produce more calves when prey is more abundant, or environmental conditions suggest it should be.
The first step in understanding the relationship between recovery and prey in New Zealand is to identify where and on what tohorā feed. The potential feeding areas for our New Zealand population could cover roughly a third of the Southern Ocean. That’s why we turn to technologies like satellite tags to help us understand where the whales are going and how they get there..
It also seems one whale may have reached his feeding grounds, likely at the subtropical convergence. The clue is in the pattern of his tracks: rather than the continuous straight line of a whale migrating, it shows the doughnuts of a whale that has found a prey patch. Migratory track of southern right whale Bill/Wiremu, where the convoluted track could indicate foraging behaviour.The subtropical convergence is an area of the ocean where temperature and salinity can change rapidly, and this can aggregate whale prey. Two whales we tracked offshore from the Auckland Islands in 2009As Bill and his compatriots migrate, we’ve begun analyzing data that will tell us about the recovery of tohorā in the past decade.
I am using genomic markers to learn about the kin relationships and, in doing so, the population’s size and growth rate. Think of it like this. Everybody has two parents and if you have a small population, say a small town, you are more likely to find those parents than if you have a big population, say a city.” approach to estimating population size.