Effective Conservation Actions Research Articles

Seasonal trends and population status of the highly threatened Pteropus livingstonii in the Comoros archipelago

Flying foxes of the genus Pteropus, especially those inhabiting islands, face increasing pressure from anthropogenic threats. A first step to implementing effective conservation actions is to establish monitoring projects to understand a species’ population status and trend. Pteropus species are highly affected by seasonality which further requires regular, repeated, and long-term data to understand population trends, and reactions to severe weather events. In the present case study, a regular, bi-annual population census was implemented on Comoros between 2016 and 2023 for the highly threatened Livingstone’s fruit bat, Pteropus livingstonii, and compared the results of standardized monitoring to historical population data. Seasonality had a large impact on the number of bats found at roost sites, with more bats present in the wet season, but the data over the past eight years revealed no significant in- or decrease in the number of bats counted on the island Anjouan. We estimated around 1,200–1,500 bats on Anjouan and 300–400 bats on Mohéli, and found that landcover type has no measurable effect on population distribution at roost sites. Our study highlights the need for long-term surveys to understand past population trends and that single counts are not sufficient to draw final conclusions of a species’ status.

Individual foraging site fidelity persists within and across stopover seasons in a migratory shorebird, Numenius phaeopus (Whimbrel)

Abstract Site fidelity—returning repeatedly to the same site—can help many migratory species reduce uncertainty in their environment, especially when migratory stopover periods leave little time to explore and evaluate new habitat. Avian taxa, though, have shown wide variation in their levels of site fidelity during migration, and few studies have been able to examine individual-level fidelity at fine spatiotemporal scales. We used a high-resolution GPS tracking dataset of Numenius phaeopus (Whimbrel), a long-distance migratory shorebird, to assess levels of fidelity to specific foraging and roosting sites during migration, both within and between stopover seasons. We found that individuals are almost exclusively faithful to one shared roost site at night, but disperse to individual foraging territories during the day that overlap with each other by <20%. We show that individuals remain faithful to these distinct territories over time, on average, shifting the center of their daily home ranges by <1.5 km within a single season, and overlapping with their previous season’s home range by 70% when they return during subsequent stopovers. Our findings reveal for the first time that a shorebird species exhibits fine-scale, individual foraging site fidelity during and between migratory stopovers—an important insight to inform effective conservation and management action.

Niche-based approach to explore the impacts of environmental disturbances on biodiversity.

Globally, species are increasingly at risk from compounding threatening processes, an increasingly prominent driver of which is environmental disturbances. To facilitate effective conservation efforts following such events, methods that evaluate potential impacts across multiple species and provide landscape-scale information are needed to guide targeted responses. Often, the geographic overlap between a disturbance and species' distribution is calculated and then used as a proxy for potential impact. However, such methods do not account for the important influence of environmental heterogeneity throughout species' ranges. To address this shortcoming, we quantified the effects of environmental disturbances on species' environmental niche space. Using the Australian 2019 and 2020 Black Summer fires as a case study, we applied a niche-centric approach to examine the potential impacts of these fires on 387 vertebrate species. We examined the utility of established and novel niche metrics to assess the potential impacts of large-scale disturbance events on species by comparing the potential effects of the fires as determined by our various niche measures to those derived from geographic-based measures of impact. We examined the quality of environmental space affected by the disturbance by quantifying the position in niche space where the disturbance occurred (center or margin), the uniqueness of the environmental space that was burned, and the degree to which the remaining, unburned portion of the niche differed from a species' original prefire niche. There was limited congruence between the proportion of geographic and niche space affected, which showed that geographic-based approaches in isolation may have underestimated the impact of the fires for 56% of modeled species. For each species, when combined, these metrics provided a greater indication of postdisturbance recovery potential than geographic-based measures alone. Accordingly, the integration of niche-based analyses into conservation assessments following large-scale disturbance events will lead to a more nuanced understanding of potential impacts and guide more informed and effective conservation actions.

