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BACKGROUND: As a primary vector of bluetongue virus (BTV) in the US, seasonal abundance and diel flight activity of Culicoides sonorensis has been documented, but few studies have examined how time of host-seeking activity is impacted by environmental factors. This knowledge is essential for interpreting surveillance data and modeling pathogen transmission risk. METHODS: The diel host-seeking activity of C. sonorensis was studied on a California dairy over 3 years using a time-segregated trap baited with CO2. The relationship between environmental variables and diel host-seeking activity (start, peak, and duration of activity) of C. sonorensis was evaluated using multiple linear regression. Fishers exact test and paired-sample z-test were used to evaluate the seasonal difference and parity difference on diel host-seeking activity. RESULTS: Host-seeking by C. sonorensis began and reached an activity peak before sunset at a higher frequency during colder months relative to warmer months. The time that host-seeking activity occurred was associated low and high daily temperature as well as wind speed at sunset. Colder temperatures and a greater diurnal temperature range were associated with an earlier peak in host-seeking. Higher wind speeds at sunset were associated with a delayed peak in host-seeking and a shortened duration of host-seeking. Parous midges reached peak host-seeking activity slightly later than nulliparous midges, possibly because of the need for oviposition by gravid females before returning to host-seeking. CONCLUSIONS: This study demonstrates that during colder months C. sonorensis initiates host-seeking and reaches peak host-seeking activity earlier relative to sunset, often even before sunset, compared to warmer months. Therefore, the commonly used UV light-baited traps are ineffective for midge surveillance before sunset. Based on this study, surveillance methods that do not rely on light trapping would provide a more accurate estimate of host-biting risk across seasons. The association of environmental factors to host-seeking shown in this study can be used to improve modeling or prediction of host-seeking activity. This study identified diurnal temperature range as associated with host-seeking activity, suggesting that Culicoides may respond to a rapidly decreasing temperature by shifting to an earlier host-seeking time, though this association needs further study.

In many socially monogamous bird species with biparental care, occasional social polygyny has been detected. We provide information about a case of facultative polygyny in the European Nightjar (Caprimulgus europaeus). The male nightjar (I96) formed a pair with two females (I95: the presumed primary female with whom he already bred since 2018; M042: the presumed secondary female, an inexperienced yearling). GPS and accelerometer data demonstrate how the male only sang in proximity of the primary nest, while assisting both females during incubation, as well as during the nestling period. When the male came to the nest, the primary and/or secondary female went foraging, but the secondary female received less assistance during incubation than the primary female, and her eggs were often left unattended. However, once the chicks of the secondary female hatched, male assistance suddenly increased, presumably at a cost to the primary female. Being only the second record of social polygyny in the European Nightjar, we do not have a direct explication for the occurrence of this polygynous event. We note that male density at the study site was lower than that observed in previous seasons. The male may have taken over the female that was initially paired to a neighbouring territory holder that then died. Alternatively, the inexperienced female might have mated with an already paired male, either because she was not aware of the mating status of the male, or because she could not find an unpaired male, or because mating with this paired male was better than mating with another unpaired male. In any case, the breeding ecology and mating behaviour of this crepuscular bird species remains little understood. [ABSTRACT FROM AUTHOR]

ABSTRACT In many socially monogamous bird species with biparental care, occasional social polygyny has been detected. We provide information about a case of facultative polygyny in the European Nightjar (Caprimulgus europaeus). The male nightjar (I96) formed a pair with two females (I95: the presumed primary female with whom he already bred since 2018; M042: the presumed secondary female, an inexperienced yearling). GPS and accelerometer data demonstrate how the male only sang in proximity of the primary nest, while assisting both females during incubation, as well as during the nestling period. When the male came to the nest, the primary and/or secondary female went foraging, but the secondary female received less assistance during incubation than the primary female, and her eggs were often left unattended. However, once the chicks of the secondary female hatched, male assistance suddenly increased, presumably at a cost to the primary female. Being only the second record of social polygyny in the European Nightjar, we do not have a direct explication for the occurrence of this polygynous event. We note that male density at the study site was lower than that observed in previous seasons. The male may have taken over the female that was initially paired to a neighbouring territory holder that then died. Alternatively, the inexperienced female might have mated with an already paired male, either because she was not aware of the mating status of the male, or because she could not find an unpaired male, or because mating with this paired male was better than mating with another unpaired male. In any case, the breeding ecology and mating behaviour of this crepuscular bird species remains little understood.

