Habitat suitability modulates the response of wildlife to human recreation

Outdoor recreation activities are growing in popularity, causing increasing pressure on wildlife. There arevarious ways in which wildlife reacts to recreation activities, ranging from behavioural to physiological re-sponses, with regional variation in response-intensity within the same species. We tested whether the effects ofhuman recreation are modulated by overall structural habitat suitability, using a model that included vegetationand topography, at both the regional and local habitat use scale. By undertaking a systematic, plot-based surveyover 13 years in 13 study regions across central Europe, we studied how recreation infrastructure and habitatsuitability interact and affect the variation in regional densities and local habitat use of an endangered modelspecies: the western capercaillie (Tetrao urogallus). Both regional densities and local habitat use varied greatlybetween study years and regions. Capercaillie densities were positively correlated with average habitat suit-ability, but significantly reduced when over 50% of the area was influenced by recreation activities. Habitatsuitability was the main predictor determining local habitat use. Recreation infrastructures were avoided: theeffect being stronger in poor habitat conditions, while slightly mediated by high habitat suitability. Our resultsindicate that effects of recreation activities might be mitigated by improving habitat suitability; however this haslimits because it only affects local scale habitat use but not regional densities. We stress the importance ofrecreation-free areas which must cover extensive (i.e. > 50%) parts of the species range

Remote Cameras Reveal Experimental Artifact in a Study of Seed Predation in a Semi-Arid Shrubland

Granivorous animals may prefer to predate or cache seed of certain plant species over others. Multiple studies have documented preference for larger, non-native seed by granivores. To accomplish this, researchers have traditionally used indirect inference by relating patterns of seed removal to the species composition of the granivorous animal community. To measure seed removal, researchers present seed to granivorous animals in the field using equipment intended to exclude certain animal taxa while permitting access to others. This approach allows researchers to differentiate patterns of seed removal among various taxa (e.g., birds, small mammals, and insects); however, it is unclear whether the animals of interest are freely using the exclusion devices, which may be a hindrance to discovering the seed dishes. We used video observation to perform a study of seed predation using a custom-built, infrared digital camera and recording system. We presented native and non-native seed mixtures in partitioned Petri dishes both within and outside of exclusion cages. The exclusion cages were intended to allow entrance by rodent taxa while preventing entrance by rabbits and birds. We documented all seed removal visits by granivorous animals, which we identified to the genus level. Genera exhibited varying seed removal patterns based on seed type (native vs. non-native) and dish type (open vs. enclosed). We documented avoidance of the enclosed dishes by all but one rodent taxa, even though these dishes were intended to be used freely by rodents. This suggests that preference for non-native seed occurs differentially among granivorous animals in this system; however, interpretation of these nuanced results would be difficult without the benefit of video observation. When feasible, video observation should accompany studies using in situ equipment to ensure incorrect assumptions do not lead to inappropriate interpretation of results