Population status

Gray-cheeked Thrush
(Catharus minimus)

Populations of Gray-cheeked Thrush are poorly monitored in Canada, with most of the breeding population occurring north of the Breeding Bird Survey (BBS) coverage area. The species winters in South America, where it is not well covered by the Christmas Bird Count. The only data comes from BBS coverage of a small number of routes primarily in northern British Columbia, Yukon, and Newfoundland and Labrador. Although considered to be of low reliability because of poor coverage of the breeding population and small sample size, BBS results suggest that there has been a large decrease in the Canadian population since about 1970. At the regional level, apparent decreases have occurred in the Boreal Softwood Shield Bird Conservation Region (BCR; data mostly from Newfoundland) and to a lesser extent in the Taiga Shield and Hudson Plains BCR (data mostly from Labrador since 1989). These decreases are reflected in the national trend for the most recent decade (2006-2016), which includes data from all BCRs and shows a higher magnitude of decrease then the long-term trend, but is also considered to be of low reliability. The species consists of two subspecies: the broadly distributed aliciae subspecies and the minimus subspecies, which occurs in Newfoundland and southeastern Labrador (FitzGerald et al. 2017). Different factors could potentially influence the two subspecies, causing differences in population trend. The species is below the lowest acceptable level relative to its national population goal (see Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Gray-cheeked ThrushMean abundance (first 5 years of survey)Goal minus 25% 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 1972-2016; Breeding Bird Survey (BBS) - Canadian analysis1972-2016-3-5-1.1
Canada Select to view graph of the geographic area: Canada 2006-2016; Breeding Bird Survey (BBS) - Canadian analysis2006-2016-5-14.22.6
Northwestern Interior Forest Select to view graph of the geographic area: Northwestern Interior Forest 1972-2016; Breeding Bird Survey (BBS) - Canadian analysis1972-20160-2.92.9
Taiga Shield And Hudson Plains Select to view graph of the geographic area: Taiga Shield And Hudson Plains 1989-2016; Breeding Bird Survey (BBS) - Canadian analysis1989-2016-3.2-8.72.9
Boreal Softwood Shield Select to view graph of the geographic area: Boreal Softwood Shield 1976-2016; Breeding Bird Survey (BBS) - Canadian analysis1976-2016-11.3-13.9-8.8
North America Select to view graph of the geographic area: North America 1972-2016; Breeding Bird Survey (BBS) - Canadian analysis1972-2016-3.3-4.7-1.9
 

References