Abstract Background As a primary vector of bluetongue virus (BTV) in the US, seasonal abundance and diel flight activity of Culicoides sonorensis has been documented, but few studies have examined how time of host-seeking activity is impacted by environmental factors. This knowledge is essential for interpreting surveillance data and modeling pathogen transmission risk. Methods The diel host-seeking activity of C. sonorensis was studied on a California dairy over 3 years using a time-segregated trap baited with CO2. The relationship between environmental variables and diel host-seeking activity (start, peak, and duration of activity) of C. sonorensis was evaluated using multiple linear regression. Fisher’s exact test and paired-sample z-test were used to evaluate the seasonal difference and parity difference on diel host-seeking activity. Results Host-seeking by C. sonorensis began and reached an activity peak before sunset at a higher frequency during colder months relative to warmer months. The time that host-seeking activity occurred was associated low and high daily temperature as well as wind speed at sunset. Colder temperatures and a greater diurnal temperature range were associated with an earlier peak in host-seeking. Higher wind speeds at sunset were associated with a delayed peak in host-seeking and a shortened duration of host-seeking. Parous midges reached peak host-seeking activity slightly later than nulliparous midges, possibly because of the need for oviposition by gravid females before returning to host-seeking. Conclusions This study demonstrates that during colder months C. sonorensis initiates host-seeking and reaches peak host-seeking activity earlier relative to sunset, often even before sunset, compared to warmer months. Therefore, the commonly used UV light-baited traps are ineffective for midge surveillance before sunset. Based on this study, surveillance methods that do not rely on light trapping would provide a more accurate estimate of host-biting risk across seasons. The association of environmental factors to host-seeking shown in this study can be used to improve modeling or prediction of host-seeking activity. This study identified diurnal temperature range as associated with host-seeking activity, suggesting that Culicoides may respond to a rapidly decreasing temperature by shifting to an earlier host-seeking time, though this association needs further study. Graphical Abstract

How animals use the diel period (24‐h light–dark cycle) is of fundamental importance to understand their niche. While ecological and evolutionary literature abound with discussion of diel phenotypes (e.g. diurnal, nocturnal, crepuscular, cathemeral), they lack clear and explicit quantitative definitions. As such, inference can be confounded when evaluating hypotheses of animal diel niche switching or plasticity across studies because researchers may be operating under different definitions of diel phenotypes.We propose quantitative definitions of diel phenotypes using four alternative hypothesis sets (maximizing, traditional, general and selection) aimed at achieving different objectives. Each hypothesis set is composed of mutually exclusive hypotheses defined based on the activity probabilities in the three fundamental periods of light availability (twilight, daytime and night‐time).We develop a Bayesian modelling framework that compares diel phenotype hypotheses using Bayes factors and estimates model parameters using a multinomial model with linear inequality constraints. Model comparison, parameter estimation and visualizing results can be done in the Diel.Niche R package. A simplified R Shiny web application is also available.We provide extensive simulation results to guide researchers on the power to discriminate among hypotheses for a range of sample sizes (10–1280). We also work through several examples of using data to make inferences on diel activity, and include online vignettes on how to use the Diel.Niche package. We demonstrate how our modelling framework complements other analyses, such as circular kernel density estimators and animal movement modelling.Our aim is to encourage standardization of the language of diel activity and bridge conceptual frameworks and hypotheses in diel research with data and models. Lastly, we hope more research focuses on the ecological and conservation importance of understanding how animals use diel time. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) is predicted to have far-reaching consequences for natural ecosystems given its influence on organismal physiology and behaviour, species interactions and community composition. Movement and predation are fundamental ecological processes that are of critical importance to ecosystem functioning. The natural movements and foraging behaviours of nocturnal invertebrates may be particularly sensitive to the presence of ALAN. However, we still lack evidence of how these processes respond to ALAN within a community context. We assembled insect communities to quantify their movement activity and predation rates during simulated Moon cycles across a gradient of diffuse night-time illuminance including the full range of observed skyglow intensities. Using radio frequency identification, we tracked the movements of insects within a fragmented grassland Ecotron experiment. We additionally quantified predation rates using prey dummies. Our results reveal that even low-intensity skyglow causes a temporal shift in movement activity from day to night, and a spatial shift towards open habitats at night. Changes in movement activity are associated with indirect shifts in predation rates. Spatio-temporal shifts in movement and predation have important implications for ecological networks and ecosystem functioning, highlighting the disruptive potential of ALAN for global biodiversity and the provision of ecosystem services. This article is part of the theme issue 'Light pollution in complex ecological systems'. [ABSTRACT FROM AUTHOR]

