A team of scientist wanted to know if certain genes govern avian migration patterns. So, they placed a knapsack on a Swainson’s thrush that held a tracking device. Upon returning a year later ,the bird had also returned. In their study they learned that the two subgroups of thrushes go in two different directions. They both return to Canada and interbreed. This could not have been learned, so they focused on the clock gene. There may be problems that occur, but they have years to find out.