Seasonal Activity Patterns Research Articles

Sex- and age-related variations in seasonal and circadian activity of the Nose-horned Viper Vipera ammodytes (Linnaeus, 1758)

The seasonal and circadian activity patterns of Vipera ammodytes were studied in five sites in western Bulgaria between 2014 and 2017. Vipera ammodytes was active from the end of February to the first half of November. In spring, adult males emerged a few weeks earlier than females and immature vipers. In autumn, the different sex/age groups started their hibernation approximately at the same time. We registered differences in the seasonal and circadian activities between the different sex/age groups. Adult males and subadults were mostly encountered during spring and autumn, and juveniles mainly in autumn, while the encounter rate of adult females was steady throughout the activity period. Females’ circadian activity varied according to their reproductive status. The observed patterns might be a result of the complex effects of many factors, such as climatic conditions, differences in the reproductive behaviour and the cost of reproduction between sexes, as well as the trade-off between precise thermoregulation, predation risk and foraging needs.

One Health Approach to Identify Research Needs on Rhipicephalus microplus Ticks in the Americas.

We aim to provide a harmonized view of the factors that affect the survival and promote the spread of R. microplus in the Neotropics, approaching its different facets of biology, ecology, distribution, and control. We review the interactions among environmental niche, landscape fragmentation, vegetal coverage (abiotic traits), and the biotic aspects of its ecology (abundance of domesticated or wild competent hosts), proposing emerging areas of research. We emphasize a holistic view integrating an economically and ecologically sustainable control of infestations and transmitted pathogens by R. microplus in the Neotropics. Examples of research link the trends of climate, the composition of the community of hosts, the landscape features, and a tailored management based on ecological grounds. Our view is that factors driving the spread of R. microplus are complex and deeply interrelated, something that has been seldom considered in control strategies. The effects of climate may affect the dynamics of wildlife or the landscape composition, promoting new patterns of seasonal activity of the tick, or its spread into currently free areas. In this paper we encourage a One Health approach highlighting the main aspects governing the components of the tick’s life cycle and its interactions with livestock and wild animals.

Behavioural responses of a cold-water benthivore to loss of oxythermal habitat

Climate-driven declines in oxythermal habitat in freshwater lakes can impose prolonged constraints on cold-water fishes sensitive to hypoxia. How fish cope with severe habitat limitations is not well understood, yet has implications for their persistence. Here, we use acoustic-positioning telemetry to assess seasonal habitat occupancy and activity patterns of lake whitefish (Coregonus clupeaformis), a cold-water benthivore, in a small boreal lake that regularly faces severe oxythermal constraints during summer stratification. During this stratified period, they rarely (< 15% of detections) occupied depths with water temperatures > 10 °C (interquartile range = 5.3–7.9 °C), which resulted in extensive use (> 90% of detections) of water with < 4 mg L−1 dissolved oxygen (DO; interquartile range = 0.3–5.3 mg L−1). Lake whitefish were least active in winter and spring, but much more active in summer, when only a small portion of the lake (1–10%) contained optimal oxythermal habitat (< 10 °C and > 4 mg L−1 DO), showing frequent vertical forays into low DO environments concurrent with extensive lateral movement (7649 m d−1). High rates of lateral movement (8392 m d−1) persisted in the complete absence of optimal oxythermal habitat, but without high rates of vertical forays. We found evidence that lake whitefish are more tolerant of hypoxia (< 2 mg L−1) than previously understood, with some individuals routinely occupying hypoxic habitat in winter (up to 93% of detections) despite the availability of higher DO habitat. The changes in movement patterns across the gradient of habitat availability indicate that the behavioural responses of lake whitefish to unfavourable conditions may lead to changes in foraging efficiency and exposure to physiological stress, with detrimental effects on their persistence.

Seasonal Landslide Activity Lags Annual Precipitation Pattern in the Pacific Northwest

AbstractSeasonal variations in landslide activity remain understudied compared to recent advances in landslide early warning at hourly to daily timescales. Here, we learn the seasonal pattern of monthly landslide activity in the Pacific Northwest from five heterogeneous landslide inventories with differing spatial and temporal coverage and reporting protocols combined in a Bayesian multi‐level model. We find that landslide activity is distinctly seasonal, with credible increases in landslide intensity, inter‐annual variability, and probability marking the onset of the landslide season in November. Peaks in landslide probability in January and intensity in February lag the annual peak in mean monthly precipitation and landslide activity is more variable in winter than in summer, when landslides are rare. For a given monthly rainfall, landslide intensity at the season peak in February is up to 10 times higher than at the onset in November, underlining the importance of antecedent seasonal hillslope conditions.

