Reexamining the minimum viable population concept for long-lived species

Area of Science:

• Conservation Biology
• Population Ecology
• Herpetology

Background:

• Traditional Minimum Viable Population (MVP) guidelines often suggest hundreds to thousands of individuals, influencing conservation resource allocation.
• These guidelines may not adequately address the specific life history traits of iteroparous, long-lived species.
• Small and fragmented populations are often overlooked in conservation planning.

Purpose of the Study:

• To investigate if long-lived species, specifically the bog turtle (Glyptemys muhlenbergii), are exceptions to general MVP guidelines.
• To develop a demographic model for assessing population viability in bog turtles.
• To re-evaluate MVP thresholds for long-lived organisms.

Main Methods:

• Conducted a 10-year capture-recapture study in eastern New York, USA.
• Developed a comprehensive demographic model for the bog turtle.
• Assessed population viability across various initial abundances and carrying capacities.

Main Results:

• Bog turtle colonies with as few as 15 breeding females show a >90% probability of persisting for over 100 years under current vital rates and environmental variance.
• These findings suggest MVP thresholds may be overestimated by 1-2 orders of magnitude for many long-lived species.
• Inbreeding effects were not accounted for in this specific analysis.

Conclusions:

• Conservation strategies may need to be revised for long-lived species, potentially including smaller and fragmented populations.
• Protection of small and fragmented populations can be a viable conservation option, particularly within a regional or metapopulation context.
• The study challenges conventional MVP guidelines, advocating for a more nuanced approach in conservation biology.