Population ecology of a California endemic: Speyeria adiaste clemencei
Dr. Ryan Hill: 0000-0001-8513-6545
Journal of Insect Conservation
Effective management and recovery of threatened insect populations requires detailed ecological information. Here we combine count and mark recapture (MR) data to shed light on an understudied declining endemic butterfly species in California’s Southern Coast Ranges, Speyeria adiaste. Little is known about the number, size, and dynamics of S. adiaste populations, leaving few data on which to base conservation decisions. Our goal in this study was therefore to provide increased understanding of the population ecology of this species by studying a long-standing S. adiaste clemencei population. Our 2-year MR estimates were highly correlated with Pollard walk counts, and we observed declining population sizes from 2011 to 2014. Adult movements were well-described by a negative exponential function, indicating low probability of dispersal >5 km (probability < 1.8 × 10−7 for both sexes). Males had shorter lifespans than females. Coupled with lack of diapause in this species, the short life span and limited dispersal observed here indicate that S. adiaste clemencei does not have a strong capacity for re-colonization. Population declines in S. adiaste may lead to local extinctions, and together with low dispersal, may diminish connectivity among the apparently small and isolated remaining populations. Further research into the role of adult and larval resources for determining adult abundance, coupled with continued long-term monitoring is necessary in order to understand population dynamics in this declining endemic species.
Hill, R. I.
Population ecology of a California endemic: Speyeria adiaste clemencei.
Journal of Insect Conservation, 19(4), 753–763.