Ontario habitat drier than recent years, but mostly ice-free

Written by Jim Wortham
Monday, May 17, 2010

Jim Wortham.We have completed our surveys of western Ontario, Stratum 50. We were pleased with the timing of the surveys as the deciduous trees had not yet leafed out and most birds were observed as pairs or lone drakes. In this area, we survey long lines or transects that begin on the southern end of our area within a relatively populated area and traverse long stretches of country northward to areas populated only by a few outfitter camps or native communities. Because of the distances involved, flying these lines are a bit like going backwards in time in that what appears as springtime on the southern end can more resemble winter when turning the corner on the northern extents. This year some ice persisted on some of the larger lakes in northern Ontario; however, all other habitats were ice-free.

When qualifying habitats in these areas we base evaluations on two primary characteristics: 1) how wet or dry are the marshes, and 2) how available are habitats to nesting waterfowl in terms of ice and snow persistence. In general, we found habitats in this stratum to be drier than in recent years, with lake levels having fallen significantly and many shorelines exposed for great distances. This forces birds to seek nesting cover far from available water and potentially leaves them vulnerable to terrestrial predators. However, despite the drier conditions, all available habitats were unhindered by ice and accessible to birds. Those areas having healthy beaver populations were often characterized by well-charged beaver wetlands offering emergent nesting cover for breeding ducks. We describe the overall condition of these habitats as “fair” due to the decreased availability of emergent nesting cover, but “good” in that all habitats were available to birds.