College of William and Mary
Feral cats (Felis catus) are a priority-level threat for small to medium-sized native vertebrates across Australia and especially so in insular environments like that of Kangaroo Island, South Australia. The island is home to several endangered and geographically restricted species, including the Kangaroo Island Dunnart (Sminthopsis aitkeni), an endangered marsupial endemic to Kangaroo Island. When bushfires spread across the island and burned x percent of native vegetation in late 2019 to early 2020, these populations were critically impacted and post-fire feral cat predation on the island risked their extinctions, motivating the creation of a refuge with predator exclusion fencing around remaining unburnt vegetation to protect surviving dunnarts and other threatened species. The Western River Refuge was created for this purpose and protecting the area has included trapping feral cats in a variety of ways. As continued trapping is necessary, it is important to analyze capture and camera trap data to understand trapping efficiency and success rates, and how these might be improved.
This study reviewed six months of capture data and camera trap photographs from the WRR property in order to identify individual feral cats and any patterns in detections prior to either capture or disappearance from cameras, as well as in comparison to AI-targeted Felixer first detections. Camera trap photographs were filtered through the AI system eVorta for high confidence (>0.99) cat photographs. Twelve cats were captured during the study period and 110 instances of cat detections were recorded on camera traps and Felixer target photos. 53.64% of detections were matched to individual cats. All detections were an average of 1.67 days (±0.27 SE) apart. Cats averaged 51.9 days (±16.66 SE) between first camera detection and capture. 58.33% of captured cats were recorded as targets by Felixers while 41.67% were either not detected or not identified as targets. Felixer activation will increase speed of removing cats from the area, but various trapping methods are still necessary to catch all cats that enter the area. Higher levels of detections in the WPA indicate the successes of trapping and align with capture hotspots, but all conclusions are limited by small sample sizes and require further data collection.
Animal Studies | Environmental Health and Protection | Research Methods in Life Sciences | Zoology
Boget, Leah, "Understanding invasive predation: detections of feral cats (Felis catus) on Kangaroo Island’s Western River Refuge" (2023). Independent Study Project (ISP) Collection. 3650.