Population status

Eared Grebe
(Podiceps nigricollis)

The highly gregarious Eared Grebe is best surveyed aerially (Cullen et al. 1999), but targeted aerial surveys do not exist for most breeding colonies. Thus, Canadian population trends must be inferred from continental data during staging and wintering. Christmas Bird Count (CBC) data suggest that the current North American abundance has shown a slight decrease but is similar to that measured around 1970, though with some strong fluctuations over the last four decades. However, these CBC results have low reliability because trends for Canadian breeders cannot be distinguished from the continent-wide trend, and because much of the population winters far offshore beyond the range of CBC coverage. Annual aerial surveys of birds at a major fall staging site on Mono Lake, California reveal a large decrease in numbers (see graph in table below). Though numbers have increased since 2008, they are still well below the level in 1996. Numbers at Great Salt Lake, Utah are similar to those in 1997 when the survey began. Overall, the current abundance of Eared Grebe is best assessed as having shown little change in Canada since 1970, but the reliability of this assessment is considered low.

 

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 America1965-2012-0.8-6.60.6
 

Number of Eared Grebe (+/- SE) on the surface of Mono Lake, California and Great Salt Lake, Utah, USA (no SE)

Additional information on: Number of Eared Grebe (+/- SE) on the surface of Mono Lake, California and Great Salt Lake, Utah, USA (no SE)

Table 2: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 2 - footnote 1 Limits
LowerUpper
Great Salt Lake Select to view graph of the geographic area: Great Salt Lake 1997-2010; Number of Eared Grebe (+/- SE) on the surface of Mono Lake, California and Great Salt Lake, Utah, USA (no SE)1997-2010   
Mono Lake Select to view graph of the geographic area: Mono Lake 1996-2013; Number of Eared Grebe (+/- SE) on the surface of Mono Lake, California and Great Salt Lake, Utah, USA (no SE)1996-2013   
 

References