ACCURATE news on cue rates to inform passive acoustic density estimation methods
ACCURATE news on cue rates to inform passive acoustic density estimation methodsDr Tiago MarquesUniversity of St Andrews
In the last decades passive acoustic monitoring (PAM) density estimation (DE) have been increasingly employed to estimate cetacean abundance, especially for cetacean species which are visually cryptic and spend long periods submerged, making them hard to survey by conventional visual methods. In cue counting a sample of detected sounds produced by the animals are used to estimate density. Among other multipliers related to detector performance, including false negatives and false positives, a cue production rate is required to convert the number of sounds detected into animal density. The cue production rate corresponds to the average number of sounds produced per animal per unit time. Cue counting PAM based reliable estimates of animal density therefore depend upon using accurate and unbiased estimates of the cue rate, i.e., cue rates that correspond to the time and place the survey took place. The ACCURATE project, funded by the US Navy Living Marine Resources program, is a St Andrews-led large project involving several partners, looking at everything related to cue production by marine mammals to inform PAM DE exercises. We describe advances obtained within the project. Building on PAM DE, I will present the project objectives, some of the main results to date and discuss factors that affect cue rates and report on cue rate estimates for some of the species we have been working on, showcasing the methods we have used and some of the research threads we are pursuing. This will include thoughts about what is the right sampling unit to use for cue rates, challenges with caller identification and conspecific interferences, getting cue rates from tags without acoustics and site specific cue rates. And if you have tag data with acoustics that we might have not heard about yet, please come along: we would love to hear about it.