Over the 7 previous years the Sheffield Peregrines blog and webcams have been running (2012 – 2018) there have been ups and downs and a few dramas for “our” birds but on the whole the St. Georges nest site has been a productive and generally steady urban Peregrine nest site. The webcams, blog and Twitter feed have proved popular, as have visits down to the churchyard to peer up