Bison and elk spatiotemporal interactions in Elk Island National Park

Elk Island National Park (EINP) is a fenced park in the Beaver Hills UNESCO Biosphere Reserve of central Alberta where aspen parkland is being conserved. This area maintains high densities of native ungulates including elk (Cervus elaphus), bison (Bison bison bison, B. bison athabascae), moose (Alces alces), white-tailed deer (Odocoileus virginianus), and mule deer (O. hemionus). Our objective was to evaluate spatiotemporal overlap and interspecific interactions between bison and elk in EINP using camera traps. Bison and elk have overlapping habitat use and diet and are the primary focus of ungulate management in EINP. We examined distributions of both species in relation to season, landscape characteristics, anthropogenic features, and heterospecifics using generalized linear models (GLMs). We then examined seasonal daily activity patterns of bison and elk and calculated the degree of overlap. The spatial analysis revealed that bison counts were positively associated with higher proportions of open habitats across seasons and in areas farther from water in summer and fall but had no associations with distance to water during winter. Bison removal year (years during which bison removals were conducted by Parks Canada) was a significant predictor variable for bison counts in winter when the bison roundup takes place. Elk avoided areas with high linear feature density across seasons. During fall and winter, we observed higher elk counts associated with bison presence. Temporal activity patterns revealed that elk were crepuscular in all three seasons, but bison activity patterns varied with diurnal activity being more common in the summer, crepuscular activity in winter, and intermediate activity patterns during fall. Coefficients of overlap between elk and bison were high in all three seasons with the greatest difference in daily activity patterns in summer and the highest overlap in winter when both species showed strong crepuscular activity. Despite the fenced perimeter in EINP resulting in high ungulate densities, limited dispersal, and low predation, our data show patterns of habitat use and interactions between bison and elk that were similar to those in other systems. Spatiotemporal partitioning does not appear necessary for coexistence of bison and elk in the aspen parkland.

Seasonal and diel patterns in singing activity of humpback whales migrating through Bermuda

Humpback whales (Megaptera novaeangliae) produce song and non-song vocalisations, which allows their presence to be detected through passive acoustic monitoring. To determine the seasonal and diel acoustic presence and acoustic behaviour of humpback whales at the migratory stopover site off Bermuda, three hydrophones were deployed between March 2018 and April 2019 on Challenger Bank and the Bermuda platform. Song was the predominant vocalisation type encountered, with 65% of song recordings containing whale chorus and a clear seasonal trend of humpback whale occurrence in the spring and winter months from late December to mid-May. A strong diel pattern in singing activity was detected. Singing activity significantly increased at night relative to the daytime (p&amp;lt;0.01), whilst twilight periods were characterised by intermediate levels of singing. The song structure encountered in spring 2018 consisted of 18 units, 6 themes and 5 transitional phrases. The high occurrence of whale chorus and the strong seasonal and diel patterns of male humpback whale singing activity highlights the importance of Bermuda not just on their northward migration during spring, as described historically, but also on their southward migration during winter. Bermuda therefore constitutes a two-way migratory stopover site for humpback whales. The present study also provides Bermuda’s planning authorities with better constraints on the duration and intensity of anthropogenic activities in these waters.

Earlier Morning Arrival to Pollen-Rewarding Flowers May Enable Feral Bumble Bees to Successfully Compete with Local Bee Species and Expand Their Distribution Range in a Mediterranean Habitat.

