A ghost in the mist: extension of the known range of Colombian Weasel, Neogale felipei (Izor & de la Torre, 1978) (Carnivora, Mustelidae), in the Cordillera Occidental

The Colombian weasel, Neogale felipei (Izor & de la Torre, 1978), is one of the most enigmatic and threatened carnivores in South America, with only six confirmed records in the Andes of Ecuador and Colombia. During a long-term trail camera survey conducted at Mesenia-Paramillo Natural Reserve, we recorded the northernmost occurrence of the species, which extends its distribution by approximately 120 km to the north from the nearest previously known locality in Colombia. We also provide some comments on its natural history.

Tracking the decline of weasels in North America

Small carnivores are of increasing conservation concern globally, including those formerly thought to be widespread and abundant. Three weasel species (Mustela nivalis, M. frenata, and M. erminea) are distributed across most of North America, yet several recent studies have reported difficulty detecting weasels within their historical range and several states have revised the status of weasels to that of species of conservation concern. To investigate the status and trends of weasels across the United States (US) and Canada, we analyzed four separate datasets: historical harvests, museum collections, citizen scientist observations (iNaturalist), and a recent US-wide trail camera survey. We observed 87–94% declines in weasel harvest across North America over the past 60 years. Declining trapper numbers and shifts in trapping practices likely partially explain the decline in harvest. Nonetheless, after accounting for trapper effort and pelt price, we still detected a significant decline in weasel harvest for 15 of 22 evaluated states and provinces. Comparisons of recent and historical museum and observational records suggest relatively consistent distributions for M. erminea, but a current range gap of >1000 km between two distinct populations of M. nivalis. We observed a dramatic drop-off in M. frenata records since 2000 in portions of its central, Great Lakes, and southern distribution, despite extensive sampling effort. In 2019, systematic trail camera surveys at 1509 sites in 50 US states detected weasels at 14 sites, all of which were above 40o latitude. While none of these datasets are individually conclusive, they collectively support the hypothesis that weasel populations have declined in North America and highlight the need for improved methods for detecting and monitoring weasels. By identifying population declines for small carnivores that were formerly abundant across North America, our findings echo recent calls to expand investigations into the conservation need of small carnivores globally.

Current status of the Mohave ground squirrel: an update covering the period 2013–2020

The Mohave ground squirrel (Xerospermophilus mohavensis) is endemic to the western Mojave Desert of California. It is restricted to a small geographic area and is listed as Threatened under the California Endangered Species Act. Human development has resulted in loss and degradation of its desert habitat and climate change is believed to pose an additional threat. To determine its current conservation status and geographic distribution, I have assembled all available data from field studies during the years 2013-2020. These data confirm that the species is still present in 4 core areas and that it continues to be widespread in the northern and central portions of its historical range. However, the recent data also confirm earlier conclusions that the Mohave ground squirrel is now extirpated from the southernmost portion of its range. Recent surveys raise concerns about its status in other areas as well. A large-scale trail camera survey on the South Range unit of China Lake Naval Air Weapons Station in 2019 failed to detect the Mohave ground squirrel over much of this large installation. Recent trail camera surveys on Fort Irwin strongly suggest that the closely-related round-tailed ground squirrel (Xerospermophilus tereticaudus) has now replaced the Mohave ground squirrel over most of the base. There is additional evidence that the round-tailed ground squirrel is present in disturbed habitats to the west of Barstow and that hybridization with the Mohave ground squirrel is occurring there. It will be important to protect and conserve currently occupied Mohave ground squirrel habitat in view of this new information.

Natural selection in the origin: how does selection act on snails’ shell colour in the source of a diversified population?

The mechanisms of adaptive radiation with phenotypic diversification and further adaptive speciation have been becoming clearer through a number of studies. Natural selection is one of the primary factors that contribute to these mechanisms. It has been demonstrated that divergent natural selection acts on a certain trait in adaptive radiation. However, it is not often known how natural selection acts on the source of a diversified population, although it has been detected in phylogenetic studies. Our study demonstrates how selection acts on a trait in a source population of diversified population using the Japanese land snail Euhadra peliomphala simodae. This snail’s shell colour has diversified due to disruptive selection after migration from the mainland to islands. We used trail-camera traps to identify the cause of natural selection on both the mainland and an island. We then conducted a mark-recapture experiment on the mainland to detect natural selection and compare the shape and strength of it to previous study in an island. In total, we captured and marked around 1,700 snails, and some of them were preyed on by an unknown predator. The trail-camera traps showed that the predator is the large Japanese field mouse Apodemus speciosus, but this predation did not correlate with shell colour. A Bayesian approach showed that the stabilising selection from factors other than predation acted on shell colour. Our results suggest that natural selection was changed by migration, which could explain the ultimate cause of phenotypic diversification in adaptive radiation that was not due to predation.

