scholarly journals Seasonality and interspecific temporal partitioning in a semiarid grassland bat assemblage

2021 ◽  
Author(s):  
Ram Mohan ◽  
Vaibhav Chhaya ◽  
Anand Krishnan
Keyword(s):  
Seasonal Changes ◽  
Multiple Scales ◽  
Activity Patterns ◽  
Temporal Patterns ◽  
Dry Season ◽  
Water Bodies ◽  
Diel Activity ◽  
Distributed Resources ◽  
Semiarid Grassland ◽  
Arid And Semiarid

ABSTRACTArid and semiarid environments of the world are prone to dramatic seasonal changes that affect the availability of scarce, patchily distributed resources such as water. In response to these changes, animals migrate or partition resources to minimize competition, resulting in temporal patterns within assemblages across multiple scales. Here, we demonstrate that the winter dry season bat assemblage in a semiarid grassland of northwest India exhibits both seasonal changes in composition and temporal avoidance between coexisting species at water bodies. Using a passive acoustic monitoring framework to quantify activity patterns at different points in the season, we show that two species (Rhinolophus lepidus and Tadarida aegyptiaca) exhibit seasonal differences in activity, being more frequently detected in the early and late parts of the dry season respectively. Two other species (Pipistrellus tenuis and Scotophilus heathii) do not exhibit seasonal changes in activity, but structure their diel activity patterns to minimize temporal overlap (and thus competition) at water bodies. These data, some of the first on bats from this region, demonstrate the complex temporal patterns structuring bat assemblages in arid and semiarid biomes. Our results hold promise for monitoring efforts, as a baseline to ascertain how climate change may influence the behavior and ecology of desert and grassland organisms.

Seasonal patterns and influence of temperature on the daily activity of the diurnal neotropical rodent Necromys lasiurus

2010 ◽  
Vol 88 (3) ◽  
pp. 259-265 ◽  
Author(s):  
E. M. Vieira ◽  
L. C. Baumgarten ◽  
G. Paise ◽  
R. G. Becker
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Activity Patterns ◽  
Dry Season ◽  
Diel Activity ◽  
Significant Activity ◽  
Positive Relation ◽  
Wet Season ◽  
Temperature Relation ◽  
Central Brazil

We investigated the relation between temperature and diel activity patterns of Necromys lasiurus (Lund, 1841) in 10 sites of open vegetation (grassland fields) in the Cerrado (savanna-like vegetation) of central Brazil. We used live traps equipped with timing devices during two trapping sessions: in the end of the dry season (session 1, October 2001) and in the wet season (session 2, January–February 2002). Necromys lasiurus is basically a diurnal rodent with more pronounced crepuscular and nocturnal activity in the dry season than in the wet season. Only in the wet season did we detect significant between-gender differences, with males being less active than females in the first hours after sunrise but more active between 0900 and 1200. There was no significant activity–temperature relation in the dry season, but in the wet season, both genders showed a positive relation between ambient temperature and activity. Individuals might be avoiding hot midday hours in the end of the dry season to minimize time exposure to a physiologically stressful condition caused by the joint action of high temperatures and extremely low relative humidity (<15%). In the rainy season, the high relative humidity (80%–90%) might allow the animals to show a positive relation between activity and ambient temperature.

scholarly journals Annual rhythms in adults’ lifestyle and health (ARIA): protocol for a 12-month longitudinal study examining temporal patterns in weight, activity, diet, and wellbeing in Australian adults

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rachel G. Curtis ◽  
Timothy Olds ◽  
François Fraysse ◽  
Dorothea Dumuid ◽  
Gilly A. Hendrie ◽  
...  
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Weight Gain ◽  
Repeated Measures ◽  
Vigorous Physical Activity ◽  
Activity Patterns ◽  
Intervention Strategy ◽  
Temporal Patterns ◽  
Trial Registration ◽  
Multi Level

