AMERICAN BARN OWL (BNOW)
The first BNOW nest in the state was reported in 1989, in Carbon County, Montana, 48 km southwest of Billings (Holt et al. 1992). Between 1989 and 2002, less than 5 nests were reported in the state. Then in 2005, we confirmed a cliff nest in the Mission Valley. With this discovery, we initiated a study of BNOW breeding ecology and nest site characteristics in the Mission Valley.
From 2006 to present, we have discovered 11 more nests, primarily in clay cliffs. Further, we suspect that 5 more nests were active, based on such evidence as whitewash, pellets and odor, but could not access the cavities for visual confirmation. To date, we have banded 36 BNOWs.
BOREAL OWL (BOOW)
We began searching for BOOWs in Lolo National Forest in 1982. Systematic surveys, from 1985 to 1990, yielded the first discovery of a nest in Montana (Holt and Ermatinger 1989).
In 1995, we assumed the monitoring of nest boxes in the Beaverhead/Bitterroot National Forests, discovering 24 nesting attempts in boxes. Since 2004, we have also checked boxes on the Flathead Indian Reservation, but found no owls using them. The BOOW is listed as “Sensitive” by the Confederated Salish and Kootenai Tribes Wildlife Management Program (D. Becker, pers. comm.).
FLAMMULATED OWL (FLOW)
The first evidence of FLOW nesting in Montana was recorded in 1975, and the first nest discovered in 1986 (Holt et al. 1987). In 2008, we initiated a study in Lolo National Forest. We detected 9 FLOW territories, saw evidence of breeding at one territory, and confirmed a nest (incubating female and eggs) at another. The discovery represented the third FLOW nest site found in Montana.
In 2009, we doubled our efforts, detecting 14 territories with both singing individuals and pairs. However, we found no evidence of successful breeding — no eggs, brooding or incubating females, or nestlings, despite intensive searching and monitoring. In 2010, we detected 15 territories and 3 nests.
During this four-year study, we have found it fairly easy to detect singing FLOWs, pinpointing 18 separate territories. More difficult is finding nests. So far, with extensive searching, we have discovered four. Information about FLOW breeding ecology is underscored by the owl’s state and federal listings:
- Tier 1 Species of Concern, in greatest need of conservation in Montana (Montana Natural Heritage Program and Montana Fish, Wildlife and Parks)
- Sensitive species, receiving special emphasis in planning and management activities to ensure its conservation [USFS (Region 1)]
- Bird of Conservation Concern, representing a high conservation priority [USFWS (Region 10)]
- Sensitive species in Montana, and imperiled in part of its range [BLM (Montana/Dakotas)].
LONG-EARED OWL (LEOW)
This 26-year study occurs at 3 sites in the Missoula and Mission Valleys, on federal, state, tribal, and private lands. It covers many aspects of LEOW biology, including wintering, breeding, and migration. As of December 2011, we have banded ≈ 1650 LEOWs and located ≈ 216 nests.Data from all 3 sites indicates a downward trend in nesting (Figure 1). The 2011 nesting data from Ninepipes is incomplete due to unforeseen circumstances. However, it is our hope to continue this project in 2012. In the Missoula Valley, LEOW declines may be correlated to increased development. However, declines are also occurring in the Mission Valley, where conservation lands are stable or even expanding. It is possible that some other factor, within or beyond Montana, is affecting Long-eared Owls in western Montana.
The ORI believes the decline in LEOWs mirrors declines in Short-eared Owls. However, detecting these trends in LEOWs in far more difficult due to its secretive and nocturnal behaviors.
NORTHERN HAWK OWL (NHOW)
Since 1990, there is convincing evidence of over 30 instances of NHOW breeding in Montana. “Convincing evidence” comprises nests, eggs, chicks, or recently branched young. (Note: “Branched” young have limited flight abilities and are still dependent on adults.) Of these instances, most have occurred in Glacier National Park. Two took place in Flathead National Forest, and a few in other, scattered locations in western Montana. From these reports, we have confirmed 14 nest trees: 2 in 2010, 4 in 2007, 6 in 2006, 1 in 2005, and 1 in 1994. Thirteen nest trees were in Glacier National Park, and 1 in Flathead National Forest. We have banded 56 NHOWs since 1994, in FNF and GNP. These data will contribute to understanding a Potential Species of Concern in Montana (Montana Natural Heritage Program and Montana Fish, Wildlife and Parks).
