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Obtaining robust estimates of population abundance is a central challenge hindering the conservation and management of many threatened and exploited species. Close-kin mark-recapture (CKMR) is a genetics-based approach that has strong potential to improve the monitoring of data-limited species by enabling estimates of abundance, survival, and other parameters for populations that are challenging to assess. However, CKMR models have received limited sensitivity testing under realistic population dynamics and sampling scenarios, impeding the application of the method in population monitoring programs and stock assessments. Here, we use individual-based simulation to examine how unmodeled population dynamics and aging uncertainty affect the accuracy and precision of CKMR parameter estimates under different sampling strategies. We then present adapted models that correct the biases that arise from model misspecification. Our results demonstrate that a simple base-case CKMR model produces robust estimates of population abundance with stable populations that breed annually; however, if a population trend or non-annual breeding dynamics are present, or if year-specific estimates of abundance are desired, a more complex CKMR model must be constructed. In addition, we show that CKMR can generate reliable abundance estimates for adults from a variety of sampling strategies, including juvenile-focused sampling where adults are never directly observed (and aging error is minimal). Finally, we apply a CKMR model that has been adapted for population growth and intermittent breeding to two decades of genetic data from juvenile lemon sharks (Negaprion brevirostris) in Bimini, Bahamas, to demonstrate how application of CKMR to samples drawn solely from juveniles can contribute to monitoring efforts for highly mobile populations. Overall, this study expands our understanding of the biological factors and sampling decisions that cause bias in CKMR models, identifies key areas for future inquiry, and provides recommendations that can aid biologists in planning and implementing an effective CKMR study, particularly for long-lived data-limited species.

Global change is affecting the distribution and population dynamics of plant species across the planet, leading to trends such as shifts in distribution toward the poles and to higher elevations. Yet, we poorly understand why individual species respond differently to warming and other environmental changes, or how the trait composition of communities responds. Here we ask two questions regarding plant species and community changes over 42 years of global change in a temperate montane forest in Québec, Canada: (1) How did the trait composition, alpha diversity, and beta diversity of understory vascular plant communities change between 1970 and 2010, a period over which the region experienced 1.5°C of warming and changes in nitrogen deposition? (2) Can traits predict shifts in species elevation and abundance over this time period? For 46 understory vascular species, we locally measured six aboveground traits, and for 36 of those (not including shrubs), we also measured five belowground traits. Collectively, they capture leading dimensions of phenotypic variation that are associated with climatic and resource niches. At the community level, the trait composition of high‐elevation plots shifted, primarily for two root traits: specific root length decreased and rooting depth increased. The mean trait values of high‐elevation plots shifted over time toward values initially associated with low‐elevation plots. These changes led to trait homogenization across elevations. The community‐level shifts in traits mirrored the taxonomic shifts reported elsewhere for this site. At the species level, two of the three traits predicting changes in species elevation and abundance were belowground traits (low mycorrhizal fraction and shallow rooting). These findings highlight the importance of root traits, which, along with leaf mass fraction, were associated with shifts in distribution and abundance over four decades. Community‐level trait changes were largely similar across the elevational and temporal gradients. In contrast, traits typically associated with lower elevations at the community level did not predict differences among species in their shift in abundance or distribution, indicating a decoupling between species‐ and community‐level responses. Overall, changes were consistent with some influence of both climate warming and increased nitrogen availability. [ABSTRACT FROM AUTHOR]

Lowbush blueberry is an important berry crop in Maine (USA), Quebec and the Maritime provinces of Canada. The other economically important crops in Maine are potato, dairy and organic mixed vegetable produce. Lowbush blueberry is a complex of 1–4 Vaccinium species, primarily dominated by Vaccinium angustifolium Aiton. All but one of the insect pest species in this crop system are native to the regions where it is managed in North America. Insect decline has been shown to be a recent global phenomenon although it has rarely been studied in agricultural ecosystems. Long‐term datasets of insect species abundances are a powerful tool for insect population trends. To determine if native insect pests have declined over the past several decades in Maine lowbush blueberry, we surveyed three native species. All surveys were conducted in commercial blueberry fields; although, none of the sample sites were sprayed with insecticides. Insect pest sampling comprised two surveys (1961–2014 and 1998–2017) conducted on the larval stage of the blueberry maggot fly (Rhagoletis mendax Curran), one survey (1981–2016) on the larval stage of the blueberry spanworm (Itame argillacearia (Packard)), and one survey (1983–2019) on the larval stage of the blueberry flea beetle (Altica sylvia Malloch). Based upon the analysis of our long‐term population‐level datasets, we found no evidence that insect decline has occurred in this native blueberry insect pest complex intimately associated with the lowbush blueberry, a native crop plant in North America, despite recent documentation of rapid climate change occurring in the lowbush blueberry production areas. [ABSTRACT FROM AUTHOR]

Euthynnus alletteratus, a crucial commercial resource for West African states in the Northeast Atlantic Ocean (ATNE), is of high research priority in the Atlantic Ocean, but its stock assessment is limited. This study aimed to explore the implications of integrating length, catch and abundance indices on the status of ATNE stock using the LIME model. We innovatively developed time series of abundance indices using tuna purse seine catches and efforts obtained from separate ICCAT datasets, alongside length-frequencies. The scenarios (S) S1 (length-only), S2 (length + catch + abundance), S3 (length + catch), and S4 (length + abundance) were considered. We observed that S1–S3 did not converge in LIME, except for S4. The stock's spawning potential ratio and mean length were below the target (SPR< 40%) and 95% maturity length (M95), respectively. By implication, the lack of convergence in S1–S3 portrayed data conflicts, which were mitigated by the abundance index in S4. A mean length above M95 is recommended when evaluating the stock using the length-only option in LIME. The stock was unsustainable, requiring management measures. Integrating the abundance index with length improved the performance of LIME for the stock, which estimate could be replicated for other species' assessments. [ABSTRACT FROM AUTHOR]

Camera‐based abundance estimators are an alternative methodology of growing interest in both research and management applications. The statistical formulations of camera‐based abundance estimators using time‐lapse data should theoretically produce precise and unbiased estimates; however, production of unbiased results also requires meeting several important assumptions, and real‐world case studies evaluating such results remain relatively few. We applied instantaneous sampling (IS) and space‐to‐event (STE) estimators to remote camera data collected in April 2021 via time‐lapse sampling of closed populations of bighorn sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) on Wild Horse Island in western Montana, USA, and compared results for bighorn sheep to aerial and ground‐based counts. Point estimates from camera‐based approaches underestimated bighorn sheep populations by 32–44% (IS estimator) and 62–69% (STE estimator) relative to aerial and ground counts. Patchy spatial distribution and group‐living behavior of sheep resulted in a high degree of noise surrounding the IS estimate. In comparison, a low point estimate with relatively narrow confidence intervals suggested potential sensitivity of the STE estimator to violating assumptions of independence among individual animals and sampling occasions. Estimates of mule deer had improved precision over sheep estimates, as indicated by lower estimated coefficients of variation of the mean (CVmean) derived from the analytic SE estimator. Using 15‐m viewsheds and the IS estimators, mule deer density estimates came with a 26% CVmean compared to 43% CVmean for bighorn sheep. This discrepancy may be a result of differences in distribution, behavior, and relative abundance between the 2 species. Accounting for group size and increasing time between sampling may improve accuracy of density estimates and adhere better to model assumptions when estimating precision. In addition, factors influencing viewshed and resulting density extrapolations must be considered carefully. While camera‐based methods theoretically provide an alternative way to estimate density when traditional methods are impractical, our results suggest that more work is needed to ensure density estimates are accurate and precise enough to inform population management. [ABSTRACT FROM AUTHOR]

The study explored the impact of land use changes on soil biodiversity, focussing on soil invertebrates in a converted natural forest. Using parallel transects 1 km in length positioned 200 m apart across cocoa, coffee, and cashew farms and natural forest areas, we sampled soil invertebrates with pitfall traps. The findings reveal a significant decline in soil invertebrate populations in cocoa, coffee, and cashew farmlands compared to natural forest. The number of soil invertebrates recorded in the wet season was generally less than the number found in the dry season. Mean soil invertebrate count in the natural forest was approximately double that of the count in cashew farms. Soil invertebrate density was highest in the dry season in the natural forest and lowest in the cashew farms. The study contributes a holistic understanding of the intricate relationships between land use changes and soil biodiversity, emphasizing the urgency of adopting conservation measures and policy interventions to safeguard the rich diversity of soil ecosystems for future generations. [ABSTRACT FROM AUTHOR]

