Population status

Barred Owl
(Strix varia)

A combination of monitoring programs provides reliable national coverage of this species in Canada. The Breeding Bird Survey (BBS) covers the southern portion of the breeding population and provides the best data to assess population change, indicating an increase of over 200% in the national population since 1970 (results for all Bird Conservation Regions with reasonably reliable results are displayed below). Results from the Christmas Bird Count (CBC) indicate an even larger increase (>300%) in the Canadian population. Both the BBS and CBC suggest that populations are increasing at the continental level as well. Taking both sources of information into account, the Barred Owl's abundance is considered to be at an acceptable level relative to its national population goal (see BBS Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Barred OwlMean abundance (2008-2012)10th percentile of observed abundance (1970-2012)Not applicable

Breeding Bird Survey (BBS) - Canadian analysis

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

Table 1: Population trends by geographic area
Geographic areaTime Period Table 1 - footnote 1 Annual trend Table 1 - footnote 2 Limits
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20162.51.13.9
Boreal Hardwood Transition Select to view graph of the geographic area: Boreal Hardwood Transition 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20162.70.45.7
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20162.40.94.2
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20161.71.32
 

Picture of logo Christmas Bird Count (CBC)

Additional information on: Christmas Bird Count (CBC)

Table 2: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 2 - footnote 1 Limits
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2016; Christmas Bird Count (CBC)1970-20163.42.24.6
North America Select to view graph of the geographic area: North America 1970-2016; Christmas Bird Count (CBC)1970-20160.80.51.1
 

References