Data for: Differential landscape use by forest owls two years after a mixed-severity wildfire

Owls are important avian predators in forested systems, but little is
known about landscape use by most forest-adapted owl species in
environments impacted by mixed-severity wildfire. To better understand
species-specific patterns of post-wildfire landscape use within an owl
guild we used passive acoustic monitoring using autonomous recording
units. The technology is effective for multi-species surveys, especially
if some species are rare, nocturnal, or difficult to detect by traditional
means. In 2017 we surveyed the interior and adjacent unburned areas of a
10,700 ha mixed-severity wildfire that burned in 2015 in southwest Oregon.
We used occupancy modeling to identify patterns of landscape use by five
species of forest owls: barred owls (Strix varia), great horned owls (Bubo
virginianus), western screech-owls (Megascops kennicottii), northern
pygmy-owls (Glaucidium californicum), and northern saw-whet owls (Aegolius
acadicus). Our results showed a positive relationship between increasing
fire severity and probability of use by western screech-owls and a similar
but somewhat weaker relationship for northern pygmy-owls. Barred owls were
rarely detected in severely burned areas and their use decreased with
increased fire severity. We observed generally low landscape use for great
horned owls, which decreased with increased fire severity and at higher
elevations. Thus, four out of the five species appeared to use recently
burned forests at different levels, with only northern saw-whet owls
showing near-complete avoidance of the burned area. These findings
increase our understanding of the basic ecology of each species and
highlight the varied use of burned areas within this community. These
previously undocumented patterns of landscape use in burned landscapes
should provide insights to managers and policymakers in the Pacific
Northwest as climate shifts, and fires may increase in size, frequency,
and severity.