Sex and seasonal variation in the diet of the Mountain Horned Lizard (Phrynosoma orbiculare)

Sexual and seasonal variation in diet quality and the gastrointestine have important implications for forage acquisition and the feeding strategy. We assessed the botanical and chemical compositions of the diet and the gastrointestinal macrostructure of the sika deer (Cervus nippon) in western Japan. The sexual dimorphism-body size hypothesis predicts that smaller females will have a better diet than larger males to meet a higher nutritional demand due to a higher metabolic rate. According to the optimal digestion theory, the gut of larger males will retain a greater quantity of digesta of poor forage to compensate for the reduction in net energy obtained per unit of digesta. The relatively greater omasum content in winter than in summer was the only feature consistent with this prediction. This may suggest that the omasum is the organ that most sensitively reflects diet quality, because the summer diet quality is little better than that in winter. Contrary to predictions, the botanical composition of the diet did not show a sexual difference, but females had greater relative weights of stomach contents, tissues, and hindgut segments (small and large Intestines, and cecum-colon), and a relatively greater small Intestine length than males in summer. Further, females had greater relative weights of abomasum contents, ruminoreticulum tissue, and small Intestine in summer than in winter, but no seasonal variation in gastrointestinal features was detected in males. The sexual variation in diet and in the gastrointestine in summer suggest that lactating females Intake more forage and maintain more digesta in the gut, due to not body size but to higher energy requirements for lactation. The greater gut fill and tissue weight of females in summer than in winter likely resulted from a nutrient demand from lactation greater than that from gestation.

This study examined the population dynamics and seasonal variation (winter-summer) in the biological characteristics of black sea bream (Acanthopagrus schlegelii) in Zhanjiang coastal waters, China. Key growth parameters were estimated using the von Bertalanffy growth model, revealing an asymptotic length (L∞) of 505.05 mm and a growth coefficient (K) of 0.26 year-¹, with an estimated longevity of 11.24 years. Mortality analysis showed a total mortality rate (Z) of 0.35 year-¹, primarily driven by natural causes (M = 0.33 year-¹) with minimal fishing impact (F = 0.02 year-¹), resulting in a low exploitation rate (E) of 0.05. Length-weight relationship (LWR) analysis indicated positive allometric growth in females and nearly isometric growth in males, with significant seasonal variations in condition factors (K). Yield Per Recruit (YPR) analysis identified a maximum sustainable exploitation rate (Emax) of 0.421, with a conservative management approach suggested at E0.1 = 0.355. Seasonal variations in reproductive indices, with higher Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) in winter, highlight the species’ reproductive cycle. The findings suggest that Acanthopagrus schlegelii is stable, with low fishing pressure. Seasonal GSI and HSI variations suggest fisheries management should time fishing to reduce impacts on reproductive success. Maintaining exploitation rates below Emax is essential for sustainable management, contributing valuable insights for fisheries conservation in coastal China.

BackgroundWhile previous reports characterised global and regional variations in RSV seasonality, less is known about local variations in RSV seasonal characteristics. This study aimed to understand the local-level variations in RSV seasonality and to explore the role of geographical, meteorological, and socio-demographic factors in explaining these variations.MethodsWe conducted a systematic literature review to identify published studies reporting data on local-level RSV season onset, offset, or duration for at least two local sites. In addition, we included three datasets of RSV activity from Japan, Spain, and Scotland with available site-specific data. RSV season onset, offset, and duration were defined using the annual cumulative proportion method. We estimated between-site variations within a region using the earliest onset, the earliest offset, and the shortest duration of RSV season of that region as the references and synthesised the variations across regions by a multi-level mixed-effects meta-analysis. Using the three datasets from Japan, Spain and Scotland, we applied linear regression models with clustered standard errors to explore the association of geographical, meteorological, and socio-demographic factors with the season onset and offset, respectively.ResultsWe included 7 published studies identified from the systematic literature search. With the additional 3 datasets, these data sources covered 888,447 RSV-positive cases from 101 local study sites during 1995 to 2020. Local-level variations in RSV season within a region were estimated to be 6 weeks (41 days, 95% CI: 25–57) for season onset, 5 weeks (32 days, 13–50) for season offset, and 6 weeks (40 days, 20–59) for season duration, with substantial differences across years. Multiple factors, such as temperature, relative humidity, wind speed, annual household income, population size, latitude, and longitude, could jointly explain 66% to 84% and 35% to 49% of the variations in season onset and offset, respectively, although their individual effects varied by individual regions.ConclusionsLocal-level variations in RSV season onset could be as much as 6 weeks, which could be influenced by meteorological, geographical, and socio-demographic factors. The reported variations in this study could have important implications for local-level healthcare resources planning and immunisation strategy.Trial registrationPROSPERO CRD42023482432.

