Population status

Northern Pygmy-Owl
(Glaucidium gnoma)

The Northern Pygmy-Owl's range is adequately covered by both the Christmas Bird Count (CBC) and the Breeding Bird Survey (BBS), though neither survey covers more than half of the species' range. Its habit of hunting during the day and twilight periods (Holt and Petersen 2000) means that it should be better captured by these surveys than some nocturnal raptors. However, CBC methods are not highly standardized and targeted efforts to record owls may have increased over time, which could inflate trend estimates if data were sparse in the 1970s. Still, results from the CBC suggest a large increase. It should be noted though that this large increase is likely driven by the few CBC count circles in Alberta. The bulk of the resident population lies in British Columbia, which is showing a more moderate increase. The BBS also shows a moderate increase, though the estimated trends within Canadian regions rely on the species' range-wide trend (i.e., the average trend across the BBS survey area, including in the United States) since there are relatively few observations of the species in any one region. Still, both surveys suggest an increasing population in Canada. The concordance of the surveys allows the overall reliability of this assessment to be considered medium. Interestingly, both the CBC and the BBS at the continental scale show more moderated trends (little overall change and a moderate increase, respectively). The Northern Pygmy-Owl is at an acceptable level relative to its national population goal (see Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Northern Pygmy-OwlMean abundance (first 5 years of survey)10th percentile of observed abundance (1970-2012)Not applicable

Picture of logo Christmas Bird Count (CBC)

Additional information on: Christmas Bird Count (CBC)

Table 1: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 1 - footnote 1 Limits
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2016; Christmas Bird Count (CBC)1970-201620.33.77
 

Breeding Bird Survey (BBS) - Canadian analysis

Additional information on: Breeding Bird Survey (BBS) - Canadian analysis

Table 2: Population trends by geographic area
Geographic areaTime Period Table 2 - footnote 1 Annual trend Table 2 - footnote 2 Limits
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20161.2-1.23.5
 

References