Spatial Ecology Research Articles

Combining genetic and isotope frameworks improves reconstruction of fish provenance across riverscapes

AbstractUnderstanding the spatial ecology of migratory species is uniquely challenging using conventional approaches. In fisheries such as for Pacific salmon, genetic stock identification (GSI) and isotope‐based methods have emerged as strategies for reconstructing spatial ecology but are limited by the spatial resolution of genetic differentiation and isotopic heterogeneity. We show that integrating these complementary datasets improve the spatial resolution of provenance assignments. To do so, we reconstructed basin‐wide estimates of natal origin locations for Chinook salmon in the Yukon River using samples (n = 247) from an experimental fishery designed to assess in‐season run timing. A combined framework improved precision of likely provenance assignments (stream km > 0.7 posterior probability) by 92% over genetic assignments and 52% over strontium isotope methods. In doing so, we illustrate watershed scale estimates of natal origin distributions with a greater resolution available from GSI or isotope data alone.

Ecology, Spatial Structure, and Selection Pressure Induce Strong Signatures in Phylogenetic Structure.

Evolutionary dynamics are shaped by a variety of fundamental, generic drivers, including spatial structure, ecology, and selection pressure. These drivers impact the trajectory of evolution and have been hypothesized to influence phylogenetic structure. For instance, they can help explain natural history, steer behavior of contemporary evolving populations, and influence the efficacy of application-oriented evolutionary optimization. Likewise, in inquiry-oriented Artificial Life systems, these drivers constitute key building blocks for open-ended evolution. Here we set out to assess (a) if spatial structure, ecology, and selection pressure leave detectable signatures in phylogenetic structure; (b) the extent, in particular, to which ecology can be detected and discerned in the presence of spatial structure; and (c) the extent to which these phylogenetic signatures generalize across evolutionary systems. To this end, we analyze phylogenies generated by manipulating spatial structure, ecology, and selection pressure within three computational models of varied scope and sophistication. We find that selection pressure, spatial structure, and ecology have characteristic effects on phylogenetic metrics, although these effects are complex and not always intuitive. Signatures have some consistency across systems when using equivalent taxonomic unit definitions (e.g., individual, genotype, species). Furthermore, we find that sufficiently strong ecology can be detected in the presence of spatial structure. We also find that, while low-resolution phylogenetic reconstructions can bias some phylogenetic metrics, high-resolution reconstructions recapitulate them faithfully. Although our results suggest a potential for evolutionary inference of spatial structure, ecology, and selection pressure through phylogenetic analysis, further methods development is needed to distinguish these drivers' phylometric signatures from each other and to appropriately normalize phylogenetic metrics. With such work, phylogenetic analysis could provide a versatile tool kit with which to study large-scale, evolving populations.

Highs and Lows of Arboreal Life: Space use and Movement Strategies of Lion-Tailed Macaques (Macaca silenus) in the Western Ghats of India.

Lion-tailed macaques (Macaca silenus), endemic to the Western Ghats of India, are increasingly threatened by habitat loss and degradation, and are vulnerable to environmental change. Insights into their spatial ecology can reveal the strategies that enable these macaques to navigate and use spatially complex heterogeneous spaces. This is crucial for conservation, given the increasing human disturbance in and around the Western Ghats. This study, conducted in Silent Valley National Park between January and June of 2019, 2022, and 2023, focused on two macaque troops occupying habitats with varying human presence-in the park's core (Sairandhri) and in the buffer (Keeripara). The observed group sizes of the Sairandhri and Keeripara troops were 51 and 21, respectively. We examined differences in the spatial ecology of these troops by assessing their vertical space use, two-dimensional (2D) and three-dimensional (3D) home ranges, and using an integrated step-selection function to understand movement-based habitat selection. We observed similarities in movement patterns across the two troops, with notable differences mainly in their vertical use of the forest. The Keeripara troop, resident in a more disturbed area, utilized a smaller home range (1.80 km²). They spent 94.2% of their time in mid-level canopy (6-20 m), descending rarely (1.1%) into lower strata (≤ 5 m), likely due to perceived high risk from predators and humans, and proximity to roads. The Sairandhri troop, resident in the less disturbed area, had a larger home range (3.05 km²) and exhibited greater terrestriality (11.3%), with 84.2% observed time in mid-canopies. Both troops preferred areas with canopy cover and fruiting trees, displaying similar slow movements (indicated through small step lengths and large turning angles) near these resources. Our findings suggest that lion-tailed macaques may be less strictly arboreal than previously believed, displaying more terrestriality in less disturbed habitats. Strategic use of 3D space based on local ecological and anthropogenic conditions highlights the need for conservation efforts that maintain canopy connectivity to support the ecological flexibility of this vulnerable species.

