News/Reports

IBA records of Great Blue Heron Colony

Posted January 29, 2012 | Categories : 74,Research |

From http://www.bsc-eoc.org/iba/site.jsp?siteID=BC018

IBA Pacific Spirit Regional Park
U of BC – Point Grey, British Columbia
Site Summary
BC018 Latitude
Longitude
49.244° N
123.218° W
Elevation
Size
50 – 87 m
1.92 km²
Habitats:
coniferous forest (temperate), deciduous woods (temperate), mixed woods (temperate), rivers/streams, bog, urban parks/gardens
Land Use:
Nature conservation and research, Tourism/recreation
Potential or ongoing Threats:
Disturbance, Industrial pollution, Introduced species, Recreation/tourism
IBA Criteria: Nationally Significant: Threatened Species
Conservation status: Regional Park (provincial)
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Site Description

Pacific Spirit Regional Park lies on Point Grey between the University of British Columbia to the west, and Vancouver residential areas to the east. It consists of: two areas of forest almost separated by a golf course; a long narrow strip of forest on seaward-facing bluffs around the western side of the UBC campus; and adjacent beaches and inshore waters. Two adjoining areas are also included in the IBA: UBC Farm near the south end of the campus (24 ha); and Cecil Green area along the top of the bluffs at the northern edge of campus (about 2.3 ha). The Park is in the Coastal Douglas-Fir biogeoclimatic zone (Fraser wetter maritime subzone) with dominant trees Douglas fir, western hemlock and western red cedar, and understory of salal, Oregon grape, sword fern and moss. Most of the northern area was logged 50–60 years ago, and is now second growth red alder forest with some cottonwoods and maple, and an understory of salmonberry. The southern area was logged in the 1890s and is now mostly coniferous forest with some Sitka spruce. Patches of more open unlogged forest – mostly Douglas fir and broadleaf maple — survive on steeper slopes. UBC Farm encompasses 10 ha of open agricultural fields and about 10 ha of forest; including extensive edge habitat. In addition to agriculture, the site is managed to maintain different types of habitat for the abundant local wildlife. Cecil Green area consists of tiny remnants of the local forest interspersed with open areas of long grass. Most of the Park occupies a gently undulating upland at 60-100 m elevation. This is underlain (in descending sequence) by horizontal layers of beach sands; marine deposits; till from the last great glaciation; and thick white outwash sands from the last glacial advance. These sediments are exposed in the coastal bluffs and in several deep, stream-eroded ravines in the northern part of the Park. Several small creeks, generally less than 2 m wide, drain the area; 4 creeks are the focus of enhancement projects for salmon and trout. There are several small bogs on the eastern edge of the park, including recently rehabilitated Camosun Bog. The Pacific Water Shrew, which is restricted to low-elevation forests in the Fraser Valley, occurs in the park, and this is one of only three areas in Canada where Western Red-backed Vole occurs.

Birds

Continentally significant numbers of Great Blue Herons (of the nationally vulnerable BC coastal subspecies Ardea herodias fannini) nested in the Park for many years. The colony size varied throughout the years, but in most years there were 100 to 200 nests. From 1996-1999, there was an average of 147 active Great Blue Heron nests in the Park, which is almost 3% of this subspecies’ North American population. Peak numbers of herons were recorded in 1996 (217 nests). Originally the heronry was located in what is now the UBC Endowment Lands Ecological Reserve, but in 1974 birds relocated to a site about 1 km to the northeast. Most recently, this was abandoned and the herons may have joined the increasingly large heronry in nearby Stanley Park. The Park is a significant area for songbirds and other woodland and forest species due to its area and location. It is by far the largest “wild” greenspace remaining within Metro Vancouver (excluding the north shore mountains), it lies on a peninsula between the sea and the Fraser River delta, and it adjoins a major urban area. This large “fragment” or “island” of natural habitat maintains a rich and diverse bird population, and is an important stopover for migratory birds. Cecil Green, an attractive landing and foraging site next to a wide stretch of open water, is well known for the large numbers and great diversity of birds which pass through during migration. Many rarities have been found in this small area, and one local birder has personally observed over 156 species. The fields at UBC Farm attract open-country species during migration. Nature Vancouver initiated monthly bird surveys at the Farm in 2007; see www.ebird.ca for data.

Summary of bird records available for Pacific Spirit Regional Park
Click here to view all records
Species Season Number Unit Date
Great Blue Heron (BC coast) BR 364 C I 1985
Note: species shown in bold indicate that their population level (as estimated by the maximum number) exceeds at least one of the IBA thresholds (national, continental or global). The site may still not qualify for that level of IBA if the maximum number reflects an exceptional or historical occurence.
Conservation Issues

Although Pacific Spirit is a regional park within Metro Vancouver and therefore protected from development, 22.3 ha have recently been removed from the Park by the provincial government. Because of the parks proximity to a major urban center and UBC, it is subject to heavy use by hikers and cyclists, and many pedestrians (including professional dog walkers) with mostly off-leash dogs. Conflicts arise between park users. New residential developments at UBC are increasing Park use. UBC Farm may be lost to yet more housing development at UBC.