Umbrella effect of monitoring protocols for mammals in the Northeast US

Abstract

Developing cost-effective monitoring protocols is a priority for wildlife conservation agencies worldwide. In particular, developing protocols that cover a wide range of species is highly desirable. Here we applied the ‘umbrella species’ concept to the context of ecological monitoring; specifically testing the hypothesis that protocols developed for the American marten would contextually allow detecting occupancy trends for 13 other mammalian species (i.e., an umbrella effect). We conducted a large-scale four-year camera trapping survey across a gradient of forest disturbance in Maine, USA. We sampled 197 sites using a total of 591 cameras and collected over 800,000 photographs to generate detection histories for the most common terrestrial species. By combining multi-season occupancy modelling and power analyses, we estimated the required sampling effort to detect 10%, 25% and 50% declines in the fourteen species. By conducting a spatially explicit comparison of sampling effort, we found evidence that monitoring protocols for American marten would provide an umbrella effect for up to 11 other mammal species. The capacity of the umbrella effect varied among species, with fisher, snowshoe hare, red squirrel, and black bear consistently covered under several scenarios. Our results support the application of the umbrella species concept to monitoring (here defined as ‘umbrella monitoring species’), providing empirical evidence for its use by management agencies.

Monitoring mesocarnivores with tracks and technology using multi‐method modeling

“…Multi-method modeling can also complement broader monitoring strategies, such as umbrella species monitoring (Mortelliti et al 2022), and ultimately reduce the resources required for desired estimate precision while expanding the spatial scale of monitoring.…”

“…Moreover, multi‐method models can incorporate data from citizen or community scientists to augment other efforts (Gilbert et al 2021 b ). Multi‐method modeling can also complement broader monitoring strategies, such as umbrella species monitoring (Mortelliti et al 2022), and ultimately reduce the resources required for desired estimate precision while expanding the spatial scale of monitoring.…”

Differential habitat use between demographic states of black bears in managed timber forests

“…A validation of the effectiveness of our monitoring protocol is available in Mortelliti et al (2022). At each survey site, we collected data on the composition of the forest stand via 2 variable-radius basal area plots from which we calculated the percentage of hardwoods among live trees at the stand level.…”

“…We collected data using motion‐sensitive camera surveys (Fisher et al 2014, Gould et al 2019), and balanced survey effort along a gradient of forest disturbance intensities from the very lowest (e.g., Baxter State Park) to the very highest (recently harvested commercial timber properties). We then replicated study areas in different disturbance categories across the latitude range of our study area (Figure , available in Supporting Information; Mortelliti et al 2022, Evans and Mortelliti 2022 a ). Disturbance in our study refers to any tree loss event, mainly associated with timber harvest activity but also with natural tree loss.…”

“…The 3 camera stations were spaced in a linear transect 100 m apart, and we pooled the image data collected from these 3 stations for that site (Evans et al 2019). A validation of the effectiveness of our monitoring protocol is available in Mortelliti et al (2022). At each survey site, we collected data on the composition of the forest stand via 2 variable‐radius basal area plots from which we calculated the percentage of hardwoods among live trees at the stand level.…”