Spatial ecology of two emblematic deep-sea crustaceans in the Salas y Gómez, Nazca and Juan Fernández ridges Southeast Pacific

The Salas & Gómez, Nazca, and Juan Fernández ridges are among the least studied regions on the planet. Ecological knowledge of deep-sea organisms inhabiting islands and seamounts along these ridges is limited. Using various sources, including published data and in situ information from five scientific expeditions in the region, we analyzed the spatial ecology of Paromola rathbuni and Projasus bahamondei, two mobile species of benthic megafauna. Random Forest models detected different combinations of abiotic variables affecting species distribution. The distribution of P. bahamondei was primarily influenced by dissolved oxygen, longitude (W), and temperature. The distribution of P. rathbuni was mainly explained by longitude (W), followed by depth, temperature, and oxygen. Generalized Linear Models quantified significant effects of low dissolved oxygen and temperature on species presence, influencing their preference for bathymetric ranges (P. bahamondei at 400–500 m, P. rathbuni at 300–400 m). A distribution break to the west of ~ 85°W was confirmed, potentially due to the weakening of the Oxygen Minimum Zone altering oxygen and thermal conditions. This feature could act as a barrier for both species despite their high dispersal potential. Under projected climate change, shifts in latitudinal, longitudinal, and bathymetric distribution patterns are expected for both species.

Habitat and Predator Influences on the Spatial Ecology of Nine-Banded Armadillos

Mesopredator suppression has implications for community structure, biodiversity, and ecosystem function, but mesopredators with physical defenses may not avoid apex predators. We investigated nine-banded armadillos (Dasypus novemcinctus) in southwestern Oklahoma (USA) to evaluate if a species with physical defenses was influenced by a dominant predator, the coyote (Canis latrans). We sampled nine-banded armadillos and coyotes with motion-activated cameras. We used single-species and conditional two-species occupancy models to assess the influences of environmental factors and coyotes on nine-banded armadillo occurrence and site-use intensity (i.e., detection). We used camera-based detections to characterize the diel activity of each species and their overlap. Nine-banded armadillo occupancy was greater at sites closer to cover, with lower slopes, and further from water, whereas coyote space use was greater at higher elevations; both species were positively associated with recent burns. Nine-banded armadillo occurrence was not influenced by coyotes, but site-use intensity was suppressed by the presence of coyotes. Nine-banded armadillos (strictly nocturnal) and coyotes (predominantly nocturnal) had a high overlap in summer diel activity. Nine-banded armadillos are ecosystem engineers but are often considered a threat to species of concern and/or a nuisance. Thus, understanding the role of interspecific interactions on nine-banded armadillos has important implications for conservation and management.

Carnivorans of the Philippines: current knowledge and research gaps

Abstract There are 7 carnivoran species in the Philippines, and despite their ecological and conservation importance, there has never been a review of the current knowledge and research efforts on these species in the country before. Here, we present the results of a comprehensive literature review and provide a summary of current knowledge on each carnivoran species in the Philippines. We searched 2 online databases (Google Scholar, Web of Science) and found 68 journal articles and reports published between January 1990 and October 2023. Research on Philippine carnivorans increased steadily over the past 34 years, with 54% of all studies being published in the past 10 years. Research in Palawan and nearby islands accounted for 66% of all studies, likely because carnivoran species richness of Palawan is higher than in the rest of the Philippines. The “Spatial Ecology and Habitat Use” category consisted of the highest number of publications, but more than half of these papers are simply occurrence records from larger biodiversity studies. Research on human–wildlife interactions and conservation practices point to hunting and habitat degradation as the leading threats to carnivorans in the Philippines. However, population and community ecology—as well as other basic ecological requirements of many species—are virtually unknown. Compared to similar reviews on other taxa in the Philippines and on carnivorans in other countries, our review reveals that carnivorans seem to be greatly understudied in the Philippines, thus highlighting a need for more research on these species, some of which are threatened. Owing to recent changes in the taxonomic status of the Sunda Leopard Cat and Philippine Palm Civet, and recognition that the Philippine mongoose is a population of the Collared Mongoose, the IUCN Red List status of these species should be re-assessed.

