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Birds
Results
of the Biological Inventory in Red Hill Valley
Twenty-four
days of field work on breeding birds were carried out by
Michael Patrikeev between April 8 and July 10, including
a woodland/grassland monitoring program, a nest search and
a limited owl survey. Extensive supplementary observations
were provided by Bill Lamond and by Paul Rose who led the
dailyspring migratory survey from April 1 to May 31 in eight
areas of the valley. The fall survey directed by Ken Symington
from August 14 to October 31 in seven of the spring areas
and one additional one brought the total hours of migratory
observations to 630.
Great
Horned Owl.
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The
extensive data accumulated are summarized in three appendices
of the avifaunal section of the report prepared by Colin Macdonald.
Twenty years of Christmas Bird Count data from the northernend
of Red Hill Valley (provided by Kevin McLaughlin) were also
included to indicate overwintering use of the study area.
The report incorporates information from earlier breeding
bird surveys in Red Hill going back to 1976 and compares the
results of both the breeding and migratory data to other sites
in Ontario. The 1995 surveys identified 78 species of breeding
birds of which 67 were confirmed or highly likely. This compares
with 75 and 64 respectively recorded during Ontario Breeding
Bird Atlasing project from 1981 to 1985. A total of 91 species
have now been reported as breeding in the valley at some point
since 1976.
The
breeding surveys in 1995 confirmed the presence of the nationally
and provincially rare Coopers hawk. The Carolina wren was
considered a highly likely breeder and the Louisiana waterthrush
was identified as a possible breeder. Possible status was
also assigned to the provincially rare orchard oriole and
the regionally rare northern harrier. Twenty-five other species
considered uncommon in Hamilton-Wentworth were also recorded
with nineteen of these in the confirmed or highly likely categories.
The
report includes an annotated checklist of breeding species
and provides an extensive analysis of spatial and temporal
trends and contrasts breeding records with two comparative
sites in southern Ontario. Five sub-areas in the valley are
identified as particularly significant for breeding birds.,
the majority in the path of the expressway.
Black
Crowned Night Heron
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Nearly
61,000 birds of 177 species were observed during the spring
and fall migration surveys. One hundred and sixty-nine species
and 36,421 individuals were recorded in the spring, while
24,573 birds of 134 species were seen in the fall survey.
The
studies strongly confirmed that the valley is a significant
corridor for migrating birds. It provides a natural route
past the heavily-developed western end of Lake Ontario and
offers habitats that are rare or absent in much of the surrounding
area. The valley links the Niagara Escarpment with the Lake
Ontario shoreline and is the only north-south trending corridor
in the area in reasonable ecological condition. Evaluation
of the migration results suggests that the valley may be an
important part of regional migration routes.
The
report offers an explanation of the unexpectedly high levels
in the spring migration compared to the fall. It postulates
that a portion of the spring migrants are deflected by Lake
Ontario in a northwesterly direction along the Niagara Escarpment
and accumulate in Red Hill Valley because it provides an isolated
block of relatively extensive forest and natural area at the
end of the Lake. In addition, it uses regional forest cover
maps to show that birds moving due north from the Grand River
area would find only small woodlots without interior forest
in a large arc stretching south from the valley.
Red
Hill would be the first large forested area encountered for
some distance and could present an attractive resting and
foraging area before crossing the urbanized section surrounding
the western end of Lake Ontario. The tendency for both migrating
groups to be funnelled northward down the valley is offered
as an explanation for the relatively high bird diversity observed
in areas at the northern end of the valley.
The
theory goes on to suggest that in the fall, Lake Ontario deflects
some migrants in a southwesterly direction toward the relatively
high quality habitat of Cootes Paradise and the Dundas Valley,
and from there many birds fly directly south to the forests
along the Grand River. This path would avoid Red Hill and
might account for the significantly lower numbers observed
there in the fall migration.
An
examination of comparative migration data accumulated in 1995
in the Royal Botanical Gardens (RBG) properties seems to support
this postulation. Roughly similar numbers of birds were recorded
in Red Hill and the RBG areas in the spring, but much larger
numbers were observed in the fall at the RBG.
Great
Blue Heron in Red Hill Marsh |
Noteworthy
Bird Records
A
noted local historian , Lois Evans, voluntarily reviewed the
Noteworthy Bird Records of the Hamilton Naturalists' Club
accumulated from 1947 to 1994, and culled those pertaining
to both the present and historic natural areas associated
with the Red Hill Valley.
She compiled over 3000 records of 263 species seen in the
Red Hill area. Thirteen additional species were reported only
from Windermere Basin, and ten common species not considered
"noteworthy" were assumed to have been present as residents
or migrants for a total of 286. The records were also sorted
into five sub-areas, and a separate report was prepared incorporating
only the natural areas that remain in the valley and were
part of the 1995 study.
This lists 177 "noteworthy" species. The author adds 31 common
species residing in or expected to have made use of the area,
for a total of 208 species.
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Audio
Presentations: Red Hill Valley - No Place for a Road