Diel vertical migration (DVM) in marine organisms is an evolved response to maximize foraging opportunities and minimize predation risk. This pattern in vertical distribution is a widely observed phenomenon and common in pelagic forage fish species. Modelling these dynamics has important relevance to understanding marine ecosystem dynamics, predator–prey interactions, and marine food webs. We examine DVM in sand lance—an ecologically important taxa of forage fishes throughout northern hemisphere marine systems and target of commercial fisheries. Much remains unknown about their diurnal emergence from sediments. We apply data from autonomous stereo-camera deployments and tank observations to provide new insight to DVM patterns in Pacific sand lance (Ammodytes personatus). We model emergence curves using beta regression models with random effects, depicting important differences in the shape of ascent and descent. Our observations and analyses document crepuscular movement patterns, suggesting pelagic foraging occurs primarily at dawn and dusk. Results suggest critical light thresholds are necessary to initiate and maintain pelagic foraging. Results also suggest the importance of seasonality and life stage, such that adult fish exhibit reduced pelagic foraging in the fall relative to juvenile fish. These results constitute a comprehensive evaluation of DVM in this species, better define the physical drivers, and mathematically depict the pattern and shape of emergence timing. [ABSTRACT FROM AUTHOR]

Aim: Organisms primarily influence ecosystems through their functional traits when they are physically active. Following the nocturnal bottleneck, the expansion of mammals into the daytime expanded mammalian functional diversity (FD), however there is also notable overlap in trait space across diel niches leading to redundant FD. We explore how the unique and redundant contribution of each diel niche varies spatially and in relation to natural variation in light and temperature. Location: Global. Taxon: Extant mammals. Methods: Based on five major functional traits (body mass, litter size, diet breadth, foraging strata, habitat breadth) for 5033 extant terrestrial mammals, we determine biogeographical variation in nocturnal, crepuscular, cathemeral and diurnal FD. We calculate the proportion of mammalian FD that is unique to each diel niche, and the proportion that is redundant across the daily cycle. Results: The diversification of mammals into the daytime resulted in the creation of new FD (28.5% of FD is not nocturnal; Lower Quartile 17.3%; Upper Quartile 38.2%). Most of this expansion occurred at higher latitudes where uniquely cathemeral FD dominates (>55°N, 41.1% of mammalian FD; Lower Quartile 33.3%, Upper Quartile 53.6%), associated with fewer hours of biologically useful moonlight and daylight. Where there are more hours of biologically useful daylight, unique diurnal FD is common. However, more than half of non‐nocturnal FD is redundant, increasing ecosystem stability as different species carry out similar functions at different times of day, and suggesting that many mammals have not diversified far from their nocturnal ancestors. Main conclusions: Over much of the land surface more than a half of FD only occurs at night, underscoring the importance of nocturnal mammals for ecosystems. Understanding diel variation in FD not only informs on community structure and ecosystem function but also on ecosystem functional persistence in the Anthropocene, with pressures at night being particularly concerning. [ABSTRACT FROM AUTHOR]

Membrane guanylyl cyclase receptors are important regulators of local cGMP production, critically influencing cell growth and differentiation as well as ion transport, blood pressure and calcium feedback of vertebrate phototransduction. Currently, seven different subtypes of membrane guanylyl cyclase receptors have been characterized. These receptors have tissue specific expression and are activated either by small extracellular ligands, changing CO2 concentrations or, in the case of visual guanylyl cyclases, intracellularly interacting Ca2+-dependent activating proteins. In this report, we focus on the visual guanylyl cyclase receptors (GCs) GC-E (gucy2d/e) and GC-F (gucy2f) and their activating proteins (GCAP1/2/3; guca1a/b/c). While gucy2d/e has been detected in all analyzed vertebrates, GC-F receptors are missing in several clades (reptiles, birds, and marsupials) and/or individual species. Interestingly, the absence of GC-F in highly visual sauropsida species with up to 4 different cone-opsins is compensated by an increased number of guanylyl cyclase activating proteins, whereas in nocturnal or visually impaired species with reduced spectral sensitivity it is consolidated by the parallel inactivation of these activators. In mammals, the presence of GC-E and GC-F is accompanied by the expression of one to three GCAPs, whereas in lizards and birds, up to five different GCAPs are regulating the activity of the single GC-E visual membrane receptor. In several nearly blind species, a single GC-E enzyme is often accompanied by a single variant of GCAP, suggesting that one cyclase and one activating protein are both sufficient and required for conferring the basic detection of light. [ABSTRACT FROM AUTHOR]