Simple SummaryMany crops and wild plants depend on bee pollination for reproduction. Recent decades have shown evidence for a decline in the populations of many species of bees. One reason for this decline is the introduction of alien bees into new areas. We assessed the potential influence of bumble bees that are produced on an industrial scale and have continuously expanded their range in the Mediterranean climate regions of Israel. We found that all bee species in study sites in the Judean Hills in Israel tend to visit pollen-providing flowers at earlier times compared to nectar-providing flowers. Bumble bees and honey bees start foraging at earlier times and colder temperatures compared to native bee species. This means that the two species of commercially managed social bees are potentially depleting much of the pollen, which is typically non-replenished, before most local species arrive to gather it. Bumble bee ability to forage at the low temperatures of the early morning, and their capacity to collect pollen at early hours in the dry Mediterranean climate, potentially pose a significant competitive pressure on native bee fauna, and may lead to changes in the reproduction of local flower species.During recent decades, bumble bees (Bombus terrestris) have continuously expanded their range in the Mediterranean climate regions of Israel. To assess their potential effects on local bee communities, we monitored their diurnal and seasonal activity patterns, as well as those of native bee species in the Judean Hills. We found that all bee species tend to visit pollen-providing flowers at earlier times compared to nectar-providing flowers. Bumble bees and honey bees start foraging at earlier times and colder temperatures compared to other species of bees. This means that the two species of commercially managed social bees are potentially depleting much of the pollen, which is typically non-replenished, before most local species arrive to gather it. Taking into consideration the long activity season of bumble bees in the Judean hills, their ability to forage at the low temperatures of the early morning, and their capacity to collect pollen at early hours in the dry Mediterranean climate, feral and range-expanding bumble bees potentially pose a significant competitive pressure on native bee fauna. Their effects on local bees can further modify pollination networks, and lead to changes in the local flora.

Detection of Anaplasma phagocytophilum in Ovine Serum Samples—A Retrospective Study

Tick-borne fever in sheep is caused by Anaplasma phagocytophilum and this obligate intracellular bacterium multiplies mostly in neutrophil granulocytes of its host. In Europe, the pathogen is mainly transmitted by the tick species Ixodes ricinus. Data on the dissemination of A. phagocytophilum in the German sheep population are scarce. Hence, this pilot study aimed to investigate the presence of A. phagocytophilum in ovine serum samples retrospectively. The use of sera is beneficial because the specimens are available in large numbers and usually stored over a long period of time. Ten sheep flocks located in five federal states of Germany (Baden-Württemberg, Bavaria, Lower Saxony, North Rhine-Westphalia, Schleswig-Holstein) were included in the investigations, due to the high intra-flock seroprevalence (&gt;63%) of antibodies against the Anaplasma species. In total, 357 serum samples from seropositive sheep were analysed by 16S rRNA real-time PCR. DNA of A. phagocytophilum was detected in two ewes from the same farm in the northern German federal state of Schleswig-Holstein and represented an overall detection rate of 0.6%. Serum samples can be used to determine A. phagocytophilum, but sensitivity might be reduced in comparison to whole blood samples. Moreover, the sampling time may influence the detection of A. phagocytophilum in sheep, due to the seasonal pattern of tick activity in Germany. Our results support the findings of previous studies and demonstrate that A. phagocytophilum is also present in sheep from northern Germany (Schleswig-Holstein).

Seasonal Activity Patterns of Bats in High-Elevation Conifer Sky Islands

In the southern Appalachian Mountains of the southeastern USA, bat communities in high-elevation habitats tend to be relatively under-surveyed. High-elevation habitats may provide important habitat to certain species (i.e., migratory tree bats), and may serve as climate refugia during droughts or high temperatures. We conducted an opportunistic acoustic survey of bat communities in ten survey areas in high elevation (1,585–1,920 m a.s.l.) montane Picea rubens (red spruce)-Abies fraseri (Fraser fir) forest in the southern Appalachian Mountains of western North Carolina. In each survey area, we randomly placed three full spectrum acoustic detectors (N = 30) during three seasons (spring, summer and fall) in 2015. We deployed each detector for two five-day periods during each season (n = 900 survey nights). Although we detected seven bat species/groups during the surveys, 73% of echolocation files were attributed to Lasiurus cinereus (hoary bat) and Lasionycteris noctivagans (silver-haired bat). Generally rare in the Appalachians and typically present only at low densities in the summer at mid- and low-elevations, both species were detected at all sites during all seasons. Overall, mean nightly activity of bats was higher in the summer than the spring or fall. We observed 3.7–5 times greater activity of L. cinereus in spruce-fir forests during the summer compared to spring and fall, whereas L. noctivagans had 1.3–5 times more activity in the summer compared to other seasons. After accounting for precipitation events, our finite mixture models showed that season, temperature, elevation, and canopy height influenced L. cinereus activity, whereas season and temperature affected L. noctivagans activity. Our observations suggest that high-elevation spruce-fir forests are providing summer foraging and possibly day-roosting habitat of tree bats not previously documented this far south in North America.

