End Of Season Research Articles

Possible Mechanisms behind Dominant Modes of Seasonal Cycle of Rainfall over India

Abstract The South Asian summer monsoon that occurs over four months from near summer solstice (June) to near Autumnal equinox (September) evolves within the season due to interaction with other climate components. Since most climate patterns are seasonally phase-locked, their interaction and feedback with monsoon should also be season-dependent. Here, using rain-gauge-based precipitation over India for seventy-four years, we show that the onset phase of the monsoon (June) is uncorrelated with rest of the season (July to September). Propagation of Madden Julian Oscillation (MJO) over the Indian Ocean triggers northward-propagation of precipitable water that plays a key role during the onset phase. MJO appears over the Western equatorial Indian Ocean both during the early and late Central Indian onset years. Normal and slow MJO phase propagation during early and late onset years respectively give rise to interannual variations in June rainfall. After onset, till the end of the monsoon season, interannual variability of the dominant seasonal mode of precipitation is regulated by the phase of the El Nino Southern Oscillation (ENSO) through anomalous moisture convergence. We show that, in June, ENSO doesn’t play key role because of the opposing impact on wind and moisture. However, from July to September, ENSO perturbs wind and moisture in a way that gives rise to positive feedback between monsoon, ENSO, and large-scale circulation. Such feedback of monsoon with ENSO results in a coherent impact of ENSO on monsoon precipitation in July-September. Our results suggest that dominant mechanisms for interannual variations of Indian monsoon rainfall in June and the rest of the season are different.

Dissolved phosphorous through dry-wet-dry transitions in a small-dammed river basin: integrated understanding on transport patterns, export controls, and fate.

An integrated understanding of dissolved phosphorous (DP) export mechanism and controls on export over dry and wet periods is crucial for riverine ecological restorations in dammed river basins considering its high bioavailability and retention rates at dams. Riverine DP transport patterns (composition, sources, and transport pathways), export controls, and fate were investigated over the 2020 wet season (5 events) and dry seasons before and after it (2 events: dry(before) and dry(after)) in a semi-arid, small-dammed watershed to comprehend the links between terrestrial DP sources and aquatic DP sinks. Close spatiotemporal monitoring of the full range of phosphorous and total suspended solids (TSSs) and subsequent analyses (hysteresis, hierarchical partitioning, and coefficient of variation) provided the basis for the study. Total-DP (TDP) shared 13-39% (25%) of total-P (TP) through storms, dissolved organic-P (DOP) shared 6-21% (12%), and phosphate-P shared (PO4-P) 7-22% (13%). DP forms displayed strong connections with discharge trends across the wet season, and marked changes in the shares were reported over dry-wet and wet-dry transitions. The DOP fraction of TDP increased from 4% in dry(before) baseflow to 64% at the end of the wet season. The DOP flux increment in stormflow was 20 folds compared to dry(before) baseflow, while that of PO4-P was 2 folds. DOP displayed the least spatial source heterogeneity with minimum anthropogenic pressure on inherent fluxes. DOP originated from overland and near-stream soil sources and was transported via surface runoff and soil water runoff, respectively. Across the wet season, the attrition of overland DOP sources and activation of near-stream soil DOP sources through strengthened hydrological connectivity governed the seasonal DOP trends. Surface and groundwater runoff pathways were important for PO4-P delivery during stormflow; nonetheless, wastewater treatment plant (WWTP) effluent was the main PO4-P source under both baseflow and stormflow regimes, followed by near-stream traditional agriculture lands. The interaction patterns of small dam systems with DP inputs through dry-wet periods were explained. The riverine PO4-P fluxes were profoundly impacted by in-stream biogeochemical and physical processes and small dam systems, while riverine DOP fluxes were relatively less influenced.

Impact of seasonal malaria chemoprevention timing on clinical malaria incidence dynamics in the Kedougou region, Senegal.

Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine is recommended by the World Health Organization since 2012 for clinical malaria prevention in children in the Sahelian region of Africa. In Senegal, SMC implementation began in 2013 and is given to children under 10 years old. This study aimed to describe clinical malaria incidence in the general population during routine SMC implementation and to analyse how SMC timing impacted clinical malaria dynamics in eligible children. We conducted an ecological study in the Kedougou region of Senegal in 27 villages included in the Bandafassi Health and Demographic Surveillance System (HDSS). We calculated weekly Plasmodium falciparum malaria incidence by age group using malaria case data recorded by community health workers and health-posts, and population denominators obtained from Bandafassi Health and Demographic Surveillance System. We used negative binomial generalized additive multilevel models to analyse the incidence of clinical episodes in children under 10 years during the expected SMC prophylactic period and at the end of the transmission period. Malaria incidence was strongly seasonal with a high transmission period starting in June. Children under SMC presented an overall lower incidence compared to older children and young adults. Among children eligible for SMC, the incidence was lowest for approximately 3 weeks after treatment administration and increased subsequently, suggesting a gradual loss of protection. At the end of the high transmission period, a higher malaria incidence was recorded from the 3rd to 6th week after the week of administration of the fourth (final) SMC round. While protecting children under 10 years, SMC warrants adjustment to reduce exposure before the next round, to increase protection of 5-9 years, and to cover the high transmission period completely. The addition of a 5th round of SMC in 2023 was necessary to cover the end of the transmission season, but individual-level studies are required to ensure that drug efficacy and adequate dosing are maintained.

How Do Changes in Grassland Phenology and Its Responses to Extreme Climatic Events in Central Asia?

Extreme climate events have become more frequent under global warming, significantly affecting vegetation phenology and carbon cycles in Central Asia. However, the mediating effects of intensity of compound drought and heat events (CDHEs) and compound moisture and heat events (CMHEs) on grassland phenology and their trends in the relative contributions to grassland phenology over time have remained unclear. Based on the calculation results of grassland phenology and compound events (CEs), this study used trend analysis, partial least squares regression structural equation modeling (PLS-SEM), and ridge regression analysis to investigate the mediating effect and the temporal trend in relative contribution of CEs to grassland phenology in Central Asia, and the magnitude of sensitivity of grassland phenology to CEs. This study revealed that the start of season (SOS) was advanced by 0.4 d·a−1, end of season (EOS) was delayed by 0.5 d·a−1, and length of season (LOS) extended by 0.8 d·a−1 in 1982–2022. The duration of the CDHEs (0−37 days) was greater than that of the CMHEs (0−9 days) in Central Asia. The direct effects of CDHEs and CMHEs on grassland phenology were generally negative, except for the direct positive effect of CDHEs on LOS. The indirect effects of temperature and precipitation on grassland phenology through CDHEs and CMHEs were greater than their direct effects on phenology. The relative contribution of CDHEs to grassland phenology was consistently greater than that of CMHEs, and both the relative contribution curves showed a significant upward trend. The sensitivity of grassland phenology to CDHEs was higher than its sensitivity to CMHEs at 0.79 (SOS), 1.18 (EOS), and 0.72 (LOS). Our results emphasize the mediating effects of CDHEs and CMHEs on grassland phenology. Under the influence of CDHEs and CMHEs, the LOS will further lengthen in the future.

Temporal and spatial pattern analysis of escaped prescribed fires in California from 1991 to 2020

BackgroundPrescribed fires play a critical role in reducing the intensity and severity of future wildfires by systematically and widely consuming accumulated vegetation fuel. While the current probability of prescribed fire escape in the United States stands very low, their consequential impact, particularly the large wildfires they cause, raises substantial concerns. The most direct way of understanding this trade-off between wildfire risk reduction and prescribed fire escapes is to explore patterns in the historical prescribed fire records. This study investigates the spatiotemporal patterns of escaped prescribed fires in California from 1991 to 2020, offering insights for resource managers in developing effective forest management and fuel treatment strategies.ResultsThe results reveal that the months close to the beginning and end of the wildfire season, namely May, June, September, and November, have the highest frequency of escaped fires. Under similar environmental conditions, areas with more records of prescribed fire implementation tend to experience fewer escapes. The findings revealed the vegetation types most susceptible to escaped prescribed fires. Areas with tree cover ranging from 20 to 60% exhibited the highest incidence of escapes compared to shrubs and grasslands. Among all the environmental conditions analyzed, wind speed stands out as the predominant factor that affects the risk of prescribed fire escaping.ConclusionsThese findings mark an initial step in identifying high-risk areas and periods for prescribed fire escapes. Understanding these patterns and the challenges of quantifying escape rates can inform more effective landscape management practices.

