Actively Nesting Migratory Bird Survey (Nest Sweep)
Fiera Biological was retained by an Alberta highway contractor to conduct a breeding bird and nest search (nest sweep) within a site of proposed vegetation clearing along a primary highway in central Alberta. The purpose of the work was to ensure no actively nesting birds were at risk of being impacted by the proposed work and therefore, compliance the Wildlife Act and the Migratory Bird Regulations.
The worksite area proposed for clearing included both sides of the highway for 300 m in either direction centred on a watercourse crossing. At the time of field assessment, May 15th, the area proposed for tree clearing included mostly agronomic roadside grass species. Sporadic small sparse stands of willow shrubs (Salix spp.) were scattered throughout much of the survey area. Also included in the proposed clearing area was a small portion of a significant riparian tree-stand dominated by immature and mature trembling aspen (populous tremuloides), balsam poplar (Populus balsamifera), and willows. Other areas had wetland characteristics where sedges (Carex spp.), cattails (Typha latifolia), and willow dominated the habitat.
To determine the presence of actively nesting migratory birds, two professional biologists (P.Biol.) with multiple seasons of bird survey experience surveyed from 7:30 and to 10:00 am totalling 5 search-hours, and covering the entire area. All bird activity was noted, and birds detected were observed carefully for a sufficient period of time to determine the likelihood of nesting activity within the study area.
Conditions on-site at the time of the assessment were favourable for detecting breeding birds, with no precipitation and minimal wind. A total of 2.8 ha was surveyed, achieving a search effort of 0.56 ha per hour.
Taking into account the habitat quality, season, and vegetation structure, the search-effort of the is survey was thought to be rigorous by available standards. We did not detect any evidence of active nesting within the area slated for clearing, and therefore recommended that the clearing event as it had been described to us could proceed as scheduled, and offered the following cautions and recommendations.
- We advised the client not to delay the scheduled clearing, as nesting activity on the site was imminent. If for any reason the clearing could not occur within 5-days, our advice was to postpone the work until August 15, after having a professional assess it for late nesters.
- The tree vegetation adjacent both sides of the watercourse was identified as highly productive bird nesting habitat, and as such, we advised the client to conserve those areas to the full extent possible during the required work. And further recommended that in all cases, vegetation clearing be minimized to the extent possible.
- We warned the client that neither our results, nor the following report authorize the destruction of active nests or the molestation of nesting birds. As such, if at any point the client, or their agents/contractors observe or suspect the occurrence of an active nest having potential to be impacted by the slated clearing and related activities, work should stop, and a wildlife professional should be consulted.
Key Personnel / Role
Tonya Lwiwski / Professional Biologist
Joseph Litke / Professional Biologist
Alberta Highway Contractor