First Cape May Warbler Ever Seen In the Lower Mainland
Instead of spending time in Turks and Caicos or Barbados, this tiny yellow Cape May warbler has somehow ended up in Abbotsford, B.C.
Bird photographer Nick Balachanoff says, to his understanding, it’s the first identified Cape May warbler in the Lower Mainland or Fraser Valley.
The normal migration route in and out of northeastern BC is likely on a northwest-southeast axis east of the Rocky Mountains. The lower mainland bird appears to have exhibited a known migration navigation error called mirror-image migration. In this process, birds move in a flipped direction. So in this case, instead of migrating southeast as per normal in the fall, the bird moved southwest. If a bird normally migrates on a 40 degree SE direction from a centre line for example, the mirror image misorientation would send it on a 40 degree SW direction from the centre line.
This type of navigation error is now thought of as being a consistent misorientation as opposed to a random disorientation. A certain percentage of a variety of species exhibit this anomaly, with the California coast being a consistent place where these breeders from northcentral and northeastern Canada arrive. Wind drift can assist this or even push them a little more off course. Some may remain on land, but some are felt to continue out to sea where they perish. The lower mainland bird appears to be remaining in a more hospitable place.
WHAT! That’s so fascinating.