Population status

Yellow-bellied Flycatcher
(Empidonax flaviventris)

The Breeding Bird Survey (BBS) is the most reliable survey for determining the population status of the Yellow-bellied Flycatcher in Canada. BBS results suggest that at the national level, the Yellow-bellied Flycatcher population has shown a steady increase since the 1970s, leading to a large increase in abundance. However, the more northern breeding populations are not well-sampled. Further complicating this assessment is the fact that information from the only two Bird Conservation Regions (BCRs) with reasonably reliable BBS trends (displayed below) show trends that are different from the national trend: the Yellow-bellied Flycatcher population in the Boreal Hardwood Transition BCR has shown little change since about 1970, whereas the population in the Atlantic Northern Forest BCR has shown a moderate decrease. These two BCRs, along with the Boreal Softwood Shield BCR (shown below despite having low reliability), host the highest densities of Yellow-bellied Flycatchers in Canada. It is possible that the range of the Yellow-bellied Flycatcher is shifting and contracting in response to climate change (Stralberg et al. 2015). The various provincial breeding bird atlases in central and eastern Canada provide some additional information for some of the areas that are not well covered by the BBS. The results generally support a population increase, though again there are some exceptions. The Maritimes Atlas reports large declines in the probability of observation in parts of New Brunswick, but substantial increases elsewhere (Burrows 2015). The Atlas of the Breeding Birds of Quebec 2017 reports a substantial increase in the number of squares in which the species was detected. The Ontario Atlas reports an increase in the probability of occurrence in Ontario, especially in the Northern Shield and Hudson Bay Lowlands regions (Crins 2007a). Overall, based on the best information available, the Yellow-bellied Flycatcher is considered to have increased nationally. However, this assessment is considered to be of medium reliability, meaning that there is some uncertainty but that the category is likely to be within one category of that assigned, and not off by more than two. The Yellow-bellied Flycatcher 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
Yellow-bellied FlycatcherMean 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 analysis1970-20163.32.34.4
Boreal Softwood Shield Select to view graph of the geographic area: Boreal Softwood Shield 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20165.53.57.5
Boreal Hardwood Transition Select to view graph of the geographic area: Boreal Hardwood Transition 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.3-11.8
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-1-20
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20163.12.24.2
 

References