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The number of insect species at risk of population decline and extinction is increasing rapidly. Yet we know almost nothing about the ecology of these species, except for at-risk butterflies. A growing body of literature shows how butterfly vital rates, including demography and movement, are essential for guiding conservation and recovery. History has shown us that without these data, conservation decisions often weaken, rather than enhance, population viability. This is especially true in changing landscapes. We review knowledge of vital rates across all at-risk butterflies. We have information on movement for 17 of 283 butterfly species and information on demography for 19 species. We find that habitat-specific movement behavior is key to understanding how to connect populations, and habitat-specific demography is central to managing habitats. Methods and analyses worked out for butterflies can provide a scaffold around which to build studies for the conservation of other at-risk insects.

As habitat loss and fragmentation, urbanization, and global climate change accelerate, conservation of rare ecosystems increasingly relies on human intervention. However, any conservation strategy is vulnerable to unpredictable, catastrophic events. Whether active management increases or decreases a system's resilience to these events remains unknown. Following Hurricane Irma's landfall in our habitat restoration study sites, we found that rare ecosystems with active, human‐imposed management suffered less damage in a hurricane's path than unmanaged systems. At the center of Irma's landfall, we found Croton linearis' (a locally rare plant that is the sole host for two endangered butterfly species) survival and population growth rates in the year of the hurricane were higher in previously managed plots than in un‐managed controls. In the periphery of Irma's circulation, the effect of prior management was stronger than that of the hurricane. Maintaining the historical disturbance regime thus increased the resilience of the population to major hurricane disturbance. As climate change increases the probability and intensity of severe hurricanes, human management of disturbance‐adapted landscapes will become increasingly important for maintaining populations of threatened species in a storm's path. Doing nothing will accelerate extinction. [ABSTRACT FROM AUTHOR]

Abstract Substitute species (common species used to represent endangered species) are used to evaluate a range of conservation strategies globally. However, the effectiveness of this approach has not been empirically evaluated. We leveraged a large-scale habitat restoration experiment to test the validity of the substitute species concept. We selected a common butterfly, Satyrodes appalachia , that is on first inspection as near a substitute as possible - it is closely related to, overlaps in distribution, habitat requirements, host use, and life history with Neonympha mitchellii francisci , an endangered butterfly. We integrated small-scale measures of behavior, habitat preference, and demography of both species in our test, demonstrating that subtle differences between two species cause the substitute relationship to fail. Despite nearly identical habitat requirements, we found the endangered butterfly used different host plants, had higher larval survival in restored sites, and was found in more open habitat than the common butterfly. These differences added up to differences in abundances; the endangered species was more abundant than the common species in restored sites, the opposite was true in un-restored sites. Management decisions based on unvalidated substitute species run the risk of doing more harm than good for endangered species conservation. Instead, using experiments to evaluate a target species' response to management will result in effective recovery strategies. Highlights • Different responses to restoration from two similar butterflies reveal the limits of substitute species in conservation • Management decisions based on unvalidated substitutes likely do more harm than good for conservation • Best practice is to use carefully designed experiments to study endangered species directly [ABSTRACT FROM AUTHOR]