Port Colborne Egg Mystery May Be Revealed
April 22, 2013 - Port Colborne - ADM Mill
Tracy Simpson Reports:
Doug Garbutt and the staff at the ADM Mills have been watching their resident adult peregrines, Trillium and Buffalo Bill, rather closely since Trillium consumed both of her eggs by April 5th. What made matters more complex is that the monitor at the mill had failed and they were now blind to the activities inside the nest box. All that they could be certain about is that Trillium was seen on the monitor consuming her two eggs and that had staff at the mill very concerned about their peregrines. As if this story wasn’t complex enough, on one of Doug’s recent bike rides through the park beside the northern mill in town operated by Horizon Milling, he heard a familiar call, looked up and found a pair of peregrines on the east face of the mill. Well, who was this now. Are there two pairs in Port Colborne? Is this Buffalo Bill and Trillium? Bruce Massey and I went down this past weekend to see if we could help sort out some of the mysteries surrounding this new development.
When we arrived we met up with Doug and travelled straight to the northern mill. When we arrived, the winds were howling and so were the peregrines! Absolutely there were two peregrines on site, one in the air and one perched on a vent cover on the east face of the main building. The roosting bird took to the air and now both birds were up and flying. Both birds flew up and into a vent shaft on the east face of the mill and disappeared from our sight. We could clearly hear them vocalizing in the vent and then suddenly the male appeared and was in the air again. The female flew out shortly thereafter and the two peregrines were now circling. Then a third bird arrived! This peregrine was most definately a female and was now being addressed by the male. This intruder was not being treated with the ferocity I would have expected from an adult challenging the resident pair for their territory and for the most part, the male only circled with this second female. A couple of talon locks were attempted but there was no serious effort to drive out this intruder. Okay… A non threating yet annoying third peregrine. The adult resident male now escorted this female to the south towards the ADM Mill site and the adult resident female continued to circle above us for a few minutes before following them. This gave me a moment to review some pictures I had taken which revealed some interesting facts.
The male is definately an adult with the same band configuration as Buffalo Bill. I can almost make out the band number and I am 99% sure that it is him. Buffalo Bill has a black over green recovery band marked 68 over R with a silver USFW. The first female is an adult as well and is clearly unbanded which is consistent with the resident adult that ADM staff named Trillium. Ok. So this is the ADM Mills pair. Now onto bird number three. Ha! Juvenile coming into her subadult year! Probably the only thing that saved her from a serious battle is the juvenile plumage that she still wears as her moult has yet to begin. This now begins to make more sense.
We piled into our vehicles and headed down to ADM Mills to see if we could find the three peregrines and what exactly they were up to. When we arrived, the pigeons on site were wheeling madly around so we knew that they were here. It was hard to determine what exactly all three were doing as they were whipping around the mill at Mach 10 and at times were only 20 feet or so over our heads. What I got out of the observations is that the juvenile is being a serious pest. At times we had all three in the air and it was a much more serious situation. Both resident adults were now clearly frustrated and defending their site with talon locks, dives and escorts. This female juvenile was just not getting the message. We walked to the pier side and looked up at the nest box to see if we could find a roosting bird for further confirmation of identity. Just then Trillium burst out of the nest box and whipped through the mill after the juvenile. Back on the other side the dives and madness continued as now the pigeons, gulls and peregrines were all wheeling around in the screaming winds and all we could do was watch. Trillium and Buffalo Bill had finally left our view for over 5 minutes and the juvenile was nowhere to be found. Back to Horizon Mill.
Upon our return, we found Trillium on a vent cover near the top of the mill. There she roosted and preened for quite some time on her own. We suspected that Buffalo Bill was in the area as he had just circled around the back side of the mill when we arrived. After roosting for a while, Trillium flew off of the vent cover, passed Buffalo Bill who was now in the air above the canal and swooped up entering a lower vent shaft. There she stayed and Buffalo Bill took up position near the top of the mill. Bruce was able to get a view of her in the scope and Trillium was now lying down in the vent shaft and gravel picking. We suspect that she either has an egg already or is in the process of producing eggs as we speak.
The stress that this juvenile has put on Trillium is most likely the cause for her destruction of the first two eggs in the box at ADM Mills. With the monitor now replaced, the staff at ADM will be watching to see if any peregrines enter the box and just who is in there. The nest box at ADM will not stay empty for long as this location has been fought over almost each and every year. The food is so abundant, the site provides suitable nesting habitat and the location is perfect… …almost too perfect. Doug will be watching the other mill for signs of nesting by Trillium and Buffalo Bill as well as watching the activity at the ADM box. Bruce and I will be making another trip to help out as well.
The question that I can hear rattling around in your minds is who is the juvenile female???!!! Is she banded? Yes, she is. I have yet to go through all of the pictures but I can tell you that she is an Ontario hatched bird with red tape on her USFW band and we strongly believe that this is Lucky Seven hatched at the Niagara Gorge nest site last year. When I am able to confirm this for certain, you will be the first to know!!
More pictures to come!
