Resident Species Research Articles

Timing mowing for maximal energy gain - Managing foraging habitat of wintering geese under extreme drought conditions

The availability of high-quality food resources is a critical determinant of wildlife fitness. Over the past two decades, phenological mismatch - the temporal misalignment between animals’ peak nutrient demand and optimal resource availability - has emerged as a significant conservation challenge. This issue is particularly worrisome for migratory birds, which must accumulate energy reserves to meet the elevated metabolic demands of migration between breeding and wintering grounds. In Poyang Lake, a crucial wintering ground along the East Asian-Australasian flyway, increasing asynchrony between vegetation growth and the migration of herbivorous waterbirds significantly impedes conservation efforts and presents a major management challenge for this Ramsar wetland. This study evaluates the efficacy of mowing, a grassland management measure, in regulating plant growth processes and restoring food resources for geese. In-situ mowing experiments were conducted with varying timings in Carex wet meadows, the primary foraging habitats of geese. Optimal mowing times were identified, and the maximum goose carrying capacity was assessed by comparing Carex growth and nutritional dynamics with goose dietary requirements. The results reveal that mowing effectively slows down the aging process of Carex, and protein content is identified as a critical limiting factor for geese foraging. Different mowing timings extend the suitable foraging period by 11–25 days. Estimates suggest varying carrying capacities with different mowing timings, supporting goose populations ranging from 133 to 2,046 in Changhuchi Lake during wintering. The optimal mowing window is early October, avoiding dates before late September and after late November. Moreover, multiple-stage mowing is recommended to accommodate different wintering stages. The study highlights mowing as a potential habitat restoration approach for goose conservation, effectively mitigating the challenges imposed by phenological mismatch directly and indirectly caused by anthropogenic activities.

Characterization of Avian Influenza Viruses Detected in Kenyan Live Bird Markets and Wild Bird Habitats Reveal Genetically Diverse Subtypes and High Proportion of A(H9N2), 2018-2020.

Following the detection of highly pathogenic avian influenza (HPAI) virus in countries bordering Kenya to the west, we conducted surveillance among domestic and wild birds along the shores of Lake Victoria. In addition, between 2018 and 2020, we conducted surveillance among poultry and poultry workers in live bird markets and among wild migratory birds in various lakes that are resting sites during migration to assess introduction and circulation of avian influenza viruses in these populations. We tested 7464 specimens (oropharyngeal (OP) and cloacal specimens) from poultry and 6531 fresh fecal specimens from wild birds for influenza A viruses by real-time RT-PCR. Influenza was detected in 3.9% (n = 292) of specimens collected from poultry and 0.2% (n = 10) of fecal specimens from wild birds. On hemagglutinin subtyping, most of the influenza A positives from poultry (274/292, 93.8%) were H9. Of 34 H9 specimens randomly selected for further subtyping, all were H9N2. On phylogenetic analysis, these viruses were genetically similar to other H9 viruses detected in East Africa. Only two of the ten influenza A-positive specimens from the wild bird fecal specimens were successfully subtyped; sequencing analysis of one specimen collected in 2018 was identified as a low-pathogenicity avian influenza H5N2 virus of the Eurasian lineage, and the second specimen, collected in 2020, was subtyped as H11. A total of 18 OP and nasal specimens from poultry workers with acute respiratory illness (12%) were collected; none were positive for influenza A virus. We observed significant circulation of H9N2 influenza viruses in poultry in live bird markets in Kenya. During the same period, low-pathogenic H5N2 virus was detected in a fecal specimen collected in a site hosting a variety of migratory and resident birds. Although HPAI H5N8 was not detected in this survey, these results highlight the potential for the introduction and establishment of highly pathogenic avian influenza viruses in poultry populations and the associated risk of spillover to human populations.

