Hamilton Conservation Authority City of Hamilton Bruce Trail Conservancy
 
 

 

Bronte Creek Ravine

General Summary

The Bronte Creek Ravine study area straddles the City of Hamilton – Halton Region boundary. It encompasses an 8 km long east-northeast-trending re-entrant in the Niagara Escarpment, which is occupied by the main trunk of Bronte Creek. Mixes of mature forest terrestrial communities have developed on the diverse slopes, aspects, and moisture regimes present across the ravine. Groundwater discharge into this section of Bronte Creek is sufficient to support coldwater fish habitat.

Significance

Ontario Ministry of Natural Resources Designation:

  • Provincial Life Science ANSI (Area of Natural and Scientific Interest)

City of Hamilton Environmentally Significant Area (ESA) Criteria:
  • Significant Ecological Function
    • the area contains significant species
    • the area contains interior forest habitat (100-200m from forest edge)
    • the riparian area serves as a link between natural areas within Flamborough
    • the area encompasses a significant coldwater aquatic habitat
  • Significant Hydrological Function
    • the groundwater discharge zones in the area help to maintain water quality in Bronte Creek

Physical Description

The eastern end of the re-entrant valley in Halton Region is 5 km wide and flanked by the prominent headlands at Rattlesnake Point and Mount Nemo. The western end in the City of Hamilton is much narrower and here the bedrock valley is partially buried beneath extensive outwash deposits, left at some point during the retreat of the last glaciers when the valley was occupied by a large meltwater stream. Topography in this misfit stream valley is varied. Below Progreston, the steep walls of the Bronte Creek valley contrast with the undulating surface of the surrounding tableland.

The entire study area includes a 7 km stretch of Bronte Creek, including the confluences of Flamboro Creek, Kilbride Creek and Willoughby Creek tributaries. Several inline ponds have been created behind artificial barriers on the main and branch creeks.

Ecological Land Classification

Due to the valley’s topography, this natural area encompasses a mix of mature forested terrestrial communities with varied aspects. An open riparian meadow is located midway between Progreston and the Hamilton boundary. Small patches of swamp and seepage areas are present locally on the valley walls. Most of the woodlands have been subject to selective cutting in the past.

Flora and Fauna Summary

Vascular Plants

A total of 241 species have been documented, including 11 locally rare species, four locally uncommon species, and 39 (16%) non-native species.

Butterflies

During the 1991 NAI, 20 species were recorded including two locally uncommon species, one locally uncommon and provincially rare species, West Virginia White (Pieris virginiensis), and one COSEWIC special concern species, the Monarch (Danaus plexippus).

Fish

Fish community sampling on the main branch of Bronte Creek was undertaken on a number of occasions between 1958 and 2002. Twenty-six species have been collected within this reach, with 19 recorded since 1990. Significant species include: Brook Trout (Salvelinus fontinalis fontinalis), Fantail Darter (Etheostoma flabellare), Northern Hog Sucker (Hypentelium nigricans), Rainbow Darter (Etheostoma caeruleum) and Sea Lamprey (Petromyzon marinus). This coolwater reach lies within the glacial spillway that extends from the Progreston Dam downstream to the Lowville Dam. The Lowville Dam generally acts as a partition between the resident Brown Trout (Salmo trutta) population upstream of the dam and the migratory Rainbow Trout (Oncorhynchus mykiss) population that can move from downstream up to the dam.

Fish community sampling was carried out on Kilbride Creek on several occasions between 1958 and 1999; in total, 15 species were collected, with 10 recorded since 1990. Fish community sampling on Flamboro Creek in the 1980s and in 1998/99 found 18 species, with 13 recorded since 1990. Significant species within this reach include Brook Trout and the locally rare Mimic Shiner (Notropis volucellus). Willoughby Creek was sampled on several occasions between the early 1970s and 2002; 13 species were found within the ESA, with all 13 recorded since 1990.

Herpetofauna

A total of four species were recorded from 1988 to 1991, including the COSEWIC special concern species, Eastern Milk Snake (Lampropeltis triangulum triangulum).

Breeding Birds

A total of 39 species were found in 1991, including 11 locally uncommon species, one locally rare species, Canada Warbler (Wilsonia canadensis), and eight forest interior species. The Louisiana Waterthrush (Seiurus motacilla), a locally, provincially, and nationally rare species, was documented in this area four times between 1981 and 1991.

Mammals

This area did not receive adequate coverage during the Nature Counts project, but eight common species were recorded during the 1991 NAI.

Waterfalls

 


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