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BACKGROUND: Snap traps and electronic traps are the main devices for nonchemical management of rodent pests. Traps should be efficient and should not cause unnecessary suffering of animals. Harmonized, systematic test methods are required to make sure that mechanical forces or electrical parameters are optimal to achieve swift unconsciousness and death. This study aimed to describe technical trap properties that can be used to facilitate future improvements in trap efficacy and humaneness. METHODS: We constructed a device to assess spring energy, triggering force, impulse and clamping force, and developed an arrangement to assess effective voltage, current, effective current and effective energy taking effect on rodent bodies in electronic traps – all without the use of animals. Descriptive data of trap characteristics were collated. RESULTS: All factors showed variability among snap trap models and trigger types, and there was considerable overlap between mouse and rat traps. For most trap models, there was no difference among new snap traps and traps that had been trigged 20 times. Effective current and effective energy decreased with lower voltage input, but the traps indicated weak battery by LED lights, and one model switched off automatically when voltage was insufficient. CONCLUSION: With the device and the electronic arrangement, the majority of snap trap models and electronic traps available on the market can be assessed in a standardized and repeatable way. Matching the data generated in this study with data on time for trapped target animals to reach irreversible unconsciousness, and experiences from pest control practitioners, should allow relating properties of traps to efficacy and animal welfare issues. This can support further development and optimization of traps for nonchemical rodent pest control. © 2024 Julius Kuehn‐Institut and The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Leghold traps are an essential tool for managing brushtail possums (Trichosurus vulpecula) in New Zealand. However, the currently used trap design (No 1 double coil spring traps, often called Victor-type traps) has escape rates of up to 26%. This study focussed on addressing the high escape rate to improve the usefulness and acceptability of these traps. Specifically, modifications were made to the anchoring chain of the standard No 1 trap by adding one or two springs. These springs were designed to reduce the forces exerted by an animal during escape attempts. Over approximately 300 trap nights per trap configuration (unmodified No-Spring, 1-Spring, 2-Springs), the capture rates (proportion of animals caught and held until inspection) were measured. The results showed that traps with one or two springs achieved a significantly higher capture rate of 92%, compared to only 74% for the standard devices. The chain springs increased the capture rate by 24% due to a 69% reduction in escape rate. This study demonstrates that a minor modification (addition of one or two springs) to the restraining chain of No 1 double coil spring leghold traps greatly enhances their efficacy for capturing and managing possums. [ABSTRACT FROM AUTHOR]

The amount of artificial smooth surfaces in the environment increases continuously with urbanization on a global scale. There is growing evidence that smooth surfaces such as windows, solar panels and other objects can serve as sensory traps for many animal species. Artificial smooth surfaces can function as acoustic mirrors, disrupting echolocation of bats and consequently causing maladaptive behaviours such as drinking from and colliding with these surfaces. Therefore, investigating opportunities to mitigate the effects of artificial smooth surfaces is important from a conservation viewpoint. Here, we conducted a field experiment with bats, an ensonification experiment in the laboratory, and a computer simulation, in order to study the effect of mechanical surface modification on the acoustic characteristics of smooth surfaces. In the field experiment, we presented a horizontal smooth plate alone or with strings (diameters between 0.25–2.5 mm) and the behaviour of bats around the plate was video recorded. Bats significantly decreased the frequency of drinking events with increasing diameter of the strings. We also found an indication that a crossed pattern of the strings on the plate may be more effective than a parallel arrangement. The results of the ensonification experiment and the mathematical modelling revealed that a subtle modification of the smooth surfaces with long, linear thin objects can effectively modify the acoustic characteristics of smooth surfaces in general and thereby potentially change the behaviour of bats. Further investigations from sensory, behavioural and ecological viewpoints are proposed to better understand the impact of smooth surfaces on bats and the mitigation solutions that are needed. This research underscores the significance of exploring innovative approaches to minimize the negative impacts of urbanization on wildlife, highlighting the potential of practical interventions to promote coexistence between anthropogenic environments and threatened species. [ABSTRACT FROM AUTHOR]

Color mutations are a common phenomenon in vertebrates. Among these anomalies, albinism is the most common in wild mammals. We deployed 78 camera traps across the Yoko Council Forest (YCF) to inventory medium to large-sized terrestrial mammals and we obtained a total effort of 17,981 operational camera trap days, giving 169 detections of long-nosed mongoose. During this study, we obtained two independent detections of albino long-nosed mongooses (Xenogale naso). To our knowledge, this is the first report of albinism in this taxon. [ABSTRACT FROM AUTHOR]

The European lobster population on Aguda's Beach was studied between 2006 and 2023 through an annual capture-mark-recapture survey. The primary objective was to assess the abundance, sex ratio, and growth of lobsters, serving as a basis for future investigations on population density, survival, migration, and site fidelity. In the 18-years sampling period, 5 traps were set on 892 fishing days, from May and September each year, resulting in the capture of 320 lobsters in an experimental fishing area covering approximately 0.4 km2, off Aguda's Beach. The catch rate of the experimental fishery varied from 0.01 to 0.15 lobsters per trap, with an overall mean of 0.07 animals per trap. To augment the number of tagged individuals for the survey, 397 lobsters were obtained over the years from the local commercial fishery, which operated in an area approximately 10 times as large as the experimental fishing area. Out of the total number of 717 lobsters, 512 specimens were marked and released in the experimental fishing area. Between 2009 and 2022, 31 males and 15 females were caught again, resulting in a mean recapture rate of 8.9%. The maximum time a lobster spent at sea before being recaptured was 11.9 years, while the minimum was 2 months. Over the 18-year survey period, the mean absolute growth rate of 46 recaptured lobsters was 467 ± 33 g SE (standard error) and 3.3 ± 0.2 cm CL (carapace length) per year. Males achieved an average rate of 509 ± 38 g and 3.1 ± 0.3 cm CL, while females presented a rate of 379 ± 58 g and 3.6 ± 0.3 cm CL. The findings of this long-term survey did not support a decline in the lobster population at Aguda's Beach over time, what might be attributed to the decrease of the commercial fishing activity. Additionally, the population also seemed to exhibit a certain mobility, as evidenced by reduced recapture rates in recent years. The range of annual growth rates indicated a diverse composition of the population, with male lobsters exhibiting growth patterns similar to females but revealing greater activity, which led to recapture rates nearly twice as high. [ABSTRACT FROM AUTHOR]