Diversity and Conservation of Wetland Avifauna in Nanjarayan Lake, Tiruppur, Tamil Nadu, India

This paper shares the results from a big bird survey at Nanjarayan Lake in Tamil Nadu. It ran from 2022 to 2024. To check out the bird variety, see how it changes with the seasons and look at how well different bird species are doing there. Over three years, we did lots of field surveys during different times of the year. We used methods like point counts, transect walks, and habitat checks. In total, we found 184 bird species resident birds that live there all year and migrating ones that visit. We even spotted some species that need special attention. This shows how important the lake is for both local birds and those just flying between. When we looked closely at the numbers through the seasons, we found some big changes in how many birds there were. Winter was especially busy, with a lot of different kinds showing up and the migratory birds arriving. The study also identified key threats to avian biodiversity in the lake, such as habitat degradation, water pollution, and human disturbances. Based on these findings, the study recommends urgent conservation measures, including habitat restoration, pollution control, and the implementation of strict regulations to minimize human impact. This survey underscores the importance of Nanjarayan Lake as a vital bird habitat and calls for enhanced conservation efforts to protect its rich avian diversity. The findings provide valuable baseline data for future ecological studies and contribute to the broader understanding of lake ecosystems in Tamil Nadu.

Individual quality and environmental factors interact to shape reproduction and survival in a resident bird of prey.

Investigating among-individual differences in reproductive success and survival is essential for understanding eco-evolutionary processes. We used 5 years of demographic data from 556 breeding barn owls (Tyto alba) to estimate associations between intrinsic and extrinsic covariates on survival and reproduction throughout the annual cycle. As males and females have distinct roles in reproduction, environmental conditions and individual quality may be differentially linked to their fitness at different time points. Males breeding early and inhabiting prey-rich areas experienced higher reproductive success but faced greater reproductive costs. Indeed, the number of offspring a male cared for was negatively associated with his body condition and survival. However, our results indicate that these influences can be mitigated in males experiencing favourable post-breeding environmental conditions. For female owls, early breeding and high food availability during the breeding period were linked with increased reproductive success. Prey availability during incubation and higher reproductive output were associated with higher survival into the next breeding period in females. Unlike males, females did not exhibit obvious trade-offs between reproductive success and survival. Our research demonstrates trade-offs between fecundity and survival, and that females paired with males able to provide sufficient food experience higher survival and reproduction.

Avifaunal Diversity in and Around Katwal Tukum Lake, Tah-Bhadrawati, Chandrapur, Maharashtra

Abstract: The present study aimed to survey avifaunal diversity in and around Katwal Tukum Lake, located in Tah-Bhadrawati, Chandrapur, Maharashtra. Comprehensive field observations were conducted from October 2023 to April 2024 to compile a checklist of bird species, assess their migration patterns, and develop conservation recommendations based on the findings. A total of 92 bird species were recorded, representing 43 families and 16 orders, indicating a thriving and healthy ecosystem. Notable findings include the dominance of the Passeriformes order, which accounted for 33 species, followed by Anseriformes and Charadriiformes with 12 and 9 species, respectively. Additionally, Pelecaniformes, Coraciiformes, and Gruiformes were represented by 10, 6, and 4 species, respectively. Lesser represented orders included Cuculiformes, Suliformes, Accipitriformes, Podicipediformes, Columbiformes, Bucerotiformes, Ciconiiformes, Piciformes, Galliformes, and Stigiformes. The study identified 26 migratory species, 28 resident migratory species and 38 resident species, underscoring the vital role of the surrounding forests in providing essential resources and habitats for a wide range of avian species. This research contributes valuable data to our understanding of bird diversity and seasonal patterns at Katwal Tukum Lake and highlights the need for targeted conservation strategies and habitat management practices to protect this diverse avian community.

