ABSTRACT
Roads increase wildlife mortality and present a movement barrier for many species. While wildlife passages have been advocated as a solution to many of the problems associated with roads, they are expensive and many roads still have none. However, roads usually have a series of drainage culverts designed to allow water to cross underneath the road, which might also be used by some mammals. This study aims to (1) determine what variables influence the number of successful passages of drainage culverts by mammals, and to (2) parse the effects that these variables have on the entry into and subsequent full passage of drainage culverts by individual mammals, using cameras and animal track stations along a 20â¯km stretch of autoroute 10 in Southern Quebec (Canada). Overall, 20 species were observed outside of the drainage culverts, but only about half of them were detected making full crossings. While various species were often seen outside, only animals highly tolerant to water, including raccoons (Procyon lotor) and American mink (Neovison vison), were observed fully crossing the structures with regularity, whereas the number of full crossings was small (<8) for all other species. High-water levels and use of polyethylene as a construction material were the strongest deterrents for both the number of successful passages and the probability of entry into the culverts. While several variables (e.g., water level, structure material, moon luminosity, distance to forest) influenced culvert entry, none had an influence on a mammal's probability of complete passage once it had entered. The results imply that ordinary drainage culverts are unsuitable as substitutes for designated wildlife passages for mammals. We recommend the installation of designated wildlife passages and fences, and that in places where wildlife passages are not feasible, dry ledges be installed in existing drainage culverts to better allow small and medium-sized mammals to safely cross under roads while avoiding the water inside of the culverts. To our knowledge, this study is the first to successfully combine trail cameras inside of drainage culverts with track-box data in the adjacent habitat.
Subject(s)
Animals, Wild , Mammals , Animals , Canada , Ecosystem , QuebecABSTRACT
Abstract The water opossum (Chironectes minimus) is a semi-aquatic mammal that is infrequently sampled in Atlantic rainforest areas in Brazil. Here we report on new records of C. minimus in the state of São Paulo, southeastern Brazil, and comment on its behavior and ecology. We placed nine camera traps in culverts and cattle boxes under a highway, between 2017 and 2019. From a total of 6,750 camera-trap-days, we obtained 16 records of C. minimus (0.24 records/100 camera-trap-days) in two cameras placed in culverts over streams. Most of the records were made between May and August, in the dry season and in the first six hours after sunset. The new records are from a highly degraded area with some riparian forests. The records lie approximately 30 km away from the nearest protected area where the species is known to occur. We suggest that C. minimus has some tolerance to degraded habitats, as long as the water bodies and riparian forests are minimally preserved. The new records presented here also fill a distribution gap in western São Paulo state.
Resumo A cuíca d'agua (Chironectes minimus) é um mamífero semiaquático pouco amostrado em áreas de Mata Atlântica do Brasil. Neste estudo apresentamos novos registros de C. minimus no estado de São Paulo, sudeste do Brasil, e comentamos sobre seu comportamento e ecologia. Nós instalamos nove armadilhas fotográficas em drenagens fluviais e passagens de gado sob uma rodovia, entre 2017 e 2019. De um total de 6.750 armadilhas-fotográficas-dia, obtivemos 16 registros de C. minimus (0,24 registros/100 armadilhas-fotográficas-dia) em duas armadilhas fotográficas instaladas em drenagens fluviais. A maioria dos registros foram feitos entre maio e agosto, na estação seca, e nas seis primeiras horas da noite. Os novos registros são de uma área altamente degradada que possui algumas matas ciliares. Os registros estão a aproximadamente 30 km da área protegida mais próxima onde a espécie já foi registrada. Nós sugerimos que C. minimus possui certa tolerância a hábitats degradados, contanto que os corpos d'agua e as matas ciliares estejam minimamente preservados. Os novos registros aqui apresentados também preenchem uma lacuna amostral no oeste de São Paulo.
ABSTRACT
Resource extraction projects generate a diversity of negative effects on the environment that are difficult to predict and mitigate. Consequently, adaptive management approaches have been advocated to develop effective responses to impacts that were not predicted. Mammal populations living in or around mine sites are frequently of management concern; yet, there is a dearth of published information on how to minimise the negative effects of different phases of mining operations on them. Here, we present the case study of a copper mine in the Chilean Altiplano, which caused roadkills of the protected vicuña (Vicugna vicugna). This issue led to a three-step solution being implemented: (1) the initial identification of the problem and implementation of an emergency response, (2) the scientific analysis for decision making and (3) the planning and informed implementation of responses for different future scenarios and timescales. The measures taken under each of these steps provide examples of environmental management approaches that make use of scientific information to develop integrated management responses. In brief, our case study showed how (1) the timescale and the necessity/urgency of the case were addressed, (2) the various stakeholders involved were taken into account and (3) changes were included into the physical, human and organisational elements of the company to achieve the stated objectives.
