Nonmigratory

Nonmigratory refers to organisms that do not undertake long-distance seasonal movements between habitats. It is opposed to migratory behavior. In practice, populations may be sedentary or resident, remaining within or near a home range year-round. Migratory behavior is adaptive in response to resource seasonality; nonmigratory populations persist where resources are stable or unpredictable.

In birds, many tropical species are nonmigratory, and some temperate-zone populations stay year-round in their breeding or wintering ranges. Within species, there can be partial migration where some individuals migrate and others stay. In mammals and insects, nonmigratory behavior includes year-round territoriality or localized movement; some species show nomadism rather than fixed migrations.

Causes of nonmigratory behavior include genetic predisposition, developmental cues, and environmental conditions that reduce the advantage of long-distance movement. Climate change, habitat alteration, and changes in food availability can suppress migratory tendencies or convert migratory populations to resident ones. Ecological implications of nonmigratory life histories include altered local competition, predator–prey dynamics, and potential vulnerability to local environmental change. Nonmigratory species may experience different patterns of gene flow and population structure compared with migratory populations. Studying nonmigratory behavior often involves tracking technologies, banding, and isotopic analyses to distinguish residents from migrants and to understand the drivers behind residency.