Night Hunters

 

Having been involved with peregrines now for 20 years, for a good few years now it has been known and accepted that they hunt at night, I have always wondered if it differs from pair to pair in levels of activity in the dark hours however. Do other singles/pairs hunt this way (Battersea) consistently, or is it occasional and they take enough prey diurnally to sustain them through the night?

Peregrines, like a lot of birds of prey are very inactive at times and spend hour upon hour just sitting around often, usually after feeding, have they naturally just adjusted to nocturnal hunting in the City, as the odds are far easier and more levelled in their favour than diurnal hunting?

Having kindly been given access to the cameras at Battersea Power Station since 2016, it has given me an incredible insight into their nocturnal world. Recorded and with playback, you miss absolutely nothing, I know I am biased and have said it before but they are an incredible resilient and remarkably adaptable species, which is why they are such a success story in the Cities.

The pair at Battersea have always hunted extensively at night, you only have to look at the prey range in the last 4 weeks – Lapwing, 4 Woodcock, Avocet, Song Thrush, 4 Black Headed Gulls, Coot, Moorhen and Blackbird. Every one of these was taken at night at differing hours, recorded by CCTV, no pattern to it, much is down to the weather, I have noticed that on clear nights (more movement), one or both are straight out.

It’s not reactive hunting as far as I can see, whereas they are roosting and then see or hear a bird going over and then go up after it, the pair at Battersea are flying from roost to hunting and vantage points which lucky enough, are covered by the cameras. I suspect that reactive hunting does happen but for the most part, night time prey usually comes back to the same position.

On another peregrine site, I had noticed diurnally where the resident Tiercel always lands, it’s his go to spot at all times during the day and he also hunts from this position, like us they have their favorite go to chair.

This lofty position is accessible and a good distance from the nest site and is part of a maintained area so I decided to place a Trail Cam up there for a few days, hoping for a few close snaps, I was hoping really to get some good images during the day.

However on picking the Trail Cam up, great captures from it during the day, this little Tiercel was also hunting at night also, not just occasionally but most nights it seemed weather permitting.

It answered previous thoughts on other pairs but I hadn’t considered this pair would do it, simply as I had always seen him/them diurnal hunting and had never arrived at dawn with both sitting there with full crops from night hunting, unlike Battersea.

Obviously no flash from the cam during the daylight hours but it had fired during the darkness but from the images and time stamps from the many captures, it did not seem to bother him as he returned to this position all the time. There were a number of alternate positions available up there, if spooked, but he came back time and time again to this same spot.

Needless to say however, I won’t be setting the Trail Cam up there again as the flash could be intrusive to his eyes nocturnally and not ‘natural’ for him, if he looks directly at it.

                          Various date and time stamps show some regularity as he scans the skies

 

Beckton Kestrels

 

Good to see them back at the box at the Sewage Works, the female has already more or less stopped hunting with the male now providing, much the same as Peregrines.

Its hopefully a sign of imminent egg laying, I’m seeing the male around site hunting, reliable source of food on wet days seem to be earth worms.

I also saw the female slip down from the nest box the other day and eat a couple off the road; I would imagine they do have a very wide range of prey.

For some reason or other they only had a single juvenile last year, most years are 3 to 4 so not sure what happened there. I can’t see it being a food shortage, they are a pretty resilient and adaptable little raptor, so may be that she is getting a little long in the tooth and fertility may have become an issue.

I haven’t seen the Common Buzzards for a while and the Sparrowhawks are elusive as ever, hope to catch them displaying again.

We will see what 2021 brings.

Battersea Power Station

 

February 27th



I opted for a Saturday visit to the Power Station and although a little nippy, it was simply a stunning sunrise coming up over the City as I gained the roof, definitely worth negotiating all the stairs even without seeing the Peregrines.

Prior to going up there, I had marked the Falcon on the north east chimney catching the early rays facing the Thames and the Tiercel was on the Tower calling agitatedly. This is usually reserved for another peregrine or another large bird of prey; however I couldn't see anything with the Tiercel continuing to call.

However after scanning round, I was very surprised to come across another peregrine sitting on one of the Phase 3 Cranes which was no doubt the source of the resident Tiercels agitation, he was still in situ and going off no end.

A little surprised as he would normally attack an intruder on sight defending territory, so odd and out of character behaviour regarding an intruder, especially at this time of year.

After a while the Falcon flew and no doubt seeing the intruder, made a bee line straight for it, as she closed it flew and was quite clearly another Tiercel going by size as she caught up with it. There was not the level of aggression I expected in seeing another peregrine off and she shortly later returned and landed again on the north east chimney. The intruder was lost to view and I thought that was it, very mystified as to the resident Tiercels/Falcons behaviour, another adult Tiercel openly challenging his territory and no response from him other than stress calling.

A short while later with the resident Tiercel still calling from the nest tower, this intruding Tiercel again returned and actually hovered like a Kestrel in front of the Falcon before she gave chase. The chase was not full on aggression and it was more like an escorted guidance as they both went west, again after a short while she returned. The resident Tiercel had again not moved and for the rest of my visit, the intruder was not seen again.

                                                                            Falcon

                                                                         Intruder

                                                                           Falcon

                                                                  Intruder and Falcon

                                                                       Giving chase

I am pretty sure, based on both resident birds behaviour that this was one of the Falcons previous offspring, now returned as an adult bird and looking for his own territory, it is the right time of year. It would also explain why it was not attacked by our resident Tiercel with gusto, as he had probably based his level of aggression on the Falcons reaction and behaviour towards the intruder. I would suspect that this was not the first time this had happened. Also to be considered is that the resident Tiercel was relatively new, this intruding Tiercel did not come from him.

Stirring stuff in the peregrine saga and it backs up what I have thought for a long time, no matter how old, a mother will always recognize previous young, I have seen this before.

This Falcon has had 19 previous juveniles since 2013 but more likely to be recent ones, possibly the 2018 juvenile, now an adult looking for his own territory.

Battersea nocturnal

 

As the Power Station itself nears completion, thoughts this year turn to relocating them back onto the main building after translocating them in 2013.A permanent nest site has been integrated into the structure of the Power Station, with the plan being to open it up in the Autumn of this year.

It is a real Des Res and hopefully they will accept it, however I never take anything for granted with peregrines, nature as they say always does it own thing. More on this at a later date.

As we know, due to the extensive CCTV coverage of 4 cameras, I am able to keep track of the pair night and day, nocturnal hunting features massively with this pair with the Falcon hunting more at night than day. Recently however, the Tiercel also hunted nocturnally and on February 25th at 10.10pm later that evening he came in with an Avocet.

Sad but that is nature, this is a rare bird to be seen in Central London, hard to say if it was on its own or one of a flock moving overhead nocturnally, but with those white wing flashes always likely to be spotted in the night sky.

Other than Woodcock nocturnally they have also bought in Song Thrush and Redwing recently, both of these, as with the Avocet taken by the Tiercel nocturnally.

Very busy of late with surveys etc, a couple further afield on the south coast, I count myself very lucky in the current climate still able to work, of course peregrine stuff is always high on the agenda as we rapidly approach egg laying this month.

                                 Myself and Paul came across these 2 crackers whilst surveying

In the last week or 2, when able I have made 2 new boxes, one is a replacement peregrine box for Parliament with works due to start this year.

The other is a Tawny Owl box that will be going up shortly, this is the first one I have made of these so hoping good things and early acceptance.