Factors affecting Southern Resident killer whale growth and recovery

Since the 1970s when the Center for Whale Research initiated a long term population census, Southern Resident killer whales have fluctuated from 74 to 97 individuals (the current population size is approximately 80). Demographic fluctuations impact small populations, but the demographic variation in SRKW has also been driven by the recovery of the population from the large removals of young animals prior to 1973. External factors are also thought to contribute to the observed cycles and trends in SRKW; while several interacting mechanisms may be responsible, the data most strongly support a link between killer whales and their food (salmon), and this pattern is repeated across several other populations of resident killer whales in the NE Pacific. Our understanding of links between killer whales and their prey has increased over the last 3 years and continues to evolve. The focus of this talk will be on updating knowledge on these linkages, highlighting (1) correlations between killer whale demography and Chinook salmon biomass, (2) increasing the number of scale and tissue samples recovered from feeding events in other parts of their range with incorporation of fecal? and stable isotope data, (3) increased resolution of winter habitat use from the integration of data from satellite tagging, acoustic recorders, and sightings