Integrating video and genetic data to estimate annual age‐structured apparent survival of American black bears

• Published in: Population ecology 2022-10, Vol.64 (4), p.300-322
• Main Authors: Reynolds‐Hogland, Melissa, Ramsey, Alan B., Muench, Carly, Pilgrim, Kristine L., Engkjer, Cory, Erba, Grace, Ramsey, Philip W.
• Format: Article
• Language: English
• Subjects: Age; age‐structured population dynamics; Annual; Bears; Cameras; Females; genetic sampling; Males; noninvasive; Parameter estimation; Survival; Ursus americanus; video capture‐recapture; Video data; Wildlife; Wildlife conservation
• ISSN: 1438-3896; 1438-390X
• DOI: 10.1002/1438-390X.12122

Camera or genetic data are increasingly used to estimate wildlife abundance and density. We integrated video camera data with genetic data over 7 years to estimate annual age‐structured apparent survival of American black bears (Ursus americanus). We identified 70 individuals through meticulous scrutiny of 7531 video captures, cross‐referenced with 721 genetic captures from hair samples concurrently collected from stations in view of cameras. We used the Cormack–Jolly–Seber model in Program Mark to estimate annual age‐structured apparent survival for yearling males, yearling females, 2+ year‐old males, and 2+ year‐old females. We manually calculated cub survival. We compared parameter estimates based on combined video and genetic data with those based on only genetic data. Combining video and genetic data provided a means to test video‐based identification accuracy, which was highest for females (97%–100%). Annual apparent survival was highest for yearling females (φ = 0.92, SE = 0.07), followed by 2+ year‐old females (φ = 0.88, SE = 0.05), 2+ year‐old males (φ = 0.84, SE = 0.06), and yearling males (φ = 0.80, SE = 0.14). Annual cub survival (φ = 0.86, SE = 0.07) was likely biased because we could not account for mortality that occurred in‐den through early spring. Annual apparent survival and recapture probabilities derived from only genetic data were lower than those derived from combined video and genetic data. Our finding that noninvasive data can be used to estimate annual age‐structured apparent survival of a species with relatively indistinct traits is broadly relevant to wildlife research and conservation. We integrated noninvasive video data with genetic data from hair snares to estimate annual age‐structured apparent survival of American black bears (Ursus americanus), a species with relatively indistinct traits. By combining video and genetic data, we were able to estimate identification accuracy and determine individual age class, which yielded additional insights into population structure that were not ascertainable via genetic data alone.