Variability in coastal habitat available for Longfin Smelt Spirinchus thaleichthys in the northeastern Pacific Ocean

An understanding of oceanographic conditions and processes important to marine animal ecology is fundamental to the development of effective management and conservation actions. Longfin Smelt (Spirinchus thaleichthys) is a pelagic forage fish found in coastal and estuarine waters along the Pacific coast of North America from Alaska to central California. Substantial population declines in California’s San Francisco Estuary, where Longfin Smelt are protected under California’s Endangered Species Act, have prompted extensive study of estuarine factors associated with the decline. However, coastal factors that affect up to two-thirds of the Longfin Smelt life cycle are poorly understood and may be important drivers of population dynamics. We compiled coastal observations from numerous sources to estimate the range-wide coastal marine distribution of Longfin Smelt and assess habitat factors affecting distribution in the northeast Pacific Ocean. Based on maximum entropy species distribution models, Longfin Smelt distribution was correlated with depth, distance from the nearest estuary, sea surface temperature, and sea surface chlorophyll. Longfin Smelt were found in shallow, higher productivity coastal waters closer to estuaries, with depth and temperature the most consistent factors influencing distribution. Habitat suitability was highly variable at the southern extent of the range, particularly off the California coast, and was largely driven by habitat contractions associated with warm-water conditions. Study results provide insights into the habitat and range-wide distribution of an at-risk estuarine-reliant forage fish and are the first step toward identifying processes that affect the marine portion of the Longfin Smelt life cycle.

Summer habitat selection by Mrs Hume’s Pheasant (Syrmaticus humiae) on Jinzhong Mountain, northwest Guangxi, China: implications for determining effective conservation actions using radio transmitters

Abstract In the present study, summer habitat preference of Mrs Hume’s Pheasant (Syrmaticus humiae) was studied in Jinzhong Mountain Nature Reserve, Guangxi Province. Eight birds were equipped with radio transmitters and habitat characteristics of experiment and control quadrat sites, respectively, were measured. Our results indicated that: 200 m to 400 m distance to habitat edge, less than 200 m distance to water, over 400 m distance to human habitation, over 601 m distance to the road, over 60% tree cover, less than 40% shrub cover, less than 20% herb cover, over 60% leaf litter cover, height of tree over 10.1 m, tree density over 20 individuals per quadrat, shrub height over 2.1 m, shrub density less than 10 individuals per quadrat, height of herb species over 0.5 m, herb density less than 10 Individuals per quadrat, diameter of tree over 30 cm, and abundant food were the habitat characteristics. The elevation, herb density, and height of tree and shrub exhibited no significant differences (), but other factors showed significant differences between quadrat sites and control quadrat plot (). Results of a principal components analysis (PCA) demonstrated that the first five components accounted for 64.282% of the total variance. Food availability in different habitat patches is the vital factor affecting habitat selection by Mrs Hume’s Pheasant; the other factors showed no significant effects on habitat selection by Mrs Hume’s Pheasant in the subtropical forest. This suggests that habitat selection behavior of Mrs Hume’s Pheasant is in fact a trade-off between obtaining food and prey escape, which is an adaptive behavior and a life strategy of this near-threatened bird species.

Shifts in grasses diversity patterns between two contrasting 40‐year climate periods in tropical dry islands

AbstractGrasses are one of the most successful and dispersed plant families worldwide and their environmental and economic values are widely acknowledged. They dominate the landscape of Cabo Verde, the southernmost and driest archipelago of Macaronesia, and are relevant natural resources for local populations, but a comprehensive evaluation of their distribution patterns is still lacking. In this study, we aim to evaluate the potential effects of climate change using the long‐term data concerning grass distribution in Cabo Verde and the widely recognized climatic variability of this archipelago, which entails a huge irregularity in spatial and temporal rainfall. We identified two contrasting climatic periods (wet, from 1929 to 1968, and dry, from 1969 to 2007) and gathered all the information available from the bibliography, herbaria, and fieldwork concerning spontaneous grass species recorded in Cabo Verde during those two periods, which amounted to 107 taxa. This information was then used to disclose the patterns of grass diversity as related to climatic and topographic variables (altitude and windward vs. leeward aspects). Different altitudinal shifts in the distribution patterns of grass species assemblages and an assemblage specific to the wet period were revealed by comparing the two climatic periods. The role of exposure in delimiting the altitudinal distribution of the various assemblages was highlighted; the trade winds clearly determine the distribution of grass assemblages. We detected shifts in the distribution of grass assemblages according to the climatic periods (related to the macroclimate) and local topographic factors (associated with mesoclimates). Also, functional traits (i.e., annuals vs. perennials, C3 vs. C4 grasses, and tropical vs. temperate species) were found to vary between wet and dry periods, as well as with altitude and with slope aspect. Understanding species distributions and the role of the climatic variability of Cabo Verde is crucial to predicting how climate change will affect them and thus to support effective management and conservation actions.

