Researchers strive to understand the factors that influence the species plight such as reproductive rats and survival rates. Forests are surveyed annually for occupancy by specific owl pairs which are identified by color leg-bands. Each pair of owls is checked in spring and summer for reproductive status. If they nest, the young are counted and banded. These techniques enable researchers to detect trends in the population over time with sophisticated population models.
Researchers also study the creatures eaten by spotted owls.
Understanding the life-cycles of these creatures has been instrumental in better understanding the owl. Northern spotted owls are well suited to living in large expanses of relatively unbroken forest. The patterns and techniques of timber harvest in this region since WWII have resulted in a patchy forested landscape. Demography of northern spotted owls on the H.J. Andrews study area in the central Cascade mountains, Oregon. Studies in Avian Biology.