Hareport hazard: Identifying hare activity patterns and increased mammal–aircraft strike risk at an International Airport

AbstractReported strike events between wildlife and aircraft are hazardous to aircraft and airfield operations and are increasing globally. To develop effective mitigation strategies, the relative hazard a species poses to aircraft, as well as information relating to its life history, are key to the development of effective mitigation strategies in Wildlife Hazard Management Plans. However, given the complex nature of airfield environments with access restrictions and the presence of sensitive equipment, the collection of high‐quality ecological data can be difficult. Here we use motion‐activated camera traps to collect activity data on a population of Irish hares (Lepus timidus hibernicus) inhabiting the airfield at Dublin International Airport, to investigate the link between hare activity and aircraft activity in relation to hare strikes. Camera traps revealed that the hare population at the airfield largely displayed a bimodal crepuscular activity pattern, with activity peaking at sunrise and at sunset. Recorded hare strike times at the airfield were closely associated with hare activity times with a high temporal overlap between these datasets. In comparison, hare activity and aircraft movement activity had a moderate overlap across all seasons, with strikes peaking at times with low aircraft movements. We demonstrate the importance of understanding the circadian and seasonal activity patterns of hazardous species at airfields for targeted strike mitigation.

The influences of the East Asian Monsoon on the spatio-temporal pattern of seasonal influenza activity in China

Previous research has extensively studied the seasonalities of human influenza infections and the effect of specific climatic factors in different regions. However, there is limited understanding of the influences of monsoons. This study applied generalized additive model with monthly surveillance data from mainland China to explore the influences of the East Asian Monsoon on the spatio-temporal pattern of seasonal influenza in China. The results suggested two influenza active periods in northern China and three active periods in southern China. The study found that the northerly advancement of East Asian Summer Monsoon (EASM) influences the summer influenza spatio-temporal patterns in both southern and northern China. At the interannual scale, the north-south converse effect of EASM on influenza activity is mainly due to the converse effect of EASM on humidity and precipitation. Within the annual scale, influenza activity in southern China gradually reaches its maximum during the summer exacerbated by the northerly advancement of EASM. Furthermore, the winter epidemic in China is related to the low temperature and humidity influenced by the East Asian Winter Monsoon (EAWM). Moreover, the active period in transition season is related partially to the large rapid temperature change influenced by the transition of EAWM and EASM. Despite the delayed onset and instability, the climatic condition influenced by the East Asian Monsoon is one of the potential key drivers of influenza activity.

Seasonal pattern of basking activity in Nerodia sipedon (Serpentes: Colubridae) along a western Michigan lakeshore, USA

Seasonal pattern of basking activity in Nerodia sipedon (Serpentes: Colubridae) along a western Michigan lakeshore, USA

Seasonal activity patterns of sympatric eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) in a Midwestern metropolitan region

Seasonal activity patterns of sympatric eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) in a Midwestern metropolitan region

Microhabitat and patch selection detection from GPS tracking collars of semi-free ranging Mashona cattle within a semi-arid environment

Over the last 30 years, the global positioning system (GPS) tracking collars have significantly enhanced livestock grazing behavior studies. Practices designed to understand and improve livestock grazing distribution can now be accurately and cost-effectively monitored with GPS tracking. The behavior and spatiotemporal microhabitat selection of Mashona cattle relative to the season in a semi-free-range grazing system was evaluated using a low‐cost GPS herd activity monitoring (GPSHAM) collar. The GPSHAM automatically logged the position of the lead cow at 20-second intervals over a 7–hour daily grazing period. Additionally, the GPS data was complemented by visually observing the lead cow during daylight hours for nine successive days each in winter (July – August) and summer (February – March) of 2017. Summer and winter tracks were used to identify the Mashona cattle preferred grass species and hotspot areas by identifying the concentration of the GPS generated tracks and points (n ≥ 30) in each grid and were used to calculate the distance from the water source using the shortest distance to the water point from the hotspot patch (HSP). The activities of the lead cow were recorded at five-minute fixed intervals for every 60 minutes in the morning (09:00 – 10:00 hrs), afternoon (13:00 – 14:00 hrs), and evening (16:00 – 17:00 hrs). The percentage of the observation time spent on an activity for the observed animal was calculated for the duration of the observation. Results showed a significant difference in patch selection (p < 0.05) between summer and winter with 17 HSPs being identified in summer and 8 HSPs in winter. Again, the range of Mashona cattle movement was 0 – 3 km from the water source. Seasonal activity patterns varied significantly across seasons. Therefore, Mashona cattle foraging behavior depends on seasonal variation. The landscape and animal attributes responded to paddock nutritional level dynamics with more frequent use of patches with higher plant species diversity and near the water source. Our research is useful to range managers, researchers, and cattle ranchers as a guideline for forage management of cattle preferred microhabitats, pasture, and nutrition.

