Putting it all together

Figure 7: Effects of Climate Change on the Northern Spotted Owl: Each arrow represents a factor affected by climate change which in turn affects the spotted owl. Different arrow lengths indicate the probability of each factor being affected by climate change and the thresholds are shown to quantify the lengths. Arrow widths ((WIDE(most likely)- Barred Owl, MEDIUM(likely) Forest Fire/Pine Beetle, NARROW(somewhat likely) Prey Abundance)) represent the impact/importance of each factors on the owl's decline.  The gray arrow represents uncertainty of whether climate change is the major factor in the migration of Barred owl into Northern spotted owl territory.   (original figure: Huang. 2012)

The Barred Owl seemed to have the greatest impact (Fig. 7: represented by wide arrow) on the Northern Spotted Owl decline currently (refer to solutions tab), as the direct competition is leading to displacement by the Barred Owls. However uncertainty (gray arrow) of whether climate change has pushed Barred Owls to migrate from their prior range in the Eastern U.S. to the Pacific Northwest . So even though this competition is leading to such devastating effects, global warming and climate change can only be a factor out of many influencing the migration of the Barred Owls towards the Northern Spotted Owls. Many theories attempt to explain this range expansion, but there is a big deal of uncertainty and most likely the expansion is due to multiple factors including introduction of new forests in prairies of the Great Plains.

 Increased pine beetle outbreaks, forest fires, and drought show great correlation with recent warming climates as suggested by many studies. Therefore, identifying these factors as most likely to be already affected by climate change and in turn affecting the spotted owls is concluded while, pine beetle infestation, forest drought, and fire are difficult to differentiate based on effect. The Pine beetle outbreaks currently are more severe and local in the PNW and affecting the range of Spotted Owl territory greater than the increased frequency of droughts and forest fire due to climate change. However, the lack of research suggesting the decline of owls directly through forest fire and pine beetle outbreaks in old-growth forests suggests that these factors are only likely to affect these owls. The more important factor in the contributions of forest decline revolve more around the prior logging of old-growth forests.

 Lastly, prey abundance  seems to show the least evidence to the decline of the owls, despite the fact that it is likely climate change is affecting the migration of the primary prey: the Northern flying squirrel. (prey abundance tab)