Diurnal and seasonal variations of raindrop size distribution (DSD) at Gadanki (GD), Singapore (SG) and Kototabang (KT) are studied to elucidate characteristics of DSD in the Asian monsoon region. It is found that DSDs are affected by diurnal convective cycles and seasonal variations in precipitation characteristics. GD has the most significant seasonal variation in DSD. Clear difference in rainfall characteristics between the Southwest and Northeast monsoon seasons is considered to be the main cause of such clear seasonal variation. KT has the most significant diurnal variation of DSD, which is probably caused by the fact that KT is greatly affected by ocean-land contrast and mountain effects to generate local convection in the afternoon. SG has less diurnal and seasonal variations compared with the other two locations, which is related to the fact that SG is affected both by land and oceanic rainfall. Z-R relations applicable to radar rainfall measurement in these areas are derived. It is shown that the use of the Marshall-Palmer Z-R relation (Z = 200R1.6) gives bias errors of about 1.5 dB or less in rain rate estimation except for the northeast monsoon season in GD, for 12∼18 local time during pre-southwest monsoon season in GD, and for 06∼12 local time during some monsoon seasons in KT.

This study investigates the impact of season and sex variations on the total lipid contents and fatty acid composition of Scomber scombrus fillets from the Middle East Coast of Tunisia in order to dertermine the most favorable periods for consumption, and to see if the nutritional quality of the meat depends on the sex of the animal. The effect of fishing season induced significant changes in the lipid profile, and the highest values for total lipids were obtained in the spring for females with 13.2% and for males with 18.9%. The highest values for proteins were obtained in the summer for females with 22.0% and for males with 21.8%. Protein content variations were not significant (p > 0.05). The n-3/n-6 ratio showed a significant level, indicating a tendency toward n-3 fatty acid accumulation in mackerel fillets mainly represented by DHA, whose values were high during the study period for both sexes, except in autumun, which is the period of mackerel gonad maturation, when DHA decreased significantly (p < 0.05), reaching 23.2 and 34.0% for males and females, respectively. It was concluded that Scomber scombrus has high levels of proteins, lipids, and fatty acid contents mainly n-3 PUFA. DHA sex variations were not significant (p > 0.05). The Atherogenicity index (AI) and Thrombogenicity index (TI) were calculated. In our study the AI index was comprised between 0.3 and 0.6 for males and between 0.4 and 0.5 for females. The TI index values ranged from 0.6 to 0.8 for males, and was about 0.6 for females.

Kelly, RA, and Collins, K. The seasonal variations in anthropometric and performance characteristics of elite inter county gaelic football players. J Strength Cond Res 32(12): 3475-3482, 2018-There is limited research assessing the anthropometric and performance variations in elite Gaelic football. The aim of this study was to assess the anthropometric and performance characteristics of an elite intercounty squad within a season. After ethical approval and informed consent, 26 participants were assessed at the start of preseason (November), after early in-season (January), and midseason (March). Measurements included stature, body mass, sum of 8 skinfold sites (ΣSkf8), estimated body fat percentage (bf%), squat jump (SJ) and countermovement jump (CMJ), 5-, 10-, and 20-m sprint times, upper body and lower-body strength (1 repetition maximum), and Yo-Yo intermittent recovery test 2 (Yo-Yo IR2). A multivariate analysis of variance was used to determine seasonal and positional variations. Anthropometric variations were observed with an overall increase in participants' body mass and a concomitant decrease in ΣSkf8 and bf% (-21.5%, p = 0.002, η = 0.15; -1.43%, p = 0.004, η = 0.13). Performance variations showed improvements in sprint time over 5-m (p = 0.001, η = 0.19) and 10-m (p = 0.008, η = 0.11), SJ (p = 0.013, η = 0.1), CMJ (p = 0.013, η = 0.1) height and Yo-Yo IR2 (p < 0.001, η = 0.34) noted from preseason to midseason. Significant anthropometric variations are observed between the preseason and early in-season; meanwhile, significant performance variations are observed between the preseason and midseason. Distinct positional variations are evident for both anthropometric and performance characteristics at all time points. Applied practitioners should consider these findings when implementing a seasonal training plan.

