BioBase
The Helen Schuler Nature Centre has been collecting local plant and wildlife sighting data, within a 100 km radius of the City of Lethbridge, since the early 1990’s.
Sightings are reported by Nature Centre staff and volunteers, as well as residents of Lethbridge, and compiled into the Nature Centre’s BioBase.
Citizen Science Sightings
The Nature Centre encourages residents and visitors to track what they are seeing outside by sharing observations on applications like iNaturalist or eBird. These platforms help you to identify the plants and animals around you and connect you with a large community of other citizen scientists and naturalists.
Sharing your observations helps create quality data for scientists working to better understand and protect nature. Consulting recent sightings on iNaturalist or eBird will help anyone planning an excursion in our river valley and wanting to know what to expect at certain times of year.
Ecosystems in Lethbridge
Each ecosystem in Lethbridge's river valley supports a variety of different animals and plants! Be sure to explore all of the different ecosystems on your outdoor adventures.
Prairie Grasslands
Lethbridge is located within the grasslands natural region of Alberta. Throughout the grasslands the dominant vegetation is grass; the terrain is flat or slightly rolling.
Lethbridge has a semi-arid climate receiving an average of 30-40 cm of precipitation annually. Spending time in the wide-open spaces of the grasslands region will reveal a diversity of living things that have adapted to the relatively harsh conditions of the area.
It is estimated that only 40 per cent of Alberta's native grasslands remain, mainly located in the South-East part of the province.
Coulees
What is a coulee? Coulees are the steep-sided, v-shaped valleys found along the river throughout Lethbridge. In Southern Alberta, coulees were formed when the last glaciers retreated from our area. Since that time, the coulees have been eroded by water and wind. Coulees are a sanctuary for wildlife and home to hundreds of native plant species.
One of the first things you will notice in the coulees is the striking difference between plant growth on north and south-facing slopes. The direction of the sun’s rays on the hottest part of a summer day and the prevailing dry wind throughout the year focus on south-facing slopes. As a result, slopes facing south or southwest are quite desert-like, and a lot of bare soil is visible. Dry, sparse grasses mingle with large, widely-spaced patches of prickly-pear cactus, skunkbush, and sagebrush.
North-facing slopes are more protected from the sun and Chinook winds, and so retain moisture longer. They are characterized by dense areas of grasses, yarrow, cut-leaved anemone, prairie crocus, smooth blue beardtongue, and three-flowered avens. Low-growing saskatoon, snowberry shrubs, and creeping juniper also survive on north-facing slopes.
On the coulee ridge-tops, or bench, look for low-growing plants, such as cushion milk vetch, early locoweed, moss phlox, scarlet mallow, blue grama grass, and pincushion cactus.
Dense tangles of chokecherry, rose, western clematis, and thorny buffaloberry flourish in the coulee bottoms. Goldenrod, aster, brown-eyed Susan, Drummond’s milkvetch, sunflower, prairie coneflower, wild bergamot, and many others are also found here.
Did you know? Lethbridge is home to a small population of Prairie Rattlesnakes. It is important to learn how to live safely in Rattlesnake territory.
Research suggests that our hybrid poplar forests support greater densities of insects and birds than single-species poplar forests.
Floodplain & Cottonwood Forest
With very rare exceptions, the native trees found in the river valleys in the prairies of southern Alberta are all poplars. Three different species can be found, including the Plains or Western Cottonwood (Populus deltoides), the Balsam Poplar (Populus balsamifera), and the Narrowleaf Cottonwood (Populus angustifolia). The area from Brocket to Lethbridge is unique, being the only place in the world where these three poplar species interbreed to produce hybrids. This hybridization creates a very diverse forest with a wide range of leaf shapes and branching patterns. Research suggests that our hybrid poplar forests support greater densities of insects and birds than single-species poplar forests.
This unique habitat is best seen from a canoe or kayak at Popson Park on the southwest side of Lethbridge, and between Peenaquim, Alexander Wilderness Park, and Pavan Park on the north side of Lethbridge.
The vegetation and soils which are dependent on the presence of water, and that are located adjacent to waterways such as rivers, streams, lakes, and wetlands, are known as riparian areas. A healthy riparian area acts as a buffer and filter for water quality and provides abundant green forage vegetation, shelter, and habitat for various wildlife species, including fish. Vegetation that overhangs water sources provides shade and reduces water temperature. This allows fish to spawn and lay eggs during the summer, and reduces ice build up to allow fish to survive over the winter. A number of tree and shrub species are able to grow in riparian areas. Cottonwood Park is a good location to see regeneration of the riparian zone between the river and the floodplain.
The greatest diversity of birds is found in the mature cottonwood forests, especially where there is a dense understory of shrubs. Between May and August, a one-hour early morning stroll in Pavan Park, the Lethbridge Nature Reserve, or the Elizabeth Hall Wetlands can reveal 20 to 30 bird species! The spring dawn chorus commonly consists of least flycatchers, American robins, yellow warblers, warbling vireos, house wrens, goldfinches, and Baltimore orioles. In late August, large numbers of migrating warblers stopover in the cottonwood forests. Over 20 species of warblers and vireos have been observed in the Nature Reserve at this time. Some of the species seen are Townsend’s warbler, black and white warbler, Tennessee warbler, yellow-rumped warbler, American redstart, blackpoll warbler, northern waterthrush, and Wilson’s warbler. The cottonwood forest is where raptors, such as great horned owls, kestrels, Swainson’s hawks, and red-tailed hawks nest. Occasionally Cooper’s hawk and saw-whet owl nests can also be found.
The Rocky Mountains feed the headwaters of the Oldman mainstream and its tributaries (Crowsnest and Castle rivers, Willow and Pincher creeks).- Oldman Watershed Council
Oldman River
The path of the river in the valley is ever changing. As the river meanders, fast-moving water on the outside of a bend undercuts the steep banks while the slower moving water on the inside of a bend deposits sediments on the outsides of point bars. Major floods cause the river to change its course dramatically, sometimes almost overnight.
In Lethbridge, the path of the river has been altered to prevent undercutting of the river crossings. The Elizabeth Hall Wetlands were formed by the construction of a dike in 1953 to channel the river in a straight line under the Highway 3 Bridge. There have been several floods in the history of Lethbridge. Major floods occurred in 1919, 1953, 1964, 1975, and in 1995. In the 1995 flood, large amounts of silt, sand, and gravel were deposited on the floodplain of the Oldman River. The action of the floodwaters, together with the silt deposits, resulted in the germination of many cottonwood tree seedlings, and the promotion of cottonwood suckers.
Throughout the winter, much of the Oldman River is frozen, but parts of it remain open below the weir in Botterill Bottom Park and below the Wastewater Treatment Plant in Peenaquim Park and Alexander Wilderness Park. The open water attracts thousands of Canada geese, mallards, and common goldeneyes. The high numbers of waterfowl in turn attract hunting bald eagles, which migrate to the Lethbridge area for the winter.
In the spring and summer, large bank swallow colonies and nesting belted kingfishers can be found along the river banks. Look for American white pelicans fishing in the river around the weir in spring and summer, as well as at Alexander Wilderness Park. Common nighthawks can be found flying over the river at dusk during summer months at Cottonwood Park.
