collected sand flies’ male-to-female ratio was 1.21:1.00 (4,556:3,758). The study also discovered that Phlebotomus argentipes, a vector of Leishmania spp., was captured in Phayao province, and Phlebotomus major major was majorly found in Uthaithani province. The widespread distribution of sand fly populations in this study may indicate the epidemiologic importance of vector ecology in this habitat. Our results confirm the presence of several sand fly species in different provinces of Thailand and provide valuable information about the distribution and behavior of phlebotomine sand flies, which can be used to develop effective control strategies for the prevention of sand fly-borne diseases. In several Thai provinces, the study also tracked the nocturnal movements of both male and female sand flies. The results showed that phlebotomine sand flies are more active at night, peaking just after dusk.

The barred warbler, Curruca nisoria, is an Afro-Palearctic migrating bird with a wide breeding distribution across eastern Europe to central Asia. Ring recoveries and direct observations have suggested they migrate to non-breeding grounds in East Africa. However, little is known about their migration routes and flight behaviour during migration and on the non-breeding grounds. Using geolocators and multi-sensor loggers, we tracked three barred warblers from a Czech breeding site to document their migration routes, stopover and non-breeding sites, and flight activity patterns across the annual cycle. All three tracked birds took south-eastern autumn migration routes through the Levant, with a shared stopover in Syria before crossing the Arabian Desert, the Red Sea and eastern Sahara Desert and stopping in Sudan for ca. two months. After 109 days (average), birds arrived at their main non-breeding sites of W Kenya or S Ethiopia. A single stopover on the Red Sea coast of Saudi Arabia was used during the spring migration before continuing NW across the Mediterranean. Pressure and acceleration data showed that warblers migrated exclusively at night, with the longest flights crossing the Sahara and travelling from Sudan to non-breeding sites. Daily diurnal activity patterns were uniform across all stationary sites. [ABSTRACT FROM AUTHOR]

Sand flies (Diptera: Psychodidae) are significant medical vectors of pathogens that cause illness in humans and animals. The most significant of these is the genus Leishmania (Kinetoplastida: Trypanosomatidae). Leishmaniasis is an important vector-borne disease. They are spread throughout the Old and New Worlds by the bites of female phlebotomine sand flies. Despite this importance, certain provinces where autochthonous leishmaniasis has historically existed and is re-emerging are lacking current data regarding their sand fly fauna. To provide a current update on the local sand fly fauna, a comprehensive entomological survey encompassing eight provinces was conducted subsequent to an analysis of past data regarding the species composition and distribution of sand flies in the area. Thus, the purpose of this study was to ascertain the species composition in various locations across eight provinces spread across four regions in Thailand. In order to gather information about the distribution of the phlebotomine sand fly, researchers used modified Centers for Disease Control and Prevention light traps between February 2021 and February 2022. At these 30 trappings in each province, we conducted 240 trapping nights in total. Collected sand flies were morphologically identified. The adult sand flies collected in this study were 8314 and represented 24 species of four genera, including 16 of Sergentomyia, 6 of Phlebotomus, 1 of Idiophlebotomus, and 1 of Chinius. Among these species, Sergentomyia anodontis had the largest population (25.71%), and population peaks were observed in Uthaithani province (51.81%). The collected sand flies' male-to-female ratio was 1.21:1.00 (4,556:3,758). The study also discovered that Phlebotomus argentipes, a vector of Leishmania spp., was captured in Phayao province, and Phlebotomus major major was majorly found in Uthaithani province. The widespread distribution of sand fly populations in this study may indicate the epidemiologic importance of vector ecology in this habitat. Our results confirm the presence of several sand fly species in different provinces of Thailand and provide valuable information about the distribution and behavior of phlebotomine sand flies, which can be used to develop effective control strategies for the prevention of sand fly-borne diseases. In several Thai provinces, the study also tracked the nocturnal movements of both male and female sand flies. The results showed that phlebotomine sand flies are more active at night, peaking just after dusk. [ABSTRACT FROM AUTHOR]

We investigated activity patterns of wildlife by using 28 camera traps from June 2021 to June 2022 in a forest in eastern Hokkaido, Japan. Sciurus vulgaris is generally known as a diurnal species. However, two photos recorded the night activity of this species in March 2022. One photo showed something resembling a pine cone in a squirrel’s mouth. Sciurus vulgaris might shift the timing of their activity patterns to avoid predators such as Vulpes vulpes and/or to forage food when scarce. [ABSTRACT FROM AUTHOR]