The influence of soil erodibility degree on the abundance and diversity of cultivated fungi and actinomycetes have been assessed for different seasons of the annual cycle. The objects of the study are sod-podzolic soils (Umbric Retisols (Abruptic)) with different erodibility degree, located on the slope of the southeastern exposure (Solnechnogorsk raion, Moscow oblast), which have been used for a long time for the cultivation of agricultural crops. The indicators of microbial abundance have been determined by the plate method, identification has been carried out on the basis of phenotypic characters. It is shown that the decline in physical and agrochemical parameters of the soil resulted from the erosion processes, leads to a change in microbiological parameters. An increase in the degree of soil erosion leads to a decrease in the abundance and species diversity of fungi and actinomycetes. Significant differences in the taxonomic composition of microbial communities of noneroded and eroded soils have been found (the Sørensen coefficient of species similarity does not exceed 0.42 and 0.30 for fungi and actinomycetes, respectively). Taxonomic units of mycelial microorganisms have been identified. Among fungi, they are represented by the species Aspergillus, Cladosporium, and Scopulariopsis, and among actinomycetes, by Streptomyces malachitospinus, S. candidus, and Micromonospora aurantiaca. [ABSTRACT FROM AUTHOR]

Sagartaal is located in Budaun with geographical coordinates 28.0512°N and 79.1305°E in Nawada region, Uttar Pradesh, Uttar Pradesh, India. Understanding the composition, diversity, and abundance of the zooplankton is vital for better utilization of such waterbodies. The present study was carried out from October 2022 to September 2023. A total of 24 species belonging to 16 species of Rotifera, 4 species of Cladocera, 2 species of Copepoda, and 2 species of Ostracoda were recorded. The prominent species were Brachionus forficula, B. calyciflourus, Keratella cochlearis, Simocephalus sp., Cyclops sp., and Mesocyclops sp. Zooplankton showed seasonal variations in their species composition, abundance, and diversity concerning water temperature, pH, total alkalinity, dissolved oxygen, and hardness. The zooplankton density was recorded as maximum in winter and minimum in monsoon. Statistically, zooplankton shows significant correlations as Rotifera with EC, BOD (r =− 0.50; − 0.58, respectively); while with total hardness (r = 0.75); Cladocera with DO (r = 0.53), alkalinity (r = 0.57), nitrate (r = 0.56), and phosphate (r = − 0.49). The highest Shannon index (2.83) was obtained for summer, due to the lowest value of the dominance index (0.07) for this season. More studies are warranted on Monitoring such ecosystems as Sagartaal to understand the effects of anthropogenic pressure on zooplankton's community structure, can help in identifying the indicator species to formulate effective conservation planning. [ABSTRACT FROM AUTHOR]

Gastropoda assemblages were investigated for four seasons in 2016–2017 (autumn, winter, spring, and summer) near Umm Al-Namil Island in Kuwait in rocky and sandy habitats to study the effect of season and habitat type on species richness, abundance, evenness, and diversity. A total of 28 gastropod species belonging to 14 families were identified (26 in sandy, 20 in rocky, 18 in common between both habitats). Clypeomorus bifasciata (31.07%) and Trochus erithreus (21.43%) were the most abundant species in the rocky habitat. Pirenella arabica (27.51%), C. bifasciata (26.15%) and Mitrella blanda (15.66%) dominated the sandy habitat. At the rocky habitat, total abundance ranged from 6.5 ± 4.71 to 40 ± 45.17 ind m−2 in autumn and summer, respectively. As for the sandy habitat, total abundance varied from 53.0 ± 22.60 to 294.0 ± 316.67 ind m−2 in summer and winter, respectively. The results of the rocky habitat showed that diversity and evenness were strongly affected by season more than habitat type. Species richness and abundance were strongly influenced by habitat type rather than the season. However, the sandy habitat had a higher value of abundance, diversity, species richness, and evenness throughout the sampling period than the rocky habitat. There was almost a distinction between the species resident in both habitats throughout the study. These findings could be attributed mainly to the feeding habits of these gastropods and their burrowing nature. [ABSTRACT FROM AUTHOR]

Our understanding of how human activities impact biodiversity comes largely from space‐for‐time substitutions. However, spatial gradients are a poor surrogate for changes through time as they do not account for dynamic processes such as delayed extinction debts. Here we contribute towards filling this research gap by assessing the trajectories of local avian assemblages over 40+ years of climate and land‐use change. Using four decades of volunteer observations in Denmark we investigated long‐term trends of local bird richness, community structure, function, abundance, and biomass to better understand their anthropogenic drivers. Between 1976 and 2020, volunteers recorded ~ 2.4 million birds at 378 routes spanning a median of 15 years (range: 10–44). At the local level, we found a restructuring of bird communities over time (6% change per decade) and declines in abundance (−7% per decade), but stability in biomass, functional diversity, and spatial turnover. Local species richness showed a shallow decline on average. These results provide evidence that temporal turnover and loss of individuals are the most prominent features of recent ecological change in these communities. We found that the rate of local warming was positively associated with trends of species richness and functional diversity, suggesting a potential redistribution of warm‐adapted species. Meanwhile, communities that were becoming more spatially homogenous were associated with urban and farmland areas. In space, environmental changes are often distinct and recognisable, e.g. between forest and farmland. Through time, however, changes can be infrequent, gradual, and non‐linear. Despite these challenges, our results illustrate the power of spatially replicated, long‐term biodiversity monitoring programs for detecting the trends and attributing drivers of local biodiversity change. [ABSTRACT FROM AUTHOR]

Rotifers are microscopic metazoans which are generally predominant in freshwater ecosystems both in terms of species richness and species abundance. Despite their small size, they are crucial in maintaining ecological balance. In the present investigation, plankton samples collected during February 2019-January 2021 from two lentic water sources of Jammu region of Jammu & Kashmir revealed 58 species of rotifers belonging to 16 families, among which five species of monogonont rotifers from three genera were recorded to be the first reports from this region. These include three species from family Lecanidae: Lecane arcula, L. inermis, L. (Monostyla) unguitata; one species from family Brachionidae: Anuraeopsis coelata; and species Pompholyx sulcata of family Testudinellidae. Among these five monogonont species, Anuraeopsis coelata shows pantropical distribution, Lecane unguitata is a palaeotropical species, while other three are cosmopolitan in occurrence. Furthermore, comments are made on the diagnosis, seasonality, biogeographical, and ecological distribution of these species. [ABSTRACT FROM AUTHOR]

Over-summering of shorebirds refers to the phenomenon where certain species of shorebirds, primarily migratory, remain on their non-breeding grounds during the summer months for one or more years instead of migrating to their breeding grounds. The present study investigates the presence and abundance of over-summering shorebird species at four distinct sites covering 24 scanning points along the southeastern coasts of Tamil Nadu for 2017-2023. A total of 13 species were observed over-summering, with Lesser Sand Plover being the most dominant species, followed by Greater Sand Plover. Notably, 10 species were found across all four sites, while three species--Black-tailed Godwit, Bar-tailed Godwit, and Common Sandpiper--were exclusive to Dhanushkodi Lagoon, observed only during 2023. The study examined the year-wise abundance of these species, revealing a decline in over-summering shorebirds across all study sites. The Eurasian Curlew, Curlew Sandpiper, Bar-tailed & Black-tailed Godwits are the 'Near Threatened' species observed during the study. Furthermore, the research highlighted variations in Shannon species diversity index (H) location-wise and year-wise - Manoli Island (H = 2.25) in 2023; Dhanushkodi Lagoon (H = 1.8) in 2023; Valinokkam Lagoon (H = 1.63), and Pillaimadam Lagoon (H = 2.08) in 2017. Key findings are that among the study sites, in Pillaimadam Lagoon all 10 species' abundance declined; in Valinokkam Lagoon, Greater Sand Plover and Little Stint marginally increased, and eight species declined; Common Redshank and Ruddy Turnstone marginally increased in Manoli Island, while other eight species declined; Grey Plover population increased in Dhanushkodi Lagoon along with a marginal decrease in Common Redshank and Ruddy Turnstone as other species declined, over the years of study. [ABSTRACT FROM AUTHOR]

