Breeding transients in capture-recapture modeling and their consequences for local population dynamics

Area of Science:

• Ecology
• Population Biology
• Quantitative Biology

Background:

• Capture-mark-recapture (CMR) modeling is standard for animal demography.
• Poor model fit in CMR is often due to transience effects, where individuals new to the study have different survival rates.
• Transience is frequently linked to dispersal or increased mortality, potentially reflecting costs of first reproduction.

Purpose of the Study:

• To review the ecological and evolutionary significance of transience in CMR studies.
• To quantify transience in a long-lived bird species and assess its population-level consequences.
• To highlight the importance of accounting for transients in population dynamics and conservation.

Main Methods:

• Literature review of nearly 1000 CMR papers to identify studies detecting transients.
• Analysis of a long-term (1988-2012) individual monitoring dataset for a long-lived bird.
• Life table response experiment (LTRE) to measure population consequences of transience.

Main Results:

• Approximately 40% of reviewed CMR studies detected transients, but few explored their ecological meaning.
• Transience increased with harsher environments and density-dependence in the studied bird population.
• LTRE revealed that changes in transient probabilities significantly affect population growth, even more than adult survival.

Conclusions:

• Transience in CMR studies is a common phenomenon with significant ecological and evolutionary implications.
• Interpreting transience as a cost of reproduction provides valuable insights into population dynamics.
• Incorporating transient states into population models can improve predictions for endangered and harvested species.