Wild boar trapping has been used as a management tool to control wild boar populations. However, it is increasingly criticized due to animal welfare concerns. While cortisol levels have been used to assess trap-related stress in wild boar, data on trap-related injuries and behavioral data are scarce. We aimed to evaluate three different corral-style traps for wild boar according to available mammal trapping standards to investigate and refine animal welfare in wild boar trapping. We examined 138 wild boars captured and killed by head shot in 27 capture events. Traps were closed by remote control only if the complete group were trapped. The behavior of the animals in the trap and during culling was recorded on video. All wild boars were examined and a pathological and radiological examination of the heads for trap- and shot-related injuries followed. Trap-related injuries occurred in 33% of the animals with superficial mild skin defects to skull fractures. One out of three traps met all the set requirements. A wire-meshed trapping system failed all. After installing an incomplete barrier in the center of the trap to slow down trapped animals, the fracture rate in one trap type was significantly reduced by 29% (p < 0.05). Our data showed that the type of trap (p = 0.007) and the number of animals trapped at once (p = 0.002) had a significant influence on the number of escape attempts. Trapping larger groups reduced the escape attempts. We emphasize the importance of an accurate pathological examination to evaluate animal welfare in traps and call for adjusting the injury categories listed in the standards and make a proposal for wild boar live trapping. [ABSTRACT FROM AUTHOR]

Entanglement in commercial fishing gear is one of the main factors inhibiting the recovery of critically endangered North Atlantic right whales. Installing low-breaking-strength (LBS) components in the buoy lines and main lines of stationary fishing gear may be a viable solution for some fisheries. But is it an effective solution for deep-water trap fisheries? This study quantified in-line rope tensions observed during fishing operations for snow crab (Chionoecetes opilio) in Newfoundland and Labrador, Canada. We conducted a controlled fishing experiment in which we documented the loads experienced while hauling fleets of traps. The results showed that several factors contributed to the loads observed, including the components of the traps, the presence of crabs, and environmental conditions such as wind direction and wave height. According to the statistical models, the maximum tension from the estimated marginal means was 477.53 kgf in the buoy line and 987.99 kgf in the main line for the baited hauls, which exceeds the safe working load (154 kgf) of the proposed low-breaking-strength components. Our results suggest that LBS components are not a viable solution for this deep-water fishery. [ABSTRACT FROM AUTHOR]

This study investigated the utilization of images collected from low-quality dash cameras on passenger vehicles for the estimation of traffic-related air pollution (TRAP). We conducted mobile monitoring along Taiwan Avenue, Taichung, Taiwan, and collected pollution concentration data including carbon dioxide (CO2), nitrogen oxides (NOx), black carbon (BC), and particle number (PN). Dash cameras record images that reveal the environment through which the vehicle passes. Image semantic information such as the proportion of sky, buildings, traffic, and vegetation can be extracted through deep learning models. Training of deep learning models requires the pixel-level labeling of each image, which is labor intensive. We propose the use of publicly available data sets for the training of the deep learning model. Transfer learning was utilized to customize the model for locally collected, unlabeled, low-quality dash camera images. TRAP was estimated with a hybrid model consisting the land-use regression (LUR) and image semantic information. With a five-fold cross-validation, the hybrid model with transfer learning resulted in improved R2 values for CO2 (R2=0.81), NOx (R2=0.64), PN (R2=0.65), and BC (R2=0.87). Public labeled data sets and transfer learning may be helpful when labeled data are difficult to acquire in the local region. This work demonstrates the adaptation of image semantic information, extracted from videos captured from vehicle dash cameras, into a LUR model to improve pollutant estimation. [ABSTRACT FROM AUTHOR]

Automated cameras (including camera traps) are an established observation tool, allowing, for example the identification of behaviours and monitoring without harming organisms. However, limitations including imperfect detection, insufficient data storage and power supply restrict the use of camera traps, making inexpensive and customizable solutions desirable. We describe a camera system and evaluation toolset based on Raspberry Pi computers and YOLOv5 that can overcome those shortcomings with its modular properties. We facilitate the set‐up and modification for researchers via detailed step‐by‐step guides.A customized camera system prototype was constructed to monitor fast‐moving organisms on a continuous schedule. For testing and benchmarking, we recorded mason bees (Osmia cornuta) approaching nesting aids on 20 sites. To efficiently process the extensive video material, we developed an evaluation toolset utilizing the convolutional neural network YOLOv5 to detect bees in the videos.In the field test, the camera system performed reliably for more than a week (2 h per day) under varying weather conditions. YOLOv5 detected and classified bees with only 775 original training images. Overall detection reliability varied depending on camera perspective, site and weather conditions, but a high average detection precision (78%) was achieved, which was confirmed by a human observer (80% of algorithm‐based detections confirmed).The customized camera system mitigates several disadvantages of commercial camera traps by using interchangeable components and incorporates all major requirements a researcher has for working in the field including moderate costs, easy assembly and an external energy source. We provide detailed user guides to bridge the gap between ecology, computer science and engineering. [ABSTRACT FROM AUTHOR]

While many ecology studies require estimations of species abundance, doing so for mobile animals in an accurate, non‐invasive manner remains a challenge. One popular stopgap method involves the use of remote video‐based surveys using several cameras, but abundance estimates derived from this method are computed with conservative metrics (e.g., maxN computed as the maximum number of individuals seen simultaneously on a single video). We propose a novel methodological framework based on a remote‐camera network characterized by known positions and non‐overlapping field‐of‐views. This approach involves a temporal synchronization of videos and a maximal speed estimate for studied species. Such a design allows computing a new abundance metric called Synchronized maxN (SmaxN). We provide a proof‐of‐concept of this approach with a network of nine remote underwater cameras that recorded fish for three periods of 1 h on a fringing reef in Mayotte (Western Indian Ocean). We found that abundance estimation with SmaxN yielded up to four times higher values than maxN among the six fish species studied. SmaxN performed better with an increasing number of cameras or longer recordings. We also found that using a network of synchronized cameras for a short time period performed better than using a few cameras for a long duration. The SmaxN algorithm can be applied to many video‐based approaches. We built an open‐sourced R package to encourage its use by ecologists and managers using video‐based censuses, as well as to allow for replicability with SmaxN metric. [ABSTRACT FROM AUTHOR]

