Beamer Conservation Area (ON023)

Beamer Conservation Area (ON023)

Grimsby, Ontario

Description du site

Beamer Memorial Conservation Area (CA) is located on the Niagara Escarpment, immediately above the town of Grimbsy and about 2 km south of the south shore of Lake Ontario. The conservation area encompasses the steep-sided, north-south gorge of Forty-Mile Creek, which is incised into the escarpment. The 5 m high Beamers Falls is located at the head of the gorge. The north-facing cliffs of the escarpment are exposed. The drier uplands support forests of oaks, hickories, maples and hemlocks, the steep-sided gorge slopes. The cliff faces are predominantly covered by White Cedar, some of which may be centuries old. The escarpment slopes have forests mainly of Sugar Maple and White Ash, but include other Carolinian species. A small abandoned quarry provides habitat for several species of amphibians and reptiles. Grimsby Point, at the northwest edge of the gorge, is an exposed rocky outcrop overlooking the Forty Mile Creek valley and the Lake Ontario plain.

Oiseaux

Over a period from 1981 to 2019, an average of about 14,000 raptors passed over Beamer CA during each spring migration. Of this total, at least two species are generally recorded in numbers greater than 1% of their estimated national population. These species are Turkey Vulture and Red-shouldered Hawk. The 2012-2019 average for Turkey Vulture was 6,670 birds. which is a significant increase of Turkey Vulture in Canada from when the count was started in 1975. The count of Red-shouldered Hawks was 444, a drop from earlier years Other species recorded in large numbers include Sharp-shinned Hawk (avg. of 1,355 birds), Broad-winged Hawk (avg. of 2,894 birds), and Red-tailed Hawk (avg. of 1,469 birds). The data also reflect the range expansion of Black Vultures with 26 birds from 2010-19. Data over all years (1975 to present) also capture the recovery of species such as Bald and Golden Eagles, Osprey, and Peregrine Falcon that suffered the effects of D.D.T. Diurnal migrant waterbirds and passerines, which use the escarpment as a flight line, are seen in some numbers.

Beamer CA is significant as a concentration point for migrating raptors because of its physiography. The Niagara Escarpment is oriented (more or less) parallel to the southwestern Lake Ontario shoreline. In many locations, the cliffs of this escarpment are up to 20 m high. On many days in March and early April strong updrafts occur along the cliff rim as a result of the microclimate created by the topography, assisted on occasion by winds with a northerly component. The migrating hawks take advantage of these updrafts. The added feature that helps concentrate hawks at Beamer CA is a change in the orientation of the escarpment. At this point, the distance between the escarpment and the Lake Ontario shoreline is at its narrowest. In addition, the escarpment surface is at a much higher elevation than the plain. All these features force larger concentrations of hawks over the escarpment at Beamer CA relative to other locations along the escarpment. After mid-April, when prevailing winds tend to have a southerly component, birds usually pass over the park in the early part of the day, then pass to the south as thermals form over nearby farmlands.

Enjeux de conservation

The Niagara Peninsula Conservation Authority owns Beamer Conservation Area. Since 1975, volunteers have monitored the spring hawk migration, spending 550 hours per season on average, with raptors being counted daily from 1 March to 15 May. The counters use a vantage point located on a tower in a clearing at the southwest corner of the conservation area. There are no immediate threats to the migrating raptors, but government cutbacks have placed all conservation areas in the local system under severe stress.

Catégories ZICO Habitats Usages Menaces Potencielles ou Existantes Status de Protection

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