Contrasting responses of plant, soil fungal and above‐ground arthropod communities to plant invasion across latitudes

Abstract The proliferation of alien species that can suppress resident species via biotic interactions represents a growing concern worldwide. Yet, how above‐ and below‐ground communities simultaneously respond to plant invasion, particularly across large spatial scales, remains poorly explored. We hypothesized plant invasion has a greater impact on recipient above‐ and below‐ground communities at lower than higher latitudes given that biotic interactions play a more significant role in shaping communities in more favourable, lower latitude environments. To test this hypothesis, we conducted a comprehensive field survey of 124 sites spanning a 1700‐km latitudinal gradient in China, to explore the effects of invasion of Alternanthera philoxeroides, a globally widespread invasive plant, on plant, soil fungal and above‐ground arthropod communities. Invasion of A. philoxeroides had divergent effects on beta diversity (i.e. variation in taxa composition among sites) of plants, above‐ground arthropods and soil saprotrophic fungi, with negative, neutral and positive responses, respectively. Notably, the compositional dissimilarity of plant and arthropod communities between adjacent invaded and non‐invaded sites remained constant across latitudes. In contrast, the compositional dissimilarity of the entire and pathogenic fungal communities between adjacent invaded and non‐invaded sites increased with latitude. This resulted in a decreasing difference in invasion effects on the composition of plant and fungal communities with increasing latitude. Synthesis. Our study provides novel insights into the complexities of invasion effects by revealing contrasting responses of above‐ and below‐ground communities to plant invasion across latitudes. The contrasting responses could weaken or reshape above‐ and below‐ground interactions, and, in turn, affect future species invasions and the functioning of terrestrial ecosystems.

Heavy Metal Contamination in Birds from Protected Regions in the Amazon.

The extraction of crude oil and gold has substantially increased heavy metal contamination in the environment, yet the study of wildlife exposure and biological response to this pollution remains nascent even in the most biodiverse places in the world. We present a survey of heavy metal exposure in the feathers of wedge-billed woodcreepers (Glyphorynchus spirurus), a resident neotropical bird found within protected regions of the Amazon near oil and gold extraction sites. Our results show elevated heavy metal contamination in samples collected from protected areas proximate to known oil and gold extraction. Surprisingly, several samples from remote reference sites also displayed elevated levels of various heavy metals, suggesting a background of natural deposition or complex heavy metal contamination in the environment from anthropogenic sources. These results highlight the need to understand the ecological and biological impacts of increased heavy metal exposure on wildlife across space and time, including remote regions of the world purportedly untouched by these human-mediated stressors. Toward this goal, historical and contemporary data from native bird populations may provide crucial indicators for heavy metal contamination and exposure in wildlife and human communities. Environ Toxicol Chem 2024;00:1-7. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Disentangling the complexity of plant-bird relationships: From monolayer to multilayer network perspectives

Most plant-bird interaction research employing complex ecological networks focuses on pollination and seed dispersal interactions. However, birds and plants are immersed in a great variety and complexity of direct and indirect relationships. Therefore, the use of multilayer networks (i.e., species interaction networks involving different types of interactions) could provide new insights into the ecological and coevolutionary dynamics of plant-bird relationships. Here, we used a multilayer network approach to determine how a bird-plant interaction network involving different types of interactions (i.e., foraging for invertebrates on plants, frugivory, nectarivory, and perching) is organized in a peri-urban Mexican cloud forest. Moreover, we added information about the interactive roles of the winter migratory and resident birds in the multilayer network. In general, we found that the bird-plant multilayer network exhibits modular but a non-nested structure. We also observed that interactions involving perching and foraging for invertebrates on plants are more frequent than frugivory and nectarivory. Moreover, just a small proportion of birds and plant species were important to the network organization and for connecting different interaction types. In this case, we observed that only two bird species, Cardellina pusilla (Parulidae) and Dumetella carolinesis (Mimidae), and the plant species Telanthophora grandifolia (Asteraceae) and Platanus mexicanus (Platanaceae) presented higher centrality values (i.e., an interactive role). Finally, we found that betweenness values (i.e., the number of times a species acts as a bridge along the shortest path between two species) and network structure's contributions are similar for both migratory and resident bird species. Our results highlight the importance of key interacting species that connect other interacting species for the preservation of community cohesion and to the persistence of species-rich assemblages.

