Population status

Northern Shrike
(Lanius borealis)

The most reliable source of data on the status of Northern Shrike populations in Canada comes from the Christmas Bird Count (CBC), which monitors the birds on their wintering grounds in southern Canada and the United States. Although the CBC analysis includes birds from Canada and Alaska, the Canadian population is well represented and results are likely reflective of birds breeding in Canada. The CBC suggests that the continental population has decreased by almost 30% relative to 1970. Numbers fluctuated considerably from year-to-year, peaking in the mid-1970s and again in the mid-1990s. The Breeding Bird Survey records this species on a very small number of northern routes, but data are too sparse to allow trend analysis. Despite the decrease in abundance, the Northern Shrike is currently at an acceptable level relative to its national population goal (see North America graph below). However, with the wide inter-annual fluctuations in population, it has dipped below the lowest acceptable levels in the recent past.

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Northern ShrikeMean abundance (first 5 years of survey)Goal minus 25% 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
North America Select to view graph of the geographic area: North America 1970-2016; Christmas Bird Count (CBC)1970-2016-0.7-1.1-0.401
 

References