Landscape connectivity for bobcat (Lynx rufus) and lynx (Lynx canadensis) in the Northeastern United States

Human land-use effects on mammalian mesopredator occupancy of a northeastern Connecticut landscape

Mammalian mesopredators-mid-sized carnivores-are ecologically, economically, and socially important. With their adaptability to a variety of habitats and diets, loss of apex predators, and forest regrowth, many of these species are increasing in number throughout the northeastern United States. However, currently the region is seeing extensive landscape alterations, with an increase in residential and industrial development, especially at the expense of existing forest and small-scale farmland. We sought to understand how important an existing mosaic of working lands (timberland and farmland) in a forested landscape is to mesopredator species. We did this by studying mesopredator occupancy across three land uses (or habitat types): forest reserve (protected), timber harvest (shelterwood cuts), and field (both crop yielding and fallow) in and around a 3200-ha forest in northeastern Connecticut. We examined coyote (Canis latrans), bobcat (Lynx rufus), fisher (Pekania pennanti), and raccoon (Procyon lotor) occupancy using paired camera traps across juxtaposed reserve, shelterwood, and field units from April 2018 to March 2019. We created a priori habitat variable models for each species and season, as well as analyzed the impact of habitat types on each species. Throughout the year bobcats were positively associated with foliage height diversity and had the highest use in shelterwoods and lowest use in fields. Land use utilization varied seasonally for coyotes and raccoons, with higher use of fields than reserves and shelterwoods for half the year and no difference between land uses and the other half. Both species were not strongly associated with any particular habitat variables. Reserve forest was moderate to highly used by all species for at least half the year, and highly use year-round by fishers. Our findings reveal that a mosaic of intact forest and working lands, timber harvest, and agriculture can support mesopredator diversity.

Visual analytics of sensor movement data for cheetah behaviour analysis

Abstract

Current tracking technology such as GPS data loggers allows biologists to remotely collect large amounts of movement data for a large variety of species. Extending, and often replacing interpretation based on observation, the analysis of the collected data supports research on animal behaviour, on impact factors such as climate change and human intervention on the globe, as well as on conservation programs. However, this analysis is difficult, due to the nature of the research questions and the complexity of the data sets. It requires both automated analysis, for example, for the detection of behavioural patterns, and human inspection, for example, for interpretation, inclusion of previous knowledge, and for conclusions on future actions and decision making. For this analysis and inspection, the movement data needs to be put into the context of environmental data, which helps to interpret the behaviour. Thus, a major challenge is to design and develop methods and intuitive interfaces that integrate the data for analysis by biologists. We present a concept and implementation for the visual analysis of cheetah movement data in a web-based fashion that allows usage both in the field and in office environments.

Graphic abstract

Spatial segregation and habitat partitioning of bobcat and Canada lynx

Harvest records suggest that the abundance of bobcats ( Lynx rufus) has increased and the leading edge of their distribution has spread northward, while the trailing edge of the Canada lynx ( Lynx canadensis) range has contracted in Ontario, Canada. There has been a debate about whether these closely related felids might compete in areas of sympatry, but there is little research on sympatric populations of bobcat and lynx. Both species are found on the north shore of Lake Huron in Ontario, Canada, which provided an opportunity to investigate their spatial patterns and habitat use. We surveyed snowmobile routes for snow tracks over three winters and estimated probability of occupancy for the two felid species while accounting for detectability. Bobcat and lynx tracks were never found on the same survey route. Bobcat occupancy increased with habitat heterogeneity, whereas lynx occupancy increased with homogeneity. Our results fit with the common assumption of the generalist and specialist natures of bobcat and lynx, respectively. Our findings suggest that bobcats invaded former lynx territory after these areas became vacant. The story of the bobcat and the lynx is one of the loss of a unique, boreal specialist due to anthropogenic change, and eventual replacement by an adaptable generalist.

Environmental impact assessment of development projects improved by merging species distribution and habitat connectivity modelling

Environmental impact assessment (EIA) is performed to limit potential impacts of development projects on species and ecosystem functions. However, the methods related to EIA actually pay little attention to the landscape-scale effects of development projects on biodiversity. In this study we proposed a methodological framework to more properly address the landscape-scale impacts of a new stadium project in Lyon (France) on two representative mammal species exemplary for the endemic fauna, the red squirrel and the Eurasian badger. Our approach combined species distribution model using Maxent and landscape functional connectivity model using Graphab at two spatial scales to assess habitat connectivity before and after development project implementation. The development project had a negative impact on landscape connectivity: overall habitat connectivity (PC index) decreased by -6.8% and -1.8% and the number of graph components increased by +60.0% and +17.6% for the red squirrel and the European badger respectively, because some links that formerly connected habitat patches were cut by the development project. Changes affecting landscape structure and composition emphasized the need to implement appropriate avoidance and reduction measures. Our methodology provides a useful tool both for EIA studies at each step of the way to support decision-making in landscape conservation planning. The method could be also developed in the design phase to compare the effectiveness of different avoidance or mitigation measures and resize them if necessary to maximize habitat connectivity.

Navigating fragmented landscapes: Canada lynx brave poor quality habitats while traveling

Anthropogenic and natural habitat fragmentation inhibit movement of animals through landscapes. An important challenge for connectivity conservation is determining which conditions facilitate or limit movements, so that these areas can be prioritized for protection or restoration. We examine Canada lynx Lynx canadensis habitat connectivity in the fragmented North Cascade Mountains of Washington, as an example of a highly mobile species that is specialized both on prey and in habitat needs. We identify lynx Habitat Concentration Areas based on Core Habitat Models, parameterize resistance surfaces from our Matrix Habitat Model, and develop linkages of habitat lynx use to move between patches of high quality habitat. We identify a number of linkages for lynx comprised of habitat conditions that differed from high quality core patches identified from our habitat modeling. Radio-locations from lynx confirm lower-quality habitats of low resistance to movement were used by traveling lynx. Our results thus suggest traveling lynx do indeed use a much broader range of habitats than do lynx moving within core areas. For lynx in the North Cascades, our results show that maintaining connectivity will require preserving habitats and linkages that would previously have been deemed unsuitable for lynx. Maintaining connectivity for lynx is particularly important given the many recent large wildfires in this region that have reduced the number of mature forest stands that form prime habitat for lynx. Policy implications. Our results strongly suggest that habitat connectivity models should be based on empirical information of animal location data and focused on matrix habitat analysis. Traveling predators use a wide suite of habitats, resulting in more and broader linkage zones that should inform conservation efforts. Failure to identify these areas of functional connectivity could result in the oversight of usable linkage zones, leaving them without protection and vulnerable to degradation.