Research Document 2020/047

Recovery Potential Modelling of Warmouth (Lepomis gulosus) in Canada

By van der Lee, A.S. and Koops, M.A.

Abstract

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has assessed the Warmouth (Lepomis gulosus) as Endangered in Canada. Here a population model is presented to assess stage-specific harm, inform population-based recovery targets, and quantify required habitat in support of a recovery potential assessment (RPA). Data were lacking for Canadian populations of Warmouth with model parameters taken from American populations. As well, simulations accounted for uncertainty in the extent of intra-annual correlation among vital rates through inclusions of three levels of parameter correlation (independent, medium correlation, and strong correlation) which strongly influenced model outputs. Warmouth populations were sensitive to perturbations to the adult stage (and age-1+). Harm affecting this portion of the life cycle should be minimized to avoid jeopardising survival and recovery of Canadian populations. Results of population viability analysis were highly dependent on the extent of intra-annual correlation among stochastic variables included in analysis. To achieve demographic sustainability (i.e., a self-sustaining population over the long term) population sizes ranging from 6,302 (using an independent correlation structure) to 383,291 (using a strong correlation structure) were required. Populations of these sizes required 41 to 2,477 ha of Warmouth exclusive habitat (assuming shared young-of-the year and age-1+ habitat). Values estimated with use of an independent correlation structure are consistent with the approaches implemented in previous RPA analysis.

Research Document 2020/047 (PDF, 1,129 KB)

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