Spatial ecology of the Neisseriaceae family in the human oral cavity.

The human oral microbiome is a diverse ecosystem in which bacterial species have evolved to occupy specific niches within the oral cavity. The Neisseriaceae family, which includes human oral species in the genera Neisseria, Eikenella, Kingella, and Simonsiella, plays a significant role in both commensal and pathogenic relationships. In this study, we investigate the distribution and functional adaptations of Neisseriaceae species across oral habitats, focusing on their site tropisms and ecological roles. We employed a metapangenomic approach in which a curated set of reference genomes representing Neisseriaceae diversity was used for competitive mapping of metagenomic reads. Our analysis revealed distinct habitat preferences among Neisseriaceae species, with Kingella oralis, Neisseria elongata, and Neisseria mucosa primarily found in dental plaque; Neisseria subflava on the tongue dorsum; and Neisseria cinerea in the keratinized gingiva. Functional enrichment analyses identified genes and pathways underpinning habitat-specific adaptations. Plaque specialists showed metabolic versatility, with adaptations in nitrogen metabolism, including nitrate reduction and denitrification, lysine degradation, and galactose metabolism. Tongue dorsum specialists exhibited adaptations including enhanced capabilities for amino acid biosynthesis, short-chain fatty acid and glycerol transport, as well as lipopolysaccharide glycosylation, which may aid in resisting antimicrobial peptides and maintaining membrane integrity. These findings provide insights into the ecological roles and adaptive strategies of Neisseriaceae species within the human oral microbiome and establish a foundation for exploring functional specialization and microbial interactions in these niches.IMPORTANCEUnraveling the distribution and functional adaptations of Neisseriaceae within the human oral microbiome is essential for understanding the roles of these abundant and prevalent commensals in both health and disease. Through a metapangenomic approach, we uncovered distinct habitat preferences of various Neisseriaceae taxa across the oral cavity and identified key genetic traits that may drive their habitat specialization and role in host-microbe interactions. These insights enhance our understanding of the microbial dynamics that shape oral microbial ecology, offering potential pathways for advancing oral health research.

Environmental preferences of green sea turtles (Chelonia mydas) for egg-laying on a fringing reef pocket beach, Mayotte Island

Understanding the spatial ecology of sea turtles is essential to ensure their long-term conservation by the preservation of their environment. The distribution and environmental preferences for egg-laying by the green turtle (Chelonia mydas) were studied on Grande Saziley beach in Mayotte (north of the Mozambique Channel). Green turtle nesting activity was geolocated during night patrols and the depth of specific nests was measured during two field campaigns in 2021 and 2022. Various original environmental parameters related to vegetation and beach morphology were extracted in a GIS environment based on this geolocated data using orthophotography and digital elevation models (DEMs) created by drones prior to field deployments. Sediment samples were also collected from the beach. Thanks to the combination of fieldwork and GIS analysis, this study makes it possible to examine a set of variables, which until now have rarely been studied simultaneously. The results showed that the Grande Saziley beach is a heterogeneous site with the distribution of egg-laying being concentrated in two hotspots. After principal component and GLMM statistical analysis, it appeared that gravid females preferentially lay in a low proportion of coarse sand at the bottom of the nest, at higher elevation and predominantly in surface sand with a low calcium carbonate content. This preference seems to be linked more to elevation, where black sand is mainly found at the top of the beach, rather than an intentional choice based on sand composition. No significant egg-laying site-related variables were found to explain the variations in nest depth. Our study was based on a new approach combining GIS techniques and drone surveys, enabling the collection of environmental parameters, a methodology that can easily be reproduced on other nesting beaches, reducing field workload. However, this work should be continued to assess the viability of sites for clutch survival while considering the spatial and temporal heterogeneity of the environment.

Migratory patterns and seasonal habitat use of great hammerhead sharks (Sphyrna mokarran) in the southeastern United States.

