Mark‐Recapture Survival Estimates of Sympatric Northern and Southern Flying Squirrels

ABSTRACT Climate change is shifting the ranges of many species, such as northern ( Glaucomys sabrinus ) and southern ( Glaucomys volans ) flying squirrels, and changing survival rates at range limits. Gaps in knowledge about vital rates exist for both species however, with no studies assessing sympatric populations. We undertook a study to address this gap, expecting higher survival for northern flying squirrels due to a slower life history. Using mark‐recapture data from a long‐term study of sympatric populations, we investigated survival rates and the effects of winter temperatures and mast seed abundance on these rates. Apparent annual survival was nearly equivalent during 2019–2023 (0.20 and 0.19 for northern and southern flying squirrels, respectively). We did not observe strong effects of acorn abundance or winter temperature on survival of either species. Our information will help with modeling to assess anticipated changes in the future as a result of ongoing climate warming.