Two decades of accelerated deforestation in Peruvian forests: a national and regional analysis (2000–2020)

The global tree cover has kept reducing in the last two decades, mainly in tropical forests, despite the global efforts to conserve biodiversity and the ecosystem services that provides. Considering South America is the region that had the highest rate of net forest loss (2000–2020), it is crucial to understand the deforestation dynamics of each country and their regions for the evaluation of effective national conservation actions. Here, we carried out a spatiotemporal analysis of the deforestation rates from 2000 to 2020 on a national and regional scale, including the forest loss inside protected areas, in Peru. It was found that Peru lost 3.4 million ha of forest between 2000 and 2020, mainly in the Not Flooded Rainforest region. National deforestation rates accelerated, while within protected areas rates showed a very small increase. Regional deforestation rates followed the national pattern with one exception—the Coast region. Our results evidence the success of the national conservation strategy based on protected areas to avoid deforestation in all regions, except in the Andean. Moreover, the increment in deforestation rates is aligned with the growth in road infrastructure; increments in anthropic activities; and the more frequent and intense natural extreme events that vary according to the region. Therefore, it is urgent to differentiate the drivers of deforestation that operate at the national versus the regional scale, consider the inclusion of all forest types in the monitoring system, and the strengthening of policies related to land use change at all scales.

Environmental drivers of global variation in home range size of terrestrial and marine mammals.

As animal home range size (HRS) provides valuable information for species conservation, it is important to understand the driving factors of HRS variation. It is widely known that differences in species traits (e.g. body mass) are major contributors to variation in mammal HRS. However, most studies examining how environmental variation explains mammal HRS variation have been limited to a few species, or only included a single (mean) HRS estimate for the majority of species, neglecting intraspecific HRS variation. Additionally, most studies examining environmental drivers of HRS variation included only terrestrial species, neglecting marine species. Using a novel dataset of 2800 HRS estimates from 586 terrestrial and 27 marine mammal species, we quantified the relationships between HRS and environmental variables, accounting for species traits. Our results indicate that terrestrial mammal HRS was on average 5.3 times larger in areas with low human disturbance (human footprint index [HFI] = 0), compared to areas with maximum human disturbance (HFI = 50). Similarly, HRS was on average 5.4 times larger in areas with low annual mean productivity (NDVI = 0), compared to areas with high productivity (NDVI = 1). In addition, HRS increased by a factor of 1.9 on average from low to high seasonality in productivity (standard deviation (SD) of monthly NDVI from 0 to 0.36). Of these environmental variables, human disturbance and annual mean productivity explained a larger proportion of HRS variance than seasonality in productivity. Marine mammal HRS decreased, on average, by a factor of 3.7 per 10°C decline in annual mean sea surface temperature (SST), and increased by a factor of 1.5 per 1°C increase in SST seasonality (SD of monthly values). Annual mean SST explained more variance in HRS than SST seasonality. Due to the small sample size, caution should be taken when interpreting the marine mammal results. Our results indicate that environmental variation is relevant for HRS and that future environmental changes might alter the HRS of individuals, with potential consequences for ecosystem functioning and the effectiveness of conservation actions.

Local and regional-scale effects of hedgerows on grassland- and forest-associated bird populations within agroecosystems.

