Abundance estimation for line transect sampling: A comparison of distance sampling and spatial capture-recapture...

Area of Science:

• Wildlife ecology
• Conservation biology
• Statistical ecology

Background:

• Accurate wildlife abundance estimation is crucial for conservation and management.
• Line transect surveys are a common method, often using distance sampling.
• Search encounter spatial capture-recapture is an alternative but less studied approach.

Purpose of the Study:

• To compare the performance of distance sampling and spatial capture-recapture for abundance estimation.
• To evaluate these methods using simulated data and North Atlantic right whale population data.
• To identify conditions favoring one method over the other.

Main Methods:

• Analysis of simulated datasets to compare abundance estimators.
• Application of distance sampling and spatial capture-recapture models to North Atlantic right whale data.
• Evaluation of root mean squared error and credible interval coverage.

Main Results:

• Spatial capture-recapture yielded lower root mean squared error and better credible interval coverage than distance sampling.
• Distance sampling estimates were more sensitive to model specification.
• North Atlantic right whale abundance estimates varied between methods.

Conclusions:

• Search encounter spatial capture-recapture is a more robust method for abundance estimation when individuals are identifiable and surveys are repeated.
• Researchers should consider spatial capture-recapture for improved accuracy and reliability in wildlife surveys.
• Distance sampling may produce overly precise estimates when spatial autocorrelation is present.