Peregrine Blog No 3 2025

Well, that is the end of another successful year for our resident Peregrines.

As far as we are aware, all four chicks are still alive and well, although of course, it becomes much more difficult to keep tabs on the birds so to speak, as they become much more proficient on the wing and spend increasing amounts of time away from the Cathedral. I imagine some of them at least will return to the Cathedral to roost, as of course will their parents. As to where they disperse to during the day, it is hard to say. Observations during the June ‘Date with Nature’ event manned by volunteers from the local RSPB group would suggest that both the adults and the chicks, when they leave the Cathedral itself, most commonly fly out in a roughly westerly direction over the water meadows and out towards Wilton. It may well be that they utilise a couple of disused chalk quarries in this direction or the electricity pylon lines up towards the racecourse; certainly Sally, our tagged and tracked adult female from some years ago, seemed to like these two locations.

It is never possible to say with any certainty when the chicks finally become independent of their parents and move out of the area and begin the fend for themselves. I think with a brood such as ours which fledged in early June, it is likely that the majority of the chicks will leave the area at the end of July or perhaps early August, but in past years, and also certainly elsewhere, some chicks seem to stay in the area in which they were bred into the autumn and still try and beg food from their parents. Whether the parents seek to actively chase their offspring out of their nesting territory or whether the chicks leave of their own volition is not really well known; perhaps it is a combination of both, and perhaps we will never know with any certainty. What is certain is that, despite their apparent speed and dexterity on the wing, young Peregrines in their first year of life face a hard time. Many will not be accomplished hunters and starve to death, whilst many fall victim to accidents such as colliding with buildings or power lines. Data on mortality is hard to come by and must vary from area to area, but it is generally thought that perhaps only about 50% of young Peregrines make it through their first year. Mortality of adults in established territories is thought to be perhaps in the 10-20% range every year, so it is clear that having survived their first year, the prospects of the birds in subsequent years improve substantially.

As I have mentioned in the past, we are lucky at the Cathedral in that the nest box is about a metre lower than the parapet wall from which they invariably take their first flight. This means that they have to have at least a modicum of flying skills to make it up onto the parapet wall from nest box level, so to speak. Thus the incidence of what are colloquially known as ‘fallers’ are fairly few and far between at the Cathedral, and we have not had one for several years. This is certainly not the case elsewhere with sites which are more open and allow chicks to sometimes make their first tentative flight before they are really ready. Sadly, this can result in the death of chicks, in sea cliff sites with chicks falling into the sea and drowning, or in urban sites with chicks falling onto busy roads and being inadvertently run over by cars. Fortunately, many urban sites are actively monitored by Peregrine enthusiasts who are often on hand to rescue such ‘fallers’ and return them to their nest boxes or at least onto a high point out of danger. On a Peregrine WhatsApp group to which I belong, I have seen photographs taken this year of ‘fallers’ perched on a dustbin, on top of a bus, and one even on the saddle of a bicycle. All as far as I am aware, were rescued and returned to a safe place.

The last job of the year, normally undertaken in late August or September, is to go out onto the south-facing walkway where the nest box is located, and collect up all of the accumulated prey remains which have built up over the breeding season. Always a messy job but essential not only to make the nest site and nest box, presumably a little more hygienic for the resident falcons for the rest of the year, but also to unblock the drains on the walkway, which could flood in heavy rains over the autumn and winter period and possibly cause water to enter the cathedral. This job is interesting as it is possible to identify some of the species on which the falcons have fed in recent months. From the evidence of observations from the ‘Date with Nature’ event, most of the prey items being brought in seemed to be Pigeons or Jackdaws. Some years ago the adults regularly brought in Black Headed Gulls, but in recent years ,the incidence of these birds being brought in has declined. Whether this is due to less Black Headed Gulls in the area in the breeding season or whether the then-resident falcons were particularly adept at catching this species, we will perhaps never know.

Lastly, let’s talk about the ever-popular ‘Date with Nature’ event run during June by the South Wiltshire local RSPB group. Like previous years, we had an information desk manned by volunteers and were able to show visitors close-up views of the adults and chicks through two telescopes. We had visitors from all over the world; their reaction to seeing a perched bird through a telescope was almost invariably ‘Oh wow!’. Some particularly adept folk took very good photographs of the birds using their mobile phones in conjunction with the telescopes. We mostly had good weather during the event and not only did we see the falcons but had other interesting birds drift over. On the first day, sadly when I was not in attendance, a White Tailed Eagle from the Isle of Wight reintroduction programme drifted over and gave good views. Luckily some days later when I was on duty so to speak, an Osprey drifted high over the Cathedral; you really do not know what you are going to see!

This is my final blog of the year. Hopefully, they have been of interest, and I look forward with anticipation to the 2026 season.

Granville Pictor 23 July 2025.

Photo Credit: James Fisher