Abstract:- The cross-dipole antenna, has another name known as turnstile antenna. It consists of two dipole antennas set up at right angles (90 degrees) to each other. The cross-dipole antenna is typically fed with a 90-degree phase shift to produce circular polarization. It is widely used radio antenna in applications for circular polarization and omnidirectional radiation patterns in the horizontal plane. The antenna is made to work in the UHF frequency range, centred around 435 MHz, and the design was done using CST Studio Suite (a simulation tool). This project focuses on designing and testing a cross-dipole antenna, which helps improve signal reception and transmission especially useful in satellite communications, aerospace systems, and telemetry, where the signal direction can constantly change. The paper looks into how the antenna is designed, how it sends out signals (its radiation pattern), how it behaves with electrical signals (impedance), and how it can be used in real-world scenarios. Both computer simulations and actual tests were done to show how well it works across different frequencies. The project looked at important performance factors like return loss, gain, radiation pattern and polarization. This cross-dipole antenna gives equal signal in all directions in horizontal plane. We fed with signals that are 90 degrees out of phase as this set up helps for circular polarization, which is useful in communicating with satellites that keep changing their position and angle. Keywords: CST Studio Suite, antenna design, cross-dipole antenna, electromagnetic simulation, UHF band, circular polarization, polarization matching, gain, return loss, satellite communication, remote sensing, telemetry, omnidirectional radiation.

Satellite telemetry is widely used to study the movements of marine mammals, but current attachment methods for seals typically rely on epoxy adhesives, which pose risks to animal welfare and the marine environment. This study presents a biomimetic, adhesive-free attachment system inspired by the seal louseEchinophthirius horridus, an ectoparasite capable of maintaining a strong grip on seal fur in aquatic conditions. A top-down biomimetic approach was used to abstract key functional principles from the louse's claw morphology and cuticular anchoring structures. These biological features informed the development of a 3D-printed comb-clamp prototype, termed 'TACS' (Transmitter Attachment Clamp[s]), designed specifically for the hair structure of harbour seals. Microscopy and x-ray microtomography revealed morphological traits such as interlocking setae, directional grooves, and a specialised euplantula, which were functionally integrated into the prototype. Tensile tests on tanned seal fur demonstrated mean maximum retention forces of 4.58 N under dry conditions and 2.42 N under wet conditions. A proof-of-concept trial on a live harbour seal showed successful attachment for up to 50 min, without signs of distress or fur damage. The TACS system fulfilled key design criteria: rapid and reversible application, low material weight (<20 g), and strong mechanical retention without the use of adhesives. This study demonstrates the potential of biologically inspired design to provide an environmentally responsible alternative to conventional tagging methods and highlights the relevance ofE. horridusas a functional model for bioinspired gripping systems in marine applications.

Relevance. The increase in the number of terminals and the intensity of connections in satellite communication networks with the «star» topology actualizes the problem of choosing an effective mechanism for accessing a common radio channel. The well-known approaches of deterministic and random access have significant limitations. At the same time, there are no clear analytical criteria for choosing between mechanisms depending on the load, which makes it difficult to optimize network performance. Purpose (research): The aim is to compare the effectiveness of two mechanisms for entering satellite terminals into a network with the "star" topology: with specific slot access and with random access. The assessment is aimed at identifying conditions under which one of the mechanisms is superior to the other in key performance indicators. Methods. The solution of the problem is based on a combination of analytical and simulation modeling. To evaluate the effectiveness of random access, a strict combinatorial derivation of the mathematical expectation formula for the number of slots selected by exactly one terminal was carried out. The verification of the analytical model was performed using stochastic modeling in Python. Result. A validated analytical model has been obtained that makes it possible to accurately predict the effectiveness of the random access mechanism. The data obtained is applicable in the design of satellite communication networks to optimize terminal entry time and channel resource allocation. The novelty elements are rigorous analytical inference and verification of the formula for the mathematical expectation of the number of successfully occupied slots with random access, which allows you to accurately predict performance without large-scale modeling. The novelty also includes the establishment of a quantitative criterion for choosing an access mechanism. The proposed model takes into account the real conditions of terminal competition for channel resources and is applicable to the analysis of protocols such as ALOHA and TDMA. Practical significance. The presented solution is proposed to be used in the design and adaptive management of the MAC layer in VSAT satellite networks, IoT systems and telemetry networks. The obtained criteria for selecting an access mechanism can be implemented as dynamic reconfiguration algorithms in software-configurable networks, allowing automatic switching between modes depending on the current load. This will ensure optimal use of bandwidth, minimize delays, and increase overall network stability.