Impacts of seasonality on mercury concentrations, polyunsaturated fatty acids, and stable isotopes: implications for the use of tetragnathid spiders as sentinels.

Riparian spiders are used in ecotoxicology as sentinels of bioavailable contaminants that are transferred from aquatic to terrestrial habitats via emergent aquatic insects. Spiders in the family Tetragnathidae are particularly of interest because a high proportion of their diet consists of emergent aquatic insects and their contaminant loads reflect the amount transferred through the food web to riparian predators. The transfer of contaminants can be determined through food web tracers such as stable isotopes and polyunsaturated fatty acids; however, it is unclear how contaminants and tracers vary over the course of a year. The objective of this study was to determine whether seasonality affected size, carbon and nitrogen stable isotopes, polyunsaturated fatty acid biomarkers, mercury, and other trace metal concentrations in tetragnathid spiders. Spiders were sampled fortnightly from a single site on the Stones River in Tennessee, USA, for an entire active season (April through October). Spider mass and length steadily increased from April to September to a maximum average value of 0.078 ± 0.03 g, then decreased in October. Seasonal trends were observed for carbon and nitrogen stable isotopes, with significantly decreased signatures occurring late in the active season. Overall, methyl mercury concentrations (range: 12.1-134.4 ng/g) and the methyl-total mercury ratio (range: 49%-98%) increased throughout the active season, with higher variability observed at the end of the active season. Collectively, our results indicate that seasonality affected several important endpoints and that spiders collected during the end of the active season may not be representative of spiders during the entire active season.

Effect of two different estrus synchronization protocols on pregnancy rate in Blonde D'aquitaine cattle breed reared in Bulgaria

In the study, two protocols for synchronization of estrus and ovulation in seventeen Blonde d’Aquitaine cows reared in Bulgaria are presented. The animals were similar in age (5-6 years), physiological status (non-pregnant with weaned calves, more than 210 days post-calving), and body condition score (average 5 on a 9-point scale). The experiment was conducted on a beef cattle farm near the Danube River at the end of the grazing season. The objective was to investigate the pregnancy rates under different estrus synchronization schemes. Two synchronization schemes with artificial insemination (FTAI – 72 hours) at fixed time were applied. The schemes were based on prostaglandin F2 alpha (PGF2α) and Gonadotropin-Releasing Hormone (GnRH), with one of them using а Progesterone Releasing Intravaginal Device Delta - PRID DELTA. After executing the two protocols, 47.92 ± 12.34% of the Blonde d’Aquitaine cows were confirmed to be pregnant. In the synchronization protocol using PRID DELTA 62.50 ± 17.87% of inseminated cows were pregnant. In the protocol without the device, 33.33 ± 16.94% of inseminated cows were confirmed to be pregnant. Keywords: beef cattle, estrus synchronization, PRID-Synchprotocol

Effect of the administration of testosterone to mixed-breed bucks during spring (non-breeding season) on the sexual behaviour of bucks

ABSTRACT The sexual response of goats submitted to the male effect by exposing them to bucks treated or not with exogenous testosterone at the beginning (February) or the end (May) of the anestrus season was evaluated. In February, a group of goats (GI-T; n = 40) was placed in contact with four bucks treated with testosterone (GT), while another group of goats (GI-C; n = 40) was placed in contact with four untreated bucks (GC). This was repeated in May, the third group (GF-T; n = 40) was joined with and the fourth group (GF-C; n = 40). GT registered a higher number of flehmen, self-urination (p < 0.05), and mounts (p < 0.1) than GC. In February, more anogenital sniffing was recorded than in May, while in May more flehmen were recorded (p < 0.05). The sexual response of goats exposed to GC and GT was similar (> 70%; p > 0.05). Nonetheless, estrus latency was ten hours shorter for GT (p < 0.05). Estrus response was similar for both periods (> 85%; p > 0.05), while ovulatory response was higher in May than in February (p < 0.05). Testosterone-treated bucks induced an earlier and more synchronized estrus response. Also, a better ovarian response and conception rate were observed at the end of the anestrus season than at the beginning.

