Population status

Winter Wren
(Troglodytes hiemalis)

The Breeding Bird Survey (BBS) is the most reliable data source for the Canadian population of Winter Wren. Despite large annual fluctuations in numbers, the results demonstrate an increase in abundance relative to the early 1970s. However, the BBS mainly covers the southern portion of the Winter Wren's breeding population, providing information for about one third of the population. At the regional level, results vary from relatively stable populations to a large increase (all Bird Conservation Regions with reasonable reliable results are displayed below). Another source of information for Winter Wren comes from the Christmas Bird Count (CBC), which covers much of the wintering range. Although CBC data include birds from both the United States and Canada, the majority breed in Canada. CBC results also suggest a moderate increase in the continental population over the same time period. With agreement between the BBS and CBC, the reliability of a moderate increase in numbers relative to the early 1970s is considered high. The Winter Wren is at an acceptable level relative to its national population goal (see BBS Canada graph below).

Population goal and acceptable levels of variation

Species/group	Goal	Lower level	Upper level
Winter Wren	Mean 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

View definitions of table column headings being used by: Breeding Bird Survey (BBS) - Canadian analysis

Table 1: Population trends by geographic area
Geographic area	Time Period ^{Table 1 - footnote 1}	Annual trend ^{Table 1 - footnote 2}	Limits
Geographic area	Time Period ^{Table 1 - footnote 1}	Annual trend ^{Table 1 - footnote 2}	Lower	Upper
Canada Select to view graph of the geographic area: Canada 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis	1970-2016	0.8	0.1	1.4
Canada Select to view graph of the geographic area: Canada 2006-2016; Breeding Bird Survey (BBS) - Canadian analysis	2006-2016	-2.5	-4.9	-0.4
Boreal Taiga Plains Select to view graph of the geographic area: Boreal Taiga Plains 1972-2016; Breeding Bird Survey (BBS) - Canadian analysis	1972-2016	1.5	-0.2	3.8
Boreal Hardwood Transition Select to view graph of the geographic area: Boreal Hardwood Transition 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis	1970-2016	0.4	-0.3	1.1
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 analysis	1970-2016	-0.2	-1.6	0.9
Atlantic Northern Forest Select to view graph of the geographic area: Atlantic Northern Forest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis	1970-2016	-0.5	-1.3	0.3
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis	1970-2016	0.7	0.1	1.3

Christmas Bird Count (CBC)

Additional information on: Christmas Bird Count (CBC)

View definitions of table column headings being used by: Christmas Bird Count (CBC)

Table 2: Population trends by geographic area
Geographic area	Time Period	Annual Trend ^{Table 2 - footnote 1}	Limits
Geographic area	Time Period	Annual Trend ^{Table 2 - footnote 1}	Lower	Upper
North America Select to view graph of the geographic area: North America 1970-2016; Christmas Bird Count (CBC)	1970-2016	0.7	-0.1	1.4

References

Chesser, R.T., R.C. Banks, F.K. Barker, C. Cicero, J.L. Dunn, W.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz and K. Winker. 2010. Fifty-first supplement to the American Ornithologists’ Union check-list of North American birds. Auk 127:726−744. Chesser, R.T., R.C. Banks, F.K. Barker, C. Cicero, J.L. Dunn, W.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz and K. Winker. 2010. Fifty-first supplement to the American Ornithologists’ Union check-list of North American birds. Auk 127:726−744. (Link)
Freemark, K.E., J.B. Dunning, S.J. Hejl and J.R. Probst. 1995. A landscape ecology perspective for research, conservation, and management. pp. 381-427. In: Ecology and Management of Neotropical Migratory Birds (T.E. Martin and D.M. Finch, Eds.). Oxford Univiversity Press, New York.
Hejl, S.J., J.A. Holmes and D.E. Kroodsma. 2002. Winter Wren (Troglodytes troglodytes), The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. Hejl, S.J., J.A. Holmes and D.E. Kroodsma. 2002. Winter Wren (Troglodytes troglodytes), The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. (Link)
Holmes, R. T. and T. W. Sherry. 1988. Assessing population trends of New Hampshire forest birds: local vs. regional patterns. Auk 105: 756–768.
Raphael, M.G., K.V. Rosenberg and B.G. Marcot. 1988. Large-scale changes in bird populations of Douglas-Fir forests, northwestern California. Bird Conservation 3:63-83.
Schmiegelow, F.K.A., C.S. Machtans and S.J. Hannon. 1997. Are boreal birds resilient to forest fragmentation? An experimental study of short-term community responses. Ecology 78: 1914-1932.