Abstract In the waters of North Carolina, on the United States east coast, Tamanend’s bottlenose dolphin ( Tursiops erebennus ) is managed as four stocks, differentiated largely based on photo-identification and satellite telemetry data. Two of the stocks reside primarily within estuarine habitats throughout the year, and two others inhabit coastal waters and make broad scale, migratory movements. The spatio-temporal overlap of these stocks in North Carolina varies seasonally, creating a complicated scenario in which stock boundaries are difficult to identify, and the demographic independence among groups is not well understood. Furthermore, incidental mortality and serious injury of dolphins occurs in several North Carolina fisheries, but the spatio-temporal overlap of the four stocks makes it difficult to assign mortalities and characterize their impact on each stock. To investigate population structure in this complex environment, we obtained biopsy samples from Tamanend’s bottlenose dolphins, and utilized next-generation molecular sequencing to produce a data set of over 6,000 single nucleotide polymorphism markers. Cluster and migration analyses supported the presence of four demographically independent populations. However, the distributions of these populations do not align well with the currently delineated stocks. Instead, our analyses support the existence of three populations in estuarine waters of North Carolina and one inhabiting coastal waters. An improved understanding of the underlying population structure of Tamanend’s bottlenose dolphins in these waters will provide a better characterization of stock distribution and support more accurate assignment of mortality, which is necessary for successful conservation and management of this species.

In the dynamic and increasingly threatened marine environment, understanding the full spatial ecology of species like the reef manta ray (Mobula alfredi) is crucial for effective conservation. While typically considered a shallow-water species, reef manta rays in New Caledonia were investigated to explore their vertical habitat use. This study utilized satellite telemetry data from 19 tagged individuals, with three tags providing sufficiently high-resolution information on dive behaviour, to describe and quantify three-dimensional movements. We found that New Caledonian reef manta rays exhibit outstanding deep-diving capabilities, with all individuals diving below 300 m and one reaching 672 m. These deep dives occurred regularly, averaging one every 4.8 days, which is notably more frequent than in other studied populations. Dive profile analysis revealed a mixture of foraging and exploratory behaviors, supporting the hypothesis that these deep excursions are driven by the search for demersal or mesopelagic food resources. Our findings highlight the ecological plasticity of M. alfredi and demonstrate that their habitat use extends far beyond the coastal, shallow waters previously assumed, a critical consideration for developing comprehensive and effective marine protected areas.

Animal movement strategies, or suites of correlated traits reflecting how individuals respond to their environment, are often shaped by spatiotemporal heterogeneity and predictability in physicochemical conditions, resources or risk. While movement strategies have been well studied in terrestrial animals using high-resolution satellite telemetry, our understanding of how seascape heterogeneity influences movement strategies in aquatic systems remains limited due to technological constraints. We used a non-gridded passive acoustic telemetry array to identify and classify movement strategies of Common Snook (Centropomus undecimalis) and Atlantic Tarpon (Megalops atlanticus) within two estuarine systems in Everglades National Park, Florida. We then evaluated how seasonal heterogeneity and environmental predictability influenced movement strategy selection. Using a suite of movement metrics, we identified three statistically distinct movement strategies that varied in movement frequency, home range size and site fidelity. Fish in more homogeneous environments tended to adopt strategies involving frequent movements, larger home ranges and shorter stays in a given location. In contrast, increased seascape heterogeneity was associated with movement strategies characterized by less frequent movements, smaller home ranges and longer residence times. We also found species-level differences in strategy use, with the predictability of dissolved oxygen, salinity and turbidity emerging as key environmental drivers of movement strategy selection. These results demonstrate that seascape heterogeneity and predictability strongly influence the emergence and selection of movement strategies in estuarine predators. Our findings provide a novel approach for identifying movement strategies in aquatic systems using passive acoustic telemetry and highlight the broader importance of seascape complexity in shaping animal behaviour and predicting responses to environmental change.

