Making use of multiple surveys: Estimating breeding probability using a multievent-robust design capture-recapture...

Area of Science:

• Ecology and Evolutionary Biology
• Population Dynamics
• Conservation Biology

Background:

• Climate change increases environmental variability, affecting life-history traits and breeding success in long-lived species.
• Estimating breeding probabilities in wild populations is challenging due to imperfect detection and unobservable nonbreeder states.
• Capture-recapture methods are crucial for monitoring population viability.

Purpose of the Study:

• To develop and apply novel multievent-robust design models to estimate annual breeding probabilities in female elephant seals.
• To overcome the challenge of unobservable nonbreeder states in capture-recapture analyses.
• To investigate state-dependent survival and breeding transitions in relation to breeding status.

Main Methods:

• Utilized multievent-robust design models integrating data from multiple surveys throughout the year.
• Incorporated a hidden Markov process to handle uncertainty in breeding state assignment (breeder vs. nonbreeder).
• Employed program E-SURGE (2.1.2) for model fitting and analysis.

Main Results:

• The novel approach made the nonbreeder state observable, allowing for precise estimation of breeding transitions.
• Found evidence for state-dependent survival, with potentially lower survival in breeders compared to nonbreeders.
• Demonstrated that current breeders have higher future breeding probabilities than nonbreeders.

Conclusions:

• Multievent-robust design models effectively integrate diverse data sources to study unobservable states.
• This flexible approach enhances the estimation of vital rates and informs conservation strategies for long-lived species facing environmental change.
• The study provides valuable insights into the breeding ecology and population dynamics of elephant seals.