Activity patterns in animals are often species-specific, and can be generally categorized as diurnal, crepuscular, or nocturnal. Understanding these patterns provides insight into ecological adaptations and behaviors. The common grass snake (Natrix natrix), one of the most common and widespread European snake species, is traditionally considered diurnal, with scarce evidence of its crepuscular and nocturnal activity. We aimed to document the distribution, environmental conditions, and potential phenotype associations of nighttime activity in N. natrix. We used citizen science data from iNaturalist (1992–2022), Observation.org (2012–2022), together with personal field observations (2010–2023) to collect 127 crepuscular and nocturnal activity records. Most observations occurred between May and August, coinciding with the peak activity period of grass snakes across their distribution range. Statistical analyses revealed no significant difference in mean daily temperatures between crepuscular and nocturnal observations. However, striped individuals displayed nocturnal activity at higher temperatures, consistent with their distribution in warmer regions, but failed to register any difference when tested on a geographic subsample, that accounted for sympatry of the phenotypes. Surprisingly, we found no significant impact of moon presence or moonlight on nighttime activity or age class, contrary to expectations based on other snake species’ responses. While our study reveals that nocturnal activity in the common grass snake is geographically widespread, further research is warranted to understand its drivers and ecological implications. This study highlights the value of citizen science platforms for biological and ecological research, offering unparalleled spatial and temporal coverage by their users. In conclusion, our work extends the knowledge of nocturnal behavior in N. natrix and underlines the critical role of citizen science in discovering behavioral aspects of common and widespread species.

A greater knowledge of the intrinsic and extrinsic factors of animal home range (HR) formation can help us to understand the fundamental biological issues underlying, for instance, movement patterns, habitat selection and survival. However, very little is known about the HRs of birds of prey fledglings, even though the post-fledging phase is recognised as crucial due to the high mortality of juvenile birds. We radio-tracked 138 Tengmalm’s owl (Aegolius funereus) fledglings from 43 broods to determine their HRs during the post-fledging dependence period and to investigate the factors affecting their sizes. The study was conducted during four breeding seasons in Czechia and two seasons in Finland. The mean fledglings’ HR size calculated according to the 95% IID Kernel Density Estimation method was 63.7 ± 43.9 ha (± SD; n = 71) during nocturnal activity and 52.0 ± 46.1 ha (n = 63) during diurnal roosting. The sizes of both nocturnal activity and diurnal roosting HRs increased with the longer individual duration of the post-fledging dependence period and also the higher rank of hatching within a brood. Diurnal roosting HRs were two times smaller in the Czech site, probably because of the very limited number of dense forest patches suitable for roosting as a legacy of the air pollution calamity in the 1970s, during which most coniferous stands died out. There was no difference in the size of nocturnal activity HR between the two study areas, although they differed markedly in terms of night length, altitude, weather, and forest age, structure and composition. This suggests that environmental factors are not decisive in determining the size of nocturnal activity HRs of Tengmalm’s owl fledglings. Since the diurnal HRs always occurred within the area of the nocturnal HRs, we suggest that conservation of the densest and preferably oldest forest stands within the areas of the study species occurrence may offer straightforward conservation tasks for protecting Tengmalm’s owl fledglings and also other species.

David J Stevens,1 Sarah Appleton,1 Kelsey Bickley,1 Louis Holtzhausen,2– 4 Robert Adams1,5 1Sleep Health, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, Australia; 2Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; 3Section Sports Medicine, Faculty of Health Science, University of Pretoria, Pretoria, South Africa; 4Department of Exercise and Sport Science, University of the Free State, Bloemfontein, South Africa; 5Respiratory and Sleep Services, Southern Adelaide Local Health Network, Bedford Park, South Australia, AustraliaCorrespondence: David J Stevens, Sleep Health, Flinders Health and Medical Research Institute, Flinders University, Level 2a, 5 Laffer Dve, Bedford Park, South Australia, 5041, Australia, Tel +61 7306 1816, Email david.stevens@flinders.edu.auPurpose: Little is known about sleep after a concussion, a form of mild traumatic brain injury. Given the importance of sleep for both maintaining brain health and recovery from injury, we sought to examine sleep acutely and subacutely after concussion.Methods: Athletes who experienced a sports-related concussion were invited to participate. Participants underwent overnight sleep studies within 7 days of the concussion (acute phase), and again eight-weeks after the concussion (subacute phase). Changes in sleep from both the acute and subacute phases were compared to population normative values. Additionally, changes in sleep from acute to subacute phase were analysed.Results: When compared to normative data, the acute and subacute phases of concussion showed longer total sleep time (p < 0.005) and fewer arousals (p < 0.005). The acute phase showed longer rapid eye movement sleep latency (p = 0.014). The subacute phase showed greater total sleep spent in Stage N3% (p = 0.046), increased sleep efficiency (p < 0.001), shorter sleep onset latency (p = 0.013), and reduced wake after sleep onset (p = 0.013). Compared to the acute phase, the subacute phase experienced improved sleep efficiency (p = 0.003), reduced wake after sleep onset (p = 0.02), and reduced latencies for both stage N3 sleep (p = 0.014) and rapid eye movement sleep (p = 0.006).Conclusion: This study indicated sleep during both the acute and subacute phases of SRC was characterised by longer and less disrupted sleep, along with improvements in sleep from the acute to subacute phases of SRC.Keywords: mild traumatic brain injury, somnolence, neural trauma, nocturnal activity

