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In wireless communication networks, the growing need for data has presented significant issues in the last years. This will continue, with mobile consumers’ needs for Quality of Service (QoS) changing and their data use skyrocketing. The complexity of Heterogeneous Network (HetNet) situations and the sharp rise in traffic demand have significantly increased the issues. It is challenging to accommodate the various traffic needs of mobile users with traditional methods as they maintain network imbalances inside the HetNets by giving priority to maximum received power in the cell association process. In this work, a Red-Tailed Hawk (RTH) algorithm with a Cell Range Extension (CRE) approach is integrated to maximize the number of users whose downlink demands are fulfilled, rather than just focusing on improving downlink rates for individual users. The suggested approach formulates a fitness function with the goal of determining appropriate CRE bias values for individual Small Base Stations (SBSs) while taking into account the workload of BS as well as the Signal to Interference-plus-Noise Ratio (SINR) of user devices. The efficiency related to the suggested strategy is demonstrated by a comparison with conventional methods. The proposed methodology meets user throughput requirements while lowering network imbalances and call drop rates. Experimental findings demonstrate the betterment of the proposed model by 56.67% load balancing, 49.23% throughput, 91.49% call drop rate, 77.55% execution time, 92.68% delay, and 20.11% convergence than the existing methods.

Poleward range extensions of coral reef species can reshuffle temperate communities by generating competitive interactions that did not exist previously. However, novel environmental conditions and locally adapted native temperate species may slow tropical invasions by reducing the ability of invaders to access local resources (e.g. food and shelter). We test this hypothesis on wild marine fish in a climate warming hotspot using a field experiment encompassing artificial prey release. We evaluated seven behaviours associated with foraging and aggressive interactions in a common range-extending coral reef fish (Abudefduf vaigiensis) and a co-shoaling temperate fish (Microcanthus strigatus) along a latitudinal temperature gradient (730 km) in SE Australia. We found that the coral reef fish had reduced foraging performance (i.e. slower prey perception, slower prey inspection, decreased prey intake, increased distance to prey) in their novel temperate range than in their subtropical range. Furthermore, higher abundance of temperate fishes was associated with increased retreat behaviour by coral reef fish (i.e. withdrawal from foraging on released prey), independent of latitude. Where their ranges overlapped, temperate fish showed higher foraging and aggression than coral reef fish. Our findings suggest that lower foraging performance of tropical fish at their leading range edge is driven by the combined effect of environmental factors (e.g. lower seawater temperature and/or unfamiliarity with novel conditions in their extended temperate ranges) and biological factors (e.g. increased abundance and larger body sizes of local temperate fishes). Whilst a future increase in ocean warming is expected to alleviate current foraging limitations in coral reef fishes at leading range edges, under current warming native temperate fishes at their trailing edges appear able to slow the range extension of coral reef fishes into temperate ecosystems by limiting their access to resources.

Aim Despite the unprecedented rate of species redistribution during the Anthropocene, there are few monitoring programmes at the appropriate spatial and temporal scale to detect distributional change of marine species and to infer climate‐ versus human‐mediated drivers of change. Here, we present an approach that combines citizen science with expert knowledge to classify out‐of‐range occurrences for marine fishes as potential range extensions or human‐mediated dispersal events. Innovation Our stepwise approach includes decision trees, scoring and matrices to classify citizen science observations of species occurrences and to provide a measure of confidence and validation using expert knowledge. Our method draws on peer‐reviewed literature, knowledge of the species (e.g. contributing to its detectability, and potential to raft with, or foul, man‐made structures or debris) and information obtained from citizen science observations (e.g. life stage, number of individuals). Using a case study of suspected out‐of‐range marine fishes in Aotearoa New Zealand, we demonstrate our approach to defining species’ ranges, assigning confidence to these definitions and considering the species detectability to overcome the data deficiencies that currently hinder monitoring the range dynamics of these species. Our classification of citizen science observations revealed that six of ten species had out‐of‐range occurrences; one of these was classified as an extralimital vagrant, four species had potentially extended their ranges and one species occurrence was likely due to human‐mediated dispersal. Conclusion The case study of marine fishes in New Zealand validates our approach combining citizen science observations with expert knowledge to infer species range dynamics in real time. Our stepwise approach helps to identify data deficiencies important in informing scientific inferences and management actions and can be refined to suit other data sources, taxonomic groups, geographic settings or extended with new steps and existing tools.