Simple Summary: Hair tubes provide a non-invasive method for determining the presence and activity of small mammals by evaluating hair left in hair tubes. Data can be converted into activity indices. In this study, a specially adapted program was developed to semi-automatically determine hair density as a proxy of activity. Adhesive tape with hair from a field experiment was processed, scanned, and analyzed by the program to obtain a quantitative measure of hair density. The validation of hair tubes with wildlife cameras in the field showed a moderate-to-strong positive correlation between hair tube data and recorded rodents. The program is simple but effective and does not require a large amount of deep learning data. Due to its reduced complexity, it facilitates error detection and fine-tuning. The use of hair tubes in combination with this program should provide an easy-to-use, non-invasive method to determine small mammal activity. Activity indices are used to determine the presence and activity of small mammals, such as the hair index derived from the use of hair tubes. In contrast to trapping animals, hair tubes are non-invasive and less labor-intensive, and appear to be a suitable alternative in appropriate settings. We developed a method to calculate hair density semi-automatically. In addition, hair tube data were validated with field data using wildlife cameras for the small mammal community in grassland, wheat crops, and hedges to assess how well data from hair tubes match data from wildlife cameras. Adhesive tape with hair from hair tubes was processed and scanned. The resulting images were analyzed using a newly developed computer program that enables background and adhesive tape to be automatically distinguished from hair, providing a quantitative measure of hair density. Based on validation with wildlife cameras, hair tubes seem to be a suitable tool to estimate small mammal activity at the community level in several habitats. There was a moderate-to-strong positive correlation of the hair tube index with the sum of voles and Apodemus individuals (activity index) recorded in grasslands (Spearman's correlation coefficient 0.43), hedges (0.79), and wheat (0.44). The newly developed computer program allows the automatic calculation of hair density, making it easier to assess the activity of small mammals. [ABSTRACT FROM AUTHOR]

We provide camera trap records of the presence of two large predators: the snow leopard Panthera uncia and common leopard Panthera pardus from the same habitats in Lapchi Valley of Gaurishankar Conservation Area. Camera traps were laid for 2,304 (mean 88.62 ± SD 103.34) trap nights in 26 locations (elevation range: 2,140 to 4,350 m, area: 141.63 km2). A total of 55, 219 pictures were recorded from November 2022 to May 2023. Out of 26 camera stations, two camera stations captured the images of both species at an altitude of 4,000 m and 4,260 m in Lapchi Valley. The Relative Abundance Indices of snow leopards and common leopards were 7.51 ± SD 6.35 and 9.84 ± SD 6.35 per 100 trap days/nights, and independent detection rates were 0.41 and 0.52 respectively. This is the first evidence of habitat overlap between two large vulnerable predators in Gaurishankar Conservation Area. The nature of the coexistence or competition between these predators needs further investigation. [ABSTRACT FROM AUTHOR]

• Monitoring small carnivores requires new approaches to the available methodologies. • The mostela is a camera-based method to monitor small mustelids that we tested in a mediterranean agroforestry landscape. • Trapping rate inside the mostela box was of 0.95 individuals per 100 trap nights. • Detection probability by the mostela was, on average, four times higher than by camera traps set on trees. Small mustelids are an understudied group partly due to the challenges in detecting and monitoring their populations. Despite the classification as Least Concern for several small mustelid species, some studies indicate a population decline in parts of their range. Therefore, efficient and group-specific methods are essential to support monitoring efforts. Camera traps are widely used, particularly to monitor cryptic and nocturnal species such as most carnivores. However, they tend to miss small-sized and fast-moving species due to the sensitivity of the passive infrared sensor. The Mostela is a device which consists of a camera trap and a tracking tunnel inside a wooden box, designed specifically to detect small mustelids. Here, we propose testing the performance of this device and comparing it to a tree-mounted camera trap, using the least weasel (M. nivalis) as a case study. We used multi-scale occupancy models to estimate differences in the detection probability between devices. Although both methods detected the least weasel, the detection probability was higher with the Mostela (0.8, BCI: 0.52–0.97 vs 0.2, BCI: 0.03–0.48). Furthermore, we obtained a higher trapping rate when using a shorter distance between sampling stations (∼350 m). Although the Mostela performed better at detecting the weasel, the number of independent events was low (N = 11). Therefore, we present recommendations in terms of deployment and future research since the development and testing of new methods are essential for the conservation efforts of small mustelids. [ABSTRACT FROM AUTHOR]

We describe a matter-wave Sagnac interferometer using Bose condensed atoms confined in a time-orbiting potential trap. Compared to our previous implementation [Moan et al., Phys. Rev. Lett. 124, 120403 (2020)], our new apparatus provides better thermal stability, improved optical access, and reduced trap anharmonicity. The trapping field can be adjusted to compensate for small tilts of the apparatus in gravity. These features enable operation with an effective Sagnac area of 4 mm2 per orbit, and we observe interference with 25% visibility after two orbits at a total interrogation time of 0.6 s. Long-term measurements indicate a phase stability of 0.2 rad or better. [ABSTRACT FROM AUTHOR]

Archaeologists commonly include climatic data in their analyses of living in the past, but rarely do current weather conditions achieve mention in our professional considerations. The Kites in Context Project (KiC) focuses on a multi-scalar investigation of desert kites in the eastern badia region of Jordan. During the Neolithic (7000–5000 b.c.) period, people began building large animal traps, known as desert kites, across a wide swath of southwestern Asia. This multi-year project is designed to provide novel insights into the chronology and function of these animal traps through an intensive study incorporating remote sensing with boots-on-the-ground excavation and survey. The 2023 season began like any other—a combination of aerial survey using drones, walking the landscape in a pedestrian survey, and excavation under sunny skies. During our 2023 field season in Jordan, we experienced dramatic, atypical weather, likely driven by climate change. In this photo essay, we present images from this surprising rain and flooding event in the Black Desert of eastern Jordan that caused us to consider on a more personal level the challenges that may have faced the hunters and herders who constructed the kites and who managed the water thousands of years ago. [ABSTRACT FROM AUTHOR]

