Temporal Niche Overlap Research Articles

Using motion-detection cameras to monitor foraging behaviour of individual butterflies.

The activity of many animals follows recurrent patterns and foraging is one of the most important processes in their daily activity. Determining movement in the search for resources and understanding temporal and spatial patterns in foraging has therefore long been central in behavioural ecology. However, identifying and monitoring animal movements is often challenging. In this study we assess the use of camera traps to track a very specific and small-scale interactions focused on the foraging behaviour of Heliconiini butterflies. Data on floral visitation was recorded using marked individuals of three pollen-feeding species of Heliconius (H. erato, H. melpomene and H. sara), and two closely related, non-pollen feeding species (Dryas iulia and Dryadula phaetusa) in a large outdoor insectary. We demonstrate that camera traps efficiently capture individual flower visitation over multiple times and locations and use our experiments to describe some features of their spatial and temporal foraging patterns. Heliconiini butterflies showed higher activity in the morning with strong temporal niche overlap. Differences in foraging activity between males and females was observed with females foraging earlier than males, mirroring published field studies. Some flowers were more explored than others, which may be explained by butterflies foraging simultaneously affecting each other's flower choices. Feeding was grouped in short periods of intense visits to the same flower, which we refer to as feeding bouts. Heliconius also consistently visits the same flower, while non-Heliconius visited a greater number of flowers per day and their feeding bouts were shorter compared with Heliconius. This is consistent with Heliconius having more stable long-term spatial memory and foraging preferences than outgroup genera. More broadly, our study demonstrates that camera traps can provide a powerful tool to gather information about foraging behaviour in small insects such as butterflies. © 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Temporal Niche Overlap Among Predators and Prey Species of Pothwar Plateau, Pakistan

Temporal Niche Overlap Among Predators and Prey Species of Pothwar Plateau, Pakistan

Spatial and temporal niche overlap of aardwolves and aardvarks in Serengeti National Park, Tanzania.

Species interactions can influence species distributions, but mechanisms mitigating competition or facilitating positive interactions between ecologically similar species are often poorly understood. Aardwolves (Proteles cristata) and aardvarks (Orycteropus afer) are nocturnal, insectivorous mammals that co-occur in eastern and southern Africa, and knowledge of these species is largely limited to their nutritional biology. We used aardwolf and aardvark detections from 105 remote cameras during 2016-2018 to assess their spatial and temporal niche overlap in the grasslands of Serengeti National Park, Tanzania. Using a multispecies occupancy model, we identified a positive interaction between occupancy probabilities for aardwolves and aardvarks. Slope, proportion of grassland and termite mound density did not affect the occupancy probabilities of either species. The probability of aardwolf, but not aardvark, occupancy increased with distance to permanent water sources, which may relate to predation risk avoidance. Diel activity overlap between aardwolves and aardvarks was high during wet and dry seasons, with both species being largely nocturnal. Aardwolves and aardvarks have an important ecological role as termite consumers, and aardvarks are suggested to be ecosystem engineers. Our results contribute to a better understanding of the spatial and temporal niche of insectivores like aardwolves and aardvarks, suggesting high spatial and temporal niche overlap in which commensalism occurs, whereby aardwolves benefit from aardvark presence through increased food accessibility.

Niche Analysis of the Main Fish in the Lhasa River Basin

The Lhasa River is one of the five tributaries of the Yarlung Zangbo River. It is the main industrial, agricultural and animal husbandry area in Tibet. It plays an important ecological security barrier role in regulating regional climate and maintaining biodiversity. In order to understand the resource utilization ability and relationship of fish in Lhasa River, and provide basic data for the protection and sustainable utilization of fish diversity in Lhasa River, the fishery resources in September 2019 (autumn), June 2020 (summer), November 2020 (winter) and March 2021 (spring) were investigated for the first time. The main fish in the catch were determined by the Index of Relative Importance (IRI). Shannon index and Pianka’s index were used to analyze the niche breadth and overlap values of the main fish caught in Lhasa River Basin from three dimensions of time, space and space–time. The results show that a total of 1399 fish of 3 orders and 4 families were collected. Among them, there is one dominant species, Schizopygopsis younghusbandi, and five common species, Schizothorax waltoni, Schizothorax oconnori, Ptychobarbus dipogon, Triplophysa stenura and Carassius auratus. The spatial–temporal niche breadth ranges from 1.395 to 3.628. They are Schizopygopsis younghusbandi, Carassius auratus, Ptychobarbus dipogon, Schizothorax oconnori, Triplophysa stenura and Schizothorax waltoni in a declining order. The temporal niche breadth is generally small, indicating that the survival activities of the main fish are greatly affected by seasonal changes. The fluctuation range of spatial–temporal overlap value is 0–0.535, and only 20% of the total logarithm is meaningful. The species pairs with temporal niche overlap values exceeding 0.300 reached 80%, while the spatial niche overlap value is generally low. The results show that the spatial and temporal distributions of the main fish in Lhasa River were quite different, and the spatial and temporal niche overlap value of the relationship between species is obviously affected by the change in spatial distribution. This demonstrates that the competition relationship and intensity of the main fish are quite different in different spatial positions.