Malayan kraits (Bungarus candidus) show affinity to anthropogenic structures in a human dominated landscape

Animal movement can impact human–wildlife conflict by influencing encounter and detection rates. We assess the movement and space use of the highly venomous and medically important Malayan krait (Bungarus candidus) on a suburban university campus. We radio-tracked 14 kraits for an average of 114 days (min: 19, max: 218), during which we located individuals an average of 106 times (min: 21, max: 229) each. Most individuals displayed some level of attraction to buildings (n = 10) and natural areas (n = 12); we identified a similar unambiguous pattern of attraction to buildings and natural areas at the population level (of our sample). Snakes remained in shelter sites for long durations (max: 94 days) and revisited sites on average every 15.45 days. Over 50% of locations were within human settlements and 37.1% were associated with buildings. We found generally seasonal patterns of activity, with higher activity in wet seasons, and lower activity in the hot season. These results show frequent proximity between Malayan kraits and humans at the university; thereby, suggesting a near constant potential for human-wildlife conflict. Despite the fact that no snakebites from this species occurred at the university during our study period, substantial education and awareness training should be considered to ensure continued coexistence on campus.

Diurnal and Seasonal Patterns of Calling Activity of Seven Cuculidae Species in a Forest of Eastern China

There is very little information on the diurnal and seasonal patterns of Cuculidae species’ calling activity in subtropical areas. In this study, we used passive acoustic monitoring to investigate the diurnal and seasonal patterns of calling activity of seven Cuculidae species at three sites in eastern China’s forest over a year. Our results showed that these species exhibited significant diurnal variations except for Cuculus micropterus. Eudynamys scolopaceus and Cuculus saturatus increased their vocal activity at dawn and dusk, whereas the other four species peaked their calling activity in the morning. Five species showed significant seasonal variations with a peak in vocal activities earlier in the season (late May or early June) and a gradual decline after that, except for Clamator coromandus, which displayed two peaks in seasonal calling activity. As for Cuculus micropterus, its calling activity was not significantly related to the season. Our study has provided basic knowledge about the calling patterns of seven Cuculidae species, and based on seasonal changes in vocal activity we propose that the breeding season of these species in east China begins in late May and ends in July.

Size structure, sex ratio, and breeding season in two intertidal grapsid crab species from Mar Chiquita Lagoon, Argentina

Life history patterns of two grapsid crab species were studied in Mar Chiquita, a brackish coastal lagoon in Argentina. Chasmagnathus granulata is a burrowing crab living in the upper intertidal, whereas Cyrtograpsus angulatus lives predominantly in the lower intertidal and subtidal. C. granulata is active (i.e. foraging and reproducing) during spring, summer and most of autumn, but remains mostly hidden inside its burrows during winter. Two dominant size groups each were found in the size-frequency distributions of males and females. Since this species builds elaborated and rather stable burrows, we found a rather uniform spatial distribution and a stable sex ratio, with only weak local deviations from a 1:1 ratio. In C. angulatus, which is a very mobile species, the sex ratio varied greatly in time and space, indicating local migrations with differential intensities or directions in males and females. Adult size structure in this species was similar at different sampling sites, with size frequency distribution of males revealing three dominant size groups, but that of females only one or two. In late autumn, most individuals of this species leave the intertidal zone and stay during winter in deeper water. Both species show a pronounced seasonal reproductive activity pattern, with a maximum percentage of ovigerous females found in the beginning of summer, and both appear to produce several subsequent egg clutches until late summer. The reproductive season is longer in C. angulatus (September-May; a few ovigerous females were found also in winter) than in C. granulata (October-March). In the intertidal, a low percentage of C. angulatus was observed to carry eggs in late embryonic stages. This suggests that ovigerous females of this species may migrate to the subtidal to release their larvae in deeper water.

Global patterns of seasonal influenza activity, duration of activity and virus (sub)type circulation from 2010 to 2020.