Given a shift in public opinion in the European Union (E.U.), the United States of America (U.S.), Canada and Russia developed standards (International Organization for Standardization, ISO, standards) to increase humaneness in trapping. However, concern for maintaining the viability of the fur industry and management of furbearing animals dependent on trapping undoubtedly catalyzed the development of a Best Management Practices (BMP) initiative to identify and compare traps and trapping techniques. Given the push for the development of BMPs, White et al. (2021) set out to develop recommendations as what they termed BMPs for trapping of "furbearers" in North America to meet agreed upon guidelines. That study is one of the few analyses comparing and evaluating restraining, primary foothold (leghold), trap devices across multiple species. As such, it has been used to justify and promote trapping and to develop trapper education courses in the US and abroad. In this evaluation of White et al. (2021), we demonstrate that 1) trap assessments did not properly use ISO standards and definitions of trap evaluation metrics, and failed to implement the most recent standards accepted by the U.S., and 2) researchers followed a research protocol that was incomplete, inadequate, and non-replicable. When sound policy depends on a solid base of evidence, then too science should be held to the highest standards of the open science movement that prioritizes transparency, reproducibility, and research integrity. We conclude that White et al.'s (2021) study should be redone with a comprehensive, standardized approach and new parameters to arrive at better best management practices for capturing furbearers. [ABSTRACT FROM AUTHOR]

We report the first records of Cuniculus paca for the Chaco or Western Region of Paraguay. The evidence consists of 18 records (63 photos and 12 videos) obtained through a camera trap located in a riparian forest of the Humid Chaco. The species showed solitary and nocturnal behavior and appeared near a stream that flows into the Paraguay River. [ABSTRACT FROM AUTHOR]

Hunting of wild animals for meat and habitat loss are the main drivers of wildlife population decline around the world, and in tropical regions in particular. While Madagascar is a hotspot for biodiversity, hunting is widespread, mostly in form of subsistence hunting, while hunting for the pet trade is less often reported. We studied hunting of the Critically Endangered black-and-white ruffed lemur (Varecia variegata) in northeastern Madagascar. Using lemur surveys (102.7 km survey effort) and 54 semi-structured and seven key informant interviews, we assessed the local knowledge, hunting pressure, and the perceived and actual abundances of V. variegata in two hunting and two non-hunting villages. V. variegata was well known (> 83%) by the respondents but abundance estimates differed significantly between hunting and non-hunting villages, with 26% and 77% of respondents, respectively, estimating a high abundance of ruffed lemurs in the adjacent forests of the villages. Actual observations of V. variegata also differed strongly, in accordance to perceived abundances. Hunting was either done by trapping animals or by pursuit hunts. In both hunting villages, adult lemurs were used for direct meat consumption and juveniles for rearing for the later trade. Hand-raised V. variegata were reported to be sold for 38–71 USD on regional markets or 'delivered' directly to buyers. While wildlife hunting has been widely reported from all over Madagascar, commercial hunting, hand-rearing and trading adds a new dimension of threat towards these Critically Endangered lemurs. As such, the extent of the trade is a priority for future studies. [ABSTRACT FROM AUTHOR]

The use of camera traps to study wildlife has increased markedly in the last two decades. Camera surveys typically produce large data sets which require processing to isolate images containing the species of interest. This is time consuming and costly, particularly if there are many empty images that can result from false triggers. Computer vision technology can assist with data processing, but existing artificial intelligence algorithms are limited by the requirement of a training data set, which itself can be challenging to acquire. Furthermore, deep‐learning methods often require powerful hardware and proficient coding skills.We present Sherlock, a novel algorithm that can reduce the time required to process camera trap data by removing a large number of unwanted images. The code is adaptable, simple to use and requires minimal processing power.We tested Sherlock on 240,596 camera trap images collected from 46 cameras placed in a range of habitats on farms in Cornwall, United Kingdom, and set the parameters to find European badgers (Meles meles). The algorithm correctly classified 91.9% of badger images and removed 49.3% of the unwanted 'empty' images. When testing model parameters, we found that faster processing times were achieved by reducing both the number of sampled pixels and 'bouncing' attempts (the number of paths explored to identify a disturbance), with minimal implications for model sensitivity and specificity. When Sherlock was tested on two sites which contained no livestock in their images, its performance greatly improved and it removed 92.3% of the empty images.Although further refinements may improve its performance, Sherlock is currently an accessible, simple and useful tool for processing camera trap data. [ABSTRACT FROM AUTHOR]

Knowledge of elephant movement and grouping patterns in the wild is critical for their management and conservation. Much of these data come from GPS collar data and aerial surveys, which have provided invaluable information, but data from these methods are often limited to small groups or entire populations. Effective elephant management requires both generalized and localized methodologies. Here, we propose the expanded use of camera traps in research relating to elephant localized movements and grouping patterns as an additional tool for elephant conservation management. In this study, we use a battery-powered camera trap to provide daily high-resolution data of African savanna elephant (Loxodonta africana) grouping patterns over the course of an entire year. We present findings on the seasonal and diurnal grouping patterns of elephants at a waterhole in the northeast corner of Etosha National Park from July 2016 to June 2017. The frequency of elephant occurrences varied seasonally and diurnally across all group types (solitary male, male, family, and mixed groups), while group sizes did not vary seasonally, except for male groups. Solitary males occurred relatively equally throughout the day, while male and mixed groups occurred the most midday, and family groups occurred the most in the afternoon. Additionally, we measured the reliability of research assistants when collecting group type and group size data from the camera trap images. Intra- and inter-observer reliability was excellent among and across research assistants, highlighting the potential for non-specialist observers to have greater involvement in camera trap data collection. Our results support the use of camera trap data where GPS collars and aerial surveys are not feasible and where higher-resolution data are needed for more localized management. Finally, we discuss our experience with two different types of camera traps to highlight the pros and cons of each approach. [ABSTRACT FROM AUTHOR]