The activities of predators and prey have been reported to influence each other. However, few studies have clarified when African leopards Panthera pardus are likely to encounter their prey. One reason for this is that the activity patterns of African forest mammals are poorly understood. Therefore, I aimed to clarify the activity patterns of leopards and their prey species by deploying camera traps on the ground and in trees in Mahale Mountains National Park, Tanzania. In total, 4468 camera days of camera traps set on the ground and 286 camera days of camera traps set in trees were analyzed. The overlap in activity patterns between leopards and their main prey species was calculated using coefficient Δ. At least seven leopards were identified in the study area. Leopards were active throughout the day, with crepuscular peaks at dawn and dusk. Blue duikers Philantomba monticola, the most consumed species in Mahale, were predominantly diurnal. The activity patterns of leopards moderately overlapped with those of blue duikers (Δ = 0.65). The activity patterns of leopards showed a moderate (Δ = 0.61) or low (Δ = 0.42) overlap with those of red‐tailed monkeys Cercopithecus ascanius when detections were captured by arboreal or terrestrial cameras, respectively. Mahale leopards may hunt blue duikers and arboreal primates in the midday on the ground, and may also attack primates in roost trees at night. Future studies on the leopard diet in various study areas, as well as comparisons of activity patterns between leopards and other animals, will elucidate leopard ecology. [ABSTRACT FROM AUTHOR]

Strepsiptera are a small order of obligately endoparasitic insects. Adult females are neotenic and never leave their host, instead bearing motile young that seek out their own insect hosts to infect. Males eclose without killing their hosts. In their 4-h adult lifespan, they fly off to search for mating opportunities, assisted by unconventional eyes with few, but large, ommatidia. Such distinctive features make Strepsiptera interesting in their own right, but also offer an opportunity to better understand evolutionary innovation. Unfortunately, Strepsiptera also are minute, reclusive, and difficult to obtain, severely reducing the study thereof, especially species not infecting solitary bees or social wasps. Here we describe methods for the successful capture of a strepsipteran species. We placed an ultraviolet light trap among Spartina alterniflora Loisel (Poaceae) shoots to attract adult male Elenchus koebelei Pierce (Strepsiptera: Elenchidae) in salt marshes in the southeastern United States. In 72 d of sampling, 488 adult males were captured between 30 min before and 15 min after sunrise. None arrived more than 63 min before or 36 min after sunrise. The majority of E. koebelei were caught at wind speeds ranging from 0 to 10 km/h; however, a light breeze of about 1.5 km/h appears to be preferred. The highest daily catches occurred when the temperature was between 23 and 26 °C. No Strepsiptera were caught at temperatures below 17 °C. With 521 adult male E. koebelei caught in a single light trap, our results show this little-known parasite may be reliably obtained, enhancing opportunities for further study.

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The temporal windows during which animals complete essential life processes (i.e. temporal niche) allow animals to match their actions to a given environmental context. When completing seasonal migrations, some migrants switch their activity patterns (e.g. from diurnal to nocturnal in multiple species of migratory birds) to take advantage of better conditions. We tested the temporal niche-switch hypothesis by comparing activity patterns before and during migration for four populations of migratory mule deer, Odocoileus hemionus , in western Wyoming, U.S.A. (2007–2019). We predicted that the physically taxing and risky event of terrestrial migration would prompt shifts in diel activity patterns. In contrast to the niche-switch hypothesis, mule deer did not drastically change their activity patterns during migration. Both before and during migration, mule deer were crepuscular (i.e. most active during twilight hours). When migrating in the spring, however, mule deer tended to concentrate activity near dawn, although they did not concentrate activity near dawn in the autumn, when less snow was present. By moving in the morning during spring migration, mule deer moved when snow was hardest, potentially allowing them to avoid the energetic costs of sinking into deep snow. Mule deer overall maintained a consistent pattern of crepuscular activity, but fine-tuned their activity patterns during migration, which may allow them to better match their behaviours with environmental conditions while completing an important life event. Rather than abandoning activity patterns, animals instead may make subtle alterations in their activity patterns to take advantage of present conditions. • Mule deer did not switch the time of day that they were most active when migrating. • Instead, migratory mule deer fine-tuned their migratory behaviour. • Shifts in temporal niches may be underappreciated behavioural strategies. [ABSTRACT FROM AUTHOR]