Influence of degree of cultivation of sod-podzolic soil on dynamics of content of soil organic carbon

In 1999–2001 on the fields of the Falenky Breeding Station (Kirov region), the dynamics of the content of soil organic carbon (Corg) and its labile part (Clab) in sod-podzolic arable soil of varying degrees of cultivation were studied. The arable layer of weakly cultivated variant of the soil was characterized by high acidity (pHKCl – 3.88) and low organic carbon content (Corg – 0.91 %). The well cultivated variant had an acidity close to neutral in the arable horizon (pHKCl – 6.14) and a total carbon content at the average level for sod-podzolic loamy soils of the region (Corg – 1.10 %). Soil samples were taken during the growing season once a month in a sixfold repetition from the arable horizon and in a threefold repetition for horizons A2B and B. It was revealed that during all years of observation in the arable horizon of the soil of the cultivated variant, the Corg content was significantly higher (by 16–76 %). In the underlying horizons of soils of both variants, the carbon content was sharply reduced to 0.2–0.6 %. The content of labile part of organic carbon did not differ by variants and varied from 0.05 to 0.19 % depending on the horizon and observation period. However, in the arable horizon of weakly cultivated soil, the proportion of labile carbon in the composition of total organic carbon was significantly higher, which indicated less stability of the soil organic matter system. The content of both forms of soil organic matter varied significantly over the years and during the growing season. Maximum values of Corg content were noted at the beginning and at the end of the observation season. Minimum values were noted in July. Content of Clab was decreasing from the beginning to the end of the season.

Extraction and Characterization of Artichoke (Cynara cardunculus L.) Solid Waste from the Industrial Processing of Fresh-Cut Products for Nutraceutical Use.

Artichoke (Cynara cardunculus L.) is an herbaceous perennial plant from the Mediterranean Basin, cultivated as a poly-annual crop in different countries. Artichoke produces a considerable amount of waste at the end of the harvesting season in the field (5.2 tons/ha/year, DW) and from the industrial processing of fresh-cut products during the harvesting time (800 tons/year). The qualitative and quantitative phenolic profile and inulin content of artichoke samples from the field and industrial processing waste have been investigated after green extraction. The best operative conditions were achieved using the dried biomass extracted with water at 80 °C for 120 min and a matrix-to-solvent ratio of 1:30. The data obtained showed that the concentration of total polyphenols in fresh artichokes followed this order: stems > heads > leaves > outer bracts. Chlorogenic acid and 3,4 di-O-caffeoylquinic acid were the most concentrated caffeoylquinic derivates, whereas luteolin 7-O-malonyglucoside, luteolin 7-O-glucoside and 7-O-rutinoside were the most abundant flavonoids. The artichoke by-products showed high polyphenolic and inulin values, thus representing an important source of health-promoting biomolecules for application in pharmaceutical and cosmeceutical fields. According to the principles of circular economy, the work scheme proposed in this article, the use of waste and its processing into useful products such as nutraceutical supplies could provide a practical and economic opportunity for companies and farmers involved in the cultivation and industrial processing of artichokes.

Mineral Composition of Feed and Mineral Soil Utilization in Haramaya District, East Hararghe Zone, Ethiopia

This study was carried out to assess feed resources mineral composition and utilization of mineral soil in the Haramaya district of the East Hararghe Zone, Ethiopia. The survey data was collected from four kebeles using a semi-structured questionnaire from 80 respondents (20 from each kebele) selected randomly. Two natural pasture samples across the wet and dry seasons were collected using a quadrant from each season. Two maize and sorghum stover samples were collected for analysis at the end of harvesting seasons. Two mineral soil samples were collected from Lake Adelle and Small Abaya. Table salt (50%), mineral water (30%), and mineral soil (20%) were used as mineral supplements for livestock. Farmers obtain mineral soil from the licking area of the mineral soil and feed animals by hiking them in the licking area and taking the mineral soil into the home. Maize stover was deficient in Ca, P, Na, Zn, and Cu, while sorghum stover was deficient in P, Na, Mg, and Cu. During the wet season, natural pasture consists of higher (p&lt;0.05) P, K, Cu, Zn, and Mn while Ca and Fe were higher (p&lt;0.05) in the dry season. During wet and dry seasons, the Ca, P, Na, Mg, and K content were 14.53 vs 20.47, 1.51 vs 0.82, 0.38 vs 0.45, 4.01 vs 3.84, and 16.50 vs 6.40 g/kg, respectively. The Mn, Fe, Cu, and Zn contents were 365.14 vs 415.22, 477.78 vs 336.11, 8.48 vs 7.38 and 42.74 vs 16.94 mg/kg in wet and dry seasons, respectively. The mineral soil of both lakes was deficient in P and K, but high in Na and Fe. Supplementation of animals with deficient minerals in their feed is necessary in the study area and the mineral soil can be used as a mineral supplement for ruminants. However, an extension service is essential to improve mineral soil utilization in the study area.