Poaching Threatens the Establishment of a Lynx Population, Highlighting the Need for a Centralized Judiciary Approach

Illegal hunting represents a major threat to the conservation of predators, but its impact remains difficult to assess as there are strong incentives to conceal this criminal activity. Attributing declines of carnivores to poaching is therefore an important conservation challenge. We present a case study of the Eurasian lynx (Lynx lynx) in the Swiss Alps (Valais) where the current distribution range is smaller than in the recent past and population density is by ≥80% lower than in the adjacent Swiss Prealps. We tested four hypotheses to explain this lower density: (1) a too low density of camera-traps deployed for lynx surveys in Valais compared to the Prealps (methodological artifact); (2) less favorable environmental conditions around the camera-trap sites; (3) lower densities of the main prey; and (4) poaching. We estimated lynx and ungulate densities and environmental conditions at trail camera sites and could clearly reject the first three hypotheses because: (1) the survey protocol was similarly effective; (2) environmental conditions around the trapping sites in Valais were even more favorable for lynx detection than in the Prealps; and (3) prey supply was even larger in Valais. Concerning hypothesis 4, we discovered a network of illegal lynx traps (neck snares) in the main immigration corridor into Valais from the thriving adjacent lynx population in the Prealps, suggesting intense local poaching. Our findings substantiate the suspicions of long-lasting lynx poaching as a threat to the establishment and survival of the Valais population. The fact that instances of poaching were publicly known since 1995 but remained unabated for at least two decades, until the first conviction occurred, questions the commitment of local authorities to address this case of wildlife crime. Our study demonstrates the need for inquiries about poaching of top predators to be carried out at the highest levels of jurisdiction to avoid any risk of collusion between law enforcement agents and poachers.

Trail camera video systems: investigating their utility in interpreting patterns of marine, recreational, trailer-boat fishers’ access to an offshore Marine Park in differing weather conditions

When monitoring marine recreational fishers at sub-bio-regional scales—for example those who are accessing a Marine Park—on-site sampling is often required. This poses various logistical challenges, such as the efficient timing of intercept interviews. Here, we examine these challenges, combining trail cameras, closed-circuit television (CCTV), weather stations, and interviews at boat ramps that bracket an offshore Marine Park. Trail camera results were similar to those from a CCTV system co-located at one of the boat ramps. Fishers’ boat launches peaked early, but return times varied considerably by ramp and weather. Both the numbers of launches and trip durations were strongly responsive to good weather, particularly at ramps used for offshore fishing. Weather was a more important factor to predict the likelihood of intercept interview opportunities than holiday period, which may reflect changing dynamics in work culture and improvements in weather prediction. Interviewed fishers reported preferences to individual ramps over the fishing season and nearly all trips to the Marine Park were reported by fishers accessing just one ramp. The strong relationships between fishing, weather, and ramp, observed by the trail camera and correlated with the weather station data, may allow for the efficient targeting of intercept interviews and potentially the modelling of fishing effort.

PSIX-37 Considerations for using game cameras for on-farm behavior of beef cattle

On-farm studies provide an opportunity to build relationships with clientele while answering applied science questions. Further, game trail cameras are a low-cost technology that may be an alternative to visually observing livestock for behavior data. An on-farm study involving eight county Extension agents and producers investigated game cameras to capture cattle visitation to mineral feeders. Three different models of Browning game trail cameras (Prometheus Group LLC, Birmingham, AL) each with timelapse feature were utilized. A three-page document provided background and methodology for the study. Details for placement of the trail camera were provided to provide consistency across farms. Cameras were pre-programmed to settings for image capture. A video for camera setup was also provided in the event that cameras reset to default settings due to battery failure. Timelapse feature was utilized providing image capture from sunrise to sunset at 2 min intervals. Several observations were noted to improve data capture in the future. Differences existed in battery utilization between camera models with one model only capturing images for approximately 2 of the 7 d periods while others had more than 80% battery life remaining after 7 d. Cameras were to be oriented facing south to avoid sun glare. Sun glare occurred at sunrise on most cameras and was particularly bad when dew was present on the camera lens. Mineral feeders need to be secured in place as livestock may move feeders out of the frame of the images captured. Still photos are insufficient in assessing behavior and short video clips are expected to improve interpretation especially when multiple animals visit the feeder at the same time. Utilization of human observation was not useful unless observation was performed at sunrise. Game trail cameras have the potential to be a cost-effective tool in capturing on-farm data of cattle behavior.