The Japanese pipistrelle Pipistrellus abramus is one of the most common bats in urban and suburban areas of Japan, from southern Hokkaido to Okinawa. Although the bat is generally nocturnal, it is also active at twilight, i.e., before and after sunset, at which time it may be preyed upon by diurnal predatory birds. During our 710 days of monitoring between April 2012 to May 2022 from the banks of the Koaze River, which flows through Kawagoe City, Saitama Prefecture, Japan, we observed 47 aerial attacks on Japanese pipistrelles by several diurnal predatory bird species. The predatory bird species included the Japanese Sparrowhawk Accipiter gularis, Common Kestrel Falco tinnunculus, Peregrine Falcon Falco peregrinus, Bull-headed Shrike Lanius bucephalus, and Carrion Crow Corvus corone. Our study suggests that bats are a food source for diurnal predatory species of birds in urban and suburban areas. [ABSTRACT FROM AUTHOR]

Abstract The research presented in this paper provides an insight into the behavioral ecology of mountain hares on heather moorland in the Lammermuir Hills of southeast Scotland. We examine the seasonal and diel activity patterns using camera traps over a period of 12 months. The rate of camera detections was calculated for the different divisions of the 24‐hr cycle (daylight, dusk, night, and dawn). During autumn and winter (October–February), the activity pattern was crepuscular with greater activity at dusk than at dawn. Daylight activity was relatively low, and there was a regular pattern of small peaks of activity during the night. In spring and summer (March–September), peaks of crepuscular activity remained evident but daylight activity was much more prevalent than during autumn and winter, and night activity was lower. We discuss the problematic definition of twilight and present an explanation for seasonal changes in the pattern of diel activity that is linked to the reproductive cycle of the mountain hare.

Being endemic to Borneo, the Earless monitor, Lanthanotus borneensis (Steindachner, 1878) is rarely found in its habitats due to its cryptic behavior. We provide care for confiscated animals in the Reptile House of Museum Zoologicum Bogoriense (MZB) in Cibinong, West Java, Indonesia since 2014. Little is known on its natural prey but from scattered descriptive reports. This study is aimed at documenting the feeding behavior of ten captive Earless monitors and events of predation on frogs. We set up two experiments, one with meat of Rice Field Frog, Fejervarya limnocharis, and the other with live frog of the same species. Our recorded observations ran for four weeks for the frog meat feeding experiment and followed by the frog predation experiment. Our results showed that lizards constantly accepted frog meat. Lizards tended to feed before sunset for a short period of time on the muddy soil surface, although a few individuals inconsistently fed under water. The average body mass for these lizards increased by 4.29 g and average SVL by 0.45 cm. We recorded predation on frogs in three out of ten individuals observed during this study. If F. limnocharis is confirmed to occur in the natural habitats of L. borneensis, it is possible that this frog species is among the natural prey for Earless monitors. Further studies on its natural diets should be conducted to gain in-depth knowledge essential for generating effective captive husbandry for this nationally protected species in Indonesia. [ABSTRACT FROM AUTHOR]

