2025/01/01 by Damien I. Mullin, Graham J. Forbes, Christopher B. Edge · 1 voice
Environmental Science · #Ecology and Vegetation Dynamics Studies #Wildlife Ecology and Conservation #Rangeland and Wildlife Management
paper · doi:10.1139/cjz-2024-0066
openalex publication_date 2025/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Data on threatened species are understandably biased as we prioritize researching populations undergoing declines rather than the few remaining stable populations. This prioritization bias reduces the availability of demographic benchmarks, resulting in continually shifting baselines and can result in flawed inferences when gathering range-wide demographic data for quantitative conservation modelling. This is particularly problematic for long-lived endangered species with relatively large ranges and spatially variable threats such as the Wood Turtle ( Glyptemys insculpta (Le Conte, 1830)). We identified a suspected large and stable population of Wood Turtles and conducted a mark–recapture study from 2019 to 2022, and used capture data from 2003 to 2005 to establish benchmark demographic parameters to guide range-wide recovery efforts of declining populations. We captured 135 turtles (55F-32M-48J), and predicted the population size to be 119 (87–170) individuals over 5.5 km of river. We predicted high apparent annual survival of females (96.8%, SE = 2.5) and juveniles (86.4%, SE = 16.5), but lower than expected rates for males (82.5%, SE = 5.7). We estimated 15-year minimum apparent annual adult survival between 2004 and 2019 to be 93.8%. We hypothesize that our low apparent male survival in 2019–2022 is due to connectivity outside our immediate study area because we regularly captured new turtles up (5M-1F-4J) and downstream (2M-8F-5J) of the defined study areas. Despite our low annual male apparent survival, we predict a stable population of Wood Turtles between 2023 and 2053 using a population viability analysis. We demonstrate that Wood Turtle populations should have among population connectivity and naturally high juvenile proportions and survival. Populations lacking these demographic traits risk future declines even with high adult survivorship. Unbiased demographic and vital rates from stable populations are essential for setting appropriate population targets by conservation and recovery programs.