The Effects of Cattle Grazing on Wetland-dependent Birds in the Aspen Parkland
This information is adapted from a poster presentation created by Robb.
Alberta is host to approximately 5.7 million cattle, and cattle numbers are expected to increase drastically in the future. The potential impacts to waterfowl include:
Reduced species diversity
Reduced attractiveness of nesting cover
Reduced nest success
Robb's objective was to investigate the diversity, relative abundance, and nest success of wetland-dependent birds in relation to grazing intensity on adjacent lands. He also investigated the relationship between grazing intensity in the uplands and the impact on emergent vegetation communities.
The study area included 90 wetlands within 45 quarter sections between Tofield and Pine Lake, Alberta. This area of Aspen Parkland responds well to rainfall, allowing intensive grazing. The pastures included native/naturalized and tame pastures, which were separated into six categories of grazing intensities:
Native idle or lightly grazed
Tame idle or lightly grazed
Point count surveys to measure species diversity and abundance relative to grazing intensity
Nest searching and nest fate monitoring to evaluate nest success relative to grazing intensity
Vegetation surveys across wetland fringes
Relate grazing intensity within wetlands to area of wetland habitat within pastures
Landowner surveys to identify stocking rates, cattle types, grazing duration, and the use of off-site watering and salting facilities