Imminent fledging at Woluwe-Saint-Pierre
The Peregrine couple of Woluwe-Saint-Pierre probably occupies one of the most beautiful nest sites of Brussels. What does "beautiful" mean to a Peregrine Falcon? This is obviously a bit subjective when evaluated through a human eye. But let's have a look anyway.
The height of the nest is a crucial parameter for Peregrines. It must be neither too high nor too low. The habitat of the Peregrine Falcon is the sky. It is in the sky that he spends most of his active time. Being installed high is therefore ideal since it gives him direct access to the sky at the lowest energy cost. It is enough for a falcon to throw himself into the void of his perch for, after a few wing beats or carried by the air currents, to end up "in the middle of the sky" and thus be fully operational in "hunting" condition". A low situation may be less than 40 m, asks Peregrines for significant energy to climb. Too high, say beyond 100 m, is not ideal either because it causes, during nesting season, significant energy expenditure to raise the prey to the young falcons in the nest. Installed at the top of the tower at 65 m height, the Peregrines of Woluwe-Saint-Pierre are probably in an ideal situation.
Height influences another criterion: the disturbance and therefore the vulnerability of the nest to predators. Peregrines, super-predators par excellence, will always look for a nest site "impregnable". It is clear that the top of the tower of the City Hall is a place that could not be more tranquil! Ideal again.
The third point of importance is an unobstructed view. And here too, the site of the tower of the City Hall of Woluwe-Saint-Pierre is at the top. When breeding, the Peregrine falcons have an unobstructed 180 ° view over kilometres towards the Woluwe Valley and the Sonian Forest. No building or trees covering the horizon. The first evidence of nesting on the site, in March 2014, was observed by going to the Stockel, on the other side of the valley, at exactly 1200 m distance. From there, it’s possible, by telescope, to see in the nest! And when the Pilgrim lands on the lightning rod that still rises a few meters above the bell tower, his view is 360 °. Nothing escapes him for miles around, that's for sure.
The last criterion of importance for assessing the quality of a site is the ability it offers juvenile falcons to exercise their wings before the big take-off. And here too, the site of Woluwe-Saint-Pierre is a must! Indeed, the terrace of their nest is an ideal playground. But actually, that was made by us specific in this regard. But it is especially the balcony of the bell tower and the railing which allow the young falcons to exercise their muscles to take off for a first perfect flight.
Well, that’s where we are! Yesterday, May 21, the juvenile male went exploring on the balcony. He jumped off his personal terrace and landed 1 m down. There he can continue to exercise, including walking. Observations of previous nesting have shown that little falcons are able to climb the railing by grasping their paws and flapping their wings. With destination: the sky! In a few hours, his sister, who still sleeps tonight on the terrace, will start exploring too...