How far animals travel to gather food for offspring or themselves is a central component of ecology. Among birds, the ‘foraging range’ (straight‐line distance between a central place and a destination) is used to assess potential interactions with anthropogenic stressors such as wind farms. Recent reviews have summarized marine foraging ranges for UK breeding seabirds. However, for species that span the terrestrial/marine divide (some gulls, terns, sawbills and divers), terrestrial ranges are unknown, as is an understanding of how ranges may vary by breeding colony and their surrounding habitat. Using global positioning satellite (GPS) telemetry, we studied the movements of Lesser Black‐backed Gulls Larus fuscus and Herring Gulls L. argentatus from 11 and seven UK breeding colonies, respectively, over 12 years. We investigated the variation in foraging range using general mixed effects models with respect to: (i) terrestrial and marine environments; (ii) stages of the breeding season; and (iii) colony types according to habitat (natural: island, coastal, inland; and urban: coastal), accounting for sources of potential sampling bias. Lesser Black‐backed Gulls had significantly larger ranges than Herring Gulls. During likely active nesting periods (incubation and chick‐rearing: ‘true breeding’), marine foraging ranges of Lesser Black‐backed Gulls (local mean 19.5 ± 23.1 km, max 175.5 km) were greater than terrestrial ranges (local mean 14.9 ± 15.9 km, max 145.4 km). By contrast, terrestrial ranges were largest for Herring Gulls (terrestrial, 9.1 ± 10.7 km, max 83.8 km; marine, 7.1 ± 8.1 km, max 74.4 km). For terrestrial environments, true breeding foraging ranges of Lesser Black‐backed Gulls were smaller than during pre‐ or post‐breeding phases, whereas for Herring Gulls the reverse was true. Marine ranges of both species were smallest during pre‐breeding and largest during post‐breeding phases. For both species, urban colonies had the smallest foraging range and island colonies some of the largest. Terrestrial and marine foraging ranges were predicted UK‐wide based on colony type and breeding phase, highlighting concentrations of foraging range. This study provides more precise foraging range information specific to foraging environment, breeding stage and colony type than has currently been available, and will therefore help to reduce uncertainty in the consenting process for proposed developments as well as in licensing control of wild birds.

MachineLearning models for identification of point anomalies in satellite telemetry data

Abstract Species that are secretive, imperilled and consequently data deficient often require conservation action despite limited available information. In such scenarios, Bayesian networks (BNs) offer a versatile and intuitive approach for utilizing various information sources, including literature reviews, community science datasets and expert knowledge. Although it has been suggested that peer review be incorporated during expert elicitations in a BN modelling context, little information exists about how to implement this approach or about how models constructed using this approach perform. We documented a double‐blind peer review approach for expert elicitation in a BN modelling context. Further, we compared BN models that were generated by experts who engaged in this peer‐review process (PRBNs) to those that were generated by a single expert whose knowledge was supplemented only by a literature review (LRBNs). These comparisons were based on the ability to predict the occurrence (via community science and satellite telemetry data) of a secretive and data deficient species, the King Rail ( Rallus elegans ), throughout a large region. We found that the LRBNs tended to predict King Rail occurrence as well as, or better than, the PRBNs. The LRBNs that we evaluated provided more consistent predictions across our study area. However, preliminary data suggest that the PRBNs may better distinguish between locations of focal and non‐focal species within smaller regions. Practical implication . Our framework for utilizing double‐blind peer review could serve as a useful guide and have practical implications for incorporating expert knowledge in BN models. Further, our model comparison case study suggests that, in some contexts, a single expert who uses a literature review to inform the creation of BN models may be able to accurately predict the occurrence of a secretive and data‐deficient focal species. Taken together, this information could help ecologists decide when a double‐blind peer review approach to expert elicitation is necessary and how to implement this approach in a BN modelling context.

