Partial stratification in capture-recapture experiments and integrated population modeling with radio telemetry

Date created: 
Capture heterogeneity
Integrated population modeling
Partial stratification
Survey-design and analysis

In this thesis, we develop and apply three new methods for ecological data sets. We present two new developments related to capture-recapture studies and one development related to integrated population modeling. In the first project, we present new methods using partial stratification in two-sample capture-recapture experiments for closed populations. Capture heterogeneity is known to cause bias in estimates of abundance in capture-recapture experiments. This heterogeneity is often related to observable fixed characteristics of the animals such as sex. If this information can be observed for each handled animal at both sample occasions, then it is straightforward to stratify (e.g. by sex) and obtain stratum-specific estimates. However in many fishery experiments it is difficult to sex all captured fish because morphological differences are slight or because of logistic constraints. In these cases, a sub-sample of the captured fish at each sample occasion is selected and additional and often more costly measurements are made, such as sex determination through sacrificing the fish. We develop new methods to estimate abundance for these types of experiments. Furthermore, we develop methods for optimal allocation of effort for a given cost. We also develop methods to account for additional information (e.g. prior information about the sex ratio) and for supplemental continuous covariates such as length. These methods are applied to a problem of estimating the size of the walleye population in Mille Lacs Lake Minnesota, USA. In the second project, we present new methods using partial stratification in k-sample (k>=2) capture-recapture experiments of a closed population with known losses on capture to estimate abundance. We present the new methods for large populations using maximum likelihood and a Bayesian method and simulated data with known losses on capture was used to illustrate the new methods. In the third project, we present an integrated population model using capture-recapture, dead recovery, snorkel, and radio telemetry surveys. We apply this model to Chinook salmon on the West Coast of Vancouver Island, Canada to estimate spawning escapement and to describe the movement from the ocean to spawning grounds considering the stopover time, stream residence time, and snorkel survey observer efficiency.

Document type: 
This thesis may be printed or downloaded for non-commercial research and scholarly purposes. Copyright remains with the author.
Carl Schwarz
Science: Department of Statistics and Actuarial Science
Thesis type: 
(Thesis) Ph.D.