Intra-annual compositions and diversity variations of waterbird communities in China

Waterbirds are often used as indicators of wetland biodiversity and ecosystem health due to their sensitivity to environmental changes. However, most studies have focused on long-term variations of waterbird communities, while the intra-annual changes have rarely been investigated. Here, we analyzed the seasonal dynamics of compositions and the intra-annual variations of species richness and abundance of waterbird communities among the nine major river basins of China, and focused on the effects of different residential types and taxonomic groups on the diversity variations. In most of the nine basins, the waterbird communities in spring and autumn showed high similarity, while those in summer and winter were quite different. Such a seasonal cycle of species composition was caused by the seasonal migration of waterbirds. The season with higher species richness shifted from summer to winter as the latitude of the basin decreased within China, but almost all basins had the lowest community abundance in summer. This was because the variation of richness was directly influenced by the variation in species composition, but the variation of abundance was more influenced by the population size of different waterbird assemblages. Our results emphasized the importance of seasonal dynamics of waterbird communities to the understanding of their migration patterns, and highlighted the impact of different waterbird assemblages on intra-annual community variations. Additionally, we also noted the potential effects of population size and behaviors at different parts of the waterbird life circle on the observations of them. The information gathered in this study will provide guidance for the conservation of waterbird species and their habitats.

Predicting avian diversity based on land use and cover on a national scale

This study explores the relationship between landscape features and avian diversity in South Korea, examining both taxonomic and functional diversity. The Korean Peninsula serves as a pivotal habitat for resident bird species and a migratory pathway in the East Asia-Pacific flyway. Using a national dataset with block sizes ranging from 3.5 to 4.5 kilometers per side, we found that less urbanized open plains exhibit higher taxonomic diversity, while coastal regions with diverse water bird populations show higher functional diversity. These findings underscore the significance of conserving the existing land types and qualities in specific regions to substantially impact bird distribution and regional biodiversity. Remarkably, closed forests display diversity patterns akin to urban/built-up areas, despite their disparate land use characteristics. The stability of bird diversity indices across different land use types enables us to predict bird diversity indices based on the particular land use and land cover configurations. This study emphasizes the complementary nature of functional biodiversity indices in comprehending bird distribution patterns alongside taxonomic diversity indices.

Does host migration affect host-parasite interaction? Migrant birds harbor exclusive parasites but have similar roles in parasite-host networks.

Parasites comprise a substantial portion of global biodiversity and play critical roles in shaping ecosystems by modulating trophic networks and affecting their hosts' abundance and distribution. The dynamics of host migration introduce new complexity to these relationships. From the host perspective, migratory behavior can either act as a defense mechanism or augment exposure to a broader spectrum of pathogens. Conversely, for parasites, host migration represents a mechanism for their dispersion and an opportunity to infect new host species. This study investigates the complex interplay between migration and parasite-host interactions, focusing on the interaction between hosts and avian malaria and malaria-like parasites in the Brazilian Atlantic Rain Forest. We captured 1466 birds representing 70 different species, uncovering 322 infections with Plasmodium/Haemoproteus parasites. We observed variations in migration timing and fluctuations in host abundance across months. By comparing the observed patterns of interaction of migratory and non-migratory birds to patterns of interaction expected at random, we show that migration affects the roles hosts take in the parasite-host network. Interestingly, despite the fact migratory species hosted more exclusive and distinct parasites, migrants did not occupy central network positions, which are mostly occupied by resident birds. Overall, we highlight the role of resident birds as a key species within parasite-host communities and the high specialization among avian haemosporidians and their hosts.

Combatting synthetic dye toxicity through exploring the potential of lignin peroxidase from Pseudomonas fluorescence LiP RL5.