Linear woody features (LWFs), like hedgerows along field edges, provide wildlife habitat and support biodiversity in agroecosystems. Assessments of LWFs usually focus on community-level indices, such as species richness. However, effective conservation actions need to balance the contrasting habitat preferences of different wildlife species, necessitating a focus on population-level effects in working landscapes. We assessed associations between LWFs and abundance for 45 bird species within an intensive agroecosystem in eastern Ontario, Canada. We used distance- and removal-sampling methods across 4 years (2016-2019) to estimate local bird abundance in habitats representing a range of LWF densities. We also predicted abundance across a subset of the study region with and without LWFs to understand their contribution to regional population density. Associations between local bird abundance and LWFs were variable among species, but overall community effects were clearly positive, particularly for forest and shrubland species. At the site level, 20/45 species (44%) had higher densities associated with greater LWF presence on average, compared to 5/45 (11%) with negative associations. At the regional scale, LWFs had predicted benefits on total abundance for 31 species (69%), contributing to an estimated 20% increase on average. Positive effects were most pronounced in areas with greater agricultural land use (primarily field crops), suggesting LWFs may provide crucial habitat in heavily modified landscapes but have little to no additional benefit for the avian community in areas with greater existing heterogeneity and habitat retention. Species that responded negatively tended to be at risk with strong habitat preferences for intact forests or large, open grasslands and, thus, greater sensitivity to potential edge effects. With rapidly declining songbird populations and a global need for food security, conservation strategies that amplify biodiversity and enhance agricultural productivity through ecosystem services such as pest control, pollination, and water regulation are vital. We demonstrate the benefits of habitat heterogeneity in agroecosystems on songbird densities and highlight the need to integrate local and landscape-level assessments in conservation planning. An effective, balanced strategy includes concentrating LWFs in areas of extensive arable crops, with habitat retention patches where possible, while maintaining heterogeneity through mixtures of natural habitats and pastoral farming in less intensive regions.

Integrative Taxonomy Clarifies the Historical Flaws in the Systematics and Distributions of Two Osteobrama Fishes (Cypriniformes: Cyprinidae) in India

The taxonomy and geographical distributions of Osteobrama species have historically posed challenges to ichthyologists, leading to uncertainties regarding their native ranges. While traditional taxonomy has proven valuable in classification, the utility of an integrated approach is restricted for this particular group due to limitations in combining information from biogeography, morphology, and genetic data. This study addresses the taxonomic puzzle arising from the recent identification of Osteobrama tikarpadaensis in the Mahanadi and Godavari Rivers, casting doubt on the actual distribution and systematics of both O. tikarpadaensis and Osteobrama vigorsii. The research reveals distinctions among specimens resembling O. vigorsii from the Krishna and Godavari riverine systems. Notably, specimens identified as O. vigorsii from the Indian Museum exhibit two pairs of barbels, while those from the Godavari River in this study are identified as O. tikarpadaensis. Inter-species genetic divergence and maximum likelihood phylogeny provide clear delineation between O. vigorsii and O. tikarpadaensis. The study suggests that O. vigorsii may be limited to the Krishna River system in southern India, while O. tikarpadaensis could potentially extend from the Mahanadi River in central India to the Godavari River in southern India. Proposed revision to morphological features for both species, accompanied by revised taxonomic keys, aim to facilitate accurate differentiation among Osteobrama congeners. The data generated by this research provide a resource for future systematic investigations into cyprinids in India and surrounding regions. Further, the genetic diversity information obtained from various riverine systems for Osteobrama species will be instrumental in guiding aquaculture practices and formulating effective conservation action plans.

Ups and downs: An insight on the stranding pattern of Guiana dolphins, Sotalia guianensis, in the Amazon Estuary, Northern Brazil

Abstract Long‐term systematic records of cetacean strandings are valuable indicators of temporal responses of specific cetacean populations and communities to natural or anthropogenic pressures. They also help guide management objectives and conservation actions. Generalized additive models (GAMs) were used to analyse 10 years of systematic and opportunistic surveys of Guiana dolphin strandings in the Amazon Estuary region, Northern Brazil. The spatial distribution of strandings was assessed through kernel density maps, and age‐at‐death structure of this population was described. The model results revealed marked seasonality in the strandings and, by extension, the mortality of Guiana dolphins in the Amazon Estuary. This seasonality varied between the inner estuarine regions and Atlantic coastal area, reflecting the environment's characteristics. Long‐term decline of strandings in the Amazon Estuary inner region and unusual high mortality of young sexually mature individuals were detected. These results, besides the high stranding rate detected for the species, are mostly attributed to the species' interaction with intense fishing activity in the region. Conservation efforts should consider the seasonality of Guiana dolphin strandings in the Amazon Estuary. The systematic monitoring of strandings, especially in high‐frequency areas, is recommended for assessing long‐term species mortality. Additionally, implementing management actions related to the species' interaction with fishing activities, such as regulatory enhancements, gillnet modifications and seasonal no‐fishing zones, is advised. Educational campaigns targeting fishermen and riverine communities are essential to reduce bycatch and the folkloric use of the species. This study underscores the effectiveness of stranding data as a source of biological and ecological information, and as a tool for understanding human actions affecting coastal populations of aquatic mammals. It emphasizes the need for urgent studies to characterize this population, clarify the influence of bycatch as an anthropogenic pressure and implement effective conservation actions to preserve the Guiana dolphin population.

