If you watched Springwatch this year you will have seen that there have been all sorts of goings-on up on the Tower balcony, where the peregrine nestbox is sited. Cameras have been monitoring the nestbox since April and we decided to share some video updates in this post.
Granville Pictor, a peregrine specialist who leads the Cathedral's RSPB Peregrine Tower tours, takes us through the saga:
The absence of Sebastian raised a number of questions. Where was he? What had happened? Had he been chased off by the incoming male? Had he died? Granville was not surprised by this turn of events as he explains:
“Whilst adults are generally site faithful, inevitably birds do die and are replaced, or other birds with no territory try to ‘muscle in’ and take over the territory from the resident bird. Quite what happened to Sebastian we will probably never know unless of course he is photographed and his ring read at another site.The Cathedral is a towering pinnacle of limestone in an otherwise fairly flat agricultural landscape and is visible from many miles away. It is therefore perhaps not surprising that it probably acts as a magnet in attracting in other unmated peregrines looking for a territory.”
In 2017 the peregrine team had agonised about whether to ring both adult peregrines and GPS tag Sally but as the story on the Tower unravelled this year that decision was vindicated. Not only had Sally's tag allowed them to observe her movements over the winter but the rings proved invaluable when it came to understanding the activity on the Tower. It also explains the absence of chicks. Without Sebastian's ring they may not have noted his absence and it would have been hard to work out which peregrine was Sally.
So what has been happening at the base of the Cathedral's famous Spire?
Things started smoothly in March, despite Sebastian being absent. Sally was seen to engage in courtship behaviour with an unringed male. On course for eggs at Easter everyone thought. Then a Tower guide amongst others reported seeing three birds flying round the Tower. On 1 April the nestbox cameras were turned on. Here's what they showed:
As April progressed the unringed couple became regular nestbox visitors and Sally’s tracker showed that she was also visiting the Tower frequently. The nestbox cameras catch the unringed pair on video looking as though they were there to stay. Sally appeared on her own. Would she let the others lay eggs on 'her' nest?
Things appeared to reach a stalemate. Granville takes up the story again:
"On the evening of Monday 23 April things really did come to a head. Captured on video is a battle lasting the best part of an hour between the two females, the fight taking place on the walkway adjacent to the nest box. Both birds can be seen with talons locked, pecking at each other and rolling around on the walkway in a really viscious fight with feathers flying in all directions."
The fight is so brutal so that if this sort of footage is likely to upset you, we suggest you don’t watch the film below:
The battle took place at both ends of the balcony, taking the best part of an hour. Sally appears to have emerged victorious and the cameras record her sitting on the nestbox through the night and into the morning. Again, the following footage may be distressing to some people:
It was a relief that there were no fatalities that night. Fights can sometimes result in the death of one of the birds. The timing of the battle was such that it offered a small window of opportunity for late egg laying, as Granville explains:
“Our hopes were high that having seemingly vanquished the new female, Sally and the male would now settle down and lay an albeit late clutch of eggs. Alas it was not to be, and as I type this note in late May, there are no eggs laid and the same three birds are still present at the site. Sadly it seems that there will be no breeding attempt at the site this year.”
The behaviour witnessed on the Tower piqued the team's interest. In spite of the fact that there were no chicks to watch a decision was taken to keep the cameras on just a little longer. In early June Sally appears to be back in charge on the Tower but there’s still a stranger around. Who is the unringed peregrine and is he here to stay? If only we had some way of identifying him - but that’s another story.
Sally still has her tracker on so we can follow her movements even when the cameras are down. We'd also like your help finding out more about our pergerines. We have ringed every chick hatched on the Tower since 2014. They all wear the distinctive blue colour ring bearing their unique ID initials and we'd love to hear from anyone who spots them. Details of the rings are below:
Looking back over an eventful season, Granville Pictor is philosphical:
“Whilst the failure to breed this year is disappointing, the video footage does reveal fascinating insights into the territorial behaviour of peregrines. The results of the very recently published 2014 British Trust for Ornithology National Peregrine survey reveals that the species is thriving in southern England, with a big increase in numbers breeding with success on man made structures like the Cathedral. With increasing numbers of adult birds joining the population and seeking territories, it is perhaps not surprising that pressure to breed on a relatively limited number of nest sites is increasing and territorial disputes such as seen this year at Salisbury may become more common place."