Abstract Background Almost one in three Australian adults are now obese, and the rate continues to rise. The causes of obesity are multifaceted and include environmental, cultural and lifestyle factors. Emerging evidence suggests there may be temporal patterns in weight gain related, for example, to season and major festivals such as Christmas, potentially due to changes in diet, daily activity patterns or both. The aim of this study is to track the annual rhythm in body weight, 24 h activity patterns, dietary patterns, and wellbeing in a cohort of Australian adults. In addition, through data linkage with a concurrent children’s cohort study, we aim to examine whether changes in children’s body mass index, activity and diet are related to those of their parents. Methods A community-based sample of 375 parents aged 18 to 65 years old, residing in or near Adelaide, Australia, and who have access to a Bluetooth-enabled mobile device or a computer and home internet, will be recruited. Across a full year, daily activities (minutes of moderate to vigorous physical activity, light physical activity, sedentary behaviour and sleep) will be measured using wrist-worn accelerometry (Fitbit Charge 3). Body weight will be measured daily using Fitbit wifi scales. Self-reported dietary intake (Dietary Questionnaire for Epidemiological Studies V3.2), and psychological wellbeing (WHOQOL-BREF and DASS-21) will be assessed eight times throughout the 12-month period. Annual patterns in weight will be examined using Lowess curves. Associations between changes in weight and changes in activity and diet compositions will be examined using repeated measures multi-level models. The associations between parent’s and children’s weight, activity and diet will be investigated using multi-level models. Discussion Temporal factors, such as day type (weekday or weekend day), cultural celebrations and season, may play a key role in weight gain. The aim is to identify critical opportunities for intervention to assist the prevention of weight gain. Family-based interventions may be an important intervention strategy. Trial registration Australia New Zealand Clinical Trials Registry, identifier ACTRN12619001430123. Prospectively registered on 16 October 2019.

scholarly journals The seasonal changes of the gut microbiome of the population living in traditional lifestyles are represented by characteristic species-level and functional-level SNP enrichment patterns

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xue Zhu ◽  
Jiyue Qin ◽  
Chongyang Tan ◽  
Kang Ning
Keyword(s):  
Gut Microbiome ◽  
Seasonal Changes ◽  
Dry Season ◽  
Urban Setting ◽  
Snp Analysis ◽  
Wet Season ◽  
Human Gut ◽  
Human Gut Microbiome ◽  
Genome Level ◽  
Prevalent Species

Abstract Background Most studies investigating human gut microbiome dynamics are conducted on humans living in an urban setting. However, few studies have researched the gut microbiome of the populations living traditional lifestyles. These understudied populations are arguably better subjects in answering human-gut microbiome evolution because of their lower exposure to antibiotics and higher dependence on natural resources. Hadza hunter-gatherers in Tanzania have exhibited high biodiversity and seasonal patterns in their gut microbiome composition at the family level, where some taxa disappear in one season and reappear later. Such seasonal changes have been profiled, but the nucleotide changes remain unexplored at the genome level. Thus, it is still elusive how microbial communities change with seasonal changes at the genome level. Results In this study, we performed a strain-level single nucleotide polymorphism (SNP) analysis on 40 Hadza fecal metagenome samples spanning three seasons. With more SNP presented in the wet season, eight prevalent species have significant SNP enrichment with the increasing number of SNP calling by VarScan2, among which only three species have relatively high abundances. Eighty-three genes have the most SNP distributions between the wet season and dry season. Many of these genes are derived from Ruminococcus obeum, and mainly participated in metabolic pathways including carbon metabolism, pyruvate metabolism, and glycolysis. Conclusions Eight prevalent species have significant SNP enrichments with the increasing number of SNP, among which only Eubacterium biforme, Eubacterium hallii and Ruminococcus obeum have relatively high species abundances. Many genes in the microbiomes also presented characteristic SNP distributions between the wet season and the dry season. This implies that the seasonal changes might indirectly impact the mutation patterns for specific species and functions for the gut microbiome of the population that lives in traditional lifestyles through changing the diet in wet and dry seasons, indicating the role of these variants in these species’ adaptation to the changing environment and diets.

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

Activity patterns of wild Bactrian camels (Camelus bactrianus) in the northern piedmont of the Altun Mountains, China

2015 ◽  
Vol 65 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Yadong Xue ◽  
Diqiang Li ◽  
Wenfa Xiao ◽  
Fang Liu ◽  
Yuguang Zhang ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Endangered Species ◽  
Activity Patterns ◽  
Relative Activity ◽  
Diel Activity ◽  
Arid Areas ◽  
Critically Endangered Species ◽  
Camelus Bactrianus ◽  
Diel Activity Patterns ◽  
Bactrian Camels

There are significant gaps in our knowledge of wild camel ecology; especially the activity patterns that allow them to adapt to desert environments. The wild Bactrian camel (Camelus bactrianus) is a critically endangered species that survives in the extreme desert conditions of Central Asia. We conducted camera trapping surveys at seven watering sites in the northern piedmont of the Altun Mountains from 2010 to 2012. We analyzed the frequency of photo-captures to elucidate the wild camels’ diel activity patterns, and the seasonal variation in their activity at watering sites. We found that these wild camels were predominantly diurnal at watering sites, with an increase in relative activity from sunrise, reaching a peak toward midday, and then gradually decreasing in activity until sunset. The camels visited watering sites more often in winter than in summer. These results provide a guide for water development in the conservation of ungulates in arid areas.

scholarly journals Effects of human settlement and roads on diel activity patterns of elephants (Loxodonta africana )