Introduction: In the world there is a serious problem of hunger, malnutrition, food loss and waste, environmental degradation and depletion of natural resources. Objective: To identify food supply habits and some sustainable practices of consumers in Toluca, State of Mexico. Methodology: The field research method used was the survey; a questionnaire was designed as an instrument and applied in the municipality of Toluca to a convenience sample of 281 adults, in the months of September and October 2023 in markets, tianguis and supermarkets. Results: Family spending on food is high; food acquisition and preparation is still a female activity; food is based on vegetables, cereals, meats, eggs; most of them check the refrigerator and pantry before going shopping, and make a shopping list of food before acquiring it. Conclusion: some food supply habits, the profile of responsible and non-responsible consumers were known; food is healthy and responsible food consumption is practiced.

This study presents the first food habit assessment for the side-blotched lizard (Uta stansburiana) in the shinnery oak-mesquite habitat (Quercus havardii-Prosopis glandulosa) of southeastern New Mexico. Ants, beetles, true bugs, grasshoppers, and spiders formed the major portion of the diet during the four year study. Discriminant analyses revealed the existence of annual, seasonal (monthly), and sexual variation. Variables separating years were incidental in occurrence; the major food categories occurred consistently between years. Seasonal variation was attributed to temporary changes in abundance of arthropods through the growing season. Sexual variation was pronounced in most samples and may be related to sexual size dimorphism or to behavioral differences related to defense of territories and attraction of mates. The sexual differ- ences in diet may act to reduce intraspecific competition for food resources.

Inter-annual and seasonal variations in columnar aerosol characteristics and radiative effects over the Pokhara Valley in the Himalayan foothills – Composition, radiative forcing, and atmospheric heating

To determine the existence and extent of seasonal variation in morphological characteristics of Trichodina sp., sixty whiting Merlangius merlangus euxinus were sampled monthly for one year, from the Eastern Black Sea coast of Turkey, using a line and hook. Strong seasonal morphological variations were detected; the denticle span, blade length and ray length showed significant seasonal variation, especially in June. The timing of primary production in the Black Sea and the changes in cellular organelles suggested a negative relationship between the body diameter of trichodinids and food availability in the surrounding environment.

Regional and temporal variations in aerosol characteristics in 35 locations spread over seven different regions in India are studied during 2001–2005 from the daily mean MODIS Terra aerosol optical depth (AOD) and fine mode fraction (FMF) data. Northeast India has the lowest annual mean AOD of 0.28 while south comes next with 0.35. In the other regions AODs are higher than 0.35. Annual mean variations in AOD and FMFs in different regions do not show any noticeable increase or decrease during the 5‐year period. High altitude locations are found to have lower AODs while densely populated, urban and industrialized locations have high AODs. Many locations show a winter low and summer high in AODs. Locations/regions dominated by pollution are found to have high FMF and high AODs, while regions in which natural (biogenic) aerosols are dominant had high FMF and range of AODs. The abundance of mechanically generated aerosols over a region results in low FMF and range of AODs. These features suggest that in addition to AOD variations knowledge on sources over a region are essential in understanding the FMF variations. Frequency distribution histograms of AODs and FMFs are consistent with the fact that aerosol sources exhibit seasonal and spatial variations over India. Dust activity peaks over north and west India during March‐May which results in low FMFs as the aerosol distributions are influenced by large size dust aerosols. In Northeast FMFs are found to be higher than 0.8 throughout the year indicating the dominance of fine mode aerosols.

