Looking like he’s gone
From the previous post on Sunday 25th visit, you will recall the adult Tiercel was constantly attacking the sub adult and had obviously upped the ante and the aggression levels, checking the cameras later that day, the last view I had of him was around 4.00pm.
At 7.00pm on the 25th, the adult Tiercel was on the tower displaying to the Falcon, the adult Tiercel was also again on the tower shortly before at 6.30p.m.
Since then and every day thereafter she has been with the adult Tiercel, he has now moved onto site with sub adult not showing since the 25th ,we will see if he appears in due course, however I now think it unlikely.
Given the sub adult’s previous form in holding to the box when threatened, it speaks volumes that the new Tiercel is now in it daily.
As its stands I like to think he has moved on thinking it a better and wiser option; however it’s also possible that the adult Tiercel has struck him given what I saw on the 25th and the level of aggression being used.
Obviously if he has gone, hopefully deciding to leave as a safer option, it is well overdue; it will then now give breeding stability going forward, especially after this year’s events.
So after all these months why the sudden increase in aggression from the Tiercel?
It’s possible that the adult Tiercel may have been holding back due to the Falcon, even though 'bonded' with her, a concern for him could have been creating 'divided loyalties' on the Falcon's part, in short would she attack him if he went at the sub adult too aggressively?
You have to remember that all Falcons are dominant,having said that she never interfered whatsoever.
It’s also been suggested that it could be related to plumage, as the sub adult was now nearing adult plumage, did it trigger higher levels of aggression as he was then seen as more of a threat being a near adult?
Right from the start, I was surprised that the adult Tiercel did not remove him, the immature for his part kept the adult Tiercel out off the Power Station site, the change in guard should now bring breeding stability hopefully.