NORTHERN PYGMY OWL (NOPO)
We began surveys for NOPOs in 1981, at the Flathead Indian Reservation, LNF, and National Bison Range Complex. We also study the owl’s nesting habitat (snag and cavity characteristics). Our data on fifteen natural nest sites combined with Graham Frye’s information on eleven sites will provide insight into the owl’s little-known nesting requirements. The NOPO is listed as Sensitive by the Confederated Salish and Kootenai Tribes Wildlife Management Program (D Becker, pers. comm.).
NORTHERN SAW-WHET OWL (NSWO)
Our NSWO surveys began in 1981 in the Lolo National Forest, and later extended into the Flathead Indian Reservation and National Bison Range Complex. We focus on snag and nest characteristics for the species. So far, we have recorded 40 natural NSWO nests (36 found by ORI and 4 contributed by Graham Frye). We believe this represents the largest sample of natural nest sites for NSWOs in North America. We have also documented NSWOs using nest boxes in our study areas. This information will help to improve snag management guidelines for cavity nesting owls. The NSWO is listed as a Sensitive Species by the Confederated Salish and Kootenai Tribes Wildlife Management Program (D. Becker, pers. comm.).
SHORT-EARED OWL (SEOW)
SEOWs are a species of concern in North America. As early as 1976, they were listed as “declining” on the Audubon Blue List of Imperiled Species. In 2005, they were deemed a species of conservation concern at the continental scale by Partners in Flight (Dunn et al. 2005). More locally, SEOWs are a potential species of concern in Montana (Montana Natural Heritage Program and Montana Fish, Wildlife and Parks). These listings stem from population data of recent decades, which suggest a large and statistically significant decrease in the SEOW population in North America: a 71.2% decline over the last 40 years (BirdLife International 2009). This decline can be further illustrated by Christmas Bird Count data (Figure 2).
These declines are attributed primarily to habitat loss (Holt et al. 1999). Indeed, in Montana, grassland is becoming extensively fragmented, to the point of being deemed “of greatest conservation need” by the state (Montana Fish, Wildlife and Parks 2010). The Missoula and Mission Valleys contain significant tracts of grassland habitat. We hope that a comprehensive management plan will be created for these biologically valuable areas.
The ORI believes the SEOW can be an indicator of the health of grasslands, marshlands, and shrub-steppe habitat. It is also one of the most iconic species of birds and can be used in the conservation of these habitat types.
SNOWY OWL (SNOW)
Begun in 1992 in Barrow, Alaska, the Snowy Owl project is focused on the owl’s diet, habitat, and reproductive success. Thanks to the United Iñupiat Corporation and Barrow Environmental Observatory for permitting access to field sites.
Through our research, we have discovered that Snowy Owl nesting fluctuates with the population cycles of the Brown Lemming.
In tracking studies, in conjunction with the Raptor Center of Boise, Idaho, we found that Snowy Owls engage in east to west, high-latitude movements from Barrow to Russia, then from Barrow to Canada. These migrations underscore the fact that conservation of this species will require large-scale, international efforts to protect Arctic habitat.
Occasionally, Snowy Owl populations irrupt into more southern latitudes. In 2005-2006, we had first-hand experience of this phenomenon when a population of Snowy Owls overwintered in western Montana. During the event, we collected dietary data and determined that the owls were primarily eating voles (95%).
The irruption emphasizes the fact that Snowy Owls require large areas of open lands, beyond the Arctic, to accommodate their nomadic tendencies.
In Fall 2010, we conducted a pilot study of fall migration site of small forest owls. The main site was at Blue Mountain Fire Lookout (in Lolo NF) and a secondary site was on the MPG Ranch. At Blue Mountain, we captured 1 FLOW, 1 NOPO, and 7 NSWOs, and we detected 7 species of owls. At the Bitterroot site, we trapped and banded 8 NSWOs. We plan to continue refining our methods in determining if Western Montana is a migration flyway for owls.