Introduction: The Indian Himalayan forests are remarkable landforms experiencing tremendous climatic variation, constituting complex and diversified ecosystems with prominent vegetation zones. Despite their global significance and substantial research efforts focused on plant diversity in the temperate Himalayan region, only a few studies have explicitly assessed the distribution patterns of understory vegetation in relation to forest compositional types along altitudinal gradients. Methods: To cover a wide range of altitudes and diverse overstory compositions, stands were sampled across four altitudinal ranges from 1500 to 3500 meters above mean sea level with increments of 500 meters in elevation steps. The overstory compositions were classified on the basis of dominant tree species in each stand on the similar sites. Vegetation in the shrub and ground layers was surveyed by visually estimating the percentage coverage within circular plots. Results: A total of 99 understory species including 37 species each in the shrub layer, 62 species in the herb layer vegetation were recorded. The abundance, species diversity and composition of understory vegetation differed significantly along the altitudinal gradient and dominant overstory composition types. Moreover, distinct understory vegetation communities were observed at lower elevations compared to higher elevations, with middle elevations exhibiting intermediate vegetation characteristics. The study also highlighted the importance of dominant overstory composition types in shaping the pattern of understory vegetation abundance, species diversity and composition in the temperate Himalayan region. The higher resource conditions associated with broadleaved stands supported higher understory species abundance at lower elevations, while the heterogeneous conditions induced by the mixedwood stands promoted higher understory species diversity. Conclusion: The hump shaped pattern along the altitudinal gradient appeared to be the most dominant pattern of plant abundance and species diversity and call for more conservation concern towards the middle elevation zones in the temperate Himalayan region. Furthermore, the management interventions should aim at maintaining diverse range of overstory composition types for conserving biodiversity and their ecological functions in the temperate Himalayan region. [ABSTRACT FROM AUTHOR]

Background: Mangrove forests are highly productive ecosystems that serve as biodiversity points, containing many organisations, contributing to carbon storage, improving water quality and providing ecosystem goods and services to improve local means of subsistence. These resilient ecosystems are characterised by their morphological modification and their particular respiratory structures (pneumatophores), which allow them to proliferate in salt-rich environments. Mangroves play a crucial role in maintaining invertebrate and fishery resources, providing shelter and nutrients to a diverse range of species. However, mangrove ecosystems are threatened by anthropogenic activities such as the extraction of building materials, firewood, crushing plants and salt manufacturing, resulting in the disintegration of ecosystems and the loss of inhabitants. This study aimed to determine the abundance and diversity of macro-benthic invertebrates on the different parts (roots, stems and leaves) of common mangrove species of the Mbegani coast, along the Indian Ocean using a completely randomised design. Results: The sampling was done using a 1 m2 quadrat focussed on the three mangrove parts, viz. roots, stems and leaves. The results showed that the highest percentage of macro-invertebrates were recorded on Bruguera gymnorhiza (66.8%), followed by Avicennia marina (20.8%) and the least were Ceriops tagal (12.4%), such variation differed significantly between the three mangrove species across the selected plots (F(2,524) = 5.71, p = 0.035). The stems (54.4%) inhabited a large number of macro-invertebrates, followed by roots (32.8%) and the least were leaves (12.8%), which varied significantly between the three mangrove parts sampled across the selected mangrove species (F(2,524) = 7.25; p = 0.008). The majority of macro-invertebrates were planktonic feeders stuck on stems or herbivores shuttling between the roots and leaves of the plants. Macro-invertebrates recorded on Bruguiera gymnorhiza were more diverse than those found in C. tagal. The findings emphasise the importance of macro-invertebrates in the ecological balance of mangrove ecosystems. Conclusion: The study concludes that mangroves in the Mbegani ecosystem have a high potential for biodiversity and are important for the coastal community and the ecosystem of the Bagamoyo District. The results contribute to coastal resources management programmes and future surveillance activities. [ABSTRACT FROM AUTHOR]

Background: Forestry and land-use change are leading causes of habitat loss, degradation, and fragmentation worldwide. The boreal forest biome is no exception, and only a small proportion of this forest type remains intact. Since forestry will remain a major land-use in this region, measures must be taken to ensure forest dependent biodiversity. Stand level features and structures promoting conservation relevant species have received much attention, but the landscape level perspective is often missing. Hence, we review the literature that has related fragmentation in the surrounding landscape to occurrence of threatened, declining, red-listed, rare, or deadwood dependent species as well as those considered to be indicator, flagship, umbrella, and/or keystone species in a given boreal forest stand. Methods: A comprehensive search string was developed, benchmarked, and adapted for four bibliographic databases, two search engines, and 37 specialist websites. The online evidence synthesis tool Cadima was used for screening of both abstracts and full texts. All articles meeting the inclusion criteria were subject to study validity assessment and included in a narrative table. Studies reporting means and variance were included in quantitative meta-analysis when more than 3 comparable studies were available. Results: The searches resulted in 20 890 unique articles that were reduced to 172 studies from 153 articles. These studies related stand level presence, abundance, species richness, and/or composition of conservation relevant species to landscape factors such as: categorical fragmentation intensity (higher vs. lower), amount of habitat or non-habitat, distance to habitat, and/or habitat configuration, on scales ranging from tens to tens of thousands of ha. Forty-three studies were suitable for meta-analysis. These showed a significant negative effect of fragmentation on both presence and abundance of conservation relevant species, as well as a near significant trend for species richness. This was particularly clear when fragmentation was measured as distance to surrounding habitat for presence, and as habitat amount for abundance. The organism groups with the strongest support for a negative effect of fragmentation were wood fungi and birds. Conclusion: As hypothesised, there is strong support for negative effects of fragmentation in boreal forest. These results emphasize the negative consequences of the intensive forestry and associated landscape transformation that has been the norm for the last century. We argue that this should have direct implications for policy makers to shift towards including a landscape perspective in all planning of harvesting, preserving, and restoring forest. In addition, we found that research effort has been very uneven between organism groups, that studies on landscape change over time were rare, and that many studies have not quantified the difference in fragmentation intensity among landscapes making it difficult to quantify the extent of the negative effect. One way forward would be to revisit the studies included here in to incorporate change over time, as well as a true quantification of landscape fragmentation. By doing so, the scale of the negative effects would be much better analysed, which would greatly assist conservation practitioners all throughout the boreal forest biome. [ABSTRACT FROM AUTHOR]

The widely observed negative scaling relationship between organism size and abundance is predicted to have a universal −0.75 scaling exponent across all life forms. However, factors influencing frequently observed deviations from this exponent, such as ecosystem succession and organism traits, remain poorly understood. We explore the dependence of size–density scaling on ecosystem succession and organism traits by analysing size–density relationships in trees and soil invertebrates across 183 temperate forest plots comprising urban secondary forests, urban old‐growth forests and non‐urban natural forests. Exponents of scaling relationships in urban tree and invertebrate communities progressively steepened with increasing restored (planted) forest stand age as small organisms increased in abundance. In contrast, non‐urban tree scaling relationships flattened during succession with exponents veering away from −0.75, whereas urban tree and invertebrate communities converged towards this prediction in later successional stages. Our results shed light on how the body size structure of tree and soil invertebrate communities spanning multiple trophic levels shift over successional time as the relative abundances of large versus small‐bodied organisms increase. This study emphasises the fundamental influence of organismal traits and ecosystem succession on scaling relationships of organism body size and abundance. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Cetoniidae (Coleoptera), known as flower and fruit beetles, form a diverse group, feed on nectar, pollen, plant exudates, and are highly attracted to fermented fruits. To evaluate their diversity in natural and agricultural areas, traps baited with fermented fruits are used. The objective of this study was to compare the effectiveness of various types of fruit used as bait, with or without the addition of sugarcane juice to accelerate fruit fermentation, on the assessment of Cetoniidae diversity in the Brazilian Cerrado. The study was conducted in two conservation units in Brasília (DF, Brazil). Two experiments were conducted, the first aiming to select the most attractive fruits (banana, pineapple, mango, grape, or cagaita), and the second to verify whether there is interference of sugarcane juice in the fruit fermentation process and, consequently, in the attractiveness to Cetoniidae. The chemical profiles of the types of bait were evaluated by identifying and quantifying the main volatile organic compounds released by the fruit traps. Insect collections were conducted weekly using fruit‐baited traps for 1 month, without interruption. We found that the diversity estimate of Cetoniidae was higher for banana‐based baits relative to grape and cagaita fruit, but not relative to pineapple, mango, and sugarcane juice. Additionally, no increase in attractiveness was observed with the addition of sugarcane juice to banana, pineapple, and mango bait. Most compounds in the fruit extracts belong to alcohol, ester, and terpene functional groups. Our results suggest that banana, pineapple, mango, and sugarcane juice, used alone, may be used for Cetoniidae diversity studies, and that banana bait seems to be the most suitable for Cetoniidae collection in the Cerrado, because it enables the collection of a high diversity of species and also of species considered rare. [ABSTRACT FROM AUTHOR]