The great hammerhead shark (Sphyrna mokarran) is a highly mobile shark species whose population in the United States declined dramatically through the early 2000s. Their spatial ecology is poorly understood, creating challenges for effective conservation of this enigmatic marine predator. Using acoustic telemetry and network analyses, we describe the movement patterns of 15 mature great hammerhead sharks (207-331.5 cm fork length) primarily within the waters of the southeastern United States from April 2019 to December 2022, including identifying movement corridors, core use areas and seasonal shifts in habitat use. Great hammerheads exhibited partial migration; some sharks undertook consistent, repeatable, round-trip migrations between the tagging site in the Florida Keys and northern points in the Gulf of Mexico and Atlantic coast. Conversely, others remained in the Florida Keys year-round. Network analysis coupled with community detection algorithms revealed that individual great hammerheads displayed oceanic basin affinity, favouring migration to either the Atlantic Ocean or Gulf of Mexico. Great hammerheads that remained in the Florida Keys shifted their habitat use seasonally from inshore channels (spring and summer) to offshore artificial reefs and the natural reef tract (summer through winter). These shifts may be driven by prey availability, as core use areas often corresponded to known locations of seasonal spawning aggregations for reef fish. These data fill an important knowledge gap for great hammerhead migratory patterns that can improve spatial management strategies for this historically overexploited species. We discuss the importance of drawing upon data from multiple tagging locations for highly mobile species management, particularly in the designation of essential fish habitat.

Spatial responses of black vultures to resource pulses during white‐tailed deer hunting seasons

AbstractPulsed resources can dramatically influence spatial ecology of wildlife. Black vulture (Coragyps atratus) movements depend on habitat structure and foraging opportunities, but their responses to pulsed resources are poorly understood. In contrast, changes to home ranges during large‐game hunting seasons are well documented in mammalian predators. Thus, we hypothesized that increased access to carrion would decrease black vulture space use. To test for changes in space use, we quantified home ranges using data from 12 GPS‐tagged black vultures during nonhunting, archery‐only, and firearms study periods in Indiana and Kentucky, USA. We compared estimated home range size, home range overlap, density of forest edge, and density of roads within each home range. Home range sizes decreased 52.9% from the nonhunting to archery‐only period (t35 = 2.77, P = 0.024), then remained stable (increased 9.98%, t35 = −0.25, P = 0.967) throughout the firearms period. Home range overlaps decreased with greater resource pulse intensities. Estimated forest edge and road densities within home ranges did not change across study periods. Black vultures in our study area changed space use in response to pulsed resources associated with deer hunting. Thus, vultures may shift space use in response to other resource pulses, such as afterbirth and stillbirths from livestock. Pulsed resource locations can serve as targeted survey sites for estimating scavenger abundance and distribution. Integrating resource pulse dynamics into wildlife management strategies can improve efforts to monitor disease risks at aggregation sites and address ecological challenges arising from human activities.

Assessing population dynamics and environmental influences of Balearic green toad in the Balearic Islands

AbstractUnderstanding the demography and spatial ecology of amphibian species is crucial for developing effective conservation measures under increasing environmental pressures. Over 4 years, we used capture–mark–recapture methods to investigate the population dynamics, apparent survival, dispersal, and body condition of the Mediterranean toad Bufotes balearicus across multiple ponds in the Balearic Islands. While movement patterns were assessed across different breeding sites, demographic estimates, body condition, and survival analyses were primarily derived from Pond 3, where sufficient recapture data were available. Our study suggests that adult B. balearicus exhibit limited movement between breeding ponds, likely influenced by the fragmented landscape of Mondragó Natural Park. We also found that individuals arriving earlier at breeding sites exhibited higher body condition indices. Estimated male population size in Pond 3 fluctuated from 32 to 108 individuals among the study years, and model‐averaged analyses suggested a constant annual apparent survival probability of 0.38. Daily capture numbers were positively correlated with rainfall and negatively correlated with temperature, underscoring the importance of hydrological and thermal conditions in determining breeding activity. Collectively, these findings highlight the need to maintain suitable aquatic habitats and account for environmental variability when devising conservation strategies for B. balearicus in fragmented landscapes.

