Estimating dispersal in spatiotemporally variable environments using multievent capture-recapture modeling.

Area of Science:

• Ecology and Evolutionary Biology
• Population Dynamics
• Conservation Biology

Background:

• Dispersal is crucial for ecological and evolutionary processes, significantly influencing metapopulation dynamics.
• Spatiotemporal variations in habitat availability and characteristics are key drivers of dispersal evolution.
• Existing capture-recapture (CR) models often assume static habitat conditions, limiting their applicability in dynamic landscapes.

Purpose of the Study:

• To generalize multievent capture-recapture (CR) models to incorporate dynamic habitat features.
• To develop models estimating survival and dispersal probabilities in landscapes where sites appear/disappear or change characteristics over time.
• To assess the efficacy of these new models using simulated data and empirical studies on amphibian metapopulations.

Main Methods:

• Development of two novel multievent CR models: MODEL 1 for dynamic site presence/absence and MODEL 2 for fluctuating site characteristics.
• Application of MODEL 1 to capture-recapture data of yellow-bellied toads (Bombina variegata) to study dispersal in relation to pond drying dynamics.
• Application of MODEL 2 to capture-recapture data of great crested newts (Triturus cristatus) to investigate the impact of competitor density on dispersal and survival.

Main Results:

• MODEL 1 revealed that facultative dispersal probability in yellow-bellied toads varied annually and was higher in previously dispersed individuals.
• MODEL 2 showed that the departure rate of great crested newts was lower in ponds with high heterospecific density, and annual survival was slightly higher.
• Both models demonstrated flexibility in estimating dispersal and survival probabilities within dynamic environmental conditions.

Conclusions:

• The generalized multievent CR models effectively handle dispersal estimation in dynamic landscapes, addressing limitations of previous static-site models.
• Environmental dynamics, such as pond availability and competitor density, significantly influence amphibian dispersal and survival patterns.
• These flexible modeling approaches enhance the understanding of metapopulation persistence and inform conservation strategies in changing environments.