The random encounter model (REM) is a camera trapping method to estimate population density (i.e. number of individuals per unit area) without the need for individual recognition. The REM can be applied considering camera trap data only by tracking the passages of animals in front of the camera (i.e. sequences). However, it has not been assessed how the number of sequences tracked (i.e. trajectory of the animal reconstructed) influences the REM estimates. In this context, we aimed to gain further insights into the relationship between the number of sequences tracked and reliability in REM estimates to optimize its applicability. We monitored multiple species using camera traps, and we applied REM to estimate population density. We considered red fox Vulpes vulpes, roe deer Capreolus capreolus, fallow deer Dama dama, red deer Cervus elaphus and wild boar Sus scrofa as model species. We tracked from a minimum of 154 (red fox) to a maximum of 527 (red deer) sequences per species, and we then sampled the dataset to simulate different scenarios in which a lower number of sequences were tracked (20, 40, 80 and 160). We also assessed the effect of adjusting the survey period to the minimum necessary to record the desired number of sequences. Our results suggest that tracking around 100 sequences returns a precision level equivalent to the one obtained by tracking a considerably higher number of sequences and reduced and optimized the human effort necessary to apply REM. Tracking less than 40 sequences could result in low precise density estimates. Our results also highlighted the relevance of considering study periods of ca. 2 months to increase the number of sequences recorded and tracking a random sample of them. Our results contribute to the optimization and harmonization of REM as a reference method to estimate wildlife population density without the need for individual identification. We make clear recommendations on the cost‐effective sample size for estimating REM parameters, optimizing the human effort when applying REM, and discouraging REM applications based on low sample sizes. [ABSTRACT FROM AUTHOR]

Despite being resident or reintroduced to multiple South African protected areas, spotted hyaena (Crocuta crocuta) have been subject to limited population monitoring and are not managed in the same intensive way as other large carnivores. Considering the species' significant influence on ecosystem processes, robust estimates of population density are necessary to inform conservation management. In this study, we ran a single‐season camera trap survey in the Main Camp section of Addo Elephant National Park (Addo), South Africa, and used spatial capture‐recapture (SCR) models to estimate spotted hyaena population density. Spotted hyaena density was estimated to be 11.13 (± SE 1.96) individuals/100 km2, with an estimated abundance of 37 (± SE 6.44) individuals. Using our database of sexed spotted hyaena individuals, we found no significant difference for sex‐specific SCR parameters (baseline encounter probability and spatial scale parameter), suggesting the incorporation of sex‐specific information may not be as necessary for spotted hyaena as it is for territorial felids and other species with more pronounced differences in range size. Spotted hyaena density in Addo was comparable to previous SCR studies and towards the higher end of known densities. Our estimate provides an important baseline for monitoring reintroduction success in Addo, and we advocate for increased SCR monitoring of spotted hyaena in South African protected areas to inform a metapopulation approach to the species' management. [ABSTRACT FROM AUTHOR]

The clearing and fragmentation of tropical forests is the single biggest threat to primate populations who depend on this habitat for survival. In contrast to primates that live in continuous, undisturbed forests, primate communities of fragmented forests need to adapt to decreased food availability and increased inter‐ and intraspecific competition typical of these degraded and anthropogenically disturbed habitats. Some primate species are highly sensitive to habitat fragmentation, whilst other species can adapt and even thrive in fragmented and degraded forests. Here, we assessed how forest fragmentation and associated edge effects impact the population density of four species of nocturnal lemur in the Sahamalaza‐Iles Radama National Park, North West Madagascar. We conducted 118 transect walks over a 3‐year period covering a total distance of 107 km to collect encounter rate (N/km) and population density (N/Ha) data for each species, which we then compared between the edge and core areas of a continuous forest and a fragmented forest. Our results were highly species‐specific, with the population densities of two species (Lepilemur sahamalaza and Microcebus sambiranensis) increasing in edge and fragmented habitat, whilst we observed the opposite for Cheirogaleus medius. Mirza zaza density appeared consistent between the continuous and fragmented forest and in both edge and core areas. We also found evidence of species‐specific population density relationships with fragment size, core area and fragment shape; however, further work is needed to support these findings. This study demonstrates that some nocturnal lemurs can adapt to degraded habitats and thrive within fragmented forests, whilst other species are less capable of doing so. [ABSTRACT FROM AUTHOR]

Accurate abundance estimates are essential for the development of effective conservation management strategies, yet they are difficult to produce for small populations that are elusive and sparsely distributed throughout their range. For such populations it is challenging to collect a representative dataset sufficient for robust estimation of detectability and abundance. Over a one‐year study, we used two methods to estimate abundance of a Nationally Critical, widely dispersed Bryde's whale population in the Hauraki Gulf, Aotearoa/New Zealand; (i) distance sampling from systematic line‐transect aerial surveys (n = 22 surveys, 9,944 km, total sightings 21–24 whales), and (ii) mark‐recapture (MR) using photo‐identification images collected from a platform‐of‐opportunity and small‐boat surveys (218 sampling occasions, 27 whales). From the aerial surveys, we estimated an average of 15 whales (95% CI = 6, 30; CV = 37%) at the sea‐surface at any time. For the boat‐based surveys, we developed a custom MR model to address seasonal and individual heterogeneity in capture probabilities and obtained an estimate of 72 distinct whales (95% CI = 38, 106; CV = 24%) in the population. These two approaches provide different perspectives on the abundance and dynamics of Bryde's whales. The aerial surveys estimate the average number of individuals present at any one time, whereas the MR model estimates the total number of animals that used the Gulf during the study. Although neither sampling method is optimal for estimating the abundance of this small, dispersed population, the use of two complementary approaches informs conservation managers about patterns of abundance and distribution over different temporal and spatial scales. It is common to have limited resources for marine research where model assumptions cannot be met. Here, we highlight pragmatic strategies showing how models can be customized to the population of interest to assist with monitoring species of conservation concern. [ABSTRACT FROM AUTHOR]

Coastal bottlenose dolphin populations are highly vulnerable due to their small population sizes and proximity to human activities. Long‐term studies in the UK have monitored populations protected within Special Areas of Conservation (SACs) since the 1990s, but a small community of bottlenose dolphins inhabiting the coastal waters of southern England has received much less attention. The English Channel is one of the most heavily impacted marine ecosystems worldwide and increasing anthropogenic pressures pose a severe threat to the long‐term viability of this population. Conservation measures to protect these animals have been hindered by a lack of knowledge of population size, distribution and ranging behaviour. This study aimed to fill these knowledge gaps. A citizen science sighting network yielded 7458 sighting reports of bottlenose dolphins between 2000 and 2020. Resightings of identified individuals were used to estimate abundance, distribution, and ranging behaviour. Social structure analysis revealed a discrete interconnected group of animals in shallow coastal waters, which did not appear to mix with conspecifics identified further offshore. A Bayesian multi‐site mark–recapture analysis estimated that this population comprises around 48 animals (CV = 0.18, 95% HPDI = 38–66). These dolphins ranged between North Cornwall and Sussex, with an average individual range of 530 km (68–760 km). Areas of high‐modelled habitat suitability were found to overlap with high levels of anthropogenic pressure, with pollution and boat traffic identified as the most pervasive threats. Although adult survival rates indicated that the population was relatively stable from 2008 to 2019 (0.945 (0.017 ± SE)), the small population size implies a significant risk to their long‐term viability and resilience to environmental change. By highlighting the most deleterious anthropogenic activities and regions of conservation significance, our results will be useful for developing management policies for threat mitigation and population conservation, to protect this vulnerable group of dolphins. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems can serve as model systems that reveal insights into biological invasions. In this article, we summarize nine lessons about aquatic invasive species from the North Temperate Lakes Long-Term Ecological Research program and affiliated projects. The lessons about aquatic invasive species are as follows: Invasive species are more widespread than has been documented; they are usually at low abundance; they can irrupt from low-density populations in response to environmental triggers; they can occasionally have enormous and far-reaching impacts; they can affect microbial communities; reservoirs act as invasive species hotspots; ecosystem vulnerability to invasion can be estimated; invasive species removal can produce long-term benefits; and the impacts of invasive species control may be greater than the impacts of the invasive species. This synthesis highlights how long-term research on a freshwater landscape can advance our understanding of invasions. [ABSTRACT FROM AUTHOR]

