For every time there is a season

During the month of March, nature is undergoing a change. It is still too early for plant life to bloom in full force, yet there are creatures on the move as the days gradually get longer and the snow pack diminishes. Deer forage for freshly exposed browse and fresh buds still hidden by the duff layer. Bear are emerging from their dens to forage, sometimes leaving a spilled trash can as a calling card. Many different species of birds are on the move, some departing and some arriving in the region.

Some of us keep note of when we catch the first shad, or when we hear a wood thrush or a katydid for the first time during a season. The scientific method of this is called phenology, in which researchers study the relationship of periodic biological events and climatic conditions, not only weather and temperature, but the solar phenomenon of increasing day length and sun angle that occur with the coming of spring.

Climate from year to year could affect migration patterns. An example was the winter migration of eagles last year, in which substantially fewer eagles were counted during the mid-winter survey in New York, probably due to a mild early winter.

Long-term study of trends for different species may indicate whether we are due for global warming or an ice age, but in the meantime, the calls from the flock of northbound geese are telling us to get the fields ready for spring planting. For more information on migration and phenology, visit learner.org/jnorth/ .