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September
1996 Newsletter
Results
Of The Biological Inventory in Red Hill Valley
In
1995 a team of eight professional biologists conducted an
inventory of the Red Hill Valley. They found a very rich
diversity of flora and fauna. More than 1000 species were
identified as residents or migrants through the study area.
These included 578 plant taxa, 18 species of fish, 15 herpetofaunal
species and 24 mammals. Up to 78 species of birds bred in
the valley in 1995, and 177 species were observed in migratory
surveys. Forty-five species of butterflies and 136 species
of moths were also noted, along with a variety of benthic
invertebrates in Red Hill Creek.
These
numbers are almost all much higher than have been recorded
in the past. For example, seven previous studies of fish
in Red Hill Creek conducted since 1985 found only a total
of eight species. Similarly, a 1991 study identified only
ten common mammals.
Copies
of the entire 235 page report can be examined in the Hamilton
and Wentworth libraries.
Rare
Species
Five
nationally and provincially rare species were recorded,
two plants and three breeding birds. The nationally and
provincially rare southern flying squirrel was also reported
(and was confirmed in 1996). A third plant species designated
as provincially rare was also identified. Nine nationally
and provincially rare bird species were observed during
the migratory surveys. Six more designated as provincially
rare were also seen during migration, one of which was assessed
as a possible breeder in the valley in 1995. In addition,
30 species considered rare in Hamilton-Wentworth were found,
including 20 plants, five moths, two butterflies, and one
each of fish, breeding birds and herpetofauna.
The
number of rare flora and fauna uncovered in the inventory
considerably increases our knowledge of the Red Hill Valley
area. For example, only seven plant taxa classified as rare
in Hamilton-Wentworth have prevously been identified in
the area, compared with 20 in the 1995 study.
A review of the eleven inventory field studies and reports
indicates that all parts of the study area were identified
as significant. The importance of maintaining the integrity
of the entire study area was emphasized by several of the
field biologists, who noted the great variety of wildlife
habitat it provides.
Vegetation and Flora
This
part of the study was conducted by Anthony Goodban who visited
the area on nineteen days between May and October. Data
was also accumulated on two days in September by the Plant
Study Group of the Hamilton Naturalists' Club. Particular
attention was paid to documenting the graminoid taxa and
to augmenting previous floristic surveys of the valley.
The final report includes detailed mapping and description
of the aquatic and terrestrial vegetation communities, including
several anthropogenic community types.
A
total of 570 species (578 taxa) are listed along with their
locations and community associations. Seventy-four percent
are native species and they represent 22% of Ontarios native
flora. Significant findings included two nationally and
provincially rare species: Slender Satin Grass (Muhlenbergia
tenuiflora) and Green Violet (Hybanthus concolor).
The provincially rare sedge, Carex artitecta, was
also identified, along with six species considered rare
in the Ministry of Natural Resources old Central Region,
and fourteen additional species classified as rare in Hamilton-Wentworth.
The latter are each known from five or fewer post-1949 sites
in the Region.
The
three provincially rare species all occur in the vicinity
of Albion Falls and Buttermilk Falls and are ranked "S2"
in Ontario by the Natural Heritage Information Centre. This
theme area also harbours several other rarities including
Chinquapin Oak, Soapberry, and Hispid Goldenrod.
Forty-nine
species with southern affinities were found in the valley,
most of which are associated with the Carolinian life zone.
Twenty-four species with northern affinities are also listed,
along with ten species associated with prairie or savannah
habitats.
Butterflies
and Moths
Bill
Lamond also spent 56 hours on eleven different days examining
the study area for butterflies between May 10 and August
30. Twenty-one hours on six nights in June, July and August
were spent sugaring and/or black-lighting for moths.
Twenty-eight
sub-areas were identified as providing habitat for 45 species
of butterflies. Two additional species have also been recorded
from the valley since 1991. Thirty-eight of the 47 are classified
as residents, seven as migrants, and two as possible residents
or strays into the area. Twelve species had not been recorded
before in Red Hill Valley.
Two
of the resident species, the Northern Cloudywing and the
Hickory Hairstreak, are classified as rare in Hamilton-Wentworth,
and four others are designated as uncommon in the Region.
