In collaboration with scientists at NOAA, DFO Canada (John Ford), and the Center for Whale Research (Ken Balcomb), Eric Ward has been working on evaluating correlations with the demographic parameters of endangered Southern Resident killer whales with abundance indices of their primary summer prey (Chinook salmon). This work has shown that for an unexplained reason, Southern Resident whales have lower survival and reduced fecundity, compared to other killer whale populations in the Northeast Pacific, such as the Northern Resident killer whale population. Output from these models have shown strong correlations between Chinook salmon and either in Southern Resident killer whale fecundity or survival, and has proven useful in projecting the Southern Resident population forward under different ocean Chinook fishing scenarios. This work was most recently highlighted in a 2012 review by an external science panel.
Ward, E.J., Semmens, B.X., Holmes, E.E., and K.C. Balcomb. 2011. Effects of Multiple Levels of Social Organization on Survival and Abundance. Conservation Biology, 25:2(350-355) doi: 10.1111/j.1523-1739.2010.01600.x
Ward, E.J., E.E. Holmes, and K.C. Balcomb. 2009. Quantifying the effects of prey abundance on killer whale reproduction. Journal of Applied Ecology, 46(3):632-640. doi: 10.1111/j.1365-2664.2009.01647.x