Climate-driven changes in ocean currents have facilitated the range extension of the long-spined sea urchin (Centrostephanus rodgersii) from Australia’s mainland to eastern Tasmania over recent decades. Since its arrival, the destructive grazing of the urchin has led to widespread formation of sea urchin ‘barrens’. The loss of habitat, biodiversity and productivity for important commercial reef species in conjunction with the development of an urchin fishery has led to conflicting objectives among some stakeholders that pose complex challenges for regional management. Stakeholders representatives and managers were engaged via a participatory workshop and subsequent one-on-one surveys to trial a structured decision making process to identify effective ecosystem-based management strategies. We directly and indirectly elicited each preferences for nine alternative management strategies by presenting them with the 10-year consequences of each strategy estimated from an ecosystem model of Tasmanian reef communities. These preferences were included in cost-effectiveness scores that were averaged (across stakeholders) to enable strategy ranking from most to least cost-effective. Rankings revealed strategies that included sea urchin removal or translocation of predatory lobsters were the most cost-effective. However, assessment of stakeholders’ individual cost-effectiveness scores showed some disparity among preferences in high ranking strategies. Additionally, inconsistencies in strategy preferences using alternative (direct or indirect) ranking scores reveal conflicting objectives as the most plausible explanation. Our study illustrates how structured decision making can effectively facilitate ecosystem-based management by engaging stakeholders step-by-step towards management strategy implementation and promoting collective learning.

Land use changes are heralded as a major driver of biodiversity loss. However, recent findings show that cities, perhaps the most radical habitat transformation, sustain increasing numbers of threatened species. This emerging trend has been mostly chronicled for vertebrates from landlocked cities, although loss of biodiversity and rates or urbanization are higher in coastal marine systems. To advance our understanding on how threatened species may conquer human‐dominated systems, we studied the threatened edible crab Cardisoma guanhumi and assessed how it is proliferating in croplands and urban systems at different spatial scales and whether populations show consequences of long‐term exploitation. We gathered the data on crab populations covering the whole distribution range, including three countries reporting this as a threatened species. The abundance, distribution, and size structure of crab populations among different land uses at local scales were compared and published data for populations thriving in different habitats throughout their distribution range were compiled. We found that at local scale this species is able to thrive in natural and human‐disturbed habitats, where food sources are heavily altered. At larger scales, the species showed no differences in abundance and size structure among natural and anthropogenic habitats. In areas near the southern distribution edge, crab populations were more abundant and composed of larger animals in urban areas and croplands than those in natural habitats, suggesting that human‐disturbed systems are stepping stones to extend the geographic range. However, we found a long‐term reduction in maximum body size, exacerbated by land use changes, that likely reflects exploitation regimes consistently targeting larger crabs. Despite its status as a threatened species, the long history of human exploitation combined with livestock farming practices may explain the proliferation of this crab in human‐dominated systems, which emphasize the need to consider conservation in human‐dominated systems. Land use change has been recognized as a major contributor to habitat destruction, the main cause of biodiversity loss. However, recent findings show that cities – probably the most radical habitat transformation – may sustain threatened species. This intriguing trend has been mostly chronicled in small‐scale studies of vertebrate communities from landlocked urban systems, despite the fact that loss of biodiversity and rates or urbanization are greatest in coastal systems. To advance our understanding on the generality and drivers of this development, we studied the threatened edible crab Cardisoma guanhumi and asked whether crab populations are thriving in human‐altered areas across its biogeographic range and whether populations are showing responses to long‐term exploitation. Despite its status as endangered species it is proliferating in human‐disturbed habitats, where food regimes are heavily altered. Indeed, human‐disturbed habitats may act as stepping stones to extend its geographic range. Thus, our work adds evidence that the future of many endangered species will be defined beyond the boundaries of parks and reserves. It is a call to overcome a long‐standing tradition in conservation biology of focusing on wild species in “natural” ecosystems and to address the need of conservation in expanding human‐dominated systems.