Niche partitioning by sympatric civets in the Himalayan foothills of Pakistan.

Niche overlap between sympatric species can indicate the extent of interspecific competition. Sympatric competing species can exhibit spatial, temporal, and dietary adjustments to reduce competition. We investigated spatial, temporal, and dietary niche overlap of sympatric Asian palm civet (Paradoxurus hermaphroditus) and small Indian civet ( Viverricula indica), in and around Pir Lasura National Park, Pakistan. We used remote cameras to determine the frequency and timing of detections to estimate spatial and temporal overlap, and prey remains from scats to estimate dietary overlap. We collected scat samples of Asian palm civet (n = 108) and small Indian civet (n = 44) for dietary analysis. We found low spatial (Oij = 0.32) and temporal (Δ = 0.39) overlap, but high dietary niche overlap (0.9) between these two civet species. Both civet species were detected at only 11 camera sites and small Indian civets were detected most frequently during 2:00-5:00 h and 8:00-10:00 h, whereas Asian palm civets detections were greatest during 20:00-2:00 h. The overall niche breadth of Asian palm civet was slightly narrower (L = 9.69, Lst = 0.31) than that of the small Indian civet (L = 10, Lst = 0.52). We identified 27 dietary items (15 plant, 12 animal) from scats of Asian palm civet including Himalayan pear (Pyrus pashia; 27%), Indian gerbil (Tatera indica; 10%), Rhesus monkey (Macaca mulatta; 4%), and insects (5%). Scat analysis of small Indian civets revealed 17 prey items (eight plant, nine animal) including Himalayan pear (24%), domestic poultry (15%), Indian gerbil (11%), and house mouse (Mus musculus; 5%). Both civet species consumed fruits of cultivated orchard species. Spatial and temporal partitioning of landscapes containing diverse foods appears to facilitate coexistence between Asian palm civets and small Indian civets.

Influence of grazing on the activity pattern and temporal niche of two dominant rodent species in Alxa desert

Grazing by large herbivores can potentially affect interspecific interactions between small herbivores by reducing the ecological fitness of animals. Desert rodents are important components in desert ecosystems and indicators of environmental change. Grazing reduces food resources, but rodents can decrease interspecific niche overlap by adaptive behavior. However, the key factors driving rodent behavioral activities and coexistence in the Alxa desert remains unstudied. We monitored population density and behavioral activities of Midday gerbil (Meriones meridianus) and northern three-toed jerboa (Dipus sagitta) in a grazing exclusion experiment in Alxa desert, Inner Mongolia, China, in 2017. We assessed the relationship between environmental factors (such as plant height, density, coverage, rainfall and temperature) and the behavioral activities of two coexisting rodent species. The results showed that: (1) In summer, grazing significantly reduced the activity time of gerbil and jerboa compared to that in grazing exclusion areas (gerbil: F = 5.98, p < 0.05, η2 = 0.22; jerboa: F = 8.57, p < 0.01, η2 = 0.28). Grazing reduced the temporal niche overlap with an obvious shifting of activity peaks between two species. (2) Grazing exclusion enhanced the temporal niche overlap between the two rodent species due to greater food availability which relieved inter-specific competition in each season. (3) Grazing strengthened the sensitivity of rodents to environmental changes in all seasons. These results indicated that grazing affected competition between the rodent species by altering vegetation conditions, which in turn affected the temporal niche and activity patterns of rodents.