Narwhals (Monodon monoceros) are deep-diving Arctic cetaceans that migrate seasonally between summering and wintering grounds. The Baffin Bay population overwinters in southern Baffin Bay and Davis Strait, where they are known to forage on high-energy benthic prey. Studying narwhal winter behaviour and prey preference has been challenged by their remote distribution and limited lifespan of satellite tags deployed in summer, restricting data on their habitat use and foraging strategies. Since prey consumption is thought to peak in the winter, understanding narwhal diet plasticity in a rapidly changing environment like Baffin Bay is critical. This study developed unique methods to examine four years of irregular satellite telemetry data from 22 narwhals tagged in their summering grounds. Locations and recorded diving data from the overwintering area were isolated, and a hidden Markov model was used to define three behaviours (“surface”, “pelagic”, and “deep-water” diving). We further examined the effects of five covariates on these behaviours to provide insight into the spatial patterns of narwhal winter prey preference. Narwhal behaviours were dominated by diving, with 37% of their time spent in pelagic waters and 40% in deep-water, while only 22% of their time was spent in surface related behaviours. Deep-water behaviours increased later in the day and into the winter season and occurred frequently in the center trough of Baffin Bay before (66°- 69°) and across Davis Strait (65° - 67°). In contrast, pelagic behaviours declined as the winter season progressed and occurred earlier in the day. Narwhals occupying the northern overwintering area exhibited more pelagic behaviours, despite it being deeper, suggesting different foraging strategies across their winter range. Our study identified behaviours suggestive of a variable winter diet and provided insight on the spatial nature of these behaviours across the winter season. The methods developed in this study present new opportunities for analysing lower resolution satellite tracking data. With advancements in bio-logging technology and remote field methods, the ability to successfully document changes in winter space use and fine-scale foraging behaviours may be possible for narwhal in the future.

Abstract Volcanic monitoring in Antarctica provides dual benefits by facilitating the study of highly volcanically active yet underexplored regions and by serving as an essential tool for maintaining the safety of both national and international Antarctic bases. Deception Island, one of the most volcanically active areas on the Antarctic continent, is now equipped with an enhanced monitoring system, modernized by the Spanish National Geographic Institute (IGN), which assumed its management in September 2020, pursuant to a protocol established between the Spanish Ministry of Transport, Mobility, and Urban Agenda and Ministry of Science and Innovation. In order to meet the challenging conditions of the polar region, six permanent stainless-steel shelters have been installed over the course of the last four Spanish Antarctic campaigns. Each shelter is outfitted with batteries, solar panels, Wi-Fi and data acquisition systems for seismic and Global Navigation Satellite System (GNSS) stations. This monitoring network also comprises a station dedicated to measuring temperature within a thermal located where there is the anomaly on the island, a visual surveillance camera, seven seismic stations and six GNSS stations. All data collected are transmitted in real time to IGN headquarters in Madrid through Gabriel de Castilla Base, operated by the Spanish Army. Due to the growing volume of recorded data, it became necessary to upgrade transmission systems, leading to the installation of a next-generation satellite telemetry system during the 2023–2024 campaign. All seismic information is continuously and immediately analysed by the IGN’s National Seismic Network and is stored at the National Polar Data Center, housed within the Marine Technical Unit of the Spanish National Research Council, in accordance with the guidelines of the Spanish Polar Committee. The establishment of this infrastructure on Deception Island delivers a robust operational model that can be replicated in other polar settings, thereby contributing to the advancement of volcanic monitoring across the continent.