The Endangered giant pangolin Smutsia gigantea is rare and elusive across its Central African range. Because of its solitary and nocturnal nature, the species is difficult to study and so its ecology is little known. Pangolins are considered the most trafficked mammals in the world. Therefore, confirming presence accurately and monitoring trends in distribution and abundance are essential to inform and prioritize conservation efforts. Camera traps are popular tools for surveying rare and cryptic species. However, non-targeted camera-trap surveys yield low camera-trapping rates for pangolins. Here we use camera-trap data from surveys conducted within three protected areas in Uganda to test whether targeted placement of cameras improves giant pangolin detection probability in occupancy models. The results indicate that giant pangolin detection probability is highest when camera traps are targeted on burrows. The median number of days from camera deployment to first giant pangolin detection event was 12, with the majority of events captured within 32 days from deployment. The median interval between giant pangolin events at a camera-trap site was 33 days. We demonstrate that camera-trap surveys can be designed to improve the detection of giant pangolins and we outline a set of recommendations to maximize the effectiveness of efforts to survey and monitor the species. [ABSTRACT FROM AUTHOR]

Background: Small-animal PET imaging is an important tool in preclinical oncology. This study evaluated the ability of a clinical SiPM-PET camera to image several rats simultaneously and to perform quantification data analysis. Methods: Intrinsic spatial resolution was measured using 18F line sources, and image quality was assessed using a NEMA NU 4-2018 phantom. Quantification was evaluated using a fillable micro-hollow sphere phantom containing 4 spheres of different sizes (ranging from 3.95 to 7.86 mm). Recovery coefficients were computed for the maximum (Amax) and the mean (A50) pixel values measured on a 50% isocontour drawn on each sphere. Measurements were performed first with the phantom placed in the centre of the field of view and then in the off-centre position with the presence of three scattering sources to simulate the acquisition of four animals simultaneously. Quantification accuracy was finally validated using four 3D-printed phantoms mimicking rats with four subcutaneous tumours each. All experiments were performed for both 18F and 68Ga radionuclides. Results: Radial spatial resolutions measured using the PSF reconstruction algorithm were 1.80 mm and 1.78 mm for centred and off-centred acquisitions, respectively. Spill-overs in air and water and uniformity computed with the NEMA phantom centred in the FOV were 0.05, 0.1 and 5.55% for 18F and 0.08, 0.12 and 2.81% for 68Ga, respectively. Recovery coefficients calculated with the 18F-filled micro-hollow sphere phantom for each sphere varied from 0.51 to 1.43 for Amax and from 0.40 to 1.01 for A50. These values decreased from 0.28 to 0.92 for Amax and from 0.22 to 0.66 for A50 for 68 Ga acquisition. The results were not significantly different when imaging phantoms in the off-centre position with 3 scattering sources. Measurements performed with the four 3D-printed phantoms showed a good correlation between theoretical and measured activity in simulated tumours, with r2 values of 0.99 and 0.97 obtained for 18F and 68Ga, respectively. Conclusion: We found that the clinical SiPM-based PET system was close to that obtained with a dedicated small-animal PET device. This study showed the ability of such a system to image four rats simultaneously and to perform quantification analysis for radionuclides commonly used in oncology. [ABSTRACT FROM AUTHOR]

Black-flanked rock-wallabies (Petrogale lateralis lateralis) exist in small and isolated populations across Western Australia, making them highly susceptible to loss of genetic diversity and increased extinction risk. Conservation translocations are frequently implemented to improve threatened species population sizes with ongoing monitoring required to assess their short- to long-term demographic and genetic success. From 2016 to 2018, 72 wallabies from two widely-separated locations (WA Wheatbelt, Cape Range NP) were translocated to Kalbarri NP. Just prior to the translocation, an extant population of rock-wallabies was discovered in the Murchison River gorge within Kalbarri NP. We used 15 microsatellite markers to investigate genetic structure amongst populations and whether genetic diversity was bolstered by introducing multiple source populations as part of the translocation process. A population viability analysis was used to model admixture within translocated populations over a 10 year period post-translocation. Twenty-five new animals were trapped during post-translocation monitoring including three indigenous to Kalbarri and four sired by Kalbarri males. Merging Wheatbelt and Cape Range wallabies, with the addition of Kalbarri individuals in the breeding pool, resulted in translocated populations showing higher genetic diversity at the end of the monitoring period (He = 0.578—0.663, AR = 2.7—3.1) and in the simulated populations 10 years post-translocation (He = 0.572—0.613, AR = 2.6—2.8), relative to the two main Wheatbelt source populations. Whilst parentage analysis demonstrated successful breeding between Kalbarri and Wheatbelt individuals, it is important to monitor the survival of offspring to assess sustainability of the population and possible outbreeding depression effects. [ABSTRACT FROM AUTHOR]