1. In an era of rapid climate change, understanding the natural capacity of species' ranges to track shifting climatic niches is a critical research and conservation need. Because species do not move across the landscape through empty space, but instead have to migrate through existing biotic communities, basic dispersal ecology and biotic interactions are important considerations beyond simple climate niche tracking. 2. Yellow-cedar (Callitropsis nootkatensis), a long-lived conifer of the North Pacific coastal temperate rainforest region, is thought to be undergoing a continued natural range expansion in southeast Alaska. At the same time, yellow-cedar's trailing edge is approaching its leading edge in the region, due to climate-induced root injury leading to widespread mortality over the past century. To examine the current dispersal capacity of yellow-cedar at its leading range edge, and potential for the species' leading edge to stay ahead of its trailing edge, we characterized recent yellow-cedar stand development near Juneau, Alaska, and surveyed the spread of yellow-cedar seedlings just beyond existing stand boundaries. 3. Despite suitable habitat beyond stand edges, stand expansion appears limited in recent decades to centuries. Large quantities of seed are germinating within stands and just beyond boundaries, but seedlings are not developing to maturity. Furthermore, c. 100-200-year-old yellow-cedar trees are located abruptly at stand boundaries, indicating stand expansion is in a period of stasis with a last pulse at the end of the Little Ice Age climate period. 4. Vegetative regeneration is common across stands and may be an adaptive strategy for this long-lived tree to persist on the landscape until conditions are favourable for successful seedling recruitment, leading to an overall punctuated migration and colonization of new landscapes. 5. Synthesis. Species ranges do not always respond linearly to shifting climatic conditions. Instead, successful colonization of new habitat may be tied to episodic, threshold-related landscape phenomena, dispersal ability, and competition with existing plant communities.

A slipper lobster species Chelarctus virgosus recently separated from C. cultrifer (Ortmann 1897 ) by Yang and Chan (2012) was caught by a baited trap at a depth of 30 m, from off Onagawa, Oshika Peninsula (southern end of the Sanriku Coast), northeastern Japan. This record verified the distribution of C. virgosus in Japan. Also, this is the first record of scyllarid lobsters from the coastal waters of the Kuroshio-Oyashio Mixing Zone, updating the northern limit of distribution by more than 300 km. In addition, possible Japanese records tentatively listed in the original description of C. virgosus are revisited, and the distribution on the Pacific coast at the Boso Peninsula to the Ryukyu Archipelago was confirmed.

Climate-driven changes in ocean currents have facilitated the range extension of the long-spined sea urchin (Centrostephanus rodgersii) from Australia’s mainland to eastern Tasmania over recent decades. Since its arrival, destructive grazing by the urchin has led to widespread formation of sea urchin ‘barrens’. The loss of habitat, biodiversity and productivity for important commercial reef species in conjunction with the development of an urchin fishery has led to conflicting objectives among stakeholders, which poses complex challenges for regional management. Stakeholder representatives and managers were engaged via a participatory workshop and subsequent one-on-one surveys to trial a structured decision-making process to identify effective ecosystem-based management strategies. We directly and indirectly elicited each stakeholder’s preferences for nine alternative management strategies by presenting them with the 10-year consequences of each strategy estimated from an ecosystem model of Tasmanian reef communities. These preferences were included in cost-effectiveness scores that were averaged (across stakeholders) to enable strategy ranking from most to least cost-effective. Rankings revealed strategies that included sea urchin removal or translocation of predatory lobsters were the most cost-effective. However, assessment of stakeholders’ individual cost-effectiveness scores showed some disparity among stakeholders’ preferences in high ranking strategies. Additionally, evaluating inconsistencies within some stakeholders’ scores that included direct or indirect preferences revealed conflicting objectives and cognitive bias as the most plausible explanations for these inconsistencies. Our study illustrates how structured decision-making can effectively facilitate ecosystem-based management by engaging stakeholders step-by-step towards management strategy implementation, identifying psychological barriers to decision-making and promoting collective learning.

Xenodon nattereri (Steindachner, 1869) is a diurnal snake primarily associated with the Cerrado ecoregion in South America, and it is considered endemic to Brazil. Here, we report a record of this species from Cerro Corá National Park (Amambay, Paraguay), extending the geographic range of this species by approximately 30 km to the southwest.

A reproducing population of the common wall lizard ( ) is reported from the Czech Silesia (Czech Republic) for the first time. The lizards live in the ruins of the castle Šelenburk which is located on the Cvilín Hill near the town Krnov. This finding extends the known range of from the nearest known Moravian locality cca 60 km to the North-West.