2018 ◽  
Vol 56 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Kaitlyn M. Gaynor ◽  
Paola S. Branco ◽  
Ryan A. Long ◽  
Dominique D. Gonçalves ◽  
Petter K. Granli ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Loxodonta Africana ◽  
Diel Activity ◽  
Human Settlement ◽  
Diel Activity Patterns

scholarly journals Amazon forest structure generates diurnal and seasonal variability in light utilization

2015 ◽  
Vol 12 (23) ◽  
pp. 19043-19072 ◽  
Author(s):  
D. C. Morton ◽  
J. Rubio ◽  
B. D. Cook ◽  
J.-P. Gastellu-Etchegorry ◽  
M. Longo ◽  
...  
Keyword(s):  
Forest Structure ◽  
Seasonal Variability ◽  
Seasonal Changes ◽  
Forest Productivity ◽  
Dry Season ◽  
Airborne Lidar ◽  
Amazon Forest ◽  
Light Saturation ◽  
Light Utilization ◽  
Saturation Effects

Abstract. The complex three-dimensional (3-D) structure of tropical forests generates a diversity of light environments for canopy and understory trees. Understanding diurnal and seasonal changes in light availability is critical for interpreting measurements of net ecosystem exchange and improving ecosystem models. Here, we used the Discrete Anisotropic Radiative Transfer (DART) model to simulate leaf absorption of photosynthetically active radiation (lAPAR) for an Amazon forest. The 3-D model scene was developed from airborne lidar data, and local measurements of leaf reflectance, aerosols, and PAR were used to model lAPAR under direct and diffuse illumination conditions. Simulated lAPAR under clear sky and cloudy conditions was corrected for light saturation effects to estimate light utilization, the fraction of lAPAR available for photosynthesis. Although the fraction of incoming PAR absorbed by leaves was consistent throughout the year (0.80–0.82), light utilization varied seasonally (0.67–0.74), with minimum values during the Amazon dry season. Shadowing and light saturation effects moderated potential gains in forest productivity from increasing PAR during dry season months when the diffuse fraction from clouds and aerosols was low. Comparisons between DART and other models highlighted the role of 3-D forest structure to account for seasonal changes in light utilization. Our findings highlight how directional illumination and forest 3-D structure combine to influence diurnal and seasonal variability in light utilization, independent of further changes in leaf area, leaf age, or environmental controls on canopy photosynthesis. Changing illumination geometry constitutes an alternative biophysical explanation for observed seasonality in Amazon forest productivity without changes in canopy phenology.

scholarly journals Activity patterns of the small and medium felid (Mammalia: Carnivora: Felidae) guild in northeastern India

2019 ◽  
Vol 11 (4) ◽  
pp. 13432-13447 ◽  
Author(s):  
Shomita Mukherjee ◽  
Priya Singh ◽  
André Pinto Silva ◽  
Chandan Ri ◽  
Kashmira Kakati ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Regional Scale ◽  
Diel Activity ◽  
Point Scale ◽  
Clouded Leopard ◽  
Northeastern India ◽  
Additional Information ◽  
Extant Species ◽  
Diel Activity Patterns ◽  
Leopard Cat

Fifteen extant species of cats inhabit India, and the northeastern region of the country is among the richest with nine species.  Among these are the “standard four”, an assemblage of Clouded Leopard Neofelis nebulosa, Asiatic Golden Cat Catopuma temminckii, Marbled Cat Pardofelis marmorata, and Leopard Cat Prionailurus bengalensis, which also occur across southeastern Asia.  Within India, despite several surveys in this region, very little information exists on the ecology of this assemblage to explain their co-occurrence.  In this paper, we put together data from several independent camera trapping studies over 10 sites across northeastern India to examine and interpret diel activity patterns of this group.  While we present results for all the four species, we focus on two species, the Marbled Cat and Leopard Cat, which are of very similar body size and are potential competitors.  We used kernel density estimates to measure diel activity patterns of all four species and overlap in activity between Marbled Cat and Leopard Cat at the regional scale as well as the point scale.  We obtained 783 captures of the standard four from >27,500 trap nights.  The Asiatic Golden Cat and Marbled Cat were strongly diurnal, Clouded Leopard largely crepuscular and nocturnal, and Leopard Cat largely nocturnal.  The degree of overlap between Marbled Cat and Leopard Cat activity was low and in consensus with other studies across southeastern Asia.  We interpret this as the differing niche spaces of the two cats due to their specific pre-existing adaptations, not restricted to the effects of competition.  The point scale analysis when both cats are captured at the same location and separately show no shift in activity pattern, supporting our hypothesis of pre-existing differences in resources, such as food, playing a major role in facilitating co-existence.  Our study, however, is preliminary and additional information with robust analysis is required to test this finding.

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