Tuesday, February 19, 2013

California Gulls Return

There are large numbers of California Gulls passing NW over Moorecroft right now. Probably due to the unsettled weather, they are passing quite low over the park and they are vocalizing continually, which is typical when these birds migrate at lower elevations in the dark. It will be interesting to see if this movement continues after sunrise.

Some years, we see massive numbers of California Gulls moving into the Salish Sea at this time of year, searching for the herring spawns which help fatten the birds for their long migration to the prairies.

Wednesday, February 13, 2013

Spring Raptor Migration At Moorecroft

In September of 2012, we discovered that raptors, vultures, and other migrant birds appeared to be moving from the Sunshine Coast onto Vancouver Island, using an island hopping route which terminated at or near Moorecroft Regional Park in Nanoose. I was curious as to whether they would use the same route as part of their northbound migration in the Spring. And on February 5, 2013, we began to see evidence that, at least in the case of Red-tailed Hawks, they do indeed. Red-tailed Hawk is not a bird we see regularly in Moorecroft Regional Park, as the near continous cover of conifer forest is simply not the type of habitat that they prefer. And after seeing virtually none of them since October, it was a bit of a surprise when I discovered an immature Red-tail perched in a fir at Vesper Point on the 6th of February. Although it was early February, I was aware that many raptors move back up the southern coast very early each year, so I sat down on a beach log and waited to see what this bird was up to. Within the hour, it took to the sky, and attempted to gain altitude by thermalling, which was not terribly successful. Twice it soared out over the open water, approximnately a third of the way to South Ballenas Island, which is about three kms offshore. It always turned back though, and after several hours I gave up watching. The bird was perched in the same fir where it was first seen, when I left the point. The next morning, a bird that I strongly suspect was the same individual was spotted flying back towards Moorecroft, from approximately half way to South Ballenas Island. It seemed that this bird wanted to reach the Ballenas islands, but was having no luck doing it. Later that afternoon, with warm and sunny conditions throughout the day, I spotted an immature Red-tailed Hawk perched in a tall fir on West Ballenas Island. On the 8th of February I noted another immature Red-tailed Hawk, this one definitely a different individual as it was a paler morph, soaring from Cook's Point in Moorecroft, to Gerald Island, where it circled for about 15 minutes, before using a combination of soaring and flapping to reach South Ballenas Island. This was repeated again on the 9th, with yet a different immature Red-tail. On the 11th, an adult western type Red-tailed Hawk used the same route, although it did very little soaring, covering most of the distance by flapping. As we experienced last Fall, once the birds reach the Ballenas islands the distance is simply too great to ascertain what goes on much beyond that point. My assumption continues to be that they then fly to Lasqueti Island, then Texada Island, before crossing to either the mainland, or perhaps another island closer to the mainland. Turkey Vultures generally begin migrating back to Vancouver Island in late February, so we hope to continue monitoring migration in Moorecroft Regional park. Hopefully, the weather will cooperate enough that we will be able to row to the Ballenas Islands to try and verify where the birds are going once they reach there.