Anticoagulant rodenticides (ARs) are an effective tool used to suppress rodent populations in urban and agricultural settings to reduce human disease risk and economic loss, but widespread use has resulted in adverse effects on predators globally. Attention has largely been focused on impacts of ARs on raptors, although there is increasing evidence that mammalian carnivores are also impacted. We conducted a literature review to assess the extent to which ARs have been documented in wild mammalian carnivores globally and identify potential overlap with imperiled carnivores. We found a small but growing body of literature documenting exposure to ARs in 8 Carnivora families, with Mustelidae (64% of studies), Canidae (44%) and Felidae (23%) most represented. At least 11 different AR compounds were documented in carnivores, and authors claimed that exposure caused mortality of at least one individual in 33.9% of species studied. ARs were listed as a threat for 2% of Red List carnivores, although we found that 19% of Red List carnivores had ranges that overlap countries that have documented AR exposure in carnivores. Collectively, our review highlights the need to prioritize conservation attention on the potential role of ARs on global carnivore declines. We suggest (1) expanding AR monitoring and research outside of the northern hemisphere, (2) supporting long‐term AR monitoring to understand the spatial and temporal variation of AR use and exposure risk, (3) expanding research across trophic levels and across the urban–wildland gradient and 4) research to further our understanding of the point at which morbidity and mortality occur.

Wild pigs (Sus scrofa), which are invasive in many regions globally, can alter ecosystems and compete with native species through interference competition and resource exploitation. Wild pig impacts on other species may increase with greater niche overlap, which could vary over time based on environmental conditions, resource availability, or biological traits like diet, especially as seasonal variation in wild pig diet has been widely documented. A limited number of studies have assessed spatial or temporal overlap between native species and invasive wild pigs, with only a handful simultaneously assessing overlap in these niche dimensions. We investigated the potential for interspecific interactions involving invasive wild pigs in the Piedmont region of South Carolina, USA, by examining seasonal spatiotemporal overlap with other wildlife using N‐mixture models and diel activity overlap analyses. Site use by white‐tailed deer (Odocoileus virginianus) and coyote (Canis latrans) was negatively associated with wild pig activity in the fall, when the species had high diel activity overlap, indicating spatial partitioning could reduce interference competition with wild pigs in this season. Conversely, white‐tailed deer site use was positively associated with wild pig activity in the winter, suggesting higher spatial overlap may be necessary if resources are limited. Site use by bobcat (Lynx rufus) and nine‐banded armadillo (Dasypus novemcinctus) in the spring, along with raccoon (Procyon lotor) and wild turkey (Meleagris gallopavo) site use in the summer, was positively associated with wild pig activity. With the exception of diurnal wild turkey, diel activity overlap between these species and wild pigs was high, although temporal partitioning could have occurred at finer spatiotemporal scales than we examined. Our results collectively emphasize the importance of accounting for seasonal spatial and temporal responses by individual species to invasive wild pigs, with special consideration given to species in seasons where high niche overlap with wild pigs is anticipated.

Supplemental feeding of wild ungulates has long been and remains a common practice across Europe and North America. Yet by drawing animals together, supplemental feeding can have unintended, negative effects on individual species and broader ecological processes. These include increased risk of disease transmission, intraspecific and interspecific competition, and predation, which are of management concern for white‐tailed deer (Odocoileus virginianus) in the southeastern United States given the arrival of nonnative wild pigs (Sus scrofa) and coyotes (Canis latrans). We conducted a field experiment between March and July of 2021 to assess the effects of supplemental feeding on spatiotemporal activity patterns of deer and wild pigs at wildlife feeders, and space use of coyotes in the Piedmont region of South Carolina, USA. We observed support for our hypothesis that interspecific competition through increased visitation by larger groups of competitor species reduces use of foraging sites by other subordinate ungulates, where feeders highly visited by wild pigs were rarely visited by deer. While adult deer and wild pigs generally did not shift their temporal activity patterns at feeders, juvenile temporal activity shifted to more frequent visits of feeders during the night, supporting our hypothesis that supplemental feed could increase risk to predator exposure, as coyotes tend to be active during crepuscular hours. Our findings suggest that supplemental feed put out to encourage deer activity could actually deter deer if wild pigs occupy that area, and has potential negative demographic effects if juveniles are at increased risk of predation. Collectively, based on our data, we do not recommend supplemental feeding in the southeastern United States where white‐tailed deer, coyotes, and wild pigs co‐occur. More broadly, given how widespread the legal use of supplemental feed remains across the United States, we encourage landowners and policymakers to consider the full suite of potential direct and indirect, short‐term and long‐term negative impacts supplemental feeding can have on both target and nontarget wildlife populations.

