Summary
Remote acoustic moorings can be used to investigate baleen whales at vastly different temporal and spatial scales. On one end of the spectrum, remote acoustic monitoring was used to locate and track movements of individual singing minke whales on the Great Barrier Reef to investigate sound function and assess spatial competition among singers. A moored, 5 sonobuoy (modified and reinforced AN-SSQ57Bs) array was used to calculate singer locations by measuring song time of arrival differences. Naturally occurring Nearest Neighbor (NN) distances between singers were measured. All NN distances were greater than 1.19km (mean=2.47km, n=63) leading to a significant deficiency of small NN distances (Pielou, p<<0.01) suggesting competition for "acoustic" space is occurring. The “acoustic spacing” function was tested with active song playback experiments to whales tracked within the sonobuoy array. A standard ABA playback protocol was used to compare whale movements and song behavior during the control periods to the playback session. During the playback period there was a significant change in movement (Wilcoxon signed ranks, p<0.05) directed away from the playback source as all 7 singers had net increases in separation from the source. This supports the hypothesis that song is used to maintain spacing between singers. At the other end of the remote monitoring spectrum, long-term acoustic recordings are currently being used to assess relative abundance and seasonality of populations of blue, fin, and potentially minke whales in the Antarctic. Autonomous, bottom mounted acoustic recording packages (ARPs) are capable of recording low frequency sound for 1 year continuously. One of these instruments has recently been retrieved, and two more have been deployed off Australian Antarctic Territory. Preliminary analysis of these data will be discussed regarding presence, relative abundance, and seasonality of baleen whales in these regions of the Antarctic.