Population and conservation status of the endangered Dracaena ombet tree in dry Afromontane forests

Dracaena ombet, a flagship tree species in arid ecosystems, holds a significant ecological, economic, and socio-cultural value. However, its persistence is currently under threat from both anthropogenic and natural factors. Consequently, the species has been listed as an endangered tree species on the IUCN Red List, requiring urgent conservation actions for its continued existence. To develop effective conservation actions, it is necessary to have information on the population dynamics of the species. A study was conducted in the lowland and midland agroecological zones (sites) within the Desa'a dry Afromontane forest, northern Ethiopia to analyze the population status of D. ombet and identify its site-specific threats. At each site, abundance, health status, diameter, height and threats of the species were collected using 60 sample plots (20 m × 20 m) distributed over six transects (500 m × 20 m) spaced one km apart. The study showed that the D. ombet population was characterized by low abundance and unstable structure. It was further characterized by a substantial number of unhealthy damaged and dead trees. The low abundance of the species with unstable age structure in the dry Afromontane forests can be attributed to various factors such as stem cutting and debarking, leaf defoliation, overgrazing, soil erosion, and competition from expansive shrubs. Alternative livelihood options for the local inhabitants should be introduced to minimize the overexploitation of D. ombet for subsistence use in the dry Afromontane forests. The impacts of overgrazing and soil erosion on D. ombet and its Desa'a habitats should also be addressed through the introduction of community-based exclosures and in-situ soil and water conservation practices, respectively.

The genome of the black-footed cat: Revealing a rich natural history and urgent conservation priorities for small felids.

Habitat degradation and loss of genetic diversity are common threats faced by almost all of today's wild cats. Big cats, such as tigers and lions, are of great concern and have received considerable conservation attention through policies and international actions. However, knowledge of and conservation actions for small wild cats are lagging considerably behind. The black-footed cat, Felis nigripes, one of the smallest felid species, is experiencing increasing threats with a rapid reduction in population size. However, there is a lack of genetic information to assist in developing effective conservation actions. A de novo assembly of a high-quality chromosome-level reference genome of the black-footed cat was made, and comparative genomics and population genomics analyses were carried out. These analyses revealed that the most significant genetic changes in the evolution of the black-footed cat are the rapid evolution of sensory and metabolic-related genes, reflecting genetic adaptations to its characteristic nocturnal hunting and a high metabolic rate. Genomes of the black-footed cat exhibit a high level of inbreeding, especially for signals of recent inbreeding events, which suggest that they may have experienced severe genetic isolation caused by habitat fragmentation. More importantly, inbreeding associated with two deleterious mutated genes may exacerbate the risk of amyloidosis, the dominant disease that causes mortality of about 70% of captive individuals. Our research provides comprehensive documentation of the evolutionary history of the black-footed cat and suggests that there is an urgent need to investigate genomic variations of small felids worldwide to support effective conservation actions.