Several life-history traits may increase vulnerability of species to extinction. Among snakes, ambush predation and dietary specialisation are factors that increase this vulnerability. European viper species, genus Vipera, display such traits and are categorised as endangered in several parts of its range. For their conservation management, a deeper knowledge of their ecology and habitat use is highly relevant. One of the species with less ecological data is the Lataste's viper Vipera latastei, a species which lives in the Iberian Peninsula and northwestern Africa. Here, we describe its diet based on the analysis of gut content of 435 museum specimens plus nine bibliographic data from the entire Iberian range. The species showed seasonal and ontogenetic shift in diet but no sexual variations. Feeding activity (percentage of vipers with prey) was low in accordance with its ambush predation tactics, being lower in spring than in summer and autumn. Prey spectrum included two main (reptiles and small mammals), and three sporadic, types of prey (arthropods, amphibians and birds). The consumption of reptiles and mammals was seasonal; the former decreased in occurrence from spring to autumn, whereas the latter showed an opposite pattern. There was an ontogenetic shift in the diet: juveniles fed mainly on reptiles and arthropods, whereas adult vipers progressively substitute this prey with insectivores, and the largest vipers primarily foraged on rodents and birds. Our results suggest that the seasonal variation in prey type was related to prey availability, whereas the ontogenetic shift was linked to gape limitation. The apparently wide prey spectrum of V. latastei must therefore be examined, taking into account that there are seasonal and ontogenetic dietary variations as well as geographic differences, the latter probably driven by climatic contrasts into the Iberian Peninsula. This new data of the endangered Iberian V. latastei can aid the effective conservation management of this species.

Background: Seasonal variation and gender preponderance have not been adequately studied in Guillain-Barre syndrome (GBS).Objective: This study aims to evaluate the seasonal variation and sex preponderance in children with Guillian Barré Syndrome.Patients and methods: A cross sectional study was carried out by reviewing wards’ registry of all cases with Guillian Barré Syndrome admitted to Children Welfare Teaching Hospital during a 10-year period (1999 - 2008). Age, sex, seasonal distribution, residence and outcome were analysed.Results: Guillian Barré Syndrome was diagnosed in 217 (126 boys, 91 girls) patients and the annual hospital rate of admission was 22.9 /100000 children. There was increase annual incidence from 1999 till 2008 with a drop in 2006, boys: girls ratio was 1.4:1 and boys were older than girls. Clustering of cases was found during January, March, May and November over the 10-year period, 37% of cases occurred during winter and 52.5% of patients were from Baghdad.Conclusion: Guillian Barré Syndrome is more common in boys. Boys were older than girls. Clustering of cases was found during winter season.

Food supply fluctuations constrain group sizes of kangaroos and in turn shape their vigilance and feeding strategies

An efficient numerical model is used to solve the linear barotropic equations of motion with North Pacific bottom topography and seasonal wind forcing (that is, monthly mean wind stresses with the annual mean removed). The model domain extends from 10°S to 60°N and from 120°E to 100°W with 1°×1° resolution. The model‐predicted seasonal transport and sea level variations are described and compared with the available data. It is found that at the Tokara Strait, to the south of Japan, the model‐predicted seasonal transport variations are very similar to those of the observed annual cycle of sea level difference across the Strait, although the amplitude of the model response is less than that suggested by the data. Both model and data indicate enhanced flow of the Kuroshio through the Strait in summer with a minimum in that flow in the winter. This is 6 months out of phase with the seasonal transport variations predicted by the flat‐bottomed Sverdrup relation. The model response is very sensitive, however, to the smoothing of the topography, with additional peaks in transport being found in the spring and the fall when the smoothing is increased. This suggests that care in handling the topography is required if a general circulation model is to reproduce this seasonal cycle. Away from the western boundary, the model‐predicted transport variations are quite similar to those in a flatbottomed ocean. The model also shows some success at reproducing features of the observed annual cycle of sea level corrected for both atmospheric pressure variations and the steric density effect. An interesting feature of the results is that the model‐calculated sea level at the offshore edge of the coastal waveguide is remarkably similar all the way along the North American coast from the Aleutian Islands to California. This shows a peak in model sea level in the summer and a minimum in the winter and indicates that it is the seasonal fluctuations of the subtropical gyre which dominate the model response even in the northern latitudes. However, the amplitude of this signal is somewhat less than that observed at the coast which, as previous studies have shown, is strongly influenced by coastal effects. The importance of wind forcing of the coastal waveguide is also apparent in the simple model described here, as is demonstrated by comparing model‐calculated sea level at the coast with that at points offshore.