The Falcon calendar and ... 5 eggs at the cathedral!
The nesting season of Peregrine Falcons begins relatively early; in February, with the courtship displays. However, these are generally brief, especially when the couple already knows each other.
The egg laying starts around the end of February or in early March, depending on the site and on the year. There does not seem to be a constant between couples and regions. A brief overview: the female in the cathedral began brooding on March 1, 2009 at the earliest and March 11, 2011 at the latest. In 2011, it was a couple nesting near the banks of the beautiful river Sambre, in the Ardennes - so in a region considered to be particularly cold in winter - which was the first in Belgium to start brooding; probably as early as around February 20th!
This spring, the female in the cathedral laid her first egg on March 3, the second on March 6, the third on March 8 and the fourth on March 10. The brooding started as it normally would - once she had laid her third egg. This is quite typical: incubating never starts when the first or second egg is laid, otherwise the difference between the hatching of the first and the last egg would cause a significant age difference between younglings of the same nest. Posing the danger that the eldest of the brood would dominate the smaller ones, by either potentially killing them or by eating their food and causing undernourishment. Exception to this rule: when the complete brood consists of only 2 eggs, which was the case in Woluwe-Saint-Pierre during the first nesting of 2014.
The female in the cathedral, in her 17th year, has again laid four eggs, which is typically considered the maximum for a Peregrine Falcon. Between her arrival in the spring of 2006, and 2017, she has laid 49 eggs, including 2 broods with 3 eggs, 7 broods with 4 eggs and 3 with 5 eggs. Five eggs in one brood is really exceptional for Peregrine Falcons. With the Peregrine, unlike with other birds of prey, the number of eggs is not related to the characteristics of the nesting biotope or to the abundance of prey. Rather, it is indicative of a female of a very particular quality. A very special female? Indeed! The viewing of all the images recorded since the beginning of March made it possible to note that the female of the cathedral has, this year again, laid 5 eggs! The 5th arrived on March 13 between 13:00 and 16:00. UNBELIEVABLE! Not content with merely being the oldest of the nesting Peregrine Falcons, the female in the cathedral still laid 5 eggs!
The story of the Peregrines in the cathedral doesn’t end here: on March 15 at 00:02, the recorded images show the female bowing her head down to her chest, passing her beak between the feathers and delicately removing a piece of shell. The morning pictures confirm it: the male is brooding 4 eggs while half a shell lies next to him. What happened remains a mystery. It is certain, however, that the breaking of this egg is not the consequence of a fight or "violent" action. It broke under the female while she was incubating. Has it been accidentally pierced by a tallon (= nail of birds of prey)? Is it the consequence of a malformed shell?
In Woluwe-Saint-Pierre, the laying took place as follows: when connecting the camera on March 12, there was already a first egg in the nest. The second was laid on March 13, the third on March 16 and the fourth on March 20. The brooding started on the morning of March 17.
No precise information for Uccle, because the camera was connected at the end of March.
Still, if there are 32 days of incubation, the first chirps should be heard at the cathedral on April 10th. This is an estimate, because brooding often lasts a little longer. In Woluwe-Saint-Pierre, it is around April 18th that the first falcons should pierce their shells!