FOX SPARROW
Fox Sparrow
George K. Peck
Bruant fauve
Passerella iliaca
Many people may have seen what appears at first glance to be
an overgrown, rusty red Song Sparrow scratching at dropped
seeds under a feeder in March or April; fewer will have actually seen an Ontario Fox Sparrow on its northerly breeding
grounds. The Fox Sparrow is widely distributed across boreal
and subarctic North America from Alaska to Newfoundland,
and south in the US to Maine in the east and to Colorado in the
western mountains.This species varies dramatically in size and
colour across its range. While as many as 18 subspecies have
been proposed in the past, more recent research suggests that
on the basis of colour, measurements, and genetics, recognition of three or four species-groups is more appropriate
(Weckstein et al. 2002). Fox Sparrows breeding in Ontario
belong to the eastern iliaca (Red Fox Sparrow) group. The Red
Fox Sparrow breeds from Alaska east to northern and central
Ontario, northern Québec, Newfoundland, and Labrador,
through the Maritime Provinces to northwestern Maine. It
winters primarily in the eastern US and irregularly and rarely
as far north as southern Ontario.
Distribution and population status: The Fox Sparrow is
widely distributed in the Hudson Bay Lowlands, where its
probability of observation is 70%. In the Northern Shield
region, the probability of observation is only 20%, but the
majority of this region lies south of the Fox Sparrow’s range.
In the part of the Northern Shield that lies north of about
52°N, the Fox Sparrow was detected quite regularly.The southernmost records were near the Little Abitibi River, about 70 km
north of Cochrane, the same area with the southernmost
records in the first atlas.
There was a significant increase between atlases in the
probability of observation in both regions where the species
occurred.The reasons for this increase are unclear.The habitat
is unlikely to have changed significantly in this remote northern part of the province, and in both atlases, northern squares
were covered by experienced birders.
No BBS routes in Ontario are located within the Fox
Sparrow’s range. Across Canada, the species shows no change
in abundance during the period covered by the two atlases.
Breeding Evidence
Possible
Probable
Confirmed
Square with adequate coverage
Found in second atlas but not in first
Found in first atlas but not in second
Relative Abundance
Birds per 25 Point Counts
0.00
0.01 – 2.85
2.86 – 5.98
5.99 – 9.48
9.49 – 13.36
13.37 – 42.35
Hudson Bay Lowlands
Northern Shield
43.7%
6.0%
70.0%*
19.7%*
Southern Shield
Lake Simcoe-Rideau
Carolinian
Ontario
0%
15.0%
20%
29.8%*
40%
60%
80%
100%
Probability of Observation
1st Atlas
2nd Atlas
Monitoring of birds passing through Long Point during
migration shows contradictory trends, significantly decreasing
in spring and significantly increasing in fall (Crewe 2006).
Breeding biology: In Ontario, the Fox Sparrow prefers
dense stands of stunted conifers in taiga areas as well as dense
thickets of conifers, willows, birches, and alders in regenerating burns and along the shores of lakes, rivers, and streams.
It is largely absent from areas of open tundra, occurring only
locally in riparian shrub thickets. The nest is probably built
entirely by the female and is placed on the ground or, occasionally, the low branches of a bush or small tree. It is well
concealed and very difficult to find. The female alone incubates the two to four heavily splotched eggs and provides
most of the food for the nestlings. Although the male rarely
feeds young in the nest, he does feed them after fledging
(Weckstein et al. 2002).
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In the majority of squares (83%), only possible breeding,
mostly in the form of singing males, was recorded. The Fox
Sparrow’s whistled song is both distinctive and far carrying
and is the easiest means of detecting its presence. Given that
many squares in the Hudson Bay Lowlands were covered by
atlassers who canoed through them, the low proportion of
probable or confirmed squares is not surprising. Probable
breeding in the form of agitated adults or pairs of birds was
recorded in 13% of squares, but breeding was confirmed in
only 11 (4% of squares with records). Despite the difficulty
of finding nests of this species, atlassers added another six
nests to the five found previously in Ontario (Peck 2001;
Peck and Peck 2006).
Abundance: Within its relatively restricted breeding range
in Ontario, the Fox Sparrow can be abundant.There were three
large areas of high abundance in the northern part of the
Hudson Bay Lowlands. Densities of over 13.4 birds/25 point
counts were recorded in a large area south of Peawanuck, in an
area adjacent to the Ontario-Manitoba border, and also on
Akimiski Island (Nunavut).The average density in the Hudson
Bay Lowlands was 7.2 birds/25 point counts. South of the
Lowlands, abundance is much lower, averaging 0.3 birds/25
point counts in the Northern Shield region. – Margaret A.McLaren
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