You can use it for research or reference. To access the current information, please visit NatureCounts - The State of Canada’s Birds (external link).
Although the Greater Yellowlegs is very conspicuous, surveys throughout North America only monitor a fraction of its population. It breeds in boreal and subarctic muskeg, where coverage by the Breeding Bird Survey (BBS) is poor. During migration, many individuals travel through inland habitats in small flocks (Elphick and Tibbitts 1998); migration surveys do not focus on these small, inland wetlands and many of these dispersed migrants are missed. In winter, a majority of individuals are south of the areas regularly covered by the Christmas Bird Count (CBC). Despite these drawbracks, the BBS is the best available source of information on the species’ population status in Canada because the trend estimates are precise and it is the only survey offering information specific to Canada. BBS results suggest a moderate increase in the Canadian population since 1970 (all Bird Conservation Regions with reliable results are shown below). Because the BBS only surveys the population along the southern edge of the species’ breeding range, it is important to also consider information from migration monitoring surveys and the CBC. Continental migration monitoring results suggest that the species has shown a slightly positive trend (28%), which is considered little overall change in abundance relative to about 1970, and the CBC shows a large increase in the North American population relative to the mid-1960s. Considering all three sources, the population is best assessed as showing a moderate increase since 1970. Despite the fact that an unknown fraction of the population is not adequately monitored, and the increase shown by the CBC results may be due at least in part to the species wintering further north than in the past, the reliability of these results is considered high because all three surveys are showing an increase in population (i.e. the population is likely not declining). The Greater Yellowlegs is currently at an acceptable level relative to its national population goal (see BBS Canada graph below).
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
Additional information on: Christmas Bird Count (CBC)
Additional information on: Analyses of Shorebird Migration Monitoring Data