Evaluating shifts in species distribution following herbicide and fertilizer applications for smutgrass (Sporobolus indicus) control in bahiagrass

Abstract Novel management strategies for controlling smutgrass have potential to influence sward dynamics in bahiagrass forage systems. This experiment evaluated population shifts in bahiagrass forage following implementation of integrated herbicide and fertilizer management plans for controlling smutgrass. Herbicide treatments included indaziflam applied preemergence (PRE), hexazinone applied postemergence (POST), a combination of PRE + POST herbicides, and a nonsprayed control. Fertilizer treatments included nitrogen (N), nitrogen + potassium (N+K), and an unfertilized control. The POST reduced smutgrass coverage regardless of PRE or fertilizer application by the end of the first season and remained low for the three-year duration of the experiment (P &lt; 0.01). All treatments, including nontreated controls, reduced smutgrass coverage during year 3 (P &lt; 0.05), indicating that routine harvesting to remove the biomass reduced smutgrass coverage. Bahiagrass cover increased at the end of year 1 with POST (P &lt; 0.01) but only the POST + fertilizer treatment maintained greater bahiagrass coverage than the nontreated control by the end of year 3 (P &lt; 0.05). Expenses associated with the POST + fertilizer treatment totaled $348 ha-1 across the three-year experiment. Other smutgrass control options could include complete removal of biomass (hay production) and pasture renovation, which can cost threefold or greater more than POST + fertilizer treatment. Complete removal of biomass may reduce smutgrass coverage by removing mature seedheads, but at a much greater expense of $2,835 to $5,825 ha-1 depending on herbicide and fertilizer inputs. Bahiagrass renovation is $826 ha-1 in establishment costs alone. When pasture production expenses are included for two seasons post-renovation, the total increases to $1,120 ha-1 across three seasons. The importance of hexazinone and fertilizer as components of smutgrass control in bahiagrass forage was confirmed in this study. Future research should focus on the biology of smutgrass and the role of a PRE in a long-term, larger-scale forage system.

Drought declaration potential of seasonally averaged vs. end of season - composite drought indices: comparative validation over Karnataka state of India

Drought declaration potential of seasonally averaged vs. end of season - composite drought indices: comparative validation over Karnataka state of India

Reservoir surface water area variations change research using Sentinel 2 MSI data. A case study in Dak Lak province, Central Highlands (Vietnam)

Agriculture is one of the most important economic sectors in Vietnam, however, in recent times, agricultural production has been negatively affected by drought, reducing crop productivity and quality. Due to the effects of climate change, drought occurs in most regions of the country with varying degrees and duration, seriously affecting water resources and agricultural production. Particularly for the Central Highlands region, drought is a natural disaster with the most negative impacts on life and production. This paper presents the results of monitoring the changes in water surface area of some reservoirs in Dak Lak province in the dry season in early 2020 from Sentinel 2 data. The MNDWI index calculated from green and NIR band of Sentinel 2 images is used to extract surface water, and thereby evaluating the change in surface water area of the reservoirs. The obtained results show a very strong decrease in water surface area of reservoirs in Dak Lak due to the influence of drought. The water surface area of Ea Sup Thuong Lake decreased about 6 times at the end of the dry season (May 2020) compared to the period of January 2020. The water surface area of Ea Uy Lake decreased about 4 times, while with the Krong Buk Ha Lake, the decrease in water surface area was lower, reaching about 28% compared to the beginning of the dry season. The results obtained in the study provide timely information to help managers effectively respond to the effects of drought on water resources.