BackgroundSeasonal influenza viruses undergo unpredictable changes, which may lead to antigenic mismatch between circulating and vaccine strains and to a reduced vaccine effectiveness. A continuously updated knowledge of influenza strain circulation and seasonality is essential to optimize the effectiveness of influenza vaccination campaigns. We described the global epidemiology of influenza between the 2009 A(H1N1)p and the 2020 COVID‐19 pandemic.MethodsInfluenza virological surveillance data were obtained from the WHO‐FluNet database. We determined the median proportion of influenza cases caused by the different influenza virus types, subtypes, and lineages; the typical timing of the epidemic peak; and the median duration of influenza epidemics (applying the annual average percentage method with a 75% threshold).ResultsWe included over 4.6 million influenza cases from 149 countries. The median proportion of influenza cases caused by type A viruses was 75.5%, highest in the Southern hemisphere (81.6%) and lowest in the intertropical belt (73.0%), and ranged across seasons between 60.9% in 2017 and 88.7% in 2018. Epidemic peaks typically occurred during winter months in Northern and Southern hemisphere countries, while much more variability emerged in tropical countries. Influenza epidemics lasted a median of 25 weeks (range 8–42) in countries lying between 30°N and 26°S, and a median of 9 weeks (range 5–25) in countries outside this latitude range.ConclusionsThis work will establish an important baseline to better understand factors that influence seasonal influenza dynamics and how COVID‐19 may have affected seasonal activity and influenza virus types, subtypes, and lineages circulation patterns.

Seasonal and diel activities of the Yangtze finless porpoise in natural and highly disturbed habitats: Implications for conservation planning of freshwater cetaceans

Abstract Knowledge of fine‐scale seasonal and diel activity patterns of animals provides insights into habitat utilization dynamics and informs conservation action planning against potential human impacts. Such information is particularly important for riverine cetaceans, such as the Yangtze finless porpoise, which is threatened by habitat loss and disturbances by a variety of human activities. Passive acoustic monitoring (PAM) techniques were used to survey the seasonal and diel activities of the Yangtze finless porpoise in two natural habitat patches of the Anqing Yangtze Finless Porpoise Natural Reserve, and in one highly disturbed area adjacent to the reserve. In the two natural habitat patches, significantly higher detection rates of porpoises were observed during autumn and winter. The detection rates during autumn and winter were significantly higher at night than during daytime, whereas during spring and summer the diel difference in porpoise detection rates was not statistically significant. In the highly disturbed habitat, the porpoise detection rates were significantly lower than those in the two natural habitats. Although seasonal differences in porpoise detection rates were not statistically significant, diel detection rates were significantly different in autumn and winter. Information on seasonal patterns of porpoise activities suggested strengthening monitoring and law enforcement during autumn and winter, during the period in which diel activity patterns implied a potential conservation gap during nighttime. Extremely low levels of porpoise activities in port areas implied an ecological impact of coastal engineering on megafauna viability through the alteration of habitat functionality. To provide information on animal occurrences and activities and to minimize the bias of ‘false‐absence’ from visual surveys, the census survey design should consider both visual and PAM techniques. In seasons when occurrences of river cetaceans and habitat use are increasing, heightened conservation monitoring and law enforcement efforts are required, particularly during nighttime.

Daily and Seasonal Patterns in the Singing Activity of Birds in East China

The vocal behaviour of birds can change daily and seasonally. Understanding the daily and seasonal acoustic activity patterns of birds helps to understand their behavioural ecology and is crucial for designing effective monitoring protocols. We studied daily and seasonal acoustic activity patterns for a complete annual cycle of three bird species: Alström's Warbler Phylloscopus soror, Brownish-flanked Bush Warbler Horornis fortipes and Streak-breasted Scimitar Babbler Pomatorhinus ruficolli at three different sites in Yaoluoping National Nature Reserve, Anhui Province, East China. All three species displayed a peak in singing activity in the morning; however, they differed in their acoustic activity during the daytime. Alström's Warbler was vocally active for five months (April–August), with higher singing activity earlier in the season. Brownish-flanked Bush Warbler was vocally active for six months (March–August) and showed a significant variation in singing activity over time. Streak-breasted Scimitar Babbler was vocally active for nine months (March–November) and displayed a slight variation in singing activity among months at different sites. The acoustic activity of the Alström's Warbler and Brownish-flanked Bush Warbler was negatively correlated with precipitation, whereas in Streak-breasted Scimitar Babbler there was no relationship with precipitation. Overall, we found large temporal variation in singing activity within a day and between seasons. To better understand the function of the daily and seasonal pattern of singing, future studies should investigate the functioning of different song types used during daytime and morning.