Population status

Long-billed Curlew
(Numenius americanus)

The Long-billed Curlew declined significantly in both abundance and range in the late 19th and early 20th centuries (Dugger and Dugger 2002). The Breeding Bird Survey (BBS) is the only range-wide and long-term source of trend data for this species. BBS results indicate a long-term decrease in the population of Long-billed Curlew in Canada. The trend during the most recent period (2006-2016) appears to have stabilized at that lower level. Although the BBS takes place in June, a time when curlews are largely inconspicuous, the precision of the trend estimates is good and the survey covers the majority of the breeding population. Stanley and Skagen 2007 also determined that habitat along roadsides was representative of curlew habitat. A dedicated survey to estimate the population size for Long-billed Curlews was executed in 2004 and 2005 (Stanley and Skagen 2007, Jones et al. 2008). Results from this survey suggest that the population size was previously underestimated by a substantial margin (Stanley and Skagen 2007). The majority of the North American population breeds in the United States; BBS results indicate that the continental population has remained relatively unchanged since 1970. The national population goal, which is based on the BBS, is complementary to the goal stated in the Management Plan, which is to maintain or increase the species' breeding distribution in Canada (Environment Canada 2013). The Long-billed Curlew has been below the lowest acceptable level relative to its national population goal since the mid-2000s (see Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Long-billed CurlewMean 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 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-0.7-1.90.4
Canada Select to view graph of the geographic area: Canada 2006-2016; Breeding Bird Survey (BBS) - Canadian analysis2006-2016-0.3-2.62
Northern Rockies Select to view graph of the geographic area: Northern Rockies 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-201641.17.1
Prairie Potholes Select to view graph of the geographic area: Prairie Potholes 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-1.2-2.4-0.1
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.2-0.60.9
 

References