Population Size, Non-Breeding Fraction, and Productivity in a Large Urban Population of Burrowing Parrots (Cyanoliseus patagonus)

Psittaciformes are one of the bird orders with the highest number of threatened species and the most marked declining population trends. At present, the lack of information on the population size, reproductive fraction, and productivity of most parrot populations makes it difficult to design effective conservation actions. In this study, we monitored a population of Burrowing Parrots (Cyanoliseus patagonus) breeding in urbanized habitats in the southwest of Buenos Aires province, Argentina. Every December and February from 2018 to 2023, we counted the individuals arriving at a single communal roost, located in the main park of Bahía Blanca city, which gathers all the parrots breeding in 18–22 colonies within a radius of 20 km. Censuses were conducted before (December) and immediately after the incorporation of juveniles into the flocks (February). Breeding pairs were also counted annually in the colonies, and the average annual productivity and the proportion of juveniles were estimated from surveys in pre-roosting and feeding areas in February. The non-breeding fraction approached half of the population with no statistically significant differences among years (range: 37–53%), and the breeding population showed little annual variation, with a minimum of 1363 and a maximum of 1612 breeding pairs. The proportion of juveniles in the flocks and the estimated productivity showed larger variations among breeding seasons. Our results add insight to the scarce information available on the breeding-to-non-breeding-population ratios in parrots, and birds in general, and show key breeding parameters for a species that is thriving well in urban habitats.

The Role of Religion, Wealth, and Livelihoods in the Hunting Practices of Urban and Rural Inhabitants in Western Amazonia

Hunting by rural and urban populations is essential for securing access to protein and other nutrients throughout the tropics. The hunting patterns of urban hunters in Amazonia, and the similarities with those of rural hunters, are unclear, as are the social factors that influence hunting practices. We analyze the effects of socioeconomic and cultural factors on hunting frequency and composition of species hunted by urban and rural Amazonian hunters. We interviewed 49 urban hunters and 57 rural hunters within 10 municipalities in western Amazonia in Brazil. A total of 44 species were cited as hunted. Our analyses show that the probability of engaging in sport hunting (for recreation) is greater among urban hunters. Rural inhabitants, hunters with lower monetary incomes, and hunters who were non-practicing Christians and atheists hunted more frequently. The composition of species hunted was similar, regardless of the hunters’ livelihood (rural or urban) or religion. We found that hunting frequency is influenced by hunters’ socioeconomic and cultural backgrounds, but these factors do not affect the composition of the harvest. This similarity between urban and rural hunters might be related to species distribution and availability and could potentially impact the most hunted species if hunting grounds overlap. Understanding hunting patterns, especially those of urban hunters, allows for more effective hunting management strategies, improvements in law enforcement against illegal hunting, as well as development of more effective and sustainable conservation actions.

Tropical forest birds after 20 years of the establishment of a reservoir: Extinction, colonization, and recolonization events

Reservoirs are fundamental for human well-being but can cause landscape changes (e.g., habitat fragmentation and loss), altering biodiversity and ecosystem services. However, we know little about reservoir long-term effects on bird communities of tropical rainforests at different temporal scales. We assessed species richness and composition changes in four consecutive periods in a reservoir area in the Colombian Tropical Andes. After 20 years of monitoring avifauna within the reservoir, we recorded 360 bird species along with 47 local extinction and 184 colonization events. We found that species richness increased by 42% during the first 11 years after reservoir establishment. After that, changes in species bird composition were largely explained by species turnover. Eighty-two percent of the expected species in the region were recorded within the reservoir area. Also, forests surrounding the reservoir are a habitat for several threatened bird species. Bird community changes observed can be explained by secondary succession, changes in vegetation cover (i.e., increase in forest area), the transformation of aquatic ecosystems, forest protection, and restoration programs focused on biodiversity conservation. Long-term systematic bird sampling in tropical forests is key to understanding biodiversity dynamics and the effectiveness of conservation actions.

Development and Application of Potentially Universal Microsatellite Markers for Pheasant Species

Pheasants are widely distributed in the southwest of China, but many of them are endangered due to habitat fragmentation and environmental changes. Genetic diversity is crucial for species to maintain their evolutionary potential, and thus it is important to develop universal genetic markers for facilitating the assessment of genetic diversity and planning effective conservation actions in these endangered species. In this study, 471 microsatellite loci which are common among eight pheasant species were screened based on genome data, and 119 loci were selected to develop microsatellite markers. After PCR amplifications and reaction condition optimizations, and validation of microsatellite loci in 14 species of 11 genera within Phasianidae. Finally, 49 potentially universal microsatellite markers in pheasant species were obtained. These microsatellite markers were successfully applied to assess the genetic diversity of 3 pheasant species. The Sichuan hill partridge (Arborophila rufipectus), blood pheasant (Ithaginis cruentus), buff-throated partridge (Tetraophasis szechenyii) and Sichuan hill partridge had a relatively low genetic diversity level. These 49 microsatellite loci are potentially universal microsatellite loci for pheasants and are of great significance to establish a shared platform in population genetics study of pheasants.