Canada’s eastern boreal forest provides important breeding and foraging habitat for many wildlife species, including sandhill cranes (Antigone canadensis (Linnaeus, 1758)), a species of conservation concern. Following significant population declines in the early 20th century, sandhill crane populations have since rebounded and rapidly expanded their breeding ranges into the boreal forest, yet habitat selection in these newly occupied areas remains poorly understood. Using high-resolution satellite telemetry, we developed resource selection functions to assess how land cover and land use influence breeding habitat selection of 42 sandhill cranes in Ontario and Quebec, Canada. Within the home range (95% minimum convex polygon), sandhill cranes exhibited the strongest selection for wetlands, which were selected approximately twice as often as croplands, forest disturbances, and open water. Intact forests and urban areas were consistently avoided. These findings highlight wetlands as key predictors of habitat use, emphasing the need for targeted management strategies that prioritise wetland conservation. While current forestry practices do not appear to negatively impact breeding habitat selection in the boreal forest, their long-term effects on breeding success remain unknown, requiring further research to explore the detailed impacts of forestry development, industrial development, and urban expansion on breeding behaviour and success.

Migration and non-breeding movements are common across animal groups and are often driven by seasonal changes in habitat conditions. This behaviour is prevalent in crested penguins (Eudyptes sp.), which have evolved in and still primarily inhabit the subantarctic regions of the Southern Hemisphere. These species migrate outside the reproductive phase due to the limited year-round productivity around the breeding sites. Tawaki/Fiordland penguins (Eudyptes pachyrhynchus) are unusual in that they breed in temperate, continental New Zealand, an environment that appears productive enough to support year-round residency, yet they undertake extensive migrations during the non-breeding period. To investigate the drivers and patterns behind this behaviour, we used satellite telemetry to track 14 adult tawaki from across their breeding range during the winter of 2019. We examined whether migration routes differed by breeding location, and used maximum entropy (Maxent) modelling to identify environmental predictors of habitat use during the non-breeding period. All penguins followed a similar south-westerly trajectory toward the subantarctic waters south of Tasmania, irrespective of origin. Birds reached maximum distances of up to 2,193 km from their colonies, traveling a median total distance of 6,086 km over 135 days. Maxent models showed that mixed layer depth (i.e., the mixing height at the ocean surface) around 80 m was the strongest predictor of habitat suitability, aligning with known foraging depths in this species. Tawaki were associated with oceanic habitats ranging from polar to subtropical regions—a broader environmental range than other crested penguins, which tend to remain within a single water mass. These findings highlight the flexibility of tawaki in their use of marine habitats. This behavioural plasticity may suggest resilience to environmental variability, offering insights into why tawaki appear to be maintaining stable population trends while other New Zealand crested penguins are in decline.

The blue-eared pheasant (Crossoptilon auritum), a Near Threatened (NT) species endemic to China, is primarily distributed across the northeastern region of the Qinghai-Tibetan Plateau. To bridge the fine-scale spatiotemporal gap in blue-eared pheasant behavioral ecology, this study combines satellite telemetry, movement modeling, and field-based habitat assessments (vegetation, topography, human disturbance). This multidisciplinary approach reveals detailed patterns of their behavior throughout the breeding season. Using satellite-tracking data from six individuals (five males tracked at 4 h intervals; one female tracked hourly) in Wanglang National Nature Reserve (WLNNR), Sichuan Province during breeding seasons 2018-2019, we quantified their home ranges via Kernel Density Estimation (KDE) and examined the female movement patterns using a Hidden Markov Model (HMM). The results indicated male core (50% KDE: 21.93 ± 16.54 ha) and total (95% KDE: 158.30 ± 109.30 ha) home ranges, with spatial overlap among individuals but no significant temporal variation in home range size. Habitat selection analysis indicated that the blue-eared pheasants favored shrub-dominated areas at higher elevations (steep southeast-facing slopes), regions distant from human disturbance, and with abundant animal trails. We found that their movement patterns differed between sexes: the males exhibited higher daytime activity yet slower movement speeds, while the female remained predominantly near nests, making brief excursions before returning promptly. These results enhance our understanding of the movement ecology of blue-eared pheasants by revealing fine-scale breeding-season behaviors and habitat preferences through satellite-tracking. Such detailed insights provide an essential foundation for developing targeted conservation strategies, particularly regarding effective habitat management and zoning of human activities within the species' range.