Temporal Niche Overlap of Medium Sized Herbivores in the Seoraksan and Jirisan National Parks, South Korea

Temporal Niche Overlap of Medium Sized Herbivores in the Seoraksan and Jirisan National Parks, South Korea

同域分布的野猪与狍活动节律及与月光周期的关系

PDF HTML阅读 XML下载 导出引用 引用提醒 同域分布的野猪与狍活动节律及与月光周期的关系 DOI: 10.5846/stxb202203100582 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 穆棱红豆杉国家级自然保护区野生动物监测;黑龙江省省属科研院所科研业务费项目(CZKYF2021B002);藏财预指(2020-11-05) Activity rhythm of wild boar and roe deer and its relationship with moonlight cycle in sympatric distribution Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:完全的竞争者不能共存,物种间生态位分化是同域物种长期稳定共存的基础。不同物种在同一分布区时间生态位的分化对其共存至关重要。为研究同域分布物种的共存机制,在2018年11月到2021年7月利用远红外相机监测技术对穆棱东北红豆杉国家级自然保护区同域分布的野猪(Sus scrofa)和狍(Capreolus pygargus)进行了野外监测研究,并利用核密度估计方法和雅各布斯选择指数(JSI)对日活动节律和一段时间内的活动周期选择进行了评估,同时还利用非参数检验评估了2个物种的活动与月光周期的关系。研究结果表明,狍不管在全年还是在不同的季节,日活动节律均为双峰模式,而野猪的活动模式表现出明显的可塑性,在全年和冷季为单峰型,暖季为双峰型,二者在日活动节律上的重叠程度较高(Dhat>0.59),在暖季的重叠系数最高(Dhat=0.65)。此外,在时间段的选择上,狍在全年和冷季更喜欢在黎明和黄昏活动(0.170.32),而野猪活动在全年和冷季对白天和黄昏的选择更多(JSI>0.3),暖季则更喜欢在白天活动(JSIday=0.86),二者在夜晚的活动都较少(JSInight< 0),其中野猪尤为明显(JSInight< -0.63)。狍在各月光周期间的出现频次存在显著差异(P<0.05),满月期活动较频繁,下弦月期活动频次最少,而野猪的活动与月光周期的相关性较弱(P>0.05)。研究野猪和狍的时间重叠,为研究大型食肉动物与猎物的互作关系奠定了基础。 Abstract:Complete competitors cannot coexist, and the long-term stable coexistence of sympatric species is based on interspecific niche differentiation. The temporal niche differentiation of different species in the same distribution area is very important for their coexistence. In order to study the coexistence mechanism of sympatric species, we used camera trapping to conduct field survey on wild boar (Sus scrofa) and roe deer (Capreolus pygargus), which were both distributed in the same area in the Muling Japanese Yew National Nature Reserve from November 2018 to July 2021. We used the kernel density estimation method and the Jacobs Selection Index (JSI) to evaluate the daily activity rhythm and the selection for a period of the diel cycle, and also analyzed the relationship between the activities of the two species and the moonlight cycle by nonparametric tests. The results showed that the daily activity rhythm of roe deer was two higher peaks of activity in the whole year or in different seasons. Nevertheless, the activity pattern of wild boar showed obvious plasticity, which was unimodal in the whole year and the cold season, and bimodal in the warm season. The results showed that there was a moderate degree of overlap between them in daily activity rhythm (Dhat>0.59), and the degree of overlap was the highest (Dhat=0.65, 0.55-0.75) in warm season. In addition, in terms of time period selection, the roe deer were more likely active at dawn and dusk in the whole year and the cold season (0.170.32). However, the wild boar activities were more frequent during the day and dusk in the whole year and the cold season (JSI>0.3), and preferred to be active during the day in the worm season (JSIday=0.86). Furthermore, two species of wild boar and roe deer were less active at night (JSInight<0), especially for wild boar (JSInight<-0.63). The frequency of roe deer behaviors differed significantly by moon phase (P<0.05), and roe deer were more active during the full moon period. However, the activity of wild boar was not related to the moonlight cycle (P>0.05). The study of temporal niche overlap of wild boar and roe deer provides research basis for the interaction between large carnivores and prey. 参考文献 相似文献 引证文献

Winter weather conditions result in temporal niche overlap among three sympatric medium-sized carnivores in northeastern Japan

Winter weather conditions result in temporal niche overlap among three sympatric medium-sized carnivores in northeastern Japan

Species differences in temporal response to urbanization alters predator-prey and human overlap in northern Utah