The sleep–wake patterns and nocturnal activity of diurnal birds have been little studied. Here, we analysed, by chance, those behaviours for free-living Eurasian Blue Tits (Cyanistes caeruleus, Linnaeus, 1758) roosting in nest boxes equipped with motion sensor-triggered Internet Protocol (IP) cameras. By monitoring individual birds over six sessions for more than one hundred nights each session, we found repetitive activity patterns during the night as well as a correlation between daylength and roosting times. Using the same method, we found the roosting behaviour of Eurasian Blue Tits (Cyanistes caeruleus, Linnaeus, 1758) to be comparable to that of Great Tits (Parus major, Linnaeus, 1758) and Common Starlings (Sturnus vulgaris, Linnaeus, 1758) in nest boxes in the same structure. These data, which we showed can be collected relatively easily and inexpensively, suggest that in rural areas the sleep–wake behaviours of free-living birds are mainly determined by the circadian rhythm associated with natural light. [ABSTRACT FROM AUTHOR]

Simple Summary: Ensuring proper sleep is essential for the health of all animals, including chimpanzees. Many studies have demonstrated that sleep plays a crucial role in physical and behavioral regulation, and sleep disruptions may cause negative consequences for both. This study explores how environmental conditions and nocturnal disturbances affect the sleep and daytime behavior of sanctuary-housed chimpanzees, respectively. Our results indicate that indoor temperature and humidity affect chimpanzee nocturnal activity. Furthermore, the frequency and intensity of nocturnal disturbances influence the chimpanzee's behavior the following day, i.e., time spent in inactivity, abnormal, self-directed, and affiliative behaviors. These findings highlight the importance of controlling factors that affect the quality of chimpanzees' sleep at night. The use of affordable audio recordings has the potential to provide valuable information regarding the chimpanzee's nocturnal activity and wellbeing. Chimpanzee's nocturnal sleep is a dynamic and complex process, still not fully understood. As in humans, not getting enough quality sleep due to frequent or lasting disruptions may affect their physical and mental health, hence wellbeing, which may be reflected in their daytime behavior. This study aims to understand the impact of abiotic factors, such as temperature and humidity on the nocturnal activity as well as the impact of nocturnal awakening events on daytime behavior in sanctuary-housed chimpanzees. We monitored noisy nocturnal activity through audio recordings for one year, documenting the number and duration of sound events produced by chimpanzees to indicate sleep fragmentation and disruption intensity, respectively. Our results indicate that indoor temperature and humidity indeed influence the chimpanzee's nocturnal activity. Furthermore, sleep fragmentation and intensity of nocturnal events significantly influenced the following day's behavior. After nights marked by frequent and/or intense sleep disruptions, higher levels of inactivity, and abnormal and self-directed behaviors were observed, and chimpanzees spent more time on affiliative interactions and in social proximity. These findings highlight the importance of controlling factors influencing nocturnal sleep quality. Furthermore, we demonstrated that economic audio recordings used to monitor nocturnal activity, provide insights into the chimpanzee's behavior and wellbeing. [ABSTRACT FROM AUTHOR]

