May 14, 2008

West Seattle eyasses banded

Today, Wednesday May 14, 2008, with the indispensable help of a Seattle Department of Transportation (SDOT) crew, Mark Gleason and yours truly 'descended' upon the peregrines in the nest box beneath the West Seattle high-rise.

This past winter, FRG volunteers have kept an eye on 'our' local peregrine population, and we noticed some changes. In West Seattle the female disappeared (for unknown reasons), while in Ballard the male disappeared. The Ballard female (double-banded) then showed up in West Seattle, and has now produced her first set of offspring in this site.

In the 2006 and 2007 seasons, the West Seattle pair chose not to use the nest box placed for their use beneath the bridge. Instead the female laid her eggs on top of piles of feathers and bones, left over from meals, in the bridge expansion joint.

The Ballard female, who nested in the box beneath the Ballard Bridge during the 2006 and 2007 seasons (raising a single chick each season), opted to use the nest box at West Seattle. The box and its contents are easier to observe from the bridge control tower than the expansion joint, making planning for banding activities simpler. Our thanks go to SDOT Mary Brown and Ed Morteson for helping schedule the banding.
The only way to access the nest site is by blocking off one of the lanes of traffic on the bridge and removing a man hole cover at the top of a ladder leading to a maintenance catwalk. The nest box was placed next to this cat walk many years ago, when peregrines started wintering in the area, and we suspected they might try and nest here.

In this picture the SDOT crew has removed the man hole cover out of the roadway, exposing the ladder leading to the cat walk.
We found four healthy-looking eyasses in the box, and two attentive adults who flew around and vocalized to show their displeasure at our unannounced visit.
The four young were banded with USFWS bands and VID bands and returned to the nest box
Even before Mark and I could retreat up the ladder, the female was back at the nest box, checking out her young (below).

The final image of the female shows the value of outfitting the birds with the VID band, in addition to the USFWS band. In real life the code (vertical 07 over vertical P) is easy to read, making identification possible without having to re-capture the bird.
In this case, it made it possible for us to track her from her old nest site to her new nest site, and document her third breeding season, as her most productive season to date.