Objective: The diamondback terrapin Malaclemys terrapin is frequently caught as bycatch in both commercial and recreational blue crab Callinectes sapidus fisheries throughout its range along the Atlantic and Gulf coasts of North America. Bycatch reduction devices (BRDs) are plastic or wire rectangles mounted in the entrance funnels of crab traps, designed to exclude terrapins while still allowing crabs to enter. In this study conducted in two tidal creeks in Virginia, USA, we assessed the effectiveness of four BRD designs, including two novel oval designs, against control traps with no BRDs. Methods: We tested four replicates of each of the five trap treatments (1.75‐inch oval BRD, 2‐inch oval BRD, 1.75‐inch rectangular BRD, 2‐inch rectangular BRD, and a control trap without a BRD) in each tidal creek, for a total of 20 traps per creek and 40 traps total. We fitted traps with wire chimneys that extended above the high tide water line to allow trapped terrapins to surface for air. For eight weeks during summer 2021, we baited traps with Atlantic Menhaden Brevoortia tyrannus each day, beginning on Monday. Tuesday–Friday, we emptied traps of any animals inside, and recorded terrapin sex, terrapin carapace length, terrapin carapace width, and terrapin shell height, as well as blue crab carapace length. Result: We found that all four BRD designs were highly effective at excluding terrapins and maintaining crab catch when compared to control traps. We found a significant difference (p = 0.003) in catch per unit effort (CPUE) of diamondback terrapins among treatments, with the control group (those without BRDs) having the highest CPUE (0.97 ± 0.18). All traps fitted with BRDs decreased terrapin capture significantly compared to the control group. Oval BRDs excluded more terrapins than their rectangular counterparts with the same height dimension, although these differences were not significant. We found no significant difference in CPUE of blue crabs among treatments (p = 0.392), or in the size of legal crabs caught in each treatment (p = 0.216). Conclusion: This study provides evidence of the effectiveness of both rectangular and oval‐shaped BRDs to exclude terrapins and maintain crab catch in Virginia waters, where BRDs are not currently required. Impact statementDiamondback terrapins often drown in blue crab traps, especially in tidal areas. We found that oval and rectangular bycatch reduction devices reduce terrapin bycatch and maintain crab catch. Bycatch reduction devices of any type are an easy way to aid in terrapin conservation when fishing for blue crabs. [ABSTRACT FROM AUTHOR]

Field studies of behavior provide insight into the expression of behavior in its natural ecological context and can serve as an important complement to behavioral studies conducted in the lab under controlled conditions. In addition to naturalistic observations, behavioral testing can be an important component of field studies of behavior. This mini review evaluates a sample of behavioral testing methods in field studies to identify ways in which behavioral testing can be animal-friendly and generate ethologically relevant data. Specific examples, primarily from studies of ground squirrels, are presented to illustrate ways in which principles of animal-friendly behavioral testing can be applied to and guide testing methods. Tests conducted with animals in their natural habitat and that elicit naturally occurring behavioral responses can minimize stress and disturbance for animals, as well as disruption of the larger ecosystem, and can have high ethological validity. When animals are trapped or handled as part of a study, behavioral testing can be incorporated into handling procedures to reduce overall disturbance. When behavior is evaluated in a testing arena, the arena can be designed to resemble natural conditions to increase the ethological relevance of the test. Efforts to minimize time spent in testing arenas can also reduce disturbance to animals. Adapting a behavioral test to a species or habitat conditions can facilitate reduced disruption to subjects and increased ethological relevance of the test. [ABSTRACT FROM AUTHOR]

Water supplies in arid regions have traditionally been assured by cisterns, channels, wells, among other man-made structures with smooth vertical walls that can be deadly traps for several animals, including amphibians and reptiles. In this study, we investigate the incidence of such "trap structures" on the herpetofauna of the eastern Iberian Peninsula. We explored which features of these structures and which biological traits are associated with higher incidence of falling into these traps. We studied 205 trap structures and found 1224 amphibians or reptiles representing 25 different species, including endangered and protected ones. Broad-scale macroclimate and landscape variables were not associated with the incidence of traps. Instead, trap impact was influenced mainly by trap morphology and season of the year, which suggests that construction design and species phenology are the main factors to affect the incidence of a trap. Biological traits (subterranean or aquatic habits, diet, nocturnal activity or emission of reproductive calls) in some species were related to the probability of falling into these traps. Some species of snakes, lizards, and toads were more prone to fall in trap structures than other species. We conclude that trap structures can strongly impact amphibian and reptile survival, especially in arid or semi-arid regions where wells and water cisterns are widespread. [ABSTRACT FROM AUTHOR]

Contextualization: the American red crayfish [Procambarus clarkii] is an invasive species whose presence has been confirmed in central Colombia. In the southern part of the United States, where it is naturally distributed, it is an important aquaculture resource; however, high environmental impacts have been documented in areas where it has been introduced, precisely because of its high colonization capacity and the consequent impact on native species. The growing record of its presence in different systems, in the center of the country, suggests an accelerated expansion pattern and implies that, as has occurred in other countries, negative effects may occur on the general structure of these highland ecosystems if mechanisms are not applied that allow some level of control. Knowledge gap: the possibility of controlling the expansion of the red cray-fish through manual eradication is a viable alternative, if some type of use is validated; this should include an economic incentive to motivate people to fish for it. The process to obtain a meal that serves as a protein source, for aquaculture concentrates, is an option that should be evaluated. Purpose: evaluate the inclusion of cray-fish meal, as a partial replacement of fish meal, in a concentrate formulated for rainbow trout at a fingerling stage. Methodology: specimens of P. clarkii were captured using traps with animal bait. The crayfish were processed to obtain a meal. The experimental food was elaborated after analyzing the composition of the meal. Four treatments were applied, three with difierent percentages of crayfish meal inclusion [T1: 2 %, T2: 4 % and T3: 6 %] and another treatment [control] did not include meal. The trout fingerlings were fed with the treatments until they reached 6 cm of total length. Total length [cm] and weight [g] were sampled every ten days for a period of 60 days. Through analysis of variance [ANOVA], the following variables of the fingerlings were compared at the end of the period: final weight [Pf, g], total length gains [GLT], weight [GP], feed conversion factor [FCA], speci fic growth rate [TCE], condition factor [K] and percentage of mortality [%]) Results and conclusions: among treatments, and for the variables evaluated, were no statistically significant differences among treatments. It was concluded that, until the length reached for the fishes, the inclusion at a level of 6 % of crayfish meal is acceptable as a partial replacement of other fish meals. Obtaining the meal from whole specimens makes it dificult to balance the diets of fishes that require higher replacement percentages of protein. [ABSTRACT FROM AUTHOR]

Carnivorous plants often spark broad interest due to their specialized adaptations for trapping and consuming animals. These notable organisms not only fix carbon through photosynthesis, but they also obtain essential nutrients such as nitrogen and phosphate from their captured prey. In typical angiosperms, interactions with animals are usually confined to such processes as pollination and herbivory, but another layer of complexity in these interactions is added for carnivorous plants. Here, we introduce carnivorous plants and their associated organisms — ranging from their prey to their symbionts — and highlight biotic interactions beyond carnivory to discuss how the 'default' interactions typical for flowering plants have changed in the case of the carnivorous plants (Figure 1). Montero and Fukishima introduce carnivorous plants and their associated organisms, ranging from their prey to their symbionts. [ABSTRACT FROM AUTHOR]