Recently, several diurnal nonhuman anthropoids have been identified displaying varying degrees of nocturnal activity, which can be influenced by activity "masking effects"—external events or conditions that suppress or trigger activity, temporarily altering normal activity patterns. Environmental masking characteristics include nocturnal temperature, rainfall, cloud cover, and moon brightness. Similarly, other ecological characteristics, including proximity to humans and predators and daytime activity, may also trigger or suppress nocturnal activity. Understanding the effects of external conditions on activity patterns is pertinent to effective species conservation. We investigated the presence of nocturnal activity and the influence of masking effects on the level of nocturnal activity displayed by wild proboscis monkeys (Nasalis larvatus) in Sabah, Malaysian Borneo. Dual‐axis accelerometers were attached by collar to six male proboscis monkeys from different one‐male, multi‐female groups to record activity continuously (165–401 days each). We measured the monkeys' nocturnal and diurnal activity levels and investigated the effects of seven potential masking effects. Nocturnal activity was much lower than diurnal activity. Still, proboscis monkeys did display varying levels of nocturnal activity. Generalized linear mixed models identified higher nocturnal activity in the study individuals during nights with cooler temperatures, higher rainfall, and after higher diurnal activity. These three masking effects affected nocturnal activity levels during the observation period that informed our model, although they did not predict nocturnal activity outside of this period. While the generalizability of these results remains uncertain, this study highlights the utility of accelerometers in identifying activity patterns and masking effects that create variability in these patterns. Research Highlights: Six male proboscis monkeys displayed low levels of nocturnal activity, consistent with a diurnal activity pattern.Nocturnal activity in five of these male proboscis monkeys increased during nights that had cooler temperatures, higher rainfall, and after higher daytime activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Chimpanzee’s nocturnal sleep is a dynamic and complex process, still not fully understood. As in humans, not getting enough quality sleep due to frequent or lasting disruptions may affect their physical and mental health, hence wellbeing, which may be reflected in their daytime behavior. This study aims to understand the impact of abiotic factors, such as temperature and humidity on the nocturnal activity as well as the impact of nocturnal awakening events on daytime behavior in sanctuary-housed chimpanzees. We monitored noisy nocturnal activity through audio recordings for one year, documenting the number and duration of sound events produced by chimpanzees to indicate sleep fragmentation and disruption intensity, respectively. Our results indicate that indoor temperature and humidity indeed influence the chimpanzee’s nocturnal activity. Furthermore, sleep fragmentation and intensity of nocturnal events significantly influenced the following day’s behavior. After nights marked by frequent and/or intense sleep disruptions, higher levels of inactivity, and abnormal and self-directed behaviors were observed, and chimpanzees spent more time on affiliative interactions and in social proximity. These findings highlight the importance of controlling factors influencing nocturnal sleep quality. Furthermore, we demonstrated that economic audio recordings used to monitor nocturnal activity, provide insights into the chimpanzee’s behavior and wellbeing.

Species are commonly described as either diurnal or nocturnal, with rare reports of deviations outside their normal activity period. Observations of nocturnal activity by diurnal Anolis are limited to lizards utilizing anthropogenic light sources (night-light niche) to prolong their daily activity period. Here, we report nocturnal activity by Anolis cristatellus facilitated solely by natural moonlight and discuss implications for when this behavior would be recognized as common in the future. The identification of nocturnal activity in Anolis is particularly noteworthy given, in contrast to other taxa, our extensive knowledge of this study system which will allow for future ecological studies to better test hypotheses.

Many vertebrates exhibit a diel activity, steered by light–dark cycle. However, some colonial waterbirds, in that several species of gulls, are active not only in day hours but also at night. In this study, we aimed to investigate 24 h cycle of black-headed gulls (BHG) Chroicocephalus ridibundus activity with focus on sleep behaviour. We expected that 24 h patterns of activity differ between colonies located in various habitats, and within a colony between nests located in the centre vs at the edge. We studied behaviour based on 9600 of 30 s videos from camera-traps taken in six colonies and data from 10 GPS-tracked individuals from one colony recorded during incubation. BHGs stayed active on average during 48.1% of a night, mainly spent on passive and active nest defence, and on nest maintenance. BHGs spent similar time on these activities in day hours. Individuals breeding in the colony centre slept at night longer than those at its edge. BHGs stayed active during on average 76.5% of daytime. In two urban colonies with the highest nest densities and highest level of light pollution birds slept less during the day than in other studied colonies (three rural and one urban) characterized by lower densities and light intensity after sunset near the colony. Knowledge of nocturnal behaviour is crucial to comprehend 24 h activity patterns of an organism, especially to understand flexibility of behaviour crucial for restoration, like sleep. [ABSTRACT FROM AUTHOR]