Untreated release of toxic synthetic and colorful dyes is a serious threat to the environment. Every year, several thousand gallons of dyes are being disposed into the water resources without any sustainable detoxification. The accumulation of hazardous dyes in the environment poses a severe threat to the human health, flora, fauna, and microflora. Therefore, in the present study, a lignin peroxidase enzyme from Pseudomonas fluorescence LiP-RL5 has been employed for the maximal detoxification of selected commercially used dyes. The enzyme production from the microorganism was enhanced ~ 20 folds using statistical optimization tool,response surface methodology. Four different combinations (pH, production time, seed age, and inoculum size) were found to be crucial for the higher production of LiP. The crude enzyme showed decolorization action on commonly used commercial dyes such as Crystal violet, Congo red, Malachite green, and Coomassie brilliant blue. Successful toxicity mitigation of these dyes culminated in the improved seed germination in three plant species, Vigna radiate (20-60%), Cicer arietinum (20-40%), and Phaseolus vulgaris (10-25%). The LiP treated dyes also exhibit reduced bactericidal effects against four common resident microbial species, Escherichia coli (2-10mm), Bacillus sp. (4-8mm), Pseudomonas sp. (2-8mm), and Lactobacillus sp. (2-10mm). Therefore, apart from the tremendous industrial applications, the LiP from Pseudomonas fluorescence LiP-RL5 could be a potential biocatalyst for the detoxification of synthetic dyes.

No general support for functional diversity enhancing resilience across terrestrial plant communities

AbstractAimUnderstanding the mechanisms promoting resilience in plant communities is crucial in times of increasing disturbance and global environmental change. Here, we present the first meta‐analysis evaluating the relationship between functional diversity and resilience of plant communities. Specifically, we tested whether the resilience of plant communities is positively correlated with interspecific trait variation (following the niche complementarity hypothesis) and the dominance of acquisitive and small‐size species (following the mass ratio hypothesis), and for the context‐dependent effects of ecological and methodological differences across studies.LocationGlobal.Time Period2004–2021.Major Taxa StudiedVascular plants.MethodsWe compiled a dataset of 69 independent sites from 26 studies that have quantified resilience. For each site, we calculated functional diversity indices based on the floristic composition and functional traits of the plant community (obtained from the TRY database) which we correlated with resilience of biomass and floristic composition. After transforming correlation coefficients to Fisher's Z‐scores, we conducted a hierarchical meta‐analysis, using a multilevel random‐effects model that accounted for the non‐independence of multiple effect sizes and the effects of ecological and methodological moderators.ResultsIn general, we found no positive functional diversity–resilience relationships of grand mean effect sizes. In contrast to our expectations, we encountered a negative relationship between resilience and trait variety, especially in woody ecosystems, whereas there was a positive relationship between resilience and the dominance of acquisitive species in herbaceous ecosystems. Finally, the functional diversity–resilience relationships were strongly affected by both ecological (biome and disturbance properties) and methodological (temporal scale, study design and resilience metric) characteristics.Main ConclusionsWe rejected our hypothesis of a general positive functional diversity–resilience relationship. In addition to strong context dependency, we propose that idiosyncratic effects of single resident species present in the communities before the disturbances and biological legacies could play major roles in the resilience of terrestrial plant communities.

Unexpected stability in faunal population abundances following an estuary‐wide collapse of oysters

