Population status

Sora
(Porzana carolina)

The Breeding Bird Survey (BBS) provides better trend data for this species than for many other marsh birds, presumably due to relatively higher rates of spontaneous unsolicited vocalizations. BBS results suggest little overall change in abundance in Canada since 1970 (all Bird Conservation Regions with reasonably reliable BBS results are displayed below). However, BBS results show large, inter-annual fluctuations (see graph). Both the Great Lakes and the Quebec Marsh Bird Monitoring programs also suggest little change overall or a very slight decline (since 1995 and 2004, respectively) in the areas covered by these surveys. Because all 3 sources of information agree (and despite the incomplete coverage of the species’ entire breeding range), the Sora’s national status is perhaps best assessed as having shown little change relative to 1970, with high reliability (i.e., the category is likely to be correct, or at worst within one status category of the actual status, which in this case would be a moderate increase or a moderate decrease). The Sora is currently at an acceptable level relative to its national population goal (see Canada BBS graph below). For more detailed information on Sora, see the Population Status of Migratory Game Birds in Canada report (summarized version). To obtain a copy of the full version of this report, including tables and graphs, please contact ec.scf-oismiggibiers-cws-miggamebirds.ec@canada.ca.

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
SoraMean abundance (2008-2012)10th percentile of observed abundance (1970-2012)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 analysis1970-20160.2-1.11.2
Boreal Taiga Plains Select to view graph of the geographic area: Boreal Taiga Plains 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160-21.8
Great Basin Select to view graph of the geographic area: Great Basin 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-0.4-2.82.2
Northern Rockies Select to view graph of the geographic area: Northern Rockies 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.7-12.5
Prairie Potholes Select to view graph of the geographic area: Prairie Potholes 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.5-0.61.7
Boreal Hardwood Transition Select to view graph of the geographic area: Boreal Hardwood Transition 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-0.6-2.41.1
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 analysis1970-2016-0.2-2.61.7
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20161.3-0.22.7
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.2-0.91
 

Great Lakes Marsh Monitoring Program

Additional information on: Great Lakes Marsh Monitoring Program

Table 2: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 2 - footnote 1 Limits
LowerUpper
Great Lakes Basin in Ontario Select to view graph of the geographic area: Great Lakes Basin in Ontario 1995-2016; Great Lakes Marsh Monitoring Program1995-2016-0.028-0.045-0.011
 

Quebec Marsh Monitoring Program

Additional information on: Quebec Marsh Monitoring Program

Table 3: Population trends by geographic area
Geographic areaTime PeriodAnnual Trend Table 3 - footnote 1 Limits
LowerUpper
Quebec Select to view graph of the geographic area: Quebec 2004-2016; Quebec Marsh Monitoring Program2004-2016-0.088-0.129-0.044
 

References