Some inhabitants of terrestrial and aquatic life zones cover great distances—in the case of migra­tory fish and birds, even global distances. Pot exam­ple, many young albacore tuna migrate from the California coast across the Pacific Ocean to Japan! Flycatchers spend their summers in Canada and the United States and their winters in Central and South America. Like the flycatchers, many other migratory birds commonly spend critical parts of their life cycles in entirely different countries, which can make their conservation difficult. It does little good, for instance, to protect a song­bird in one country if the inhabitants of the next put it in the cooking pot as soon as it lands. Such large-scale interaction makes ecological concepts difficult for many people to grasp and apply.