Natural vegetation in and around crops effectively increases predators. Semi‐natural habitats (SNHs; non‐crop vegetation) surrounding crops provide refuge and resources. However, the function of SNHs may depend on several factors, and the response of natural predators may vary among crops and regions. Here, we examined the spider community in a SNH and at an adjacent vineyard in a semi‐arid region of Argentina. We collected spiders in a gradient from an adjacent SNH, towards the vineyard at three distances from the SNH using two techniques: beating and pit‐fall traps. We collected spiders in December and February during two consecutive years at two strata: in vegetation and on the ground. In vegetation, spider abundance significantly decreased from SNH towards the interior of the vineyard at 80 m. On the ground, spider abundance was also significantly higher in SNH. However, after decreasing at the 5 and 20 m sites inside the vineyard, the abundance increased at 80 m. For foliage spiders, species richness followed the same pattern as abundance, whereas ground spider richness significantly increased from SNH to the interior of the vineyard. Species composition also showed different tendencies between foliage and ground spiders. The foliage spider community differed between SNH vs. all the vineyard sites. Contrarily, at the ground stratum, SNH was similar in composition to the edge of the vineyard, and they both differed from the other vineyard sites. We found that the adjacent SNH influenced the spider community in the vineyard and that this effect depended on the distance from that habitat and the association of the community to various strata. These results highlight the importance of studying the whole community of spiders when aiming to increase predator abundance to enhance biological control in this kind of crop. In addition, we found species that may act as indicators of native vegetation which has important implications for the management of natural habitats in this region. [ABSTRACT FROM AUTHOR]

Estuaries are essential habitats for recreational and commercial fish that are shaped by both natural and anthropogenic processes. In Louisiana a combination of climate change and planned coastal restoration actions is predicted to increase freshwater introduction to coastal estuaries. As such there is a need to quantify the relationships between estuarine fish ecology and salinity to aid in predicting how species will respond to shifts in salinity. We investigated the relative abundance and dietary niches of adult (24.5 ± 5.4 cm standard length) spotted seatrout Cynoscion nebulosus across varying salinity regimes (oligohaline, mesohaline, and polyhaline) within Barataria Bay, Louisiana, using a combination of net sampling and gut content and stable isotopes analysis. We found that the relative abundance of C. nebulosus was lowest at the oligohaline site, translating to approximately five fewer fish captured for every single psu decrease in a site's average annual salinity. In contrast, we found that diets and, to a lesser extent, isotopic niches had a high degree of overlap across sites with differing salinity regimes. Fish and penaeid shrimp were the most common and important prey taxa recovered from guts at all sites. The small isotopic differences found among sites were likely due to spatial variation in hydrogeochemical baselines, and the observed isotopic overlap provides support for the idea that C. nebulosus move between adjacent salinity regimes and forage throughout Barataria Bay. Our results contribute to a greater understanding of the salinity preference and trophic ecology of C. nebulosus that can aid in predicting their responses to future salinity and habitat changes within Barataria Bay associated with predicted climate change and planned coastal restoration actions. [ABSTRACT FROM AUTHOR]

Mussels (Mytilus spp.) are abundant in the North Atlantic, sessile, and sensitive to environmental change, and suitable as sentinels of environment and climate change of costal ecosystems. We aimed to determine the baseline for the Northeast Atlantic (58–70°N) Mytilus species complex, and to show the present distribution to surveys conducted 60 years ago. Baseline was obtained by investigating a total of 509 stations in the intertidal zone, in four regions comprising the environmental gradient from head of fjord to coast, and distributed over the latitudinal gradient from 58 to 70°N. The baseline shows a range in continuous abundance of mussels from 12% to 36%, patchy abundance from 26% to 57% and no or very limited mussel abundance from 26% to 46% between the four regions. The presence of mussels in the southeast and west region was visualized to previous surveys conducted 60 years ago. The data points to similar past and present presence of mussels in both regions, yet past major mussel fields in the inner section of region southeast was not detected in this study. The baseline of Mytilus spp. in the Northeast Atlantic (58–70°N) is now available for future reference. The baseline, plotted to surveys conducted 60 years ago, points to awareness of the population situated in the southeast section of the investigated region. Continued monitoring and modeling are needed to clarify drivers of temporal and spatial variation in the mussel populations along the Northeastern Atlantic coast. [ABSTRACT FROM AUTHOR]

The joint influence of abiotic and biotic factors is important for understanding the transmission of generalist pathogens. Abiotic factors such as temperature can directly influence pathogen persistence in the environment and will also affect biotic factors, such as host community composition and abundance. At intermediate spatial scales, the effects of temperature, community composition, and host abundance are expected to contribute to generalist pathogen transmission. We use a simple transmission model to explain and predict how host community composition, host abundance, and environmental pathogen persistence times can independently and jointly influence transmission. Our transmission model clarifies how abiotic and biotic factors can synergistically support the transmission of a pathogen. The empirical data show that high community competence, high abundance, and low temperatures correlate with high levels of transmission of ranavirus in larval amphibian communities. Discrete wetlands inhabited by larval amphibians in the presence of ranavirus provide a compelling case study comprising distinct host communities at a spatial scale anticipated to demonstrate abiotic and biotic influence on transmission. We use these host communities to observe phenomena demonstrated in our theoretical model. These findings emphasize the importance of considering both abiotic and biotic factors, and concomitant direct and indirect mechanisms, in the study of pathogen transmission and should extend to other generalist pathogens with the capacity for environmental transmission. [ABSTRACT FROM AUTHOR]

The nematode community was studied at eight stations in the eastern part of the East Siberian Sea shelf (43 m), along the slope, and at a deep-sea site (1350 m). All samples (depth range 43–1350 m) were collected with a MUC corer in the northeastern part of the East Siberian Sea during cruise ARA10C of the R/V Araon in 2019. The taxonomic composition of the nematode community is typical of the Siberian Arctic seas in summer–autumn. The nematode diversity of the East Siberian Sea is poor in comparison with other Russian Arctic seas. Nematode genera typical of the shelf and deep sea were identified. The nematodes density in the uppermost sediment layer increases from the southernmost station along the shelf, amount a maximum on the outer shelf, and decreases downhill with the minimum at the deepest site. It is suggested that the high nematode abundance and diversity on the outer slope was provided by high organic matter fluxes at the boundary of water masses, increasing the oxygen and silt content in sediments. [ABSTRACT FROM AUTHOR]

Simple Summary: Cotesia ruficrus (Haliday) (Hymenoptera: Braconidae) is a native enemy of the important invasive fall armyworm pest, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), in China, exhibiting significant pest control capabilities. To investigate the impact of Cotesia ruficrus on the gut bacteria of fall armyworm caterpillars following parasitism, we used 16S rRNA sequencing technology to analyze the diversity and richness of gut bacteria in both long-term and short-term laboratory fall armyworm caterpillars. Our study reveals that Cotesia ruficrus parasitism induces changes in fall armyworm larval gut microbiota, thereby shedding light on the capacity of parasitoid parasitism to impact host gut microbiota. These findings lay the foundation for deeper exploration of the gut microbiota's role in the parasitoid–host interaction mechanism. Parasitoids have the potential to alter the gut microbiota of their host insects post-parasitization, thereby influencing the host's physiological functions and creating a more favorable environment for the survival of the parasitoid's progeny. Cotesia ruficrus is a native enemy of the important invasive fall armyworm (FAW) pest, Spodoptera frugiperda, in China, exhibiting significant pest control capabilities. To investigate the impact of C. ruficrus on the gut bacteria of FAW caterpillars following parasitism, we used 16S rRNA sequencing technology to analyze the diversity and richness of gut bacteria in both long-term laboratory and short-term laboratory FAW caterpillars. The results revealed Enterococcus as the predominant bacteria across all treatments, while no significant differences were observed in the diversity and richness of gut bacteria between non-parasitized and parasitized long-term laboratory FAW caterpillars. Similarly, while the diversity of gut bacteria in non-parasitized and parasitized short-term laboratory FAWs showed no significant variance, a marked discrepancy in richness was noted. Moreover, the richness of gut bacteria in short-term laboratory FAW caterpillars surpassed that of their long-term laboratory counterparts. In addition, it was found that Corynebacterium existed only in the intestinal tract of FAW caterpillars that were parasitized by C. ruficrus. These results substantiate that C. ruficrus parasitization can alter the gut microbiota of FAW caterpillars, providing valuable insights into the interplay between gut microbiota and the dynamics of parasitoid–host interactions. [ABSTRACT FROM AUTHOR]

A near-unique pair of adjacent bays in the karst region of western Ireland provided the opportunity to compare phytoplankton diversity and abundance in an area of submarine groundwater discharge (SGD) side by side with a 'control' region of similar size and with the same marine influences. Freshwater input to Kinvara Bay comes from the surrounding karst hinterland via a subterranean groundwater network, emerging at several sites within the inner bay as submarine groundwater discharge (SGD). Aughinish Bay in contrast has no connection to a SGD network and negligible overground fresh water input. Sampling was carried out in both bays during spring and neap tides over Winter, Spring/Summer and Summer/Autumn of 2016 and 2017. Comparison of the phytoplankton communities in the two bays showed higher diversity in Aughinish, while a bloom of Prorocentrum micans (Ehrenber, 1834), a brackish-water-tolerant marine dinoflagellate, was observed only in Kinvara. This work demonstrates how SGD can control phytoplankton community structure even in well-flushed macro-tidal bays and thus controls the biogeography at local scales. [ABSTRACT FROM AUTHOR]

