Any freshwater forage, from invertebrates to panfish, can be cropped down, suffer poor year-classes, or simply disperse. When it happens, whatever creature depends on that prey has to seek a new grocery outlet. Fish must adapt to changing forage options on a regular basis. ¶ Switching forage generally requires a change of scenery, however. The prey often inhabits different areas, at different depths with different substrates, or around different types of cover. ¶ Walleyes are no different. When they need to change forage, they typically need to move, eliciting “here today, gone tomorrow” comments from local anglers. These events can take place almost any time. But wherever you fish—lakes, rivers, reservoirs, or the Great Lakes—late summer is a time of change. Vegetation starts to wilt, water temperatures drop. In northern…