ABSTRACT Capsule Unlike in its African range, very little information is available on the movement patterns of Lesser Flamingos in India. In one of the first satellite telemetry studies of Lesser Flamingos in India, we provide novel insights into the species’ movement patterns, which may further supplement the existing management of their key feeding and breeding sites. Aims We investigated the daily movement patterns corresponding to the Lesser Flamingo’s feeding strategies, long-distance movements corresponding to potential nomadism, home range patterns and habitat use across important feeding sites in India. Methods We deployed GPS-GSM satellite transmitters on four sub-adults and tracked their movements between September 2022 and July 2023. Their home ranges were calculated using kernel density estimators, and movement patterns were calculated using the Tracking Analyst toolbox in ArcGIS software. Habitat use was investigated by employing a robust machine-learning algorithm, Random Forest. Results The four Lesser Flamingos covered a mean ± SD distance of 2541.55 ± 1946.04 km per month, and an average daily distance of 83.45 ± 64.63 km. Long-distance movements were observed in two individuals. Overall, the mean home ranges (95% KDE) were calculated as 223.82 ± 337.48 km2 and core areas (50% KDE) as 39.14 ± 65.71 km2. The birds’ movements were positively associated with saltpans, mudflats, waterbodies and intertidal swamps. Conclusion The long-distance movement pattern observed hints at the Lesser Flamingos’ nomadism, switching between key feeding sites across Gujarat and Maharashtra. This requires the conservation of their key feeding sites, in particular, and their breeding sites in general.

Abstract Consistent intraspecific variation in behavior directly impacts reactions to environmental challenges, including life in human-altered landscapes. Yet, it is rarely considered in free-ranging species thriving in anthropogenic landscapes and causing human-wildlife conflict. Here, we examine the consistent inter-individual variability in wild boar movement traits and highlight its potential for ecology and practical management. We used satellite telemetry data from 95 GPS-tracked wild boars monitored in Czechia and computed weekly movement rate (activity), intensity of space use (exploration), and diurnality (boldness). Using a variance partitioning approach, we tested whether these traits were repeatable over time and therefore considered personality traits, and using Bayesian multivariate mixed-effect models, we examined the correlations among these traits to describe a behavioral syndrome while controlling for external and internal sources of variation. Wild boar showed significant consistent inter-individual variation in all three traits, with repeatability ranging from 0.16 to 0.35. We found significant correlations between traits, indicating the existence of a remarkable movement syndrome. Individuals staying within familiar areas were less nocturnal and moved slower, as opposed to individuals roaming more outside familiar areas, faster and with striking nocturnality. The movement syndrome and, most importantly, its variability, with individuals ranging in between extremes of activity and exploration, likely contributes to the success of this species and helps them thrive in human-dominated landscapes while maximizing resource acquisition. Integrating intraspecific behavioral variation into ecology and practical population management could improve models predicting wild boar movement and alleviate the biodiversity and economic loss caused by expanding wild boar populations.

In response to global climate change, numerous taxa are expanding their living ranges. In highly migratory species such as sea turtles, this expansion may be driven by individuals from nearby or distant areas. Recent nests outside the species' typical nesting range and reports of adult-sized individuals in the western Mediterranean suggest agreen turtle (Chelonia mydas) range expansion into the central and western Mediterranean. To assess the green turtles' origin in these novel habitats, we built a genomic baseline using 2bRAD sequencing on five individuals from each ofthree Regional Management Units (RMUs): North Atlantic, South Atlantic and Mediterranean. We then compared this baseline with genotyped hatchlings from three nests laid in new central and eastern Mediterranean sites and four mature-sized green turtles tagged with satellite telemetry in the western Mediterranean. Our analyses revealed that the Tunisia nest originated from the South Atlantic RMU, while the Crete nests were produced by turtles from the Mediterranean RMU. Additionally, the three adult-sized turtles sampled in the southwestern Mediterranean were assigned to the South Atlantic RMU, while the mature-sized individual sampled in the northwestern Mediterranean belonged to the Mediterranean RMU. These results suggest a simultaneous incipient colonisationby two geographically distant RMUs. We propose that the range expansion of green turtles into the central and western Mediterranean is likely climate driven and these populations may become globally important as temperatures rise. Finally, our results highlight the essential role of the cost-effective RAD-Seq genomic assessment combined with tagging data to understand potential new colonisations.