AbstractLive oyster reefs are considered a critical recruitment habitat for estuarine faunal populations as localized in situ or mesocosm studies have demonstrated many faunal species prefer live oyster habitat. It has therefore been assumed that the loss of live oyster habitat would precipitate faunal population declines, but this has been largely untested at large (estuary) scales. Here, we assessed how estuary‐wide faunal populations were affected by a 95% loss of live oyster habitat following the 2012 oyster collapse of Apalachicola Bay, FL, which previously supported one of the largest oyster fisheries in the United States. We standardized long‐term fisheries‐independent monitoring seine and trawl data to create relative indices of resident, associated, and transient faunal species' overall abundance and recruit abundance (restrictive to sizes between 15% and 35% of ). We expected that both relative abundance indices would decrease following the oyster collapse, particularly among species that reside on or recruit to oyster reefs. However, analyses via a series of one‐sided Bayesian t tests did not indicate that faunal recruitment or overall abundance significantly declined in 2012 post‐collapse. As the response of the faunal population could be lagged relative to the 2012 collapse, we also conducted change point analyses to search for lagged declines. Of the 24 relative abundance time series, only two had significant change points post‐collapse, and only black sea bass overall relative abundance declined with an associated change point at the end of the time series. The surprising paucity of faunal decline following oyster loss may be due to the use of alternative habitat types, exceptionally lagged faunal responses, or, perhaps most compelling, a disconnect between preferred and required habitats. Our failure to detect faunal consequences following an oyster population collapse suggests that assumptions of habitat loss (or restoration) effects on estuarine fauna at ecosystem scales are not straightforward and the extrapolation of sub‐estuary‐scale studies may result in poor predictions of future outcomes.

The herpetofauna of the Sporades Islands (Aegean Sea, Greece): New discoveries and a review of a century of research

The Sporades are one of the most biologically important archipelagos in the Aegean Sea (Greece) and have received priority conservation over the last 50 years. However, despite numerous early efforts, its herpetofauna is only partially described, resulting in many distributional gaps that have prevented adequate understanding and management of the resident species communities. We review one century of bibliography from the Northern Sporades and combine this information with a review of museum specimens and insights from numerous extensive field surveys over the last near-decade to provide for the first time a comprehensive picture of the reptiles and amphibians of the archipelago. We report here on 26 new island records and find that the herptile communities of the region are largely derived from the herpetofauna of the nearby Thessaly mainland, with only a few introduced taxa. There is also a small but significant set of endemic taxa in the archipelago. Island species richness declines with decreasing island size and increasing duration of island isolation. Herptile communities on smaller islands are progressively nested subsets of the communities on larger islands. The presence of reptile species depends sensitively on the condition and management of native ecosystems. While non-aquatic species maintain largely healthy populations, most populations are under pressure from the combined effects of rampant tourist development, the destruction and degradation of rare wetland habitats, and the abandonment of traditional agricultural landscapes. We provide recommendations regarding sustainable management of the local reptile and amphibian populations.

Nocturnal avian migration drives high daily turnover but limited change in abundance on the ground

Every night during spring and autumn, the mass movement of migratory birds redistributes bird abundances found on the ground during the day. However, the connection between the magnitude of nocturnal migration and the resulting change in diurnal abundance remains poorly quantified. If departures and landings at the same location are balanced throughout the night, we expect high bird turnover but little change in diurnal abundance (stream‐like migration). Alternatively, migrants may move simultaneously in spatial pulses, with well‐separated areas of departure and landing that cause significant changes in the abundance of birds on the ground during the day (wave‐like migration). Here, we apply a flow model to data from weather surveillance radars (WSR) to quantify the daily fluxes of nocturnally migrating birds landing and departing from the ground, characterizing the movement and stopover of birds in a comprehensive synoptic scale framework. We corroborate our results with independent observations of the diurnal abundances of birds on the ground from eBird. Furthermore, we estimate the abundance turnover, defined as the proportion of birds replaced overnight. We find that seasonal bird migration chiefly resembles a stream where bird populations on the ground are continuously replaced by new individuals. Large areas show similar magnitudes of take‐off and landing, coupled with relatively small distances flown by birds each night, resulting in little change in bird densities on the ground. We further show that WSR‐inferred landing and take‐off fluxes predict changes in eBird‐derived abundance turnover rate and turnover in species composition. We find that the daily turnover rate of birds is 13% on average but can reach up to 50% on peak migration nights. Our results highlight that WSR networks can provide real‐time information on rapidly changing bird distributions on the ground. The flow model applied to WSR data can be a valuable tool for real‐time conservation and public engagement focused on migratory birds' daytime stopovers.