Surveys optimized to coincide with peak detectability of target species are critical to the success of monitoring programs, especially those targeting species of conservation concern. Established species-specific survey protocols are often inconsistent between jurisdictions, with limited spatial and temporal data to inform survey timing. The recent proliferation of programmable autonomous recording units (ARUs) and automated detection software enables the processing of huge volumes of acoustic data, which can improve our understanding of the acoustic phenology of many bird species. In May–July 2014, we deployed ARUs across a gradient of latitude near the northern limit of the breeding range of the Common Nighthawk (Chordeiles minor), a species of conservation concern, to quantify variation in temporal detection patterns. Most activity occurred after sunset and before sunrise, with a pronounced peak during civil twilight. We found considerable latitudinal differences in the activity patterns of birds, related to variation in the occurrence or duration of twilight periods. At northern sites (> 60° N), birds were active from dusk until dawn, likely because civil twilight lasted the entire period. At southern sites (< 55° N), twilight periods were short, resulting in concentrated, bimodal activity. Activity peaked in the middle of the breeding season, which occurred earlier in the south than the north. Our results suggest surveys should occur in June in southern Canada (> 50° N) and between mid-June and mid-July further north, given high activity rates throughout the breeding season. Given that non-vocal booms are more strongly associated with breeding activity and nesting sites, future surveys should focus on targeting this acoustic signal. Considering the timing of activity patterns in this species, we recommend a targeted, species-specific survey to ensure documentation of their abundance and distribution. Finally, we provide recommendations to improve survey timing and provide advice for acoustic data management and processing in relation to this species.

The research presented in this paper provides an insight into the behavioral ecology of mountain hares on heather moorland in the Lammermuir Hills of southeast Scotland. We examine the seasonal and diel activity patterns using camera traps over a period of 12 months. The rate of camera detections was calculated for the different divisions of the 24‐hr cycle (daylight, dusk, night, and dawn). During autumn and winter (October–February), the activity pattern was crepuscular with greater activity at dusk than at dawn. Daylight activity was relatively low, and there was a regular pattern of small peaks of activity during the night. In spring and summer (March–September), peaks of crepuscular activity remained evident but daylight activity was much more prevalent than during autumn and winter, and night activity was lower. We discuss the problematic definition of twilight and present an explanation for seasonal changes in the pattern of diel activity that is linked to the reproductive cycle of the mountain hare. [ABSTRACT FROM AUTHOR]

Summary: Large‐scale deforestation and forest fragmentation in the tropical area of the Atherton Tablelands in Far North Queensland, Australia, have placed extensive strains on populations of many endemic species of this area, such as the Lumholtz's Tree‐Kangaroo (LTK). Despite LTKs predominantly arboreal life and their ability to quickly colonize and adapt to restored forested habitats, little is known about their terrestrial activity patterns within these habitats which put them at risk to predation by canines and to roadkill when crossing nearby roads. Using motion‐sensing cameras, forest floor‐related activities of LTKs were recorded in a restored riparian rainforest habitat in relation to seasons and moon phases. The results show that LTKs exhibit a cathemeral activity pattern of forest floor‐related movements with a tendency towards crepuscular activity at dawn. While there was a significant association between the daytime recordings and the seasons with more activity during the days of the wet season, there was no association between the nighttime recordings and the seasons, as well as the moon phases. These results suggest that seasonal changes in temperature and precipitation, but potentially also in food quality, are likely to affect the frequency at which LTKs access the forest floor. Mitigating threats to LTKs in restored habitats should focus on facilitating terrestrial movements of LTKs, the control of feral dogs, enlarging and connecting available habitat, and educating drivers about peak times of LTK movements on the ground. [ABSTRACT FROM AUTHOR]

This study is the first attempt to document troglofaunal diversity of crepuscular cave ecosystem from the state of Goa. Twelve faunal species (seven invertebrates and five vertebrates) have been documented from an insular crepuscular cave which measures 18.62m in floor length and shows a transition of light and hygrothermal profile between its entrance and dead end. Absence of primary producers, thermal constancy, high humidity, poor ventilation, and competitive exclusion due to limited food resources restricts the faunal diversity of this cave; though trophic linkages are interesting yet speculative, as is typical of subterranean ecosystem. Among the macro-invertebrates, cavernicolous Whip Spider is a significant species here; whereas the important vertebrates encountered are the Fungoid frog and the Indian Cricket frog, besides roosts of the Rufous Horseshoe bat. Eco-energetic subsidy, possibly offered by crickets and bats that regularly feed outside this oligotrophic cave ecosystem is discussed. The need to document the unique and vulnerable troglofauna of this sensitive ecosystem from the conservation perspective is highlighted. [ABSTRACT FROM AUTHOR]

