Single-Camera Trap Survey Designs Miss Detections: Impacts on Estimates of Occupancy and Community Metrics.

The use of camera traps as a tool for studying wildlife populations is commonplace. However, few have considered how the number of detections of wildlife differ depending upon the number of camera traps placed at cameras-sites, and how this impacts estimates of occupancy and community composition. During December 2015-February 2016, we deployed four camera traps per camera-site, separated into treatment groups of one, two, and four camera traps, in southern Illinois to compare whether estimates of wildlife community metrics and occupancy probabilities differed among survey methods. The overall number of species detected per camera-site was greatest with the four-camera survey method (P<0.0184). The four-camera survey method detected 1.25 additional species per camera-site than the one-camera survey method, and was the only survey method to completely detect the ground-dwelling silvicolous community. The four-camera survey method recorded individual species at 3.57 additional camera-sites (P = 0.003) and nearly doubled the number of camera-sites where white-tailed deer (Odocoileus virginianus) were detected compared to one- and two-camera survey methods. We also compared occupancy rates estimated by survey methods; as the number of cameras deployed per camera-site increased, occupancy estimates were closer to naïve estimates, detection probabilities increased, and standard errors of detection probabilities decreased. Additionally, each survey method resulted in differing top-ranked, species-specific occupancy models when habitat covariates were included. Underestimates of occurrence and misrepresented community metrics can have significant impacts on species of conservation concern, particularly in areas where habitat manipulation is likely. Having multiple camera traps per site revealed significant shortcomings with the common one-camera trap survey method. While we realize survey design is often constrained logistically, we suggest increasing effort to at least two camera traps facing opposite directions per camera-site in habitat association studies, and to utilize camera-trap arrays when restricted by equipment availability.

A GIS approach to prioritizing habitat for restoration using neotropical migrant songbird criteria.

Restoration efforts to increase wildlife habitat quality in agricultural landscapes have limited funding and are typically done on a first come, first serve basis. In order to increase the efficiency of these restoration efforts, a prioritized ranking system is needed to obtain the greatest increase in habitat quality possible for the fewest amount of hectares restored. This project examines the use of a GIS based multi-criteria approach to prioritize lands for reforestation along the Kaskaskia River in Illinois. Loss of forested area and corresponding increase in forest fragmentation has decreased songbird habitat quality across the Midwestern United States. We prioritized areas for reforestation based on nine landscape metrics: available agricultural land, forest cover gaps, edge density, proximity to river, 200 m corridor area, total forest core area, fringe core area, distance to primary core value, and primary core area. The multi-criteria analysis revealed that high priority areas for reforestation were most likely to be close to the riparian corridor and existing large blocks of forest. Analysis of simulated reforestation (0, 0.5, 1.0, 5.0 10.0, 25.0, and 50.0% of highest priority parcels reforested) revealed different responses for multiple landscape metrics used to quantify forest fragmentation following reforestation, but indicated that the study area would get the greatest rate of return on reforestation efforts by reforesting 10.0% of the highest priority areas. This project demonstrates how GIS and a multi-criteria analysis approach can be used to increase the efficiency of restoration projects. This approach should be considered by land managers when attempting to identify the location and quantity of area for restoration within a landscape.

The relationship between fire history and an exotic fungal disease in a deciduous forest.

Exotic diseases have fundamentally altered the structure and function of forest ecosystems. Controlling exotic diseases across large expanses of forest has proven difficult, but fire may reduce the levels of diseases that are sensitive to environmental conditions. We examined Cornus florida populations in burned and unburned Quercus-Carya stands to determine if burning prior to anthracnose infection has reduced the impacts of an exotic fungal disease, dogwood anthracnose, caused by Discula destructiva. We hypothesized that fire has altered stand structure and created open conditions less conducive to dogwood anthracnose. We compared C. florida density, C. florida health, and species composition and density among four sampling categories: unburned stands, and stands that had burned once, twice, and 3 times over a 20-year period (late 1960s to late 1980s). Double burn stands contained the greatest density of C. florida stems (770 stems ha(-1)) followed by triple burn stands (233 stems ha(-1)), single burn stands (225 stems ha(-1)) and unburned stands (70 stems ha(-1); P < 0.01). We observed less crown dieback in small C. florida trees (<5 cm diameter at breast height) in burned stands than in unburned stands (P < 0.05). Indicator species analysis showed that burning favored species historically associated with Quercus-Carya forests and excluded species associated with secondary succession following nearly a century of fire suppression. Our results suggest that fire may mitigate the decline of C. florida populations under attack by an exotic pathogen by altering forest structure and composition. Further, our results suggest that the burns we sampled have had an overall restorative effect on forest communities and were within the fire return interval of the historic fire regime. Consequently, prescribed fire may offer a management tool to reduce the impacts of fungal disease in forest ecosystems that developed under historic burning regimes.