Objective To analyze the factors influencing the abundance of floor fleas from households of the commensal rodent plague foci in Yunnan Province. Methods A total of 320 households in 16 natural villages in the commensal plague natural foci were selected from Mangshi City, Lianghe County, and Mile City in Yunnan Province. Floor fleas were collected using the water-containing plate method, with 10 pans placed per household for two consecutive nights. The potential factors influencing the abundance of floor fleas in households were collected through a self-made questionnaire. A hurdle Poisson regression model under R4.3.0 was performed to analyze the factors influencing the abundance of floor fleas in households. Results A total of 6 400 plates were placed per night in 320 households, with 44 households capturing floor fleas, resulting in an infestation rate of 13.75% (44/320). A total of 136 floor fleas were collected in water pans, with a floor fleas index of 0.021 (136/6 400). Ctenocephalides felis felis was the dominant flea species, accounting for 61.76% (84/136), followed by Xenopsylla cheopis and Pulex irritans, each accounting for 19.12% (26/136). The multivariate hurdle Poisson regression model of the abundance of floor fleas showed that the probabilities of capturing floor fleas in households with other houses ground structure, garbage dumping outdoors, raising cat, rodent's activities, and fleas activities were 4.39, 3.16, 3.09, 3.08, and 2.29 times higher than the corresponding reference groups. The probability of capturing floor fleas in households with the Dai ethnic group was 0.30 of that in the Han ethnic group. The number of captured floor fleas in households in Mile City, of the Dai ethnicity, with chickens, and surrounded by other houses were 3.84, 2.95, 7.58, and 5.37 times higher than the corresponding reference group, while the number of captured floor fleas in households with migrant workers, other ground structure, and rodent eradication behavior were 0.32, 0.45, and 0.28 of the corresponding reference group. Conclusions The abundance of floor fleas from households of the commensal rodent plague foci in Yunnan Province is influenced by the basic family situation, indoor and outdoor environmental factors, and human interference factors. To avoid the spread of flea-borne diseases to humans, it is necessary to take comprehensive measures to control the abundance of floor fleas in households. [ABSTRACT FROM AUTHOR]

We recently published a study discussing the pitfalls of non‐probability sampling when selecting monitoring sites. We demonstrated that selecting sites based on abundance can often lead to biased inference, and we suggested that researchers use probability sampling. We also called for nuance when interpreting results of monitoring programs that use non‐probability sampling. We suggested that inference from sites of great abundance might still be useful for inference into population dynamics of long‐lived species such as raptors.Perret et al. seem to misinterpret our call for nuance as advocating for non‐probability sampling. They state that we concluded the general recommendation of using probability sampling should be revised. We did not conclude this. In fact, we agree with their recommendation.Perret et al. implemented simulations that are unrealistic within the context of our study. We use empirical data for 12 raptor species to demonstrate that our previous results are valid and that simulations implemented by Perret et al. do not reflect the biology of long‐lived raptors. The time series simulated by Perret et al. fluctuated greatly in abundance with populations often more than doubling within a year. This is extremely unlikely for populations of long‐lived species having high site fidelity.Many historical programs monitor sites of great abundance and thus risk biased results. We demonstrate that this risk is minimal under some important conditions and our results likely apply to other long‐lived species. Acknowledging this nuance could rescue many long‐term monitoring programs and their data thereby preserving efforts of costly conservation programs. Consistent with our original study, these exceptions do not invalidate the general recommendation to avoid non‐probability sampling; however, they do support our call for nuance when interpreting results of studies that monitored animals at sites of great abundance. [ABSTRACT FROM AUTHOR]

In the Critique of Gotha Programme, Karl Marx famously argues that a communist society will be characterised by the principle, 'From each according to his abilities, to each according to his needs!' I take up a question about this principle that was originally posed by G.A. Cohen, namely: what makes communism (so conceived) possible for Marx? In reply to this question, Cohen interprets Marx as saying that communism is possible because of limitless abundance, a view that Cohen takes to be implausible for ecological reasons. I develop a new interpretation of Marx's position. On this interpretation, people in communist society achieve self-realisation through providing others with the goods and services required for their self-realisation. Coupled with a reasonably high (but not immense) development of productive power, self-realisation generates conditions in which people can produce according to their abilities and receive according to their needs. I defend this view as an interpretation of Marx and I argue that it represents a more plausible account of what makes communism possible than Cohen's interpretation in which technological advance and limitless abundance play the predominant role. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the number and distribution of the Bohemian waxwing in the territory of Northern Eurasia within the borders of the Soviet Union in 1990. The work uses materials collected in the period from 1880 to 2022 (intermittently and mainly since 1960) in the first half of summer (during nesting), in winter, and partially throughout the year. The Bohemian waxwing abundance was estimated on the basis of the results of bird counts on routes with a length of about 300 000 km. [ABSTRACT FROM AUTHOR]

The ability to conduct cost‐effective wildlife monitoring at scale is rapidly increasing due to the availability of inexpensive autonomous recording units (ARUs) and automated species recognition, presenting a variety of advantages over human‐based surveys. However, estimating abundance with such data collection techniques remains challenging because most abundance models require data that are difficult for low‐cost monoaural ARUs to gather (e.g., counts of individuals, distance to individuals), especially when using the output of automated species recognition. Statistical models that do not require counting or measuring distances to target individuals in combination with low‐cost ARUs provide a promising way of obtaining abundance estimates for large‐scale wildlife monitoring projects but remain untested. We present a case study using avian field data collected in the forests of Pennsylvania during the spring of 2020 and 2021 using both traditional point counts and passive acoustic monitoring at the same locations. We tested the ability of the Royle–Nichols and time‐to‐detection models to estimate the abundance of two species from detection histories generated by applying a machine‐learning classifier to ARU‐gathered data. We compared abundance estimates from these models with estimates from the same models fit using point‐count data and to two additional models appropriate for point counts, the N‐mixture model and distance models. We found that the Royle–Nichols and time‐to‐detection models can be used with ARU data to produce abundance estimates similar to those generated by a point‐count‐based study but with greater precision. ARU‐based models produced confidence or credible intervals that were on average 31.9% (±11.9 SE) smaller than their point‐count counterpart. Our findings were consistent across two species with differing relative abundance and habitat use patterns. The higher precision of models fit using ARU data is likely due to higher cumulative detection probability, which itself may be the result of greater survey effort using ARUs and machine‐learning classifiers to sample significantly more time for focal species at any given point. Our results provide preliminary support for the use of ARUs in abundance‐based study applications, and thus may afford researchers a better understanding of habitat quality and population trends, while allowing them to make more informed conservation recommendations and actions. [ABSTRACT FROM AUTHOR]

Marine fish populations can be affected by various infectious and parasitic diseases. The species investigated during 2021–2023 along the Romanian coast was European anchovy [Engraulis encrasicolus (Linnaeus, 1758)], a small pelagic fish with both economic and ecological value. Four species of endoparasites (nematodes) were identified, namely: Hysterothylacium sp. Ward & Magath, 1917, Contracaecum sp. Railliet & Henry, 1912, Porrocaecum sp. Railet & Henry, 1912, and Anisakis sp. Dujardin, 1845. Nematode worms were found as larvae and infested the abdominal cavity, both in the free state and enclosed in internal organs. The parameters analyzed included abundance, prevalence, and average intensity. Abundance results indicated 14 parasites/fish in length classes ranging from 11–12 cm. A prevalence of 100% was reported in the anchovy population sampled from several stations. A high level of infestation intensity was recorded in 11 cm long specimens (15 nematode worms/host). In this study, the accumulation of nematode worms was observed in large mature specimens, with a negative impact on the host organism through the presence of internal lesions, slowing of growth rate, appetite reduction, and disturbance of the reproductive process. The potential risks to anchovy stock status, threats to human health, and control measures are also tackled. [ABSTRACT FROM AUTHOR]

