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College students in natural resources continue to encounter instructor-centered teaching, despite strong evidence that suggests active-learning experiences benefit students more than passive learning activities. Case studies provide an active-learning alternative to lectures by teaching students new content and challenging them to engage in contemporary and relevant natural resource issues. In this article we present an interrupted teaching case that introduces students to problems associated with invasive species and the challenges of ecosystem-level management. We challenge students to assume the role of a lake manager that is faced with the introduction of a non-native plant about which little is known. Invasive species are a key area of research and management in the fields of ecology and natural resources. Students hoping to pursue a career in these fields should possess critical analysis, creative thinking, and collaboration skills, which are all fostered through the uses of case studies in the classroom. The interrupted case study technique used here models a real-life management experience by asking students to think critically about scientific information that they are provided, develop a study to collect information, make management decisions based on a suite of information provided, and finally to justify their management decision in light of prior and current knowledge. This case study is based on a wide-spread invasive species problem; one that has yet to be completely solved, although there are several success stories.

The presence of exotic predators in ecosystems across the world is a leading driver of native species' declines. Exotic predators largely influence native species through predation and harassment, which may cause native species to avoid them spatially. We used a camera trap dataset from seven sites in Madagascar's largest protected area complex to investigate spatial co‐occurrence patterns between three exotic predators (free‐ranging domestic dogs Canis familiaris and cats Felis silvestris, and small Indian civet Viverricula indica) and native ground‐dwelling forest birds (n = 5) and small mammals (n = 4). We created 216 two‐species occupancy models for 27 exotic predator‐native species pairings to examine how habitat, exotic predator presence or both, influenced each native species' occupancy and/or detection. We found that native bird and small mammal occupancy and/or detection were strongly related to an exotic predator's presence 52% of the time (i.e. 14 of 27 exotic predator‐native species pairings). Six of the 14 species pairings (i.e. 43%) had non‐independent co‐occurrence patterns, four of which were habitat‐mediated. The effect of exotic predator presence on native species' detection was largely negative, depressing native species' detection in seven out of 12 instances (i.e. 58% of the time). The small Indian civet and free‐ranging cats each strongly influenced the occupancy and/or detection of six species for a combined impact on seven native species, while domestic dogs strongly influenced two species. By including habitat covariates in two‐species occupancy models, we gained deeper insight into the effect exotic predator presence has on native species' distribution. We also note that the strong effect of exotic predator presence on our ability to detect native species can hinder the ability of researchers to provide accurate parameter estimates. We recommend future research into the synergistic effects that habitat degradation and exotic species presence has on native species. The presence of exotic predators is one of the leading causes for declines in native biodiversity across the world. In northeastern Madagascar, we found that three exotic predators (free‐ranging dogs and cats, and small Indian civets) and habitat degradation are causing declines in native small mammal and bird occupancy and detection. In particular, free‐ranging cats and small Indian civets each strongly influenced six species. We recommend that further research on the influence of exotic predators on native populations take into account other possible influences (such as habitat degradation) to pinpoint any possible synergistic effects. [ABSTRACT FROM AUTHOR]

Carnivores are often sensitive to habitat loss and fragmentation, both of which are widespread in Madagascar. Clearing of forests has led to a dramatic increase in highly disturbed, open vegetation communities dominated by humans. In Madagascar's increasingly disturbed landscape, long-term persistence of native carnivores may be tied to their ability to occupy or traverse these disturbed areas. However, how Malagasy carnivores are distributed in this landscape and how they interact with humans are unknown, as past research has concentrated on populations within continuous and fragmented forests. We investigated local ecological knowledge of carnivores using semi-structured interviews in communities 0 to 20 km from the western edge of continuous rainforest in central-southeastern Madagascar. Responses from 182 interviews in 17 different communities indicated distinct distribution patterns for two native and two exotic carnivore species, suggesting a range of tolerances to the human-dominated landscape. The largest extant native carnivore, the fossa C ryptoprocta ferox, does not persist in much of this landscape; they were only observed in communities < 5 km from the continuous forest within the last five years. In contrast, the ring-tailed mongoose G alidia elegans was observed by most communities (82%), but was observed by a higher proportion of interviewees from communities in close proximity to continuous forest. The exotic small Indian civet V iverricula indica was ubiquitous, while the exotic/feral cat ( F elis sp.) was observed by a higher proportion of interviewees in communities farther from continuous forest. Over 20% of interviewees had experienced loss of poultry to wild carnivores in the last year and negative perceptions of carnivores were common. We found the human-dominated landscape to provide little conservation value to native carnivores, emphasizing the need for adequate protected areas and increased engagement of local communities to sustain Madagascar's carnivore species. This information is critical to multitaxon conservation planning in Madagascar. [ABSTRACT FROM AUTHOR]