Workshop 3: An Introduction to Density Estimation from Passive Acoustic Data
25th August 2012
Passive acoustic monitoring is often used to obtain indices of relative abundance, such as number of detections per unit time. However, for many applications, the quantity we really want to estimate is absolute population abundance (i.e., the number of animals in the population) or density (number of animals per unit area). This day-long tutorial will give an insight into methods to achieve this. Although our primary focus (and experience) is on marine mammals, the methods are also applicable to some terrestrial species.
We will begin with an overview of the concepts and available methods. These are largely based on adaptations of standard animal abundance methods (like distance sampling and mark recapture). A key requirement is to estimate the area effectively sampled by the hydrophones, and we will discuss various approaches to achieve this.We will then examine some of the potential methods in more detail, motivating each with a case study, and having short hands-on exercises (all data and software will be provided). The case studies will include density estimation of North Pacific right whales using conventional distance sampling, Bahamian beaked whales using a regression-based approach to estimate the area effectively sampled, Hawaiian minke whales using spatially explicit capture recapture and Indian Ocean blue whales using a sound propagation model.
Time allowing, the tutorial will close with discussions of a short selection of themes chosen by the participants.***Workshop Schedule now available here***
More information for participants about software downloading and key references can be found here.