The development of urban areas imposes challenges that wildlife must adapt to in order to persist in these new habitats. One of the greatest changes brought by urbanization has been an increase in anthropogenic noise, with negative consequences for the natural behavior of animals. Small mammals are particularly vulnerable to urbanization and noise, despite some species having successfully occupied urban environments. To understand some of the traits that have enabled small mammals to deal with the consequences of urbanization, we compared the behavioral responses of urban and rural greater white-toothed shrews, Crocidura russula, to different sound stimuli. A total of 32 shrews, 16 from each habitat, were exposed in captivity to four sound treatments: silence, tawny owl calls, traffic noise, and white noise. Urban and rural shrews showed different behaviors, with urban animals being more active, feeding more frequently, and using less torpor than rural individuals. However, responses to sound treatments were similar in both populations: urban and rural shrews exhibited a slight decrease in activity and feeding behavior, as well as more fleeing responses, when exposed to traffic noise or white noise, but not to owl calls. These results suggest urbanization induces long-term changes in the general activity of C. russula, but the short-term behavioral response to sound disturbance remains similar in rural and urban populations. [ABSTRACT FROM AUTHOR]

Upon a drastic decline of the giraffe population in the wild, conservation efforts and therefore the role of zoos have become more important than ever. With their unique opportunities, zoos provide excellent conditions to study animal behavior, expanding the knowledge about the giraffe's behavior repertoire and their ability to adapt. This study therefore examined the nocturnal behavior of 63 giraffe living in 13 different EAZA zoos across Germany and the Netherlands. Giraffe were observed and videos recorded via infrared sensitive cameras during the winter seasons 2015–2018. The observation period spanned nightly from 17:00 to 7:00. Thus, 198 nights, with a total of 2772 h were recorded and analyzed. Linear mixed models were then used to assess potential biological and environmental factors influencing behavior during the dark phase. Results show that individual variables such as age, subspecies and motherhood determined nocturnal activity and sleep behavior most. Among the variables studied, husbandry conditions and environmental factors complying with EAZA standards had no influence on the giraffe's nocturnal behavior. By combining nocturnal activity analyses and an assessment of potential influencing factors, our findings present a holistic approach to a better understanding of captive giraffe behavior and allow for management implications. Research Highlights: Our study presents nocturnal activity budgets of 63 captive giraffe from 13 different zoos. Giraffe spent about half of the 14 h observation period resting on the ground, either lying down or in REM sleep position. It is likely that nocturnal behavior of captive giraffe depends more on individual characteristics such as age, subspecies and motherhood than on environmental factors. [ABSTRACT FROM AUTHOR]

The main goal of this work was to investigate how the abundance and richness of Arctiinae moths varies over time, during the night. Specifically, we analyzed the following questions: (1) Is there a relationship between Arctiinae abundance and richness with the temperature and relative humidity? (2) What are the hours of activity of each species of moth? (3) Does the species composition differ over night? (4) Is it necessary to sample this group of moths throughout the night to have a representative sample of the species? We sampled the moths in Emas National Park (17°49’-18°28’S and 52°39’-53°10’W), Brazil. We selected seven sampling points in an area of savanna. At each sampling point, we collected the Arctiinae moths with a light trap (with a 15-W black light fluorescent light bulb), reflected in a white cloth (2 x 3 m) extended vertically. We sampled the moths in seven consecutive nights (one night in each sampling point, from December 13 to December 19, 2012, from 7 p.m. until 7 a.m.). We divided the samplings in twelve periods over the night, with an hour each. At each period of time, we measured the temperature and the relative humidity with a digital termohygrometer. We sampled 149 individuals belonging to 17 species of Arctiinae moths. Most species (70.5%) were active only for one or two hours at night. The species differed in terms of time activity. The higher abundance occurred at 8 p. m. (44 individuals), followed by 38 individuals at 9 p. m. and 23 at 10 p. m. The species richness was also higher in the early hours of the night. The temperature was the only variable that showed a positive and significative relationship with the Arctiinae moth abundance. The species richness was not influenced neither by the temperature nor by the relative air humidity. The possible causes of the peak of abundance and species richness in specific hours of the night are discussed. [ABSTRACT FROM AUTHOR]

As cities expand to accommodate a growing human population, their impacts to natural ecosystems and the wildlife residing within them increase. Some animals that persist in urban environments demonstrate behaviors distinct from their non-urban counterparts. These potential behavioral changes are the subject of a growing body of research in the areas of wildlife ecology, biology, and conservation. In spite of increasing urban wildlife research, studies focused specifically on changing behavior in urban mammals is limited. We conducted a systematic literature review to synthesize current research on behavior changes in wild urban mammals. We included 83 papers published between 1987 and March 2020. Omnivores were the leading subject of study, closely followed by carnivores and the specific behaviors most widely studied were home range and vigilance. Among the reviewed studies, there were 166 observations of 44 distinct behaviors with 155 occurrences of behavior change relative to conspecifics in non-urban areas. The most commonly studied and observed type of behavior change was alert behavior. Results indicate urban environments drive adaptive responses in behavior including changes in home range and diet preference, shifts in activity budget and vigilance, decreased flight initiation distance, and increased nocturnal activity. Some urban mammal species even demonstrated the ability to modulate behaviors based on environmental cues. Our results highlight the need for long-term wildlife behavior studies across a variety of urban settings to promote successful urban wildlife management and conservation.