Large carcasses often attract multiple carnivore species, so subordinate carnivores must weigh the reward of a profitable meal with the risk of being attacked by dominant carnivores. These risk–reward trade‐offs are likely influenced by a variety of factors, including scale‐dependent risk from dominant carnivores (e.g., short‐ vs. long‐term risk) and the amount of carcass remaining. In the southeastern United States, human hunters provision a large amount of white‐tailed deer carrion, which appears to be an important food source for coyotes (a novel top predator), but we know little about how coyotes influence the scavenging behavior of smaller carnivores. In this study, we evaluated the relative importance of risk from coyotes, vulture activity, forest structure, and remaining food on bobcat, gray fox, raccoon, and opossum scavenging by deploying 71 deer carcasses within a managed forest in South Carolina during January 2020 and 2021. We found that coyotes only had direct effects on bobcat behavior, suggesting that competition for carcasses was greatest between these two species. However, the relative importance of long‐ versus short‐term risk from coyotes was dependent on the stage in the scavenging process. Effects from forest structure were also stage‐dependent, where tree density and age were related to carcass discovery for bobcats and raccoons, while minimal understory cover facilitated bobcat, gray fox, and opossum scavenging, despite short‐term risk from coyotes. Vulture activity appeared to serve as a cue for gray foxes to discover carcasses. Ultimately, we found that risk from coyotes had species‐specific and context‐dependent effects on smaller carnivore scavenging. This represents some of the first direct evidence of how coyotes alter smaller carnivore behavior in a region where coyotes are a novel top predator. However, forest structure (particularly understory cover) seemed to mediate risk from coyotes, highlighting how habitat can influence predator–predator interactions. Future research should also investigate these interactions during other times of the year and try to quantify how human‐provisioned carcasses influence populations and communities.

River systems face negative impacts from development and removal of riparian vegetation that provide critical shading in the face of climate change. This study used supervised deep learning to accurately classify the land cover, including shading, of the Chauga River watershed, located in Oconee County, South Carolina, for 2011 and 2019. The study examined the land cover differences along the Chauga River and its tributaries, inside and outside the Sumter National Forest. LiDAR data were incorporated in solar radiation calculations for the Chauga River inside and outside the National Forest. The deep learning classifications produced land cover maps with high overall accuracy (97.09% for 2011; 97.58% for 2019). The most significant difference in land cover was in tree cover in the 50 m buffer of the tributaries inside the National Forest compared to the tributaries outside the National Forest (2011: 95.39% vs. 81.84%, 2019: 92.86% vs. 82.06%). The solar radiation calculations also confirmed a difference between the area inside and outside the National Forest, with the mean temperature being greater outside the protected area (outside: 455.845 WH/m²; inside: 416,770 WH/m²). This study suggests that anthropogenic influence in the Chauga River watershed is greater in the areas outside the Sumter National Forest, which could cause damage to the river ecosystem if left unchecked in the future as development pressures increase. This study demonstrates the accurate application of deep learning for high-resolution classification of river shading combined with the use of LiDAR data to estimate solar radiation reaching the Chauga River. Techniques to monitor riparian zones and shading at high spatial resolutions are critical for the mitigation of the negative impacts of warming climates on aquatic ecosystems.