Biodiversity monitoring is valuable for reversing the global trend of biodiversity loss. The typical indicators in biodiversity monitoring are wild animals like vertebrates which can be effectively monitored via autonomously triggered cameras called camera traps. Since camera traps may produce numerous images due to uncontrollable monitoring conditions, it is relatively difficult to obtain reliable and timely animal records from camera trap images. Even though the neural networks may automate camera trap image classification, their applications are challenged by the limited transferability and operating costs. This challenge may be mounted by using neural architecture search with consideration of edge devices. Since the search is computationally expensive, the search cost is usually lowered by sacrificing resolutions of images in search. The objective of this study is to design a search method for classifying camera trap images on edge devices at acceptable search costs without sacrificing image resolutions of animal regions. The experiments show that the proposed method consumed about 95 h and 170 h to find networks, respectively, for camera trap image dataset NACTI-b and D3-a. The resulting networks achieve average accuracies 95.31 and 82.03%, respectively, for NACTI-b and D3-a. The networks are also tested on the edge device NVIDIA Jetson TX2 and lead to average accuracies 95.35 and 81.86%, respectively, for NACTI-b and D3-a. [ABSTRACT FROM AUTHOR]

With their advantages in wildlife surveys and biodiversity monitoring, camera traps are widely used, and have been used to gather massive amounts of animal images and videos. The application of deep learning techniques has greatly promoted the analysis and utilization of camera trap data in biodiversity management and conservation. However, the long-tailed distribution of the camera trap dataset can degrade the deep learning performance. In this study, for the first time, we quantified the long-tailedness of class and object/box-level scale imbalance of camera trap datasets. In the camera trap dataset, the imbalance problem is prevalent and severe, in terms of class and object/box-level scale. The camera trap dataset has worse object/box-level scale imbalance, and too few samples of small objects, making deep learning more challenging. Furthermore, we used the BatchFormer module to exploit sample relationships, and improved the performance of the general object detection model, DINO, by up to 2.9% and up to 3.3% in terms of class imbalance and object/box-level scale imbalance. The experimental results showed that the sample relationship was simple and effective, improving detection performance in terms of class and object/box-level scale imbalance, but that it could not make up for the low number of small objects in the camera trap dataset. [ABSTRACT FROM AUTHOR]

The basis of any animal experimentation begins with the housing of animals that should take into account the need for splitting animals into similar groups. Even if it is generally recommended to use the minimum number of animals necessary to obtain reliable and statistically significant results (3Rs rule), the allocation of animals is currently mostly based on randomness. Since variability in gut microbiota is an important confounding factor in animal experiments, the main objective of this study was to develop a new approach based on 16S rRNA gene sequencing analysis of the gut microbiota of animals participating in an experiment, in order to correctly assign the animals across batches. For this purpose, a pilot study was performed on 20 mouse faecal samples with the aim of establishing two groups of 10 mice as similar as possible in terms of their faecal microbiota fingerprinting assuming that this approach limits future analytical bias and ensures reproducibility. The suggested approach was challenged with previously published data from a third-party study. This new method allows to embrace the unavoidable microbiota variability between animals in order to limit artefacts and to provide an additional assurance for the reproducibility of animal experiments. [ABSTRACT FROM AUTHOR]

Some capture–recapture models for population estimation cannot easily be fitted by the usual methods (maximum likelihood and Markov‐chain Monte Carlo). For example, there is no straightforward probability model for the capture of animals in traps that hold a maximum of one individual ('single‐catch traps'), yet such data are commonly collected. It is usual to ignore the limit on individuals per trap and analyse with a competing‐risk 'multi‐catch' model that gives unbiased estimates of average density. However, that approach breaks down for models with varying density.Simulation and inverse prediction was suggested by Efford (2004) for estimating population density with data from single‐catch traps, but the method has been little used, in part because the existing software allows only a narrow range of models. I describe a new R package that refines the method and extends it to include models with varying density, trap interference and other sources of non‐independence among detection histories.The method depends on (i) a function of the data that generates a proxy for each parameter of interest and (ii) functions to simulate new datasets given values of the parameters. By simulating many datasets, it is possible to infer the relationship between proxies and parameters and, by inverting that relationship, to estimate the parameters from the observed data.The method is applied to data from a trapping study of brushtail possums Trichosurus vulpecula in New Zealand. A feature of these data is the high frequency of non‐capture events that disabled traps (interference). Allowing for a time‐varying interference process in a model fitted by simulation and inverse prediction increased the steepness of inferred year‐on‐year population decline. Drawbacks and possible extensions of the method are discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Mosquitoes are pests of horses. We evaluated the ability of traps to protect horses from these blood feeders. To evaluate comparative attraction, a horse was placed 3.5 m from a mosquito trap. Fewer mosquitoes were trapped because mosquitoes were more attracted to the horse. Trapped mosquitoes increased after removing the horse from the area. Increasing trap attraction by adding horse odors into the trap airstream was unsuccessful because the horse supplying the odors could not be moved far enough away. Three mosquito traps spaced at the study site showed that mosquitoes were not evenly distributed and fewer were collected near structures. This shows the importance of trap placement. When horses were vacuumed, 324 and 359 mosquitoes/h were found feeding on the animals during summer and fall studies, respectively. A nearby mosquito trap simultaneously captured 224 mosquitoes/h. The numbers of mosquitoes vacuumed simultaneously from two horses showed that one horse attracted twice as many mosquitoes as the other. All horses are not equally attractive to mosquitoes. For better mosquito management with traps, the attractive range of traps and host animals must be known. Traps must be as attractive to mosquitoes as host animals so traps can better protect host animals. Mosquitoes are pests of horses, but mosquito trap efficacy data, especially the ability of traps to protect horses, are lacking. Studies were conducted to investigate the comparative attraction between traps and horses, increase trap attraction by adding horse odors to the airstream of a trap, determine the spatial distribution of adult mosquitoes, estimate the numbers of mosquitoes feeding on horses, determine the relative attraction of horses to mosquitoes, and estimate the range of mosquitoes' attraction between two horses. When a horse and a mosquito trap were placed 3.5 m apart, there was a significant reduction in mosquitoes entering the trap. Adding horse odors to the airstream of a trap produced equivocal results because the horse providing the odors influenced the trap catches. Mosquitoes were not evenly distributed across the study site, which emphasized the importance of trap placement. Vacuuming mosquitoes from the horses in different seasons demonstrated that 324 and 359 mosquitoes per hour were feeding during the two studies. Separate analysis of data from the two horses vacuumed simultaneously revealed that one horse attracted twice as many mosquitoes as the other. This caused the results of a study to determine the attraction range of two horses moved from 3.5 to 20.4 m apart to be inconclusive. [ABSTRACT FROM AUTHOR]

