Monitoring changes in movement patterns is important for the conservation and management of bird populations. Such changes might affect the seasonal distributions of populations and might lead to increases or decreases in population sizes.
The demographic effect of the taking of individuals from a population by man varies in relation to numbers, sex- and age-class of the individuals taken, as well as the stage of the annual cycle when the killing or trapping takes place.
Proper knowledge of the timing of prenuptial migration is essential and data of individually marked birds can provide this information.
Migratory connectivity is defined as the linkage among individuals between the periods and areas where they spend different phases of their annual cycle. The strength of migratory connectivity thus represents the extent to which individuals mix in different seasons.