The barred owl (Strix varia) is a widely recognized North American species, known for its distinctive hooting call. Many people wonder if these common owls migrate like other bird species.
Resident Behavior
Barred owls are generally considered non-migratory throughout most of their expansive range. They typically exhibit strong site fidelity, remaining in the same area year-round. Individuals have been documented to stay within a few miles of their birthplace for their entire lives, with some banded birds found no farther than six miles from where they were originally tagged.
These owls are highly territorial, defending their chosen habitats regardless of the season. Their home ranges, which can average between 670 to 835 acres, are maintained through vocalizations and interactions, often remaining stable across years. This consistent presence contrasts sharply with the seasonal movements characteristic of many other bird species that migrate to warmer climates or areas with more abundant food resources.
Irruptive and Dispersal Movements
While barred owls are largely sedentary, they undertake movements distinct from traditional migration. One such phenomenon is an “irruptive movement,” which involves irregular, large-scale shifts in populations. These movements are not seasonal but can occur when environmental conditions, such as a scarcity of prey, compel owls to seek new foraging grounds, often leading them southward.
Another distinct movement is “dispersal,” primarily observed in younger owls. After leaving their natal territories, juvenile barred owls establish their own independent home ranges. This natal dispersal can involve significant distances, with some young owls traveling up to 62 miles (100 kilometers) from where they hatched. This type of movement has been a primary mechanism behind the barred owl’s notable westward expansion across North America in recent decades.
Triggers for Movement
The movements observed in barred owls are primarily driven by environmental and population factors. Food scarcity is a significant trigger for irruptive events, especially during harsh winters or when populations of their primary prey experience sharp declines. Such conditions force owls to expand their foraging areas or move to new locations where food is more readily available.
High population density within their established territories can also prompt movements, as increased competition for resources encourages some individuals to disperse. Human-induced changes to the landscape, such as the planting of trees in previously open plains, have created new corridors, facilitating the barred owl’s expansion.