Replicability of Strength Domains in Australian Rules Football Athletes.

Geneau, MC, Carey, DL, Gastin, PB, Robertson, S, and James, LP. Replicability of strength domains in Australian rules football athletes. J Strength Cond Res XX(X): 000-000, 2024-Maximal lower body strength is a multidimensional construct defined as the maximum force application under specific task constraints. It is crucial for many athletic tasks and is frequently assessed in strength and conditioning environments. Recent technological advancements have increased the number of measurement options for lower body strength, making data interpretation and translation challenging. Principal component analyses (PCA) methods have been proposed to inform strength test and metric selection in field sport athletes, but these methods are limited to cross-sectional designs. This study aimed to investigated the replicability of a PCA method for metric reduction and selection at 2 time points. Thirty-three Australian rules football athletes completed 7 lower body extensor strength tests during preseason (T1) and end of season (T2), each resulting in 280 force-time metrics. At each time point, 9 PCA components were required to explain at least 70% of the variance in the data set, and 7 components demonstrated similar metric loadings onto the components. However, the variable selection procedure did not return the exact same set of variables at both time points. These results suggest that while the number and loading of strength domains are consistent in Australian rules football athletes, the variable selection procedure was not fully replicable. Overall, practitioners can use this information to select tests and metrics within the domains and subdomains identified in this study to capture a range of lower body strength information from their athletes.

Impact of late rainy season indoor residual spraying on holoendemic malaria transmission: a cohort study in northern Zambia.

Indoor residual spraying (IRS) is a malaria control strategy implemented before the rainy season. Nchelenge District, Zambia is a holoendemic setting where IRS has been conducted since 2008 with little impact on malaria incidence or parasite prevalence. Pre-rainy season IRS may not reduce the post-rainy season peak abundance of the major vector, Anopheles funestus. A controlled, pre-post, prospective cohort study assessed the impact of late-rainy season IRS on malaria prevalence, incidence, hazard, and vector abundance. Three hundred eighty-two individuals were enrolled across four household clusters, of which two were sprayed in April 2022 toward the end of the rainy season. Monthly household and individual surveys and indoor overnight vector collections were conducted through August 2022. Multivariate regression and time-to-event analyses estimated the impact of IRS on outcomes measured by rapid diagnostic tests, microscopy, and quantitative polymerase chain reaction. Seventy two percent of participants tested positive by rapid diagnostic test at least once and incidence by microscopy was 3.4 infections per person-year. Residing in a household in a sprayed area was associated with a 52% reduction in infection hazard (hazards ratio: 0.48, 95% confidence interval [0.29, 0.78]) but not with changes in incidence, prevalence, or vector abundance. The study-wide entomological inoculation rate was 34 infectious bites per person per year. Monthly tracking of incidence and prevalence did not demonstrate meaningful changes in holoendemic transmission intensity. However, hazard of infection, which provides greater power for detecting changes in transmission, demonstrated that late rainy season IRS reduced malaria risk.

Silent uncrewed surface vehicles reveal the diurnal vertical distribution of lesser sandeel

Abstract Lesser sandeel (Ammodytes marinus) exhibits a peculiar diel vertical migration (DVM) during the feeding season, burying into the seabed at night and emerging during daytime to form schools that feed on zooplankton. Large schools may consist of a pelagic component searching for prey and a bottom component connected by collective bridge-like formations. However, the temporal variation in the schools’ vertical distribution is poorly understood. In this study, 38 and 200 kHz acoustic data recorded with Saildrones were used to examine the schooling dynamics during their main feeding season in May–June. A total of 1497 sandeel schools that were identified by linear discriminant analysis displayed two distinct vertical components throughout the season: one in the pelagic zone and one near the seabed. The pelagic component was distributed deepest at noon and had a similar pattern to zooplankton DVM, suggesting that sandeel followed the vertical distribution of their prey. Their diurnal ascension was greater in both distance and hours in May than June, suggesting a decline in feeding motivation towards the end of the feeding season. These findings were made possible with the long-term monitoring by silent Saildrones, which did not seem to affect the natural behaviour of sandeel schools.