Wildlife are under continuous pressure to adapt to new environments as more land area is converted for human use and human populations continue to concentrate in suburban and exurban areas. This is especially the case for terrestrial mammals, which are forced to navigate these habitat matrices on foot. One way in which mammals may occupy urbanized landscapes is by altering their temporal activity behavior. Typically, studies have found that mammals increase their nocturnal activity within urbanized environments to avoid overlap with humans. However, to date, the majority of studies on this topic have focused on single species, and studying whether this trend holds across an entire community has important ecological implications. Specifically, understanding how differences in species temporal activity response alters predator-prey dynamics and sympatric interspecies competition can provide insight into urban wildlife community assembly and provide a mechanistic understanding of species co-occurrence within these systems. In this study, we used data from a community science camera trapping project in northern Utah to elucidate how human influence alters the temporal activity behavior of five medium- to large-sized mammals and how differences in species response affect predator-prey, human, and sympatric competitor temporal niche overlap. We found community-wide changes in activity across study sites, with increases in late night and midday activity and decreases in crepuscular activity within the more-urbanized site. However, species-specific behavioral changes varied, and these changes resulted in reduced overlap, especially between coyotes (Canis latrans) and their potential prey species. These results provide information on how human influence may alter community assembly and species-species interactions within a wildland-urban interface.

Interspecific Asymmetries in Behavioral Plasticity Drive Seasonal Patterns of Temporal Niche Partitioning in an Island Carnivore Community.

Animals vary considerably in the amount of behavioral plasticity they exhibit in daily activity timing and temporal niche switching. It is not well understood how environmental factors drive changes in temporal activity or how interspecific differences in the plasticity of activity timing ultimately manifest in free-living animals. Here, we investigated the temporal structure and organization of activity patterns of two insular mammalian carnivores living in sympatry, the island fox (Urocyon littoralis) and island spotted skunk (Spilogale gracilis amphiala). Using collar-mounted accelerometers, we assessed the plasticity of behavioral activity rhythms in foxes and skunks by investigating how environmental factors drive the distribution of locomotor activity across the day and year, and subsequently examined the dynamics of temporal niche overlap between the two species. We documented that foxes express phenotypic plasticity in daily activity timing across the year, ranging from nocturnal to diurnal to crepuscular rhythms depending on the individual and time of year. Most notably, foxes increased the proportion of daytime activity as seasonal temperatures decreased. Overall, activity patterns of foxes were consistent with the circadian thermoenergetics hypothesis, which posits that animals that switch their patterns of activity do so to coincide with the most energetically favorable time of day. In contrast to foxes, skunks exhibited little behavioral plasticity, appearing strictly nocturnal across the year. While the duration of skunk activity bouts increased with the duration of night, timing of activity onset and offset extended into daytime hours during summer when the duration of darkness was shortest. Analysis of temporal niche overlap between foxes and skunks suggested that niche overlap was highest during summer and lowest during winter and was dictated primarily by temporal niche switching in foxes, rather than skunks. Collectively, our results highlight how interspecific asymmetries in behavioral plasticity drive dynamic patterns of temporal niche overlap within an island carnivore community.

The Native Hymenoscyphus albidus and the Invasive Hymenoscyphus fraxineus Are Similar in Their Necrotrophic Growth Phase in Ash Leaves.

The populations of European ash and its harmless fungal associate Hymenoscyphus albidus are in decline owing to ash dieback caused by the invasive Hymenoscyphus fraxineus, a fungus that in its native range in Asia is a harmless leaf endophyte of local ash species. To clarify the behavior of H. albidus and its spatial and temporal niche overlap with the invasive relative, we used light microscopy, fungal species-specific qPCR assays, and PacBio long-read amplicon sequencing of the ITS1-5.8S-ITS2 region to examine fungal growth and species composition in attached leaves of European ash. The plant material was collected from a healthy stand in central Norway, where ash saplings in late autumn showed leaflet vein necrosis like that commonly related to H. fraxineus. For reference, leaflet samples were analyzed from stands with epidemic level of ash dieback in southeastern Norway and Estonia. While H. albidus was predominant in the necrotic veins in the healthy stand, H. fraxineus was predominant in the diseased stands. Otherwise, endophytes with pathogenic potential in the genera Venturia (anamorph Fusicladium), Mycosphaerella (anamorph Ramularia), and Phoma, and basidiomycetous yeasts formed the core leaflet mycobiome both in the healthy and diseased stands. In necrotic leaf areas with high levels of either H. albidus or H. fraxineus DNA, one common feature was the high colonization of sclerenchyma and phloem, a region from which the ascomata of both species arise. Our data suggest that H. albidus can induce necrosis in ash leaves, but that owing to low infection pressure, this first takes place in tissues weakened by autumn senescence, 1–2 months later in the season than what is characteristic of H. fraxineus at an epidemic phase of ash dieback. The most striking difference between these fungi would appear to be the high fecundity of H. fraxineus. The adaptation to a host that is phylogenetically closely related to European ash, a tree species with high occurrence frequency in Europe, and the presence of environmental conditions favorable to H. fraxineus life cycle completion in most years may enable the build-up of high infection pressure and challenge of leaf defense prior to autumn senescence.