Species are commonly described as either diurnal or nocturnal, with rare reports of deviations outside their normal activity period. Observations of nocturnal activity by diurnal Anolis are limited to lizards utilizing anthropogenic light sources (night-light niche) to prolong their daily activity period. Here, we report nocturnal activity by Anolis cristatellus facilitated solely by natural moonlight and discuss implications for when this behavior would be recognized as common in the future. The identification of nocturnal activity in Anolis is particularly noteworthy given, in contrast to other taxa, our extensive knowledge of this study system which will allow for future ecological studies to better test hypotheses. [ABSTRACT FROM AUTHOR]

An increasing body of evidence indicates that moonlight influences the nocturnal activity patterns of tropical mammals, both predators and prey. One explanation is that brighter moonlight is associated with increased risk of predation (Predation Risk hypothesis), but it has also been proposed that nocturnal activity may be influenced by the sensory ecology of a species, with species that rely on visual detection of food and danger predicted to increase their activity during bright moonlight, while species relying on non-visual senses should decrease activity (Visual Acuity hypothesis). Lack of an objective measure of "visual acuity" has made this second hypothesis difficult to test, therefore we employed a novel approach to better understand the role of lunar illumination in driving activity patterns by using the tapetum lucidum as a proxy for "night vision" acuity. To test the alternative predictions, we analyzed a large dataset from our long-term camera trap study in Costa Rica using activity overlap, relative abundance, and circular statistical techniques. Mixed models explored the influence of illumination factors (moonrise/set, cloud cover, season) and night vision acuity (tapetum type) on nocturnal and lunar phase-related activity patterns. Our results support the underlying assumptions of the predation risk and visual acuity models, but indicate that neither can fully predict lunar-related activity patterns. With diurnal human "super predators" forcing a global increase in activity during the night by mammals, our findings can contribute to a better understanding of nocturnal activity patterns and the development of conservation approaches to mitigate forced temporal niche shifts. [ABSTRACT FROM AUTHOR]

Although alpha-synuclein has been reported to participate in neurodegenerative diseases, the actual normal biological function of alpha-synuclein remains unclear. I investigated the correlation of alpha-synuclein expression with nocturnal and diurnal activity for various species. Hematoxylin and eosin staining, periodic acid-Schiff's reaction (PAS) and immunohistochemistry of alpha-synuclein expression were performed for the retinas of diurnal, nocturnal, nocturnal with diurnal activity species. I found different intensity of alpha-synuclein expression in the retinal layers. I found alpha-synuclein expression in the outer segment of the photoreceptor layer in the diurnal studied species and absence of alpha-synuclein expression in the compartments of photoreceptor layer in the retina of nocturnal species. I found localization of alpha-synuclein in the inner and outer segments of photoreceptors of the retina of nocturnal with diurnal activity species. The retinas of diurnal animals exhibited glycogen in the paraboloid structure in the inner segment of the photoreceptor layer. The retinas of nocturnal and nocturnal with diurnal activity species were devoid of glycogen in the photoreceptor layer. I conclude that the function of alpha-synuclein is more related to diurnal than to nocturnal species. [ABSTRACT FROM AUTHOR]

Habitat structure may have a significant influence on the occurrence, abundance, and activity patterns of forest mammals. However, anthropogenic habitat disturbance changes habitat structure, which may alter those patterns of activity. We assessed occurrence, relative abundance, and activity patterns of Dromiciops gliroides , an arboreal marsupial endemic to the temperate rainforests of southern South America, contrasting four forest conditions at a regional scale: old-growth, second-growth, and logged forests, and abandoned exotic plantations. We conducted a camera-trap assessment in two consecutive austral summers across most of the Chilean range of D. gliroides , and compared habitat structure along a disturbance gradient. All structural features assessed differed among forest conditions. Dromiciops gliroides was present in all forest conditions, but its abundance decreased and activity got narrower as disturbance increased, being significantly lower in the exotic plantations. Activity patterns were variable among forest conditions and months, and were significantly more restricted temporally at exotic plantations. Although D. gliroides is tolerant to habitat disturbance, we show that structural alteration results in lower abundances and narrower activity patterns. [ABSTRACT FROM AUTHOR]