The effects of environmental factors on phytoplankton are not simply positive or negative but complex and dependent on the combination of their concentrations in a fluctuating environment. Traditional statistical methods may miss some of the complex interactions between the environment and phytoplankton. In this study, the temporal–spatial fluctuations of phytoplankton diversity and abundance were investigated in a shallow temperate mountain river. The machine learning method classification and regression tree (CART) was used to explore the effects of environmental variables on the phytoplankton community. The results showed that both phytoplankton species diversity and abundance varied fiercely due to environmental fluctuation. Microcystis aeruginosa, Amphiprora sp., Anabaena oscillarioides, and Gymnodinium sp. were the dominant species. The CART analysis indicated that dissolved oxygen, oxidation-reduction potential, total nitrogen (TN), total phosphorus (TP), and water temperature (WT) explained 36.00%, 13.81%, 11.35%, 9.96%, and 8.80%, respectively, of phytoplankton diversity variance. Phytoplankton abundance was mainly affected by TN, WT, and TP, with variance explanations of 39.40%, 15.70%, and 14.09%, respectively. Most environmental factors had a complex influence on phytoplankton diversity and abundance: their effects were positive under some conditions but negative under other combinations. The results and methodology in this study are important in quantitatively understanding and exploring aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Forest management practices creating small‐scale forest edge habitats in managed forests have substantial impacts on the formation of beetle assemblages. In 2021, we conducted research in a managed oak woodland in Central Slovakia using three flight interception traps (FITs) to study beetle assemblages. Two FITs were installed at the forest edge, facing both, the clearing and the closed‐stand forest, while the third FIT was positioned 100 m within the closed‐canopy forest. We employed a novel methodological approach, which involved separately collected subsamples within the ecotone using FITs differentiated as ‘ecotone inwards’ and ‘ecotone outwards’ to capture distinct directional movements at the edge. We recorded 5.997 beetle specimens, encompassing 417 species across 284 genera and 58 families. We found that the species diversity and abundance of beetles were not significantly different between the FITs. However, the species composition was significantly different. The partial detrended canonical correspondence analysis suggests that these compositional differences might be closely associated with the distribution of trophic guilds, indicating varied responses to habitat modifications induced by forest edge creation. The results of our study showed that phloephagous, saproxylophagous, xylomycetophagous, xylophagous and zoophagous beetles exhibited a positive association with the forest edge, while mycophagous, phytophagous and saprophagous groups were distinctly associated with the closed‐canopy forest. Our analyses indicated that the ‘ecotone outward’ part of forest edges of managed forest may attract higher number of trophic groups, while the ‘ecotone inward’ part of the forest edge hosted high abundances of phloephagous and xylomycetophagous species. [ABSTRACT FROM AUTHOR]

Introduction: Recent minimum population estimates are critical for effective marine mammal conservation, yet such estimates are often lacking at the stock or management level. Throughout the Main Hawaiian Islands, pantropical spotted dolphins (PSD; Stenella attenuata attenuata) are comprised of a pelagic and three island-associated stocks (O‘ahu, 4-Islands, and Hawai‘i Island). The insular stocks, in particular, face multiple anthropogenic and natural threats such as vessel impacts, fisheries interactions, marine debris, climate change, and disease. Prior to this study, no abundance estimates of the 4-Islands (i.e., the Maui Nui region) PSD stock existed that were suitable for management use and inclusion in stock assessment report calculations. Methods: We generated annual mark-recapture abundance estimates of naturally marked adults in a POPAN-framework using photo-identification data collected from small-boat surveys during 2014–2022 in the Maui Nui region. We extrapolated these estimates to the wider population using dorsal fin mark rates. Results and discussion: We collected data on 62 groups of PSD, throughout all months of the year, and with an average group size of 55.70 (SD = 17.31). We analyzed encounter histories of 174 distinct individuals. Annual recapture rate averaged 1.84 (SD = 1.32) with a maximum of 7. Individuals detected per year averaged 35.67 (SD = 21.16) with a maximum of 77 in 2017. Overall mark rate was 0.495 (SE = 0.010), resulting in total annual abundance estimates that averaged 154.87 (SE = 14.25) and ranged from 105 (SE = 13) in 2014 to 232 (SE = 31) in 2017. Although abundance estimates fluctuated, generally 250 animals or less used the study area each year and we found no overall evidence of a trend. Our benchmark results revealed a small population in need of monitoring given the numerous threats facing this stock, the uncertainty of their impacts, and the decreased resiliency and recovery potential of small populations to negative demographic and environmental stochastic events. Our findings, including documenting long-term site fidelity and year-round presence of PSD in Maui Nui, further signify this area as one of future research and conservation importance. [ABSTRACT FROM AUTHOR]

Rodents are maintenance hosts of numerous pathogens, and both their density and the pathogen prevalence determine the risk they pose to other animals or humans. However, density is often overlooked. We investigated a capture‐mark‐recapture‐sampling strategy to study introduced mice (Mus musculus) and Leptospira as a model and demonstrate the advantages of a combined approach. We estimated population density and Leptospira prevalence in mice in a replicated longitudinal survey conducted between 2016 and 2018. Capture‐mark‐recapture sessions were undertaken at two sites in Spring and Autumn and blood and kidney samples were collected at the end of each session. Mouse density and areas of activity were estimated using spatially explicit capture–recapture (SECR) models and both were compared between Leptospira positive and negative mice. Leptospira exposure and shedding status were estimated using Microscopic Agglutination Test, and a combination of culture and lipL32 PCR on kidneys. Leptospira prevalence was higher in spring (83%–86%) than in autumn (31%–37%) and mouse densities simultaneously varied from 3.6 to 55.9/ha. However, despite these variations in prevalence and density, the density of infected animals remained relatively constant over time (3–8/ha). Shedding or being seropositive was also associated with the activity of mice. Shedding or seropositive mice had a larger activity area, and seropositive mice were trapped on average 1 day earlier than seronegative mice. Synthesis and applications: Our results show how understanding the population dynamics of pathogen‐carrying rodents is critical in epidemiology. The wider movement patterns and easier encounters of positive mice highlight the possibility of biases in classical prevalence surveys and have implications for disease transmission within and between species. Importantly, and quite counter‐intuitively, Leptospira prevalence was negatively associated with mouse density, resulting in a constant density of shedders that contradicts the conventional view of higher exposure risk at high rodent density. More broadly, such sampling designs can improve animal and disease control policies and better inform modelling studies by providing more parameter estimates than classical prevalence surveys. [ABSTRACT FROM AUTHOR]

Most information on rotifers living in lake sands comes from the 1930s, when the first reports on this subject by Jerzy Wiszniewski appeared. After some decline in the interest in lake psammon in the following years, research on lake psammon returned in the last decade of the twentieth century. The last comprehensive review of ecology of psammon Rotifera was included in the excellent 1998 publication by Schmid-Araya on Rotifera in interstitial sediments. More than 20 papers have been published since that time. So far, research conducted almost exclusively in the northern hemisphere have dealt with issues related to distribution of rotifers, their species structure and diversity as well as to their relation to abiotic and biotic factors. The aim of the present study was to collect all available information on psammon rotifers, assess the shortcomings in our knowledge and fill these gaps with the results of some of my recent research. The results of the study show that the species richness of this group in geographical terms is still unknown. It means we also do not know the level of endemism among the psammon rotifers. The role of psammon rotifers in benthic food webs is another issue requiring research. [ABSTRACT FROM AUTHOR]

This study examines the compositional (taxonomic) and functional diversity changes in the fish fauna of a Mediterranean urban lake (Lake Kastoria) over a period of 12 decades (1900–2020, as of 2022). Moreover, the current status (2010 and 2022) of the fish fauna is assessed along with the lake's ecological quality. Intentional or accidental species introductions resulted in significant compositional changes in the lake's fish fauna. The functional richness among the assemblages from 1900 and 2020 was increased due to species introductions, resulting in a peak of functional dissimilarity in 1990, when most introductions took place. However, the functional dissimilarity measures revealed that there have been moderate changes in groups of the functional traits which may be indicative of high species competition. The lake's open waters are dominated by Rutilus rutilus and the introduced species Perca fluviatilis and Lepomis gibbosus. The estimated ecological quality was higher in 2022 than in 2010, categorizing the lake as having "Moderate" quality and providing an upgrade from its earlier 'Poor" condition. This positive shift is attributed in part to the burgeoning population of Perca fluviatilis, as evidenced by increased catch rates. The species' resurgence may be linked to enhancements in the lake's physicochemical parameters, potentially facilitated by more effective treatment of urban wastes. The study underscores the complex interplay between species introductions, functional diversity, and ecological quality in the urban Lake Kastoria, highlighting the need for continued monitoring and management efforts to sustainably preserve and enhance the biodiversity and ecological integrity of urban aquatic ecosystems. [ABSTRACT FROM AUTHOR]