Predator niche overlap and partitioning and potential interactions in the mountains of Central Asia

AbstractDirect and indirect interactions among predators affect predator fitness, distribution, and overall community structure. Yet, outside of experimental settings, such interactions are difficult to observe and thus poorly understood. Patterns of niche overlap among predators reflect and shape community interactions and may therefore help elucidate the nature and intensity of intraguild interactions. To better understand the coexistence of two apex predators, snow leopards (Panthera uncia) and wolves (Canis lupus), we investigated their spatial, temporal, and dietary niche overlap in summer in the Pamir Mountains of Tajikistan. We estimated population-level space use via spatial capture–recapture models based on noninvasive genetics and camera traps, diel activity patterns based on camera trap detections, and diet composition from prey remains in carnivore scats, from which we estimated coefficients between 0 and 1 for overlap in space, time, and diet, respectively. Snow leopards and wolves displayed moderate spatial partitioning (0.26, 95% confidence interval [CI]: 0.17–37), but overlapping temporal (0.77, 95% CI: 0.64–0.90) and dietary (0.97, 95% CI: 0.80–0.99) niches. Both predators relied on seasonally abundant marmots (Marmota caudata) rather than wild ungulates, their typical primary prey, suggesting that despite patterns of overlap that were superficially conducive to exploitation competition and predator facilitation, prey were likely not a limiting factor. Therefore, prey-mediated interactions, if present, were unlikely to be a major structuring force in the ecosystem. By implication, carnivore conservation planning and monitoring in the mountains of Central Asia should more fully account for the seasonal importance of marmots in the ecosystem.

What factors relate with the activity synchronization intensity among big cats and their ungulate prey in Northeast China?

The activity synchronization rhythm is an important aspect of measuring interspecific interactions between predators and prey, and crucial for large carnivores conservation. However, little is known about what factors relate their activity synchronization dynamics. With the climate change and human society development, the spatial-temporal distribution and activity synchronized rhythm of large carnivores and their prey would inevitably be affected, which would further affect the adaptability of large carnivores and bring new challenges to their conservation. In this study, we hypothesized the ambient temperature and human activity would influence the activity synchronization intensity among Amur tiger, Amur leopard and ungulates (roe deer, sika deer and wild boar) through cross-correlation function and temporal niche overlap model based on the camera traps data. The result show that the activity rhythms of the five target species showed species and seasonal differences, the temporal niche overlaps between ungulates were normally higher than that between the cats and prey, the weakest overlap was observed between the two big cat species, and time-lags of similar rhythmic activity can reduce the temporal overlap pressures of species. Furthermore, we found that ambient temperature relate interspecific synchrony of roe deer-sika deer and roe deer-wild boar pairs at the daily scale. And at hourly scale, temperature and human activities exerted significantly positive or negative stresses on the interspecific activity synchronization of all target species, observed in all three seasons. Our study provides new insights on our understanding of the mechanisms by which sympatric predators and ungulate prey coexist and interact in view of temporal niche overlap, as well as how wildlife managers can manage the mammal assembly effectively. As the Amur tiger and leopard populations in China are being recovered quickly, the rapidly increasing predation pressure and limited environmental resources could have profound implications for the interaction and coexistence among these two large carnivores and their ungulate prey. Managers should strengthen the monitoring, and understand its causes and consequences, so as to develop effective protective measures.