Changes in breeding activity of Southeast Asian songbirds in response to the severity of the dry season

Droughts are expected to become more frequent and severe as the climate changes. Tropical songbirds likely reduce reproductive output during extreme droughts such as El Niño events in Southeast Asia as a tradeoff for reducing mortality risks. However, the timing of these rainfall responses and the extent of these reproductive costs are largely unknown in this region. Here we quantified how the amount and frequency of rainfall impacted nest initiation (first egg dates), and how the amount of rainfall may impact the duration of nesting in a given season (last expected fledging date). We tested these hypotheses on seven species of understory passerines in a secondary dry evergreen forest in northeastern Thailand. Using ten years of data (2014–2023) we examined the relationship between rainfall examining both total amounts occurring at key parts of the year (such as just prior to the breeding season) as well the number of “no-rain” days (rainfall gap) on (1) first egg dates and the (2) last expected fledging date of a given season. More severe dry seasons (longer time gaps in rainfall) caused longer delays in the start of egg laying and gap days tended to have a stronger effect than total rainfall. Lower breeding season rainfall resulted in later fledge dates for four species; lower rainfall amounts during the dry season resulted in later fledge dates for three species. There was no relationship between first egg dates and last expected fledging dates for any target species. Overall, it appears that droughts are likely shortening the breeding seasons of many tropical forest birds, but the reproductive costs are still difficult to estimate precisely. Further investigation is also recommended as to how rainfall is affecting nesting success particularly whether greater rainfall is regularly associated with earlier end of season fledging dates.

Fatigue and recovery in ballet: Exploring the experiences of professional South African ballet dancers

BackgroundProfessional South African ballet dancers face a higher risk of overuse injuries and overtraining syndrome as compared to dancers from other countries; especially towards the end of a ballet season. Fatigue is a major factor leading to overtraining syndrome and injuries in professional ballet dancers. The study aimed to explore the fatigue and recovery experiences of South African ballet dancers, highlighting how they navigate these aspects and the strategies they employ for recovery.MethodsSnowball sampling was employed to recruit ten professional South African ballet dancers. Between March and June 2023, individual semi-structured interviews were conducted online using Microsoft Teams. The interview schedule, informed by previous research, delved into the dancers’ fatigue and recovery experiences. Interviews were recorded, transcribed, and analysed using inductive thematic analysis.ResultsSeven main themes were developed from the data. Participants distinguished between mental and physical fatigue, highlighting the impact of mental fatigue on their well-being. They identified factors contributing to fatigue, including high external pressure, motivated behaviours, and expectations from audiences and management. These contributors often resulted in injuries, mandatory breaks, and sub-optimal performance. Participants accepted fatigue as inherent to their profession, emphasising mental resilience. Recovery practices included psychological, nutritional, and active strategies. The COVID-19 lockdown provided a respite from external pressures, allowing for improved recovery, but participants faced challenges upon returning to work. Gradually increasing practice time and exposure to external pressures assisted ballet dancers in effectively managing fatigue and enhancing their recovery as they returned to work.ConclusionThis study offers a perspective of fatigue and recovery in a sample of professional ballet dancers in South Africa. It emphasises the ongoing significance of fatigue and recovery and the necessity for effective strategies by arts organisations, mental health professionals, and academic researchers to support artists. The insights gained from this research could be crucial in redesigning training programs for dancers, adjusting training intensity and volume to enhance performance, and promoting recovery. Furthermore, this information serves as a strong rationale for adopting a holistic approach to fatigue and recovery, emphasising the importance of a collaborative effort to address these aspects effectively.

Intraspecific plant-soil feedback in four tropical tree species is inconsistent in a field experiment.

Soil microbes can influence patterns of diversity in plant communities via plant-soil feedbacks. Intraspecific plant-soil feedbacks occur when plant genotype leads to variations in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near nonmaternal conspecific plants. How consistently such intraspecific plant-soil feedbacks occur in natural plant communities is unclear, especially in variable field conditions. In an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama, seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post-transplant) and at the end of the experiment (~7 months post-transplant). Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the four species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while seedling survival of Ormosia macrocalyx was higher under other conspecific trees. However, these differences were gone by the end of the experiment. Our results suggest that intraspecific plant-soil feedbacks may not be consistent in the field for tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant-soil feedbacks in plant communities.