Data from: Evaluating population viability and efficacy of conservation management using integrated population models

Predicting population responses to environmental conditions or management
scenarios is a fundamental challenge for conservation. Proper
consideration of demographic, environmental and parameter uncertainties is
essential for projecting population trends and optimal conservation
strategies. We developed a coupled integrated population model-Bayesian
population viability analysis to assess the (1) impact of demographic
rates (survival, fecundity, immigration) on past population dynamics; (2)
population viability 10 years into the future; and (3) efficacy of
possible management strategies for the federally endangered Great Lakes
piping plover Charadrius melodus population. Our model synthesizes
long-term population survey, nest monitoring and mark–resight data, while
accounting for multiple sources of uncertainty. We incorporated latent
abundance of eastern North American merlins Falco columbarius, a primary
predator of adult plovers, as a covariate on adult survival via a parallel
state-space model, accounting for the influence of an imperfectly observed
process (i.e. predation pressure) on population viability. Mean plover
abundance increased from 18 pairs in 1993 to 75 pairs in 2016, but annual
population growth (math formula) was projected to be 0.95 (95% CI
0.72–1.12), suggesting a potential decline to 67 pairs within 10 years.
Without accounting for an expanding merlin population, we would have
concluded that the plover population was projected to increase (math
formula = 1.02; 95% CI 0.94–1.09) to 91 pairs by 2026. We compared four
conservation scenarios: (1) no proposed management; (2) increased control
of chick predators (e.g. Corvidae, Laridae, mammals); (3) increased merlin
control; and (4) simultaneous chick predator and merlin control. Compared
to the null scenario, chick predator control reduced quasi-extinction
probability from 11.9% to 8.7%, merlin control more than halved (3.5%) the
probability and simultaneous control reduced quasi-extinction probability
to 2.6%. Synthesis and applications. Piping plover recovery actions should
consider systematic predator control, rather than current ad hoc
protocols, especially given the predicted increase in regional merlin
abundance. This approach of combining integrated population models with
Bayesian population viability analysis to identify limiting components of
the population cycle and evaluate alternative management strategies for
conservation decision-making shows great utility for aiding recovery of
threatened populations.