Despite the increasing spatial, temporal and dietary overlap between bobcats Lynx rufus and coyotes Canis latrans, these species live sympatrically throughout much of North America. To determine if differential activity patterns relative to abiotic variables might influence interspecific interactions, we investigated whether these species responded differentially to crepuscular and nocturnal abiotic variables in Texas. Using GPS collars, we calculated hourly movements from sequential locations, and compared bobcat and coyote movements relative to sex, season, moonlight intensity, night period, crepuscularity and temperature. We used generalized linear mixed effects models (GLMM) to investigate the responses of bobcats and coyotes to variables associated to their nocturnal movements. Temperature and its interactions with various abiotic variables influenced bobcat movements. Biological season and its interactions with other abiotic variables influenced coyote movements. Bobcats moved shorter hourly distances than coyotes. Female bobcats moved shorter hourly distances than males. Moonlight intensity seemed to influence coyotes but not bobcats. Differential movements between bobcats and coyotes relative to night period could possibly be due behavioral avoidance of coyotes by bobcats. Reduced crepuscular activity by coyotes may be behavioral avoidance of humans. Differential responses to nocturnal variables may dampen competitive interactions between bobcats and coyotes. [ABSTRACT FROM AUTHOR]

Low-light adapted bees are substantially understudied components of the bee fauna, particularly in Australia. Whilst several species in Australia are thought to be adapted to low-light conditions, explicit records of these taxa actually foraging at twilight or night are absent from the scientific literature. We present the first observations of Australian bees foraging in low-light conditions as well as the first evidence of low-light foraging behaviour in the colletid bee subfamily, Hylaeinae. Using morphometrics of Australian and more broadly-distributed diurnal, facultative low-light and obligate low-light adapted bees, we explore the use of morphological traits to objectively assess possible low-light behaviour and corroborate low-light collection events. Our results show that it is possible to morphologically distinguish between diurnal and low-light adapted bees, and that there is a spectrum of characters that are associated with low light conditions. We use GIS to show that low-light adapted species occur mostly in the tropics, but that some species have subtropical, arid and even temperate distributions. As low-light foraging behaviour in bees is infrequently reported, it appears that low-light foraging behaviour is more common than currently appreciated, highlighting the need for extended bee-sampling periods and more consistent collection data to increase the understanding of this little-understood aspect of bee behaviour. [ABSTRACT FROM AUTHOR]

In 2012, we explored the activity pattern of a pair of breeding Northern Pygmy-Owls based on 15 d (and 15 nights) of video monitoring of the nest-cavity entrance during the nestling period. Video monitoring ended after all 6 owlets had left the nest. All instances of nest activity (n= 288) occurred during the daylight period from 1 h before sunrise to 1 h after sunset, so the pair was not nocturnal. Most of the activity (60%) occurred during the diurnal period (1 h after sunrise to 1 h before sunset), and the rest was in the crepuscular period (the first and last 2 h of daylight). Prey type factored heavily into the frequency of activity at certain times of day, and on certain days during the nestling period. Activity during the diurnal period was dominated by the combination of vertebrate prey deliveries (80% of diurnal activity) and enticements of young from the nest (14% of diurnal activity). In contrast, activity during the crepuscular period was dominated by insect prey deliveries (60% of crepuscular activity). Overnight nest attendance activity, arriving and departing the nest to tend young through the night, accounted for 11% of crepuscular activity. For the entire 15-d monitoring period, deliveries of vertebrate prey made up 60% of all activity. The frequency of daily vertebrate prey deliveries was relatively similar for the first 10 full days of monitoring (range 9 to 13 deliveries), then peaked 3 to 4 d prior to fledging (range 15 to 20 deliveries) before declining on the last 2 d of the period, when deliveries of moths and enticement activity increased. We concluded that the pair's activity during the nestling period was consistent with a diurnal activity pattern. We encourage other researchers to refine the meanings of the terms diurnal and crepuscular and clarify how those terms should be used to define the primary activity pattern of a species. [ABSTRACT FROM AUTHOR]

Despite the increasing spatial, temporal and dietary overlap between bobcats Lynx rufus and coyotes Canis latrans, these species live sympatrically throughout much of North America. To determine if differential activity patterns relative to abiotic variables might influence interspecific interactions, we investigated whether these species responded differentially to crepuscular and nocturnal abiotic variables in Texas. Using GPS collars, we calculated hourly movements from sequential locations, and compared bobcat and coyote movements relative to sex, season, moonlight intensity, night period, crepuscularity and temperature. We used generalized linear mixed effects models (GLMM) to investigate the responses of bobcats and coyotes to variables associated to their nocturnal movements. Temperature and its interactions with various abiotic variables influenced bobcat movements. Biological season and its interactions with other abiotic variables influenced coyote movements. Bobcats moved shorter hourly distances than coyotes. Female bobcats moved shorter hourly distances than males. Moonlight intensity seemed to influence coyotes but not bobcats. Differential movements between bobcats and coyotes relative to night period could possibly be due behavioral avoidance of coyotes by bobcats. Reduced crepuscular activity by coyotes may be behavioral avoidance of humans. Differential responses to nocturnal variables may dampen competitive interactions between bobcats and coyotes. [ABSTRACT FROM AUTHOR]