Recent analyses have shown that typically diurnal primates may periodically exhibit some levels of activity at night. Despite this, there have been few studies that have explored whether diurnal primates living in temperate environments will extend their activity budgets to the nocturnal phase as a response to seasonal constraints. Using dual‐axis accelerometers, we explored whether chacma baboons (Papio ursinus; N = 3) in the western Soutpansberg Mountains, South Africa, responded to seasonally fluctuating levels of day length, lunar illumination, wind speed, precipitation and temperature by heightening or lowering nocturnal activity levels. Our results showed that chacma baboons engaged in low levels of activity at night throughout the year. Although baboons had heighted nocturnal activity as a response to shorter days, moonlit nights and lower temperatures, these responses were most likely due to disturbed sleeping patterns rather than more active movement. Nocturnal activity significantly dropped in a female baboon throughout the course of her pregnancy and remained low after giving birth suggesting that females with infants must increase resting. Our results compliment previous analyses which suggest that although diurnal primates may periodically be active at night, there is limited evidence for strategic use of the nocturnal phase even in highly seasonal environments. [ABSTRACT FROM AUTHOR]

Literature data suggests that Thamnodynastes strigatus (Serpentes, Dipsadidae) is a snake that actively forages for anurans near waterbodies, using several microhabitats for this activity (e.g., shrubs, soil, and water). However, herein we present dissonant data previously known to the species, both concerning type of prey and foraging strategy. A total of 72 observations were performed exclusively at night, when snakes were in vegetation near streams in 93% of the cases. Among these observations, 41 were active snakes, and most of them (97%) were in an ambush position on the vegetation, peering at fishes. On two occasions, the snakes used a lingual lure behavior in order to attract fishes. This is only the sixth species in which this behavior has been observed, and the first in South America. Therefore, we provide additional data on T. strigatus habitat activity and habitat use, as well as unpublished data on ambush and lingual lure behavior for the Neotropical genus Thamnodynastes. [ABSTRACT FROM AUTHOR]

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A lunar phobia is a behavioral trait in which the individual alters or ceases its nocturnal activity during periods of strong lunar illumination found throughout the animal kingdom. Current evidence indicates the changes reflect predator/prey detectability due to increased visibility. The study hypothesizes whether bat activity is more negatively influenced by a discrete threshold of high lunar illumination (nights with ≥ 90% of moon exposure) rather than a continuous linear response to variation in moon exposure. A 1202 mist net bat captures dataset from a preserved area in Northeast Brazil was used to test this hypothesis. A stepwise model was built, using Bayesian information criterion, to determine the effect of lunar luminosity (either as continuous moon exposure or discrete threshold parameter), environment (open vegetation vs canopy-covered), and season (dry/wet). The final model selected showed a significant negative threshold effect of nights above 90% of moon luminosity compared to a weaker non-significant effect of continuous moon exposure variation. The selected model also found a positive effect of forested environments and the wet season in the total number of bat captures. The model was able to detect a significant decrease in captures for the most abundant species, Artibeus planirostris. Our findings support the hypothesis that bats (especially frugivorous) present lunar phobia, which respond in a negative nonlinear fashion to high luminosity, possibly to avoid predation. [ABSTRACT FROM AUTHOR]

Many animals rely heavily on visual cues from their environment, and therefore show circadian rhythmicity in their behavioral activities. In group living animals, individuals' activity rhythms must be synchronized not only with diel light–dark cycle but also with other group members. Increasing evidence has recently shown that circadian behaviors of animals are consistent within individuals and different between individuals, but the sources and consistency of diel activity variation in social c [ABSTRACT FROM AUTHOR]

The European Cat Snake is one of the most recently discovered representatives of the Bulgarian herpetofauna, and one of the rarest snakes in Bulgaria. The research presented aims to update the data about the distribution of Telescopus fallax in south-western Bulgaria. Many new records from the Struma River valley are reported. To the north the species reaches the city of Blagoevgrad and its surroundings. Some data on the biology and ecology of the snake in this part of the country are also reported. [ABSTRACT FROM AUTHOR]

Nocturnal vocal activity in dolphins is often thought to be associated with feeding activity. However, when no food resources are available dolphins spend their time for the most part resting/sleeping. While unihemispherically sleeping, dolphins mostly swim slowly and synchronously in close proximity with one or more other individuals. Although vocal activity is lower during resting/sleeping, dolphins are not entirely silent the entire night. However, nothing is known about the temporal patterning of vocal activity at night and its potential relation with activity in dolphins. Here we recorded the vocal activity of a group of five captive bottlenose dolphins at night while having no feeding opportunity, examined whether there was any temporal pattern and/or a relation with breathing activity, used here as an index of overall activity. The temporal pattern revealed two peaks of intense whistle activity (8 p.m. and midnight), which were followed by a strong decrease of whistle rate and a slight decrease of respiration rate. We suggest that the high vocal activity at the peak periods might indicate socializing periods and that dolphins, like many other species, show periods of increased social and vocal interactions (chorusing?) before starting to rest/sleep, maybe to ensure the synchrony of slow swimming observed in this species. These findings contribute to a better understanding of nocturnal vocal activity in cetaceans and suggest new lines of research on vocal/social activity of dolphins in relation to presleep and resting behavior.

