March 20, 2008
“Round-Robin” of peregrines in the Twin Cities
It has been quite a busy month since I wrote the February field note. Even though there is still snow on the ground, the peregrine falcons are in full swing of courtship and finding a territory. We have had quite a bit of change-over occur between several of the urban territories and several new birds observed by the field team.
One of the biggest change-over to occur is between the City Center complex in downtown Minneapolis and the Wells Fargo bank building in Bloomington. The City Center building is the tallest of urban sites in the state, with the box at the 50th floor, facing east in the southeast corner of the building. This site has had several fatal territorial battles occur since the first successful nesting in 1987, and appears to be a highly sought after nesting site. In fact, in 2007, Dr. Tordoff had the opportunity to observe a battle between two females in the nest box, just a few steps away. He also had the opportunity to document the battle with his camera, and was willing to share his photos with the rest of the team.
This year, the female in residence at City Center appears to be the same bird who tried to take over the site in 2007: “Mendota”, a 1997 female that hatched off the Mendota Bridge at the Fort Snelling State Park. Mendota is known to the field team for having very aggressive and protective behaviors towards the banding team when trying to observe the site for hatching or during the banding of the chicks. She had been successful at both the Colonnade and Wells Fargo buildings in the local area since 1999 and has produced 25 chicks over her life so far. I had observed Mendota at the Wells Fargo site throughout the fall and winter months-confirming her at the Wells Fargo building as late as February 26th and then she was in the box at the City Center site on March 3rd.
The un-banded female peregrine that appears to have lost the City Center territory had nested there since 2003, and appear to migrate, and where she is from late October to mid-March is anyone’s guess. Even though I had observed Mendota at the downtown site for nearly 2 weeks, I still thought that we may have the same scenario play out with the un-banded female returning in mid-March. Imagine my surprise when I went to the Wells Fargo building in Bloomington on March 14th to try another attempt at identification, when I noticed the two birds on the south side of the building…an un-banded adult female and a banded male. I took several photos of the un-banded female and compared her to the photos of the un-banded bird that has nested at City Center since 2003…low and behold, they were THE SAME BIRD!! I wish I witnessed what had taken place between the two birds to have the current situation, but it doesn’t really matter at the end of the day. I then went back to City Center and Wells Fargo today, and the situation stands as above. This doesn’t mean it still couldn’t change, but if they stay this way into mid April with egg laying, I would guess that things are pretty much set in stone (unless something happens to one of the females due to other causes).
We still have a few sites left to figure out the identity of the birds in the metro area, and certainly have our work cut out for us with the cliff territories on Lake Superior and Mississippi River. By the end of the month, we should have the urban areas done and the others by the end of April. Look for the next field note in April-eggs should be laid and pairs incubating like crazy. It’s step 2 in the process, with the hopes of chicks to band in May and June. Stay tuned…