Detecting anomalous events in satellite telemetry is a critical task in space operations. It is time-consuming, error-prone and human dependent, thus automated data-driven algorithms have been emerging at a steady pace. However, there are no available datasets of real satellite telemetry with annotations to verify anomaly detection models. We address this gap and introduce the AI-ready benchmark dataset (OPSSAT-AD) containing the telemetries acquired on board OPS-SAT—a CubeSat mission, operated by the European Space Agency. The dataset is accompanied with the baseline results obtained using 30 supervised and unsupervised classic and deep machine learning algorithms. They were evaluated using the training-test dataset split introduced in this work, and we suggest a set of quality metrics which should be calculated to confront the new algorithms for anomaly detection while exploiting OPSSAT-AD. We believe that this work may become an important step toward building a fair, reproducible and objective validation procedure that can be used to quantify the capabilities of the emerging techniques in an unbiased and fully transparent way.

BackgroundUnderstanding the abiotic and biotic drivers of species distribution is critical for climate-informed ecosystem management. We aimed to understand habitat selection of northern fur seals in the eastern Bering Sea, a declining population that is also a key predator of walleye pollock, the target species for the largest U.S. commercial fishery.MethodsWe developed species distribution models using random forest models by combining satellite telemetry data from lactating female fur seals tagged at different rookery complexes on the Pribilof Islands in the eastern Bering Sea with regional ocean model simulations. We explored how data aggregation at two spatial scales (Pribilof-wide and complex-specific) impacted model performance and predicted distributions. Spatial predictions under hindcasted (1992–2018) and projected (2050–2059) physical and biological conditions were used to identify areas of core habitat, overlap with commercial fishery catches, and potential changes in future habitat suitability.ResultsThe most important environmental predictor variables across all models were bathymetry, bottom temperature, and surface temperature. The Pribilof-wide model both under- and overrepresented the importance of specific areas, while complex-specific models exhibited considerable variability in transferability performance. The majority of core habitat occurred on the continental shelf in areas that overlapped with commercial catches of walleye pollock during the “B” season (June – October), with an average of 76% of the total percentage of the catch occurring in core fur seal habitat within the foraging range of lactating females. Projections revealed that considerable changes in fur seal habitat suitability may occur in the coming decades, with complex-specific variation in the magnitude and direction of changes.ConclusionsOur results illustrate the need to sample multiple sites whenever possible and consider spatial scale when extrapolating species distribution model output for central-place foragers, even when terrestrial sites are < 10 km apart. The high overlap between suitable fur seal habitat and commercial fishery catches of pollock, coupled with projected changes in habitat suitability, underscore the need for targeted studies investigating fisheries impacts on this declining population.

As the number of low earth orbit (LEO) satellites increases, traditional direct communication links struggle to meet the telemetry and telecommand demands of large-scale satellite constellations. Inter-satellite routing offers a promising solution to this challenge. To enhance the reliability and timeliness of satellite telemetry and telecommand in mega-constellations, we propose the Data Copies-Based Multipath Routing (DCMR) algorithm. By transmitting multiple data copies over different paths, DCMR ensures reliable data delivery even when some paths fail. Additionally, DCMR optimizes the distribution of data across multiple paths to maximize transmission capacity and minimize end-to-end delay. To evaluate the algorithm's performance, simulations are conducted using the Starlink constellation within the STK and MATLAB environments. The results demonstrate that DCMR significantly outperforms single-path routing and backup multipath routing, showcasing its potential for telemetry and telecommand applications in LEO satellite networks.