Breeding return times and abundance in capture-recapture models

Area of Science:

• Ecology
• Wildlife population dynamics
• Conservation biology

Background:

• Long-lived species often exhibit temporary emigration, complicating population estimation.
• Traditional capture-recapture models may not accurately account for animals not breeding annually.
• Accurate abundance and survival estimates are crucial for effective wildlife management.

Purpose of the Study:

• To develop a novel statistical model for estimating abundance, survival, and return probabilities in long-lived species.
• To address limitations of existing temporary emigration models with simple sampling designs.
• To apply the model to lake sturgeon (Acipenser fulvescens) data.

Main Methods:

• Developed a likelihood-based model by incorporating return time parameters into the Schwarz-Arnason Jolly-Seber model.
• Utilized lake sturgeon data from a closed population with a simple, one-sample-per-year scheme.
• Estimated sex-specific survival, transition probabilities, and breeding return times.

Main Results:

• The new model provided plausible estimates for abundance, survival, transition, and return time parameters.
• Demonstrated that standard Jolly-Seber models can overestimate abundance when temporary emigration is present.
• Successfully estimated sex-specific parameters for lake sturgeon.

Conclusions:

• The developed model offers a more accurate approach to estimating population parameters in species with temporary emigration.
• Accounting for temporary emigration is essential to avoid biased abundance estimates in long-lived animals.
• This method enhances the reliability of demographic data for conservation efforts.