Spatial Ecology and Home Range Drivers of the Weyns's Duiker (Cephalophus weynsi) in Rainforest Habitat

ABSTRACTIn Central Africa's tropical forests, duikers (Cephalophus spp.) are essential seed dispersers and prey for apex predators and humans. However, little is known about their spatial ecology, with no studies available for medium‐sized species south of the Congo River. Here, we study forest duiker spatial use in the buffer zone of Salonga National Park, Democratic Republic of the Congo. We assess capture success of (1) collective day capture with nets and (2) collective night capture with head‐torches and use GPS/VHF collars to investigate species‐specific home‐range (a) size, (b) use and (c) overlap. Across 7 months, 47 capture attempts allowed collaring 13 Weyns's (C. weynsi), two bay (C. dorsalis), and one black‐fronted (C. nigrifrons) duiker, with similar success between techniques. Weyns's duikers mean home range size was 29.38 ha, with stable core areas and dynamic boundaries. While one breeding pair showed 72.80% overlap and a mean interindividual distance of 288 m, overlap in non‐breeding pairs ranged between 4.5% and 52.2%, with an average interindividual distance of 533 m. Our assessment of the spatial use of Weyns's duikers suggests that anthropogenic disturbances might affect spatial behaviour and reproductive success. Further research on the spatial ecology of forest ungulates is key to improving conservation strategies.

Improving white shark detection capabilities in an Australian bather protection programme using environmental DNA

Abstract Bather protection programmes rely heavily on surveillance tools capable of detecting the presence of shark species that are known to physically interact with humans. This study investigates the potential for environmental DNA (eDNA) technologies to improve shark detection capabilities and complement current survey methods. We conducted a 14-month monitoring programme at two white shark (Carcharodon carcharias) visitation hotspots in eastern Australia and assessed spatio-temporal patterns of near-shore visitation using a species-specific eDNA assay, SMART (Shark-Management-Alert-in-Real-Time) drumline captures, and acoustic telemetry data from tagged white sharks. We observed higher shark detection frequencies across both survey locations using eDNA compared to the SMART drumline and telemetry survey methods. Specifically, eDNA surveys provided relatively constant rates of detection across the survey period, whereas SMART drumline and telemetry detections were highly seasonal and largely restricted to the austral winter–spring period. Findings from the eDNA surveys are consistent with current assumptions about white shark spatial ecology with year-long presence of white sharks in near-shore subtropical habitats in eastern Australia but suggest that shark presence during the summer–autumn months is possibly more prevalent than currently assumed. Overall, this study highlights the value of eDNA as a tool for enhancing shark detection capabilities, and the importance of adopting multiple complementary survey methods when assessing shark visitation rates. We discuss the implications of these findings for bather protection and white shark mitigation programmes in Australia and overseas.

Effective protection of essential fish habitat requires understanding fish spatial ecology - lessons learnt from protected European bass nursery areas

Abstract Spatial management is a widely used technique to protect sessile species or habitats. Protection of essential fish habitat is increasingly being recognized globally within fisheries management policies, requiring further practical assessments within temperate fisheries. We provide a case study for the efficacy of spatially protecting nursery sites for a highly mobile species—the European bass (Dicentrarchus labrax). Using acoustic telemetry, 146 individual fish were tracked for up to 812 days across three independent protected bass nursery areas in the Southwest UK. Within site boundaries commercial fisheries are seasonally restricted to protect vulnerable life stages. Tagged fish were re-detected >5 million times. Detections at receivers highlighted activity hot spots at or near the seaward entrance to each site. Generalized linear modelling estimated high variation in the seasonal presence/absence of fish. Due to variation in the seasonal timing and spatial boundaries of protected sites, the amount of time fish were protected ranged 1.9%–27.4%. Further work is required to link these findings to population processes e.g. mortality, growth or recruitment. We, however, highlight the vital need to consider movement patterns to ensure boundaries of spatially protected areas are relevant to species they are designed to protect.