Effect of Photoperiod and Illuminance on Daily Activity Patterns, Physiology, and NPY Peptide Expression in Migratory Redheaded Buntings (Emberiza bruniceps).

Light is the primary source of energy and regulates seasonal changes in physiology and behavior. The role of photoperiod has been much investigated in several bird species, but the role of illumination in seasonal adaptations of passerine finches is less understood. We, therefore, investigated the effects of photoperiod and illuminance on migratory physiology in a Palearctic-Indian migratory finch, redheaded bunting (Emberiza bruncieps). Photosensitive buntings maintained under short days (8L:16D) were divided into three groups receiving 5, 25, and 100 lux of white daytime illuminance, respectively. Thereafter, using photoperiodic manipulation three life history states, i.e., nonmigratory (NM), premigratory (PM), and migratory (MIG) states were induced in the buntings. The birds in the MIG state were consecutively perfused after seven nights of Zugunruhe (nighttime migratory restlessness) for neuropeptide Y (NPY)-immunohistochemistry, which is involved in a wide range of functions including energy homeostasis, vision, and fat deposition in birds. We found differential effects of illuminance on locomotor activity and physiology. Photostimulated birds showed intense nighttime activity in the MIG state. We observed premigratory hyperphagia in the birds, with increased food intake in the 100 lux group, which was reflected in the body mass gain in the MIG state. NPY expression on the periphery of the nucleus rotundus suggests its potential role in visual acuity, where the NPY-cell count significantly decreased under 25 lux illumination. We demonstrate that migrating birds may also experience physiological effects from changes in daytime illumination. We observed illuminance-dependent variations in the quantity of food consumed by the birds. It indicates that the illuminance may also impact the encephalic centers that control food intake.

Impacts of estuarine habitat degradation on the modeled life history of marine estuarine-dependent and resident fish species.

Shallow coastal and estuarine habitats play an essential role in the life cycles of many fish species, providing spawning, nursery, feeding, and migration areas. However, these ecologically valuable habitats are increasingly threatened by anthropogenic activities, causing substantial changes in both habitat availability and quality. Fish species use these shallow coastal habitats and estuaries during various life stages, leading to their categorization into guilds based on how and when they rely on these areas. This differential functional use of estuaries means that changes to these habitats may affect each guild differently. To understand the impact of estuarine habitat degradation on fish populations, it is therefore necessary to consider the full life cycle of fish and when they rely on these coastal habitats. Here, we use conceptual size-structured population models to study how estuarine habitat degradation affects two functionally different guilds. We use these models to predict how reduced food productivity in the estuary affects the demographic rates and population dynamics of these groups. Specifically, we model estuarine residents, which complete their entire life cycle in estuaries, and marine estuarine-dependent species, which inhabit estuaries during early life before transitioning offshore. We find that total fish biomass for both guilds decreases with decreasing food productivity. However, the density of juveniles of the marine estuarine-dependent guild can, under certain conditions, increase in the estuary. This occurs due to a shift in the population biomass distribution over different life stages and a simultaneous shift in which life stage is most limited by food. At the individual level, somatic growth of juveniles belonging to the estuarine-dependent guild decreased with lower food supply in the estuary, due to increased competition for food. The somatic growth rates of fish belonging to the resident guild were largely unaffected by low food supply, as the total fish density decreased at the same time and therefore the per-capita food availability was similar. These outcomes challenge the assumption that responses to habitat degradation are similar between fish guilds. Our study highlights the need to assess not only fish biomass but also size distributions, survival, and somatic growth rates for a comprehensive understanding of the effects of habitat degradation on fish populations. This understanding is crucial not only for estuary fish communities but also for successful conservation and management of commercially harvested offshore population components.

Realities, perceptions, and strategies for implementation of an ethical population management program for dogs and cats on university campuses.