The blackchin guitarfish Glaucostegus cemiculus has suffered severe declines and regional extirpation throughout its known distributions. While this species and its relative, the common guitarfish Rhinobatos rhinobatos, have been described in the Mediterranean Sea with co-occurring habitat ranges, no research has recorded the existence or extent of these two separate populations along the Israeli coastal waters. Along a particular coast in Israel, Ma’agan Michael, fishermen have reported annual observations of juvenile guitarfish between June to November for the last forty years. Based on these citizen-based observations themain research objective is to establish whether Ma’agan Michael fulfils all three criteria fromthe literature by Dr Michelle Heupel, allowing it to be acknowledged as a nursery ground for G. cemiculus. The methodology built for this objective integrates biological characteristics data with the identification of a recurrent seasonal distribution. Visual surveys exhibited a significantly higher abundance in Ma’agan Michael when compared to an adjacent area (Caesarea), with 2,096 recorded observations overall. Additionally, using a species-specific modified Catch and Release protocol, a total of 492 juveniles were captured with a beach seine net. During these capturing events, individuals were morphometrically measured and sampled for future genetic analyses. Out of these, 327 specimens were also fitted for PIT tags to track recaptures in subsequent captures. The highest abundance of neonates was caught from August to September each year (2017–2019), and all individuals captured during this study were identified in the field as G. cemiculus, ranging from 20–35 cm in length (85% of captures). Many specimens had an umbilical cord scar (n = 88), with a large percentage possessing visual remains of the yolk sac. For the first time, this study provides an inter-year description of the species Glaucostegus cemiculus present along the Israeli shoreline. [ABSTRACT FROM AUTHOR]

Introduction: Terrestrial species in riverine ecosystems face unique constraints leading to diverging patterns of population structure, connectivity, and disease dynamics. Desert bighorn sheep (Ovis canadensis nelsoni) in Grand Canyon National Park, a large native population in the southwestern USA, offer a unique opportunity to evaluate population patterns and processes in a remote riverine system with ongoing anthropogenic impacts. We integrated non-invasive, invasive, and citizen-science methods to address questions on abundance, distribution, disease status, genetic structure, and habitat fragmentation. Methods: We compiled bighorn sightings collected during river trips by park staff, commercial guides, and private citizens from 2000-2018 and captured bighorn in 2010-2016 to deploy GPS collars and test for disease. From 2011-2015, we noninvasively collected fecal samples and genotyped them at 9-16 microsatellite loci for individual identification and genetic structure. We used assignment tests to evaluate genetic structure and identify subpopulations, then estimated gene flow and recent migration to evaluate fragmentation. We used spatial capturerecapture to estimate annual population size, distribution, and trends after accounting for spatial variation in detection with a resource selection function model. Results and discussion: From 2010-2018, 3,176 sightings of bighorn were reported, with sightings of 56-145 bighorn annually on formal surveys. From 2012-2016, bighorn exhibiting signs of respiratory disease were observed along the river throughout the park. Of 25 captured individuals, 56% were infected by Mycoplasma ovipneumoniae, a key respiratory pathogen, and 81% were recently exposed. Pellet sampling for population estimation from 2011-2015 yielded 1,250 genotypes and 453 individuals. We detected 6 genetic clusters that exhibited mild to moderate genetic structure (FST 0.022-0.126). The river, distance, and likely topography restricted recent gene flow, but we detected cross-river movements in one section via genetic recaptures, no subpopulation appeared completely isolated, and genetic diversity was among the highest reported. Recolonization of one large stretch of currently empty habitat appears limited by the constrained topology of this system. Annual population estimates ranged 536-552 (95% CrI range 451-647), lamb:ewe ratios varied, and no significant population decline was detected. We provide a multi-method sampling framework useful for sampling other wildlife in remote riverine systems. [ABSTRACT FROM AUTHOR]

A survey on the diversity, abundance, and habitat association of small mammals in Wenchi Highland, central Ethiopia, was carried out from August 2019 to January 2021. Small mammals were trapped at six different habitats (Hagenia Woodland, Erica Scrub, Qibate, Lakeshore, Erica, and Albesa Forests) using Sherman and snap traps in standard trapping grids. A total of 937 rodents belonging to 12 species (Arvicanthis abyssinicus, Desmomys yaldeni, Mastomys natalensis, M. awashensis, Stenocephaylemys albipes, Lophuromys flavopunctatus, L. brevicaudus, L. chrysopus, Dendromus lovati, Lophiomys imhausi, Graphirius murinus, and an unidentified murid rodent), and 22 insectivores belonging to 3 species (Crocidura bailey, C. fumosa and C. olivieri) were recorded. Hystrix cristata and Tachyoryctes splendens were also recorded through indirect evidence. About 52.9% of the identified small mammals were endemic to Ethiopia. A significant variation was observed in the captures of small mammals. The capture rate was higher in live traps (23.85%) than in snap traps (8.26%). The diversity and composition of small mammal species varied among habitats. The highest species diversity (H’=1.656) was recorded in Albesa Forest, while the lowest was in Erica Scrub (H’=1.409) and Qibate Forest (H’=1.407). However, after controlling for sampling effects, species diversity was the highest in the Erica Scrub (Fisher’s alpha=2.128) and the lowest in the Lakeshore Forests (Fisher’s alpha=1.318). The highest number of individuals was recorded in Lakeshore Forest (27.73%), whereas the lowest was in Erica Forest (3.96%). Mastomys natalensis (30.86%) and S. albipes (27.82%) were the two most abundant species, whereas L. imhausi (0.1%) was the least abundant one. Wenchi montane forests are essential homes for unique small mammals that need urgent conservation actions. [ABSTRACT FROM AUTHOR]

Conducting long-term conservation and monitoring activities for sea turtles provides a more precise depiction of their population status compared to studies conducted across a single year. The frequency of the nesting activity may fluctuate dramatically over time, depending on the environmental conditions. This study aimed to examine the nest count, female abundance, and reproductive output of green turtles on Yeniyurt Beach in the eastern Mediterranean between 2017 and 2022. The beach was surveyed via annual monitoring at consistent intervals. Temporal variations in the nest count and abundance of females were analyzed using the Mann-Kendall and Sen's Slope tests. A total of 803 nests were recorded, with an average of 133 nests per nesting season and an average nest density of 33.5 km-1. A total of 326 nests were excavated, with 28,546 of the 36,394 eggs successfully hatched (78% hatching success). The nest count and female abundance exhibited an insignificant, monotonic upward trend. The average nesting female count per nesting season was estimated to be 138.5 based on the observed clutch frequency (CF) and 67 based on the estimated CF. Yeniyurt Beach has a high nesting activity rate, representing 6% of the Mediterranean in terms of the nest count and 5% in terms of female abundance. Approximately 12% of nests did not produce hatchlings due to flooding and predation. Yeniyurt Beach lacks a conservation status, making it vulnerable to future threats like industrialization. In addition to the designation of the area as a protected site, the rehabilitation of the backshore habitat is of significant importance. [ABSTRACT FROM AUTHOR]

Plethodontids are organisms highly linked to variations in temperature and moisture in the environment. The major determinant of their body temperature is the interaction between microhabitat preferences and time of day. However, there are proposed differences in moisture and temperature preferences among age classes. This study examines how microhabitat exposure and time of day on the abundance, environmental and microenvironmental moisture and temperature, body temperature, and age demographics of Pseudoeurycea leprosa interact. Hatchlings appeared to be more abundant during the day, and their body temperature varied by microhabitat and time of day, the microenvironmental moisture of the sites that individual used were affected by the interaction between these variables. These results suggest segregation between age classes. Juveniles and adults may benefit by exploiting exposed microhabitats because their body temperature remains stable. These findings highlight the importance of understanding the responses of plethodontids to changes in their environment. [ABSTRACT FROM AUTHOR]

Seasonal changes in the composition and abundance of zooplankton and their responses to environmental changes were investigated at 30 stations in the upper layer and 13 stations in the lower layer (in February, May, July, and December) of the Eastern Marmara Sea in 2016. A total of 44 species/groups (including jellyfish species) were documented in the study area, with 39 identified in the upper layer water and 31 in the lower layer water. The abundances of zooplankton ranged from 29 to 2822 ind.m-3 in the upper layer and from 6 to 2283 ind.m-3 in the lower layer. Acartia clausi, Paracalanus parvus, Penilia avirostris, and Oithona similis were the dominant species in summer and autumn, whereas Calanus euxinus, Pseudocalanus elongates, Oithona nana, Oithona davisae and Pleopis polyphemoides were the dominant species in winter and spring. Aetideus spp., Clausocalanus spp., Ctenocalanus vanus, Oncaea minuta, Isopoda, and Siphonophora were observed only in bottom-layer waters. M. lucens and O. davisae were recorded only in the upper layer in December. In conclusion, our results suggest that zooplankton communities and some species are favorable indicators of the marine environment of the Sea of Marmara. [ABSTRACT FROM AUTHOR]