Applying stochastic and Bayesian integral projection modeling to amphibian population viability analysis

Area of Science:

• Ecology
• Conservation Biology
• Population Dynamics

Background:

• Integral projection models (IPMs) are effective for species with distinct life stages and continuous variables influencing demographics.
• Stochastic IPMs are crucial for population viability analyses (PVAs) of endangered species.
• Biphasic amphibians, like the California tiger salamander (CTS), are widespread, threatened, and suitable for IPM analysis.

Purpose of the Study:

• To develop a stochastic, size- and stage-structured IPM for the California tiger salamander (CTS).
• To integrate climatic factors into a PVA for CTS, assessing risks from habitat loss and climate change.
• To provide conservation guidance for CTS and a framework for similar species.

Main Methods:

• Constructed a Bayesian, stochastic, size- and stage-structured IPM for the CTS.
• Integrated the IPM with climatic drivers to perform a PVA.
• Quantified extinction risk under various threats and uncertainties.

Main Results:

• CTS population dynamics are most sensitive to juvenile and metamorph growth.
• Populations exhibit rapid growth potential at low densities.
• Long-term viability is achievable with 20%-50% terrestrial mortality, requiring 600-1000m terrestrial buffers.

Conclusions:

• Stochastic and Bayesian IPMs are valuable for studying climate-sensitive species and those with cryptic life histories.
• The developed IPM and PVA offer crucial insights for CTS conservation and recovery.
• The framework can be applied to other ecologically similar species for biodiversity conservation.