Assessing the status and conservation priorities of the short‐eared owl in North America

Abstract

The North American Breeding Bird Survey, Christmas Bird Count, and regional and national conservation assessments provide convincing evidence that the short-eared owl (Asio flammeus) is experiencing a range-wide, long-term decline in abundance in North America. However, the species has received little conservation or research attention. The short-eared owl is vulnerable to decline because it relies heavily on large, intact grasslands and a specialized diet of unpredictable small mammal prey. The species' nomadic movements compound these vulnerabilities by making a decline difficult to detect with current monitoring programs while obfuscating stewardship responsibilities for managers. The primary threat to the species is loss, fragmentation, and degradation of large tracts of native grasslands and wetlands. We propose the following conservation priorities to better understand and begin addressing the short-eared owl's decline: 1) better define and protect important habitats; 2) improve population monitoring; 3) determine seasonal and annual movements; 4) re-evaluate NatureServe's short-eared owl national conservation classifications; 5) develop management plans and tools; and 6) classify raptors, including short-eared owls, as migratory birds in Canada. We contend that the short-eared owl's need for habitat conservation at large spatial scales, status as a predator, and high reproductive potential that affords the species capacity to recover, make it an effective and useful candidate as an umbrella species for grassland conservation. Ó 2014 The Wildlife Society.KEY WORDS Asio flammeus, conservation, decline, grassland, North America, research priorities, short-eared owl, status.Empirical evidence demonstrates a long-term, range-wide decline in short-eared owl (Asio flammeus) abundance in North America since at least 1966. Multiple lines of evidence at several spatial scales corroborate this species' decline,

Short-eared Owl (Asio flammeus) surveys in the North American Intermountain West: utilizing citizen scientists to conduct monitoring across a broad geographic scale

“…However, habitat use has not been thoroughly explored within the Intermountain West of North America. Booms et al (2014) argued that the Short-eared Owl has experienced a long-term, range-wide, substantial decline in North America. To support their claim they summarize Breeding Bird Survey and Christmas Birds Count results from across North America (National Audubon Society 2012, Sauer et al 2014).…”

“…Figure 1 illustrates the general downward trend in Short-eared Owl populations in western North America between 1966 and 2013, as estimated from the Breeding Bird Survey; however, only California and Saskatchewan had sufficient sample size for a significant result (Sauer et al 2014). Booms et al (2014) acknowledge that neither the Breeding Bird Survey nor Christmas Bird Count adequately sample the Short-eared Owl population in North America because the species is not highly vocal and is most active during crepuscular periods and at night, resulting in very few detections. (Sauer et al 2014).…”

“…Their results predict that 90% of the winter range of Short-eared Owls in the year 2000 may no longer be occupied by 2080 and, even with a northward shift in winter range, the total area of winter range is expected to reduce in size by 34% (National Audubon Society 2014). Booms et al (2014) and Langham et al (2015) have highlighted the apparent disconnect of current and predicted population trends of Short-eared Owls and current conservation priorities. Booms et al (2014) proposed six measures to better understand and prioritize actions associated with the conservation of this species.…”

“…Booms et al (2014) and Langham et al (2015) have highlighted the apparent disconnect of current and predicted population trends of Short-eared Owls and current conservation priorities. Booms et al (2014) proposed six measures to better understand and prioritize actions associated with the conservation of this species. We have chosen to focus on the first two of those measures: (1) better define and protect important habitats; and (2) improve population monitoring (Booms et al 2014).…”

“…Booms et al (2014) proposed six measures to better understand and prioritize actions associated with the conservation of this species. We have chosen to focus on the first two of those measures: (1) better define and protect important habitats; and (2) improve population monitoring (Booms et al 2014). …”