Thursday, 2 July 2020

Lockdown lifted - and a mystery revealed

Britain's nationwide lockdown is finally easing. Shops and business that have been shut since mid-March because of the Covid-19 pandemic, are starting to open, and the staff at Derby Cathedral are now preparing for its reopening for private prayer from 8th July.

Earlier this week we were delighted to be permitted to go up inside the tower to check on our own favourite birds of prey after a gap of over 3 months. Many of us have missed being able to watch the online antics of our pair of nesting wild peregrine falcons as they courted, laid eggs and reared their young. 

We were deeply frustrated by not having been able to connect up our webcameras before the lockdown kicked in (as explained here), so we knew we'd have to rely on the reports of those able to view from the street below.

But something else occurred this year, too...

It was hard to be sure when it happened, but reports started to come in suggesting we had lost our old and reliable female falcon to a new, younger model. Local naturalist, Anthony Pooles, kept an eye on the Cathedral for us as he travelled to his job as a 'keyworker'. He began to conclude (see here) that the falcon had been replaced by a new, younger female, and that she might be incubating, albeit on the other side of the nest platform than usual.

Unable to see into the nest, we had no idea if egg-laying had occurred, or they'd failed to hatch, or if chicks had died. Then, in late May we concluded that this new female had probably not laid eggs.

So, finally, we can confirm and reveal at least some of what has been going on. Despite not being connected to the web this year, our cameras are set to trigger to record to an internal memory card when movement on the nest platform is detected. The oldest recordings get overwritten once the card is full, so it was a rush to retrieve them as soon as we could. As I connected up my laptop and accessed the internal recordings, I found we had over 900 short video clips, but only going as far back as 20th April.

By that date, eggs would normally have been laid and incubation well underway, and with hatching anticipated for early May. But the picture below shows what we found on Monday 29th June.

Nest platform on Derby Cathedral as seen on 29th June.

It revealed a pristine nest platform, with no signs of eggs, chicks or much activity at all. So what happened?

Reviewing the saved video clips, it seems our male peregrine falcon (with a small silver ring on his left leg) is now enchanted with a sub-mature adult female, and they have been courting one another all through April, May and June. We've seen food swaps, lots and lots (and lots) of head-bowing and eechupping. But the male has a slate grey-coloured back, whilst this new female still seems quite brown on top, despite her horizontal breast bars. For all my years with this project, I'm no expert on the peregrines' appearance once they've left their nest sites as we rarely see them again. But to me she looks like she is just coming into adulthood, so presumably a 2nd-year bird, and not quite ready to raise a family.

But, boy, have they been trying!

The video clips our camera has captured show a well-bonded pair, going through the familiar routines of food-swapping, head bowing and eee-chupping towards one another with their heads bowed.
You can see this in the two clips below, captured on 24th April and 28th April (note the ring on the male's left leg in the second one).

But what has been surprising is that this courtship continued into May, and on through June...

 and right up until 28th June, as below:

It seems probable this prolonged courtship display will continue for a little while yet, though it's far too late in the season for this new pair to lay this year. But what does seem likely is that they will bond well during 2020 and start a new, successful breeding partnership in 2021.

It has been a frustrating time for everyone, from hopeful webcam watchers on the other side of the world, to your own Project Team here in Derby. In one sense, their failure to breed means we haven't missed much with our webcams not being online this season, but in a far greater extent it seems we've missed a considerable amount!

Nick M
for the Peregrine Project Team