The eight most important habitat areas for butterflies all
lie in the path of the proposed expressway.
The
moth study found 136 species in a small area on the southern
edge of the Kings Forest Golf Course. The biologist suggested
that because of spatial and temporal limitations to the
study, the total number of moth species in the valley could
be more than double the number identified in 1995. Species
status designations have not been developed for moths, but
Mr. Lamond used his extensive experience in Brant County
and Hamilton-Wentworth to assign a preliminary status. Based
on this, he found five rare species and 23 uncommon.
Fish
and Aquatic Communities
The
1995 aquatic examination was comprised of five separate
studies carried out by Shawn Staton: spawning surveys; fish
sampling; invertebrate sampling; habitat assessment; and
a brief search for trout fry.
Twenty
stations were sampled for fish species, and specimens of
benthic invertebrates were taken at six locations. Spawning
surveys ran for six weeks in the spring and five more in
the fall.
A
total of 18 species of fish were recorded in the survey,
eleven of which had not previously been reported from Red
Hill Creek. A McMaster study carried out this spring (1996)
confirmed many of the findings and also reported spawning
by northern pike in the Red Hill Marsh and the presence
of four additional species of fish, bringing the total number
to 22. Fifteen species were captured during the sampling,
while visual observations were made of northern pike and
brown trout, and extensive spawning activity of rainbow
trout was noted. Chinook salmon and white sucker spawning
was also observed. A particularly interesting catch in the
sampling surveys was a single chinook salmon smolt which
appears to have been naturally reproduced the previous fall
in Red Hill Creek (four more smolts were found in the McMaster
survey). The discovery of a single lake chub may indicate
a small spawning run of this species in the creek. The regionally
rare threespine stickleback also appears to breed in the
creek.
Benthic
sampling revealed a moderately high degree of organic pollution,
especially at the two sites above the escarpment. However,
the highest quality invertebrate community was found at
the site just below the escarpment, south of Kings Forest
Golf Course. While noting the organic pollution, the report
concluded that excessive stormwater flows are "the most
critical perturbation affecting the aquatic ecosystem of
Red Hill Creek." The high discharges are limiting fish habitat
and salmonid reproductive success and causing extensive
erosion and channel instability. Flows more than 250 times
baseflow were recorded in an October 1995 storm.
Reptiles
and Amphibians
The
herpetofaunal study was conducted by Bill Lamond from April
until the end of August in eleven site visits totalling
39 hours. Additional incidental sightings were provided
by several volunteers. Eleven species of reptiles and amphibians
were found in the main valley. Four others were recorded
at Felkers Falls during the Hamilton Herpetofaunal Atlasing
work carried on between 1984 and 1992. Eight additional
species have previously been recorded in the valley but
not seen for several years and most of these have likely
been extirpated.
The
report notes that the 1995 cross-mountain expressway construction
in the area north of Stonechurch Road and the Upper Ottawa
Street landfill destroyed breeding habitat for three frog
species which may have been extirpated as a result.
Birds
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
daily spring 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.
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.
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.
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.
Mammals
The
mammal study combined incidental sightings primarily accumulated
during the bird migration surveys, with twelve nights of
small mammal trapping carried out by John Hannah. This was
supplemented with a review of the reports of the Hamilton
Society for the Prevention of Cruelty to Animals (HSPCA)
and an appeal to local residents to "turn in what the cat
brings home".
A
total of 24 mammal species (including four bats) were confirmed
in the study area. Unconfirmed sightings of three others,
including the flying squirrel were also recorded. Confirmed
species included mink, coyote, red fox, beaver and white-tailed
deer. Five small mammal species were found in the 60 captures
in the trapping program.
A
separate bat survey was done by Sandy Dobbyn who conducted
eight nights of field work in the valley. The first seven
nights took place in late July and early August and concentrated
on resident species. The final night, on August 29, was
for the purpose of searching for migrating bats. Tuttle
traps, mist nets and electronic bat detectors were used
to find and identify the bats.
One
hundred and thirty-five bats were observed and the presence
of four of Ontario's eight species was confirmed. The little
brown bat that is considered the most common species was
not confirmed in Red Hill although four echolocation signals
received in the bat detector could not be identified and
may have been from this species.
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