Quantitative Research Methods of Linguistic Niche and Cultural Sustainability

Building Sustainable Cities and Human Communities is one of the 17 Sustainable Development Goals of the United Nations. And the sustainability of culture plays an important role in the sustainable development of cities and human communities. Language is an important carrier of culture, and the sustainability of language is the key factor in the sustainability of culture. How to measure the sustainability of language and its niche is key to achieving sustainable cities and communities. This paper systematically summarized the concept of niche and the theory of ecolinguistics as a theoretical basis for the quantitative study of the linguistic niche, and at the same time, the methods of niche measurement were summarized to provide mathematical support for the quantitative study of the linguistic niche. The Shannon-Wiener index and Pianka index were used to quantitatively study a particular linguistic niche for the first time, based on the use of Hmong and Mandarin in Jianhe County, Guizhou Province, China. The results showed that in the temporal dimension, the niche overlap indexes of Hmong and Mandarin were all above 0.9 in the sample villages, but in the spatial dimension, the niche overlap indexes of both languages were between 0.5 and 0.6. The spatial niche separation moderated the high temporal niche overlap, which made the two languages’ spatio-temporal niche overlap at a medium-high level. The quantitative study of a linguistic niche proved helpful in quantifying the level of sustainable development of language and culture, thus providing timely, accurate, and dynamic reference data to inform macro-control policies on the sustainable development of cities and human communities.

Spatio-temporal niche of major fish species in Pishan waters off Zhejiang Province, China.

Based on seasonal bottom trawl surveys in November 2015 (autumn), February (winter), May (spring) and August (summer) in 2016, the index of relative importance (IRI), Shannon index and Pianka index were used to analyze the breadth and overlap of spatio-temporal niche of major fish species in the Pishan waters off Zhejiang Province. Redundancy analysis and interspecific competition coefficient were used to examine the competition relationship and niche differentiation of those major fish species. The results showed that a total of 61 fish species were recorded throughout the year, which belonged to 13 orders, 29 families and 48 genera. A total of 19 species with IRI&gt;100 were identified as major fish species. The temporal niche overlap value between Chelidonichthys kumu and Atule kalla was largest, indicating high temporal synchronization. Both the spatial niche overlap value and the spatio-temporal niche overlap value between Trpauchen vagina and Cynoglossus interruptus were largest, indicating that their spatial homology was high and that the use of spatial and temporal two-dimensional resource of both species were consistent. The percentage of species pairs with spatio-temporal niche overlap at the significant level (Qik&gt;0.6) was only 5.8% in Pishan waters, indicating that the spatial and temporal distribution of those species were quite different. The overlap of spatio-temporal niche significantly varied across different seasons. The results of the interspecific competition coefficient were basically consistent with the niche overlap. Results of the redundancy analysis revealed the relationships between major fish species and environmental factors (temperature, salinity, dissolved oxygen), and further explained the niche diffe-rentiation among species.

Temporal overlap among small- and medium-sized mammals in a grassland and a forest–alpine meadow of Central Asia

Assessing carnivores and prey temporal activity patterns as well as their overlap provides valuable insights into behavioural mitigations of competition. Moon phases may also play an important role in shaping wild mammals’ activity rhythms with prey showing peaks of activity in darkest nights. Camera trapping has enriched the possibility to conduct systematic studies of activity patterns and temporal niche overlap on mammalian guilds. In this study, we used camera traps to investigate intra-guild interactions and temporal partitioning among three meso-carnivores and their common prey in two Mongolian areas characterized, respectively, by a grassland and a forest–alpine meadow. We detected a moderate–high interspecific overlap in red foxes, pikas and tolai hares. We found a moderate overlap of temporal activity patterns among nocturnal carnivores as well as among nocturnal prey species. Interestingly, we observed a moderate overlap between hares and meso-carnivores. Amongst nocturnal species, the red fox and the stoat had a peak in activity in the brightest nights, the stone marten and the Mongolian silver vole preferred to range in dark nights, whereas activity of the tolai hare was not dependent on moon phases. Our work provides some first insights of temporal pattern interactions within a small- and meso-mammal assemblage in Central Asia. Our results indicate that meso-carnivores and their potential prey can co-occur in Central Mongolia by means of temporal partitioning.