Jaguar Space Use in the Working Landscape of Darien, Panama

Background and Research Aims: Very little research has been conducted on how the transformation of natural ecosystems by human activities can affect space use by large carnivores, especially in the tropics. This study aimed to describe the spatial ecology of jaguars ( Panthera onca ), one male and four females, in a transformed landscape in Darien, Panama. Methods: We used GPS tracking to document home range size, movement patterns, interactions, and habitat use by jaguars for the first time in Panama. Results: We found important differences in jaguars’ home range size (35 to 131 km 2 ) and overall were smaller than those reported for other areas of the region. We also find differences in the average movement speed across the day, with higher movement rates at dusk and dawn for the male jaguar, but consistent movement across the day for female jaguars, with an average speed of 4.2 kph for the male jaguar and 2.7 kph for females (ranging 2.6 to 3.0 kph across individuals). Jaguars in this transformed landscape exhibited extensive home range overlap with their conspecifics (mean = 59%, range = 8 - 98%), though they avoided occupying the same sites simultaneously. Step Selection Function analyses illustrated that jaguars select forested areas, shrubland, and secondary forests or those that are near the forest while avoiding cattle pastures. Implications for conservation: This study is the first to provide data on jaguars in areas that were once tropical rainforests, but were deforested (∼31% of total study area) for cattle pastures and crops, to show how jaguars can thrive in these landscapes despite human activities. This information is crucial to identify habitat quality requirements, and in addition to the search to minimize the conflict, and plan potential corridors, protected areas for the east region of Panama.

Behavioural Processes Underlying the Habitat Selection of Indo‐Pacific Bottlenose Dolphins (Tursiops aduncus) in the Ningaloo Marine Park and Exmouth Gulf, at the North West Cape, Western Australia

ABSTRACTIdentifying the behavioural processes influencing habitat use is important for understanding a species' behavioural and spatial ecology and informing their conservation. In this study, we collected information on the behavioural state of globally Near Threatened Indo‐Pacific (IP) bottlenose dolphins (Tursiops aduncus) inhabiting coastal waters at the North West Cape (NWC), Western Australia (WA). Ensemble habitat suitability modelling was used to identify key environmental and anthropogenic variables correlated with the spatial distribution of dolphin groups engaged in foraging, travelling and resting behaviours to determine whether dolphins use particular areas for such activities. The distribution of foraging groups was related to distance from the nearest boat ramp and seabed slope, with the foraging dolphins more likely to occur 3000–5000 m from the nearest boat ramp and in areas of moderate seabed slope. Resting dolphins were localised and most likely to occur in shallow waters (5–10 m deep) within designated Sanctuary Zones of the Ningaloo Marine Park (NMP). Dolphins travelling were more likely to occur 1000–2000 m from the coast and in water depths of 7–12 m but as deep as 20 m. The integration of behavioural data into habitat suitability models allowed the identification of areas of biological importance for IP bottlenose dolphins at the NWC. Given the increasing risks to dolphins from cumulative anthropogenic activities in this region, the results from this study are applicable for marine spatial planning and adaptive management of this Near Threatened dolphin species.

Lessons for Transboundary Snow Leopard Conservation: Findings From a GPS Telemetry Study in Kangchenjunga Conservation Area, Nepal

ABSTRACTEnsuring the long‐term persistence of snow leopards (Panthera uncia) in changing landscapes requires a deep understanding of their spatial ecology and movement behavior. To maintain viable metapopulations and ensure gene flow between populations, there is an urgent need to develop sound and effective conservation plans. This study presents findings from Nepal's first GPS telemetry study of snow leopards, shedding light on their home range size, habitat selection, and transboundary movements. GPS data were collected from four snow leopard individuals in the Kangchenjunga Conservation Area, eastern Nepal, over tracking periods ranging from 20 to 659 days, yielding a total of 4707 location points. We used three home range estimators for analysis: local convex hulls (LoCoH), fixed kernels (Kernel), and minimum convex polygons (MCP). Our results show that home range sizes were 6 to 97 times larger than previous estimates for Nepal, with LoCoH estimates of 310 and 102 km2 (MCP = 730 and 211 km2) for two adult females and 312 km2 (MCP = 1032 km2) for one adult male. Three snow leopards crossed international borders five to seven times, spending, on average, 10%–34% of their time in neighboring countries (China and India), with 28%–50% of their home ranges overlapping India. Our study demonstrates that snow leopards in Nepal have home ranges that are significantly larger than previously documented and frequently cross international borders. These extensive transboundary movements highlight the need for stronger coordination between Nepal, China, and India to ensure the long‐term conservation of snow leopards in this key region of their distributional range.