Thermal biology of snakes has been extensively studied, but vast majority of them deals with diurnal species distributed in temperate regions. During a long-term field study of a pitviper on subtropical Okinawa Island, the Ryukyu Archipelago, Japan, we had an opportunity to obtain body temperature data from six syntopic species of snakes belonging to the families Colubridae, Xenodermidae, Viperidae, and Elapidae that are active at night there. Mean body temperature of those nocturnally active snakes over a year was relatively low, ranging from 17.7 to 22.3°C, although research effort was largely biased to the cooler period of the year. Lowest body temperature of the six species ranged from 10.9 to 20.0°C. Irrespective of species, body temperature was highly correlated with both ambient air and substrate temperatures. Importance of future research on the activity of subtropical, nocturnal snakes under low temperature is briefly discussed. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The observed decrease in insect colour lightness with increasing latitude has been explained in earlier macroecological studies by the increased solar absorption of dark coloration, which allows extended periods of activity. However, melanin‐based dark coloration also protects against pathogens and ultraviolet radiation, which select for dark coloration at low latitudes where these selection pressures intensify. In nocturnal insects, the relative importance of these protective functions of dark coloration is expected to surpass thermoregulatory functions, as nocturnal species cannot benefit from extended periods of activity during the daytime. Hence, we expected that diurnal and nocturnal insects show contrasting geographical patterns of colour lightness. We tested these predictions using geometrid moths, which comprise both diurnal and nocturnal species. Location: Western Palearctic. Time period: Contemporary. Major taxa studied: Geometridae (Lepidoptera). Methods: We used digital image analysis to assess the colour lightness of 637 species, compiled their distribution across 3,777 grid cells of 50 km × 50 km and calculated the assemblage‐based average colour lightness. We used multiple regressions, autoregressive error models and randomizations to test for relationships between colour lightness and environmental variables associated with the thermal environment, putative pathogen pressure and ultraviolet radiation. Results: We found a clear decrease in colour lightness of assemblages of both diurnal and nocturnal moth species with increasing latitude. In every model, solar radiation was the most important predictor of colour lightness; that is, colour lightness consistently increased with increasing solar radiation. Main conclusions: These results indicate that the thermal environment is the most influential climatic driver of insect colour lightness—independent of thermoregulatory strategy and nocturnal or diurnal activity. This challenges the view that extended periods of activity are the main selection pressure for geographical variation in insect colour lightness. Consequently, the relationship between insect colour lightness and the thermal environment might be more general than previously thought. [ABSTRACT FROM AUTHOR]

Background: Leishmania 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. Methods: Sampling 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. Results: In 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. Conclusions: The 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. [ABSTRACT FROM AUTHOR]

Over the last century, the wild boar ( Sus scrofa ) has become an important wildlife species in both economic and ecological terms. Considered a pest by some and a resource by others, its rapid increase in population and distribution has raised management concerns. Studies on activity rhythms may provide useful insights into its overall ecology and help develop effective management strategies. By examining highly detailed activity data collected by means of accelerometers fitted on GPS-collars, we studied wild boar daily activity rhythms and the effect of environmental conditions on their diurnal and nocturnal activity. We thus provided evidence of the predominantly nocturnal and monophasic activity of wild boars. All year round, we reported low activity levels during the day, which opportunistically increased under the most favourable environmental conditions. Activity was found to be significantly affected by such weather conditions as temperature, precipitation and air relative humidity. Moreover, we found that nocturnal activity slightly increased as moonlight increased. Part of our analysis was focused on the hunting period in order to investigate whether wild boars modify their activity levels in response to hunting disturbance. Our results suggested that wild boar nocturnal habits are not directly influenced by the current hunting disturbance, though we hypothesised that they may have evolved over several decades of hunting harassment. Alternatively, but not exclusively, nocturnal habits may have evolved as a low-cost strategy to achieve an optimum thermal balance (i.e., behavioural thermoregulation). [ABSTRACT FROM AUTHOR]