Dominant species of cephalopods and their niche characteristics in offshore of northern South China Sea

To understand the relationships among dominant species of cephalopods in offshore nor-thern South China Sea, we examined the niche characteristics of these dominant species from both spatial and temporal dimensions using the index of relative importance (IRI), the niche breadth and overlap indices based on fishery resources data from the bottom-trawl survey for four seasons during 2014-2015. The results showed that five dominant species of cephalopods were recorded for four seasons, including Loligo edulis, L. chinensis, L. beka, Sepia esculenta, and L. duvaucelii. The first two species were shared by all seasons. Compared with historical data, the composition of dominant cephalopods species had changed. The cephalopods resource exhibited obvious temporal and spatial variations. Stock density was higher in the sea area extending from the southern Hainan Island to eastern Guangdong Province than that in Beibu Gulf. The seasonal variation was characte-rized by the largest in summer but the smallest in winter. The temporal and spatial niche analysis showed that there was inconsistent in the order between temporal and spatial niche breadths for domi-nant species. L. edulis (1.32) and L. chinensis (3.90) occupied the largest temporal and spatial niche breadths, respectively. The smallest of temporal and spatial niche breadths were shown for S. esculenta (0.98) and L. duvaucelii (2.04), respectively. Though the temporal niche overlap was numerically larger than the spatial niche overlap, both of them had higher values in interspecies among L. edulis, L. chinensis, L. beka, and the lower overlap for the species pairs between L. duvaucelii and other species. The result of correlation analysis suggested that niche breadth exhibited a significant negative correlation with variation in abundance on both temporal and spatial scales. The ecological niche could reflect the tempo-spatial changes of species resource, which enriched the traditional methods of fishery communities.

Spatio-temporal niche of dominant shrimp species in the Zhongjieshan Islands Marine Protected Area, China

To understand the characteristics and living conditions of shrimp population in the Zhongjieshan Islands Marine Protected Area (MPA), according to the trawl survey data of the area in January, April, July and October 2018, we analyzed the spatio-temporal niche of dominant shrimp species based on the indices of relative importance, Shannon index, Pianka formula and Pearson correlation coefficient. The results showed that 16 shrimp species from 10 families and 13 genera were collected and identified. Palaemon gravier, Solenocera crassicorni, Alpheus distinguendus, Parapenaeopsis hardwickii and Alpheus japonicus were dominant species, belonging to four fami-lies and four genera. The temporal niche breadth of the dominant species varied greatly, while their spatial niche breadth was stable. The temporal niche breadth was significantly correlated with temperature suitability. The spatio-temporal niche breadth value of A. japonicus, the small shrimps, was highest. The temporal niche overlap value between P. hardwickii and S. crassicornis was the largest, indicating that the time synchronization was high and the seasonal competition was severe. There was a significant spatial niche overlap in all dominant species, indicating that the dominant species of shrimp had the same spatial homology, with strong regional competition. The spatio-temporal niche overlap value between P. hardwickii and P. gravieri was the largest, indicating that they had high similarities in physical and biological environment selecting, spawning and migratory habits, and fierce inter-specific competition. Our results could provide reference for the application of spatio-temporal niche of marine organisms.

Temporal niche overlap among mesocarnivores in a Caatinga dry forest

Agonistic encounters among carnivores can be potentially avoided or minimized by shifts in daily activity patterns. Here, we investigated the temporal ecology of mesocarnivores which co-occur in a semiarid area where top predators are virtually absent. More specifically, we (i) describe the daily activity patterns of six mesocarnivore species, (ii) evaluate possible seasonal changes in their daily activity patterns, (iii) examine patterns of temporal overlap among mesocarnivores, and (iv) test the overlap in daily activity between mesocarnivores and their potential prey. Using camera-trapping data (13,976 camera-days) and circular and overlapping analyses, we studied six out of the seven mesocarnivore species recorded. Striped hog-nosed skunk and the crab-eating raccoon were nocturnal, crab-eating fox and northern tiger cat were nocturnal-crepuscular, ocelot was mainly nocturnal, and jaguarundi was diurnal. With the exception of jaguarundi, we fail to find strong temporal segregation among mesocarnivore and interspecific interactions did not vary seasonally, but we observed separation in their activity peaks and significant difference in their activity distributions. This partial temporal segregation can potentially contribute to interspecific coexistence, reducing the chances of interspecific killing, mainly in relation to the dominant species (ocelot). Mesocarnivores did not exhibit a significant synchrony of their activity with any of the preys evaluated, with the exception of jaguarundi, which significantly overlapped its distribution of activity with some preys. Temporal segregation contributes, but does not seem to be the only mechanism behind the coexistence of mesocarnivores in Caatinga dry forest; thus, other strategies such as spatial and dietary segregation should be considered.