Fluorescence of visible wavelengths under ultraviolet (UV) light has been previously detected in a wide range of birds, reptiles, and amphibians and a few marsupial mammals. Here, we report the discovery of vivid UV fluorescence of the pelage in Glaucomys, the New World flying squirrels. Fluorescence in varying intensities of pink was observed in females and males of all extant species (G. oregonensis, G. sabrinus, and G. volans) across all sampled geographic areas in North and Central America and a temporal range of 130 years. We observed fluorescence in museum specimens (n = 109) and wild individuals (n = 5) on both dorsal and ventral surfaces. Museum specimens of three co-occurring, diurnal sciurid species (Sciurus carolinensis, S. niger, and Tamiasciurus hudsonicus) were also examined but did not fluoresce. The ecological significance of this trait in the nocturnal–crepuscular flying squirrels warrants further investigation. [ABSTRACT FROM AUTHOR]

Understanding wildlife-vehicle collision risk is critical to mitigating its negative impacts on wildlife conservation, human health and economy. Research often focuses on collisions between wildlife and road vehicles, but collision risk factors for other types of vehicles, less examined in the literature, may also be informative. We studied spatial and temporal variation in wildlife-train collision risk in the State of Victoria, Australia. We quantified train movements in space and time, and mapped species occurrence likelihood, across the railway network. Using spatially- and temporally-resolved collision data, we fitted a model to analyse collisions between trains and kangaroos; accounting for time of day, train frequency and speed, and kangaroo occurrence. We then predicted collision rates on the passenger railway network under three management scenarios relating to train speed and occurrence of kangaroos near the railway lines. Temporal variation in animal activity was the strongest predictor of collision risk. Train speed was the second most influential variable, followed by spatial variation in likelihood of species occurrence. Reducing speeds in areas of high predicted species occurrence and during periods of peak animal activity (early morning and evening for kangaroos) was predicted to reduce collision risk the most. Our results suggest mechanisms that might improve existing wildlife-transport collision analyses. The model can help managers decide where, when and how best to mitigate collisions between animals and transport. It can also be used to predict high-risk locations or times for (a) timetable/schedule changes (b) proposals for new routes or (c) disused routes considered for re-opening. [ABSTRACT FROM AUTHOR]

A new species of the genus Enicospilus Stephens, 1835, E. kikuchii sp. nov., which belongs to the ichneumonid subfamily Ophioninae, is described based on two specimens that were collected in Saitama Prefecture of Honshû and Kagoshima Prefecture of Kyûshû in Japan. Enicospilus kikuchii sp. nov. belongs to the E. antefurcalis species-group. A key to species of the group and additional couplets for the key to Indo-Papuan Enicospilus species are provided. [ABSTRACT FROM AUTHOR]

Human recreation can negatively affect wildlife, particularly on weekends when human activity is highest (i.e., the weekend effect). Much of what we understand about the weekend effect is based on research conducted on diurnal species, which have greater temporal overlap with humans. Because nocturnal species generally avoid times when humans are active, they are likely less affected by anthropogenic activity on weekends. Our objective was to test the weekend effect in relation to the degree of nocturnality of mammals in a recreational area. We predicted that as nocturnality increased, the effect of human activity would decrease. To address our objective, we placed 50 remote cameras along the Diamond Fork River in Utah from January to June 2015. We found that three out of the four focal species supported our predictions. Mule deer (crepuscular) reduced activity throughout our entire study area during weekends and avoided campgrounds. Beavers and mountain lions (both nocturnal) did not negatively respond to increased human activity. Raccoons (nocturnal) reduced activity during weekends, but only within campground areas. Our findings indicate that as the temporal overlap increases between wildlife and humans, so does the influence that humans have on wildlife. [ABSTRACT FROM AUTHOR]