Explaining and predicting animal migration under global change

AbstractMany migratory species are declining due to global environmental change. Yet, their complex annual cycles make unravelling the impacts of potential drivers such as climate and land‐use change on migrations a major challenge. Identifying where, when and how threatening processes impact species' migratory journeys and population dynamics is crucial for identifying effective conservation actions. Here, we describe how a new migration modelling framework – Spatially explicit Adaptive Migration Models (SAMMs) – can simulate the optimal behavioural decisions required to migrate across open land‐ or seascapes varying in character over space and time, without requiring predefined behavioural rules. Models of adaptive behaviour have been used widely in theoretical ecology but have great untapped potential in real‐world contexts. Applying adaptive behaviour models across open environments will allow users to explore how migratory species may adapt their routes and usage of intermediate sites in response to environmental change. We outline how SAMMs can be used to model migratory journeys through aerial, terrestrial and aquatic environments, demonstrating their potential using a case study on the common cuckoo (Cuculus canorus) and comparing modelled to observed behaviours. SAMMs offer a tool to identify the key threats faced by migratory species, how they could adapt to future migratory journeys in response to changing environmental conditions and the consequences of not being able to adapt to change.

Incremental evolution of modeling a prognosis for polar bears in a rapidly changing Arctic

Updating predictions of the response of high-profile, at-risk species to climate change and anthropogenic stressors is vital for informing effective conservation action. Here, we review two prior generations of Bayesian network probability models predicting changes in global polar bear (Ursus maritimus) population status, and provide a contemporary update based on recent research findings and sea-ice projections by newer climate models. We compare predictions of polar bear population response from all 3 models among four circumpolar Arctic ecoregions, using sea ice projections based on three IPCC greenhouse gas emissions scenarios (SSP2.6, 4.5, 8.5). Consistent with the previous two model generations, polar bears will continue to experience increasing probability of declining or greatly declining populations throughout the 21st century, varying by emission scenario. Populations within the Polar Basin Divergent Ice Ecoregion have the highest predicted probability of declines, but predictions were slightly less dire relative to the previous model generation. Most of the influence, denoted by model sensitivity analysis, is from expected degradation and loss of sea ice and reduced access to marine prey. The lack of terrestrial prey adequate to substitute for loss of access to marine prey, as well as human-caused bear mortality associated with hunting and defense of life and property encountered when polar bears are increasingly forced ashore also contributed to predicted declines. Although some tidewater glacial fjords and other localized onshore resources may provide local refugia, their benefit is transient. Our findings continue to inform priorities for inventory, monitoring, and research needs, and suggest that similar updates to models of other at-risk species can capitalize on the comparison framework we present here.

New records for the wild bee fauna (Hymenoptera, Anthophila) of Serbia

Numerous scientific projects have been initiated with the aim of tackling the decline in insect pollinators, a crucial group for the functioning of terrestrial ecosystems. One of the first steps is to address information gaps on species spatial distribution, diversity, and abundance that prevent effective conservation actions in Europe. Given that Serbia belongs to the understudied areas, efforts are being made to improve knowledge of its bee diversity and abundance. The present study includes the monitoring of bees at 54 sites, surveyed three times during 2022. The conducted protocol combined two methods, transect walks and pan traps, resulting in the discovery of 312 bee species. The main results present the records of 25 species, not previously mentioned in Serbia, while another important finding is the confirmation of the presence of 26 species, without any available records from the 21st century. Moreover, 79 here examined species were known only from literature-based data. Six of the recorded species are considered threatened and 67 (10 newly recorded) have been assessed as Data Deficient in the European Red List of Bees. Therefore, the present study not only contributes to an update and confirms the list of bee species in Serbia, that now counts 731 species, but also provides additional information about European distribution, required for new assessment at the European level. In addition, the results indicate that the combination of complementary sampling methods is an effective way to assess bee diversity and abundance.