Stray dogs and cats pose significant challenges for public health and animal welfare due to their potential involvement in zoonotic disease transmission, accidents, and aggressions. Large urban centers exacerbated challenges due to the presence of these animals in public areas with high human density. Ethical Population Management Programs (EPMP), rooted in the One Health approach, are crucial for addressing this issue comprehensively. This study aimed to demonstrate the approach on cats and dogs EPMP and evaluate the perceptions of academic community regarding EPMP implementation on a campus situated in urban territory. The study was conducted at the Pampulha campus of UFMG in Belo Horizonte, Brazil. In response to issues of animal abandonment and conflicts, the Permanent Commission for Animal Policies (CPPA-UFMG) was established in 2019 to manage the campus's dog, cat, and wildlife populations. The commission implemented the Trap-Neuter-Return (TNR) method, along with health assessments and vaccinations for animals. Interviews were conducted with campus staff to gauge their perception of animal management strategies. Retrospective and prospective analyses of the commission's actions were carried out to assess implementation processes and challenges. The animal population survey conducted on campus between July 2018 and September 2021 revealed a total of 266 animals recorded. Among these animals, 195 were cats (73.3%) and 71 were dogs (26.7%), with the majority being adults. Subsequent surveys in 2019 and 2021 showed a slight increase in the animal population, with measures such as sterilization contributing to population control. Perception analysis among campus users indicated strategies such as TNR were widely endorsed for population control. The employees perception questionnaire was applied to 115 individuals, representing 42 units/departments and five gates. Associations were found between these beliefs and support for institutional actions. The majority favored sterilization (92.17%) and agreed that TNR is an appropriate approach to population control. Overall, the study reflects a community concerned about animal welfare and supportive of measures to address population management and cruelty prevention. The continuous efforts of the university's CPPA have led to stability in the resident animal population, indicating success in achieving population control objectives.

First assessment of persistent organic pollutants and halogenated natural compounds in an omnivorous resident coral-reef fish species, black triggerfish, Melichthys niger, from an Atlantic oceanic island, Brazil

Studies on the occurrence of POPs and other persistent compounds in pristine areas are extremely valuable, as they offer insights on the long-range transportation of POPs and the occurrence of natural compound producers' areas. In this regard, this study aimed to report data of both anthropogenic (polychlorinated biphenyls, PCBs, and polybrominated diphenyl ethers, PBDEs) and natural (methoxylated PBDEs, MeO-BDEs) compounds in tissues of the black triggerfish, Melichthys niger (Tetraodontiformes, Balistidae), specimens (n = 30) sampled in 2018 during a scientific expedition conducted at Trindade Island. Concentrations of ∑28PCBs ranged from 73 to 1052 ng g−1 lw in liver, 334 to 1981 ng g−1 lw in gonads, and 20 to 257 ng g−1 lw in muscle, with the predominance of PCB-180 in liver and PCB-52 in gonad and muscle. Concentrations of ∑7PBDEs ranged from <LOD to 1.8 ng g−1 lw in liver, <LOD to 14 ng g−1 lw in muscle, and they were < LOD in gonads. The BDE-47 was the most representative congener detected in liver and muscle. Mean concentrations of ∑8MeO-BDEs were 270 ng g−1 lw, 442 ng g−1 lw, and 70 ng g−1 lw in liver, gonad, and muscle, respectively. The 2-MeO-BDE-68 was the most representative congener among MeO-BDEs. The mobilization of lower chlorinated PCBs from liver to other tissues, with possible retention of higher chlorinated PCBs in liver, can be a factor of concern considering the chronic exposure of those fish. PBDEs and MeO-BDEs in fish from remote environments were reported in a low number of studies worldwide. Considering that remote sites face environmental pollution either directly by anthropogenic influence or by long-range transportation, more studies on the occurrence of persistent compounds in these environments are paramount, and it is fundamental to understand the dispersion and accumulation of POPs.