Population status

Swamp Sparrow
(Melospiza georgiana)

The Breeding Bird Survey (BBS) is the most reliable source of data for the Swamp Sparrow, although it does not provide good coverage of the northern portion of the population. BBS results show that populations were roughly stable between about 1970 and about 1990, and have shown a steady increase since that time. The Bird Conservation Regions for which reliable trends are available (displayed below) all show positive trends, although of different magnitudes. The Christmas Bird Count (CBC) provides good coverage of this species' wintering grounds, and while it includes birds breeding in the United States, trends are dominated by Canadian birds, which make up over 80% of the continental population. CBC results suggest the continental wintering population shows a negative trend. Between these two sources, the BBS is considered the more reliable survey in part because of its well-standardized design. Thus the Swamp Sparrow is assessed as showing a moderate increase, based on BBS results, but the reliability of that assessment is low due to the conflicting trends and the lack of good coverage of the northern range. The Swamp Sparrow is at an acceptable level relative to its national population goal (see BBS Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Swamp SparrowMean abundance (2008-2012)Mean long-term abundance (1970-2012) 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 analysis1970-20161.10.31.8
Boreal Taiga Plains Select to view graph of the geographic area: Boreal Taiga Plains 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20162.41.33.7
Prairie Potholes Select to view graph of the geographic area: Prairie Potholes 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20162.9-0.46
Boreal Hardwood Transition Select to view graph of the geographic area: Boreal Hardwood Transition 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.70.21.3
Lower Great Lakes / St. Lawrence Plain Select to view graph of the geographic area: Lower Great Lakes / St. Lawrence Plain 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20161.50.72.4
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.4-0.21.1
 

Picture of logo Christmas Bird Count (CBC)

Additional information on: Christmas Bird Count (CBC)

Table 2: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 2 - footnote 1 Limits
LowerUpper
North America Select to view graph of the geographic area: North America 1970-2016; Christmas Bird Count (CBC)1970-2016-1.2-1.6-0.897
 

References