The value of winter studies is quite high. Winter is a time when populations are resident and relatively stable, thus providing excellent data on survivorship and mortality. The methods outlined here have full applicability in the non-breeding seasons, both in North America and Latin America. In the tropics, mist netting throughout the year at the same site would clarify many questions about molt, skull, and plumage patterns. Maintenance of a Study Plot Plots should be permanently marked with stakes, markers, or flagging that will survive over at least one winter.
Tags are available from biological supply companies.
In general, markers should be laid out along a compass direction, be placed at regular intervals, and be visible at any point between the markers. Each marker should correspond to a numbered grid point on a map. In colder areas, be aware that in years with heavy snowfall, plot markers can still be buried in the spring. Net and census points should also be permanently marked. Customized maps of the study area should be traced from a large scale map or from aerial photographs.