Migration isn't just heading south

In New England, the mention of migration has people thinking of fall's noisy flocks of Canada Geese heading southward. The reason behind migration is to move to a new location where there is better food, shelter, and water. Conditions caused by changing seasons are a major force behind seasonal migration. But it is not the only type. Birds’ heading south is latitudinal migration, the movement of animals north and south. Attitudinal migration is the movement of animals up and down major land features such as mountains. By physically moving north and south globally or up and down a mountain, animals are trying to improve their living conditions. Reproductive migration is the movement of animals to bear their young. Some areas provide more food, shelter and protection for rearing young. Or the young of a species requires different living conditions than the adult. Salmon return to fresh water to spawn while the American eels return to the sea. Complete migration is when virtually all of a species, like our hummingbirds, leave their breeding grounds in non-breeding season. Partial migration is when only some of a species, like our red-tailed hawks and herring gulls, leaves the breeding grounds. The herds of wildebeest roaming the Serengeti is nomadic migration. For some species, the journey is not necessarily done by one individual but by generations. The monarch butterfly winters in Mexico. However, not all individuals complete the round trip from CT, but their offspring do. Climate change and/or resource depletion and/or overpopulation are factors in removal migration. In this case, the animals do not return. For our wildlife, habitat fragmentation contributes greatly to this. For humans, removal migration is a major factor in population shifts. Next - Torpor