Photo-identification of Beluga Whales in Upper Cook Inlet Alaska
Final Report of Mark Analysis Mark-Resight Estimates and Color Analysis from Photographs Taken in 2008
This report is divided into three chapters. Chapter 1 presents results of an analysis of mark types and mark locations seen in photographs of CIBW. The purpose of Chapter 1 was to examine mark-longevity, -causation, -change over time, and -accumulation rate, in order to understand and document markings that persist across years. Chapter 2 describes the selection and processing of photographs, a suitable mark-resight model, and mark-resight abundance estimates of beluga whales obtained from photographs taken in the summer and fall of 2008. The purpose of Chapter 2 was to examine the feasibility of using photographs of CIBW and mark re-sight methods to estimate abundance. A precise method of abundance estimation will provide more power for detecting trends in the population. Chapter 3 summarizes techniques and analyses developed in 2008 to quantitatively determine whale color from photographs. The purpose of Chapter 3 was to develop methods that will allow us to document the chronology of color change by identified whales, which will contribute to a better understanding of the relationship between age-class and whale color. The potential to derive demographic indices for the population by using color as a proxy for age-class represents a tool for monitoring the status of this population through changes in age structure.