If These Walls Could Talk: Investigating Bottlenose Dolphin Occupancy and Range in Fiord Ecosystems Using Passive Acoustic Monitoring and Visual Surveys

ABSTRACTEffective management of protected species requires a comprehensive understanding of their ecology. Within the Fiordland (Te Moana o Atawhenua) Marine Area (FMA) in south‐western Aotearoa/New Zealand, two of the four recognised bottlenose dolphin (Tursiops truncatus) subpopulations are considered resident to discrete fiord systems. Opportunistic sightings outside the Patea/Doubtful and Tamatea/Dusky Sound complexes, however, indicate these subpopulations occupy a larger space than is currently recognised. To investigate bottlenose dolphin use of remote spaces in the FMA, passive acoustic monitoring equipment was deployed in six of the southern fiords. Acoustic data were collected between February 2022 and November 2023 using two types of devices: F‐PODs to detect click trains of odontocetes and SoundTraps to collect recordings to explore a variety of call types. We used automated classifiers/detectors and manual browsing to detect various vocalisation types. To better understand dolphin occupancy at each acoustic monitoring site, we constructed a hierarchical Bayesian model to estimate detection probabilities of the different data collection and signal detection approaches. Photo‐identification was used to identify individual dolphins in remote areas, and differences in detection between visual and acoustic methods were explored. This study demonstrates that dolphins, including two resident subpopulations of Fiordland bottlenose dolphins, regularly use fiords that are not currently considered part of their habitat range and may often use spaces outside the FMA. This increased understanding of the spatial ecology of Fiordland bottlenose dolphins underscores the need for a re‐evaluation of their habitat and potential threats throughout this region.

Mapping red algal blooms and their albedo-reducing effect on seasonal snowfields at Hardangervidda, Southern Norway

Red snow algae bloom at the surface of snowfields worldwide, and their detection is relevant for ecological, biogeochemical and mass balance studies. In this study, we co-located RGB imagery acquired with a light-weight Uncrewed Aerial Vehicle (UAV) to 129 hyperspectral reflectance spectra from which the snow surface properties were retrieved, thereby enabling high-resolution aerial mapping of algal properties. We present maps of red snow algae abundance and albedo reducing effect over ∼ 9700 m2 of seasonal snowfields across Hardangervidda, Southern Norway, in July and August 2023. The average albedo reducing effect of the algae over the entire area was 0.012 ± 0.005, and attained 0.028 ± 0.004 on a snowfield of ∼ 710 m2. Across snow surfaces with visible blooms only, the algal albedo reducing effect was 0.045 ± 0.003, equivalent to an additional ∼ 3 mm of daily melting under local illumination conditions, and aggregating to 5,500 ± 2,300 kg of daily snowmelt. The intensity and spatial coverage of surface algal blooms were very variable between and within the individual snowfields. Analysis of the UAV imagery suggests that multiple small and distributed samples are at least twice more likely to yield representative estimates of the average snow algal concentration of a snowfield compared to fewer, larger samples. Our study demonstrates the potential of low-cost and easy to deploy UAVs for red snow algal monitoring at the cm to sub-cm scale, which can be used to better understand their spatial ecology and role in albedo reduction.

A novel method for mapping high‐precision animal locations using high‐resolution imagery

AbstractInvestigating ecological questions at the scale of individual organisms is necessary to understand and predict the biological consequences of changing environmental conditions. For small organisms, this can be challenging because ecologists need tools with the appropriate accuracy, precision, and resolution to record and quantify their ecological interactions. Unfortunately, many existing tools are only appropriate for medium to large organisms or those that are wide‐ranging, inhibiting our ability to investigate the spatial ecology of small organisms at fine scales. Here, we tested a novel workflow for recording animal locations at very fine (decimeter) spatial scales, which we refer to as high‐resolution orthomosaic location recording (HOLR). The workflow for HOLR combined direct observations with data collection of locations on high‐resolution uncrewed aerial vehicle (UAV) imagery loaded on smartphones. Observers identified landscape features they recognized in the imagery and estimated positions relative to these visual landmarks. We found HOLR was approximately twice as accurate as consumer‐grade GPS devices, with a mean error of 0.75 m and a median error of 0.30 m. We also found that performance varied across landscape features, with the highest accuracy in areas that had more visual landmarks for observers to use as reference points. In addition to submeter accuracy, HOLR was cost‐effective and practical in the field, requiring no bulky equipment and allowing observers to easily record locations away from their own position. This workflow can be used to record locations in a variety of situations, but it will be particularly cost‐effective when users simultaneously utilize the high‐resolution environmental data contained within UAV imagery. Together, these tools can expand the application of spatial ecology research to smaller organisms than ever before.