Efforts to preserve, protect and restore ecosystems are hindered by long delays between data collection and analysis. Threats to ecosystems can go undetected for years or decades as a result. Real‐time data can help solve this issue but significant technical barriers exist. For example, automated camera traps are widely used for ecosystem monitoring but it is challenging to transmit images for real‐time analysis where there is no reliable cellular or WiFi connectivity.We modified an off‐the‐shelf camera trap (Bushnell™) and customised existing open‐source hardware to create a 'smart' camera trap system. Images captured by the camera trap are instantly labelled by an artificial intelligence model and an 'alert' containing the image label and other metadata is then delivered to the end‐user within minutes over the Iridium satellite network. We present results from testing in the Netherlands, Europe, and from a pilot test in a closed‐canopy forest in Gabon, Central Africa. All reference materials required to build the system are provided in open‐source repositories.Results show the system can operate for a minimum of 3 months without intervention when capturing a median of 17.23 images per day. The median time‐difference between image capture and receiving an alert was 7.35 min, though some outliers showed delays of 5‐days or more when the system was incorrectly positioned and unable to connect to the Iridium network.We anticipate significant developments in this field and hope that the solutions presented here, and the lessons learned, can be used to inform future advances. New artificial intelligence models and the addition of other sensors such as microphones will expand the system's potential for other, real‐time use cases including real‐time biodiversity monitoring, wild resource management and detecting illegal human activities in protected areas. [ABSTRACT FROM AUTHOR]

The article focuses on contrasting Indigenous and modern approaches to artificial intelligence (AI), highlighting the impact of cultural perspectives on its development. Topics include the historical use of AI in pre-colonial Indigenous cultures, the human-centric model of contemporary AI, and the potential benefits of integrating Earth-centric principles into modern AI development.

Trapping bears (Ursidae) with Aldrich leg snares has established itself as one of the most successful methods of trapping live animals with minimal injury. Most documented injuries are related to damage caused by the trap and prolonged exposure to it. Various physiological and behavioural responses have been observed, however self-eating of the toes of the captured foot has not been described so far. In November 2017 an adult male brown bear was caught with a standard Aldrich type leg snare. When the research team arrived, the bear teared off and swallowed phalanges of the first toe of its rear left foot before it could be sedated. The bear was measured and marked with GPS-GSM collar. Following the instalment of the collar, the animal was monitored for the duration of 23 months when the drop-off mechanism of the collar was activated. This rule out the possibility that a serious life threatening complications arised from the trauma. [ABSTRACT FROM AUTHOR]

Long ground-Rydberg coherence lifetime is interesting for implementing high-fidelity quantum logic gates, many-body physics, and other quantum information protocols. However, the potential well formed by a conventional far-off-resonance red-detuned optical-dipole trap that is attractive for ground-state cold atoms is usually repulsive for Rydberg atoms, which will result in the rapid loss of atoms and low repetition rate of the experimental sequence. Moreover, the coherence time will be sharply shortened due to the residual thermal motion of cold atoms. These issues can be addressed by a one-dimensional magic lattice trap, which can form a deeper potential trap than the traveling wave optical dipole trap when the output power is limited. In addition, these common techniques for atomic confinement generally have certain requirements for the polarization and intensity stability of the laser. Here, we demonstrated a method to suppress both the polarization drift and power fluctuation only based on the phase management of the Mach–Zehnder interferometer for a one-dimensional magic lattice trap. With the combination of three wave plates and the interferometer, we used the instrument to collect data in the time domain, analyzed the fluctuation of laser intensity, and calculated the noise power spectral density. We found that the total intensity fluctuation comprising laser power fluctuation and polarization drift was significantly suppressed, and the noise power spectral density after closed-loop locking with a typical bandwidth of 1–3000 Hz was significantly lower than that under the free running of the laser system. Typically, at 1000 Hz, the noise power spectral density after locking was about 10 dB lower than that under the free running of a master oscillator power amplifier system. The intensity–polarization control technique provides potential applications for atomic confinement protocols that demand fixed polarization and intensity. [ABSTRACT FROM AUTHOR]

Different types and systems to discriminate plankton samples at different strata in the water column have been developed in recent decades. For sampling at sufficient depth, opening and closing zooplankton multinets are ideal because there is no contamination of one sample with organisms of the previous one. However, for bigger nets, such as those used to collect micronektonic organism, it is difficult to use multiple net units, and multiple cod ends are preferred because of their simplicity, but with the problem of sample contamination from having a common net passageway. We present here a cod-end Multisampler design, VERDA, that uses a carrousel-like system. Similar to some sediment traps, the system works like a revolver with six or eight compartments whose turning mechanism is triggered when the net arrives to a programmed depth level. This prototype was built with inexpensive and recycled components and electronics similar to Arduino® and Teensy PCB to carry out electronic control. The net we used for testing the equipment was a mid-size midwater trawl of ca. 30 m2 and total length of 58 m that works with a single towing cable and no doors. The overall system is useful for all type of ships, due to the relatively easy deployment operations and because the Multisampler does not need electrical cable or acoustics. In our case, we used a Marport® (Reykjavik Iceland) and Scanmar (Åsgårdstrand, Norway) sensors for real-time depth monitoring and opening distance. [ABSTRACT FROM AUTHOR]