Population status

Pine Grosbeak
(Pinicola enucleator)

Although there is no single survey that provides ideal population trend data for the Pine Grosbeak, both the Christmas Bird Count (CBC) and Breeding Bird Survey (BBS) provide some information. In this assessment, the CBC is used as the primary source because it provides better range coverage and precision than the BBS. CBC results suggest an overall increase in the population since the early 1970s. There appears to be a latitudinal gradient in Pine Grosbeak trends across North America, a possible indicator that the species may be shifting its wintering range poleward: decreases in the northern United States and southern Canada, and increases in the northernmost portion of the species' range (Meehan et al. 2018, National Audubon Society 2015). A similar pattern has also been documented in other species (Sorte and Thompson 2007). Results from the BBS suggest little overall change in abundance over the long term. Although the trajectory of the BBS annual indices suggests a possible decrease (see Canada graph below), this may be due in part to particularly poor precision in the early years of the survey. However, it does suggest the possibility that the CBC trend is not as positive as it appears. At the regional level, the only two Bird Conservation Regions with reasonably reliable BBS results (Atlantic Northern Forests and Northern Rockies) suggest large, long-term decreases in their populations. Considering these varying results, it is clear that the population trend for this species is poorly understood. Relying mainly on CBC and with no major contradiction from the BBS, the species' population status in Canada is perhaps best assessed as having experienced a moderate increase relative to 1970, though the magnitude of that increase is not clear and the reliability of this assessment is considered low. Currently, the Pine Grosbeak is at an acceptable level relative to its national population goal (see CBC Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Pine GrosbeakMean 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)1970-20162.6-0.44.81
North America Select to view graph of the geographic area: North America 1970-2016; Christmas Bird Count (CBC)1970-20163.10.24.96
 

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 analysis1970-2016-0.4-2.51.5
Northern Rockies Select to view graph of the geographic area: Northern Rockies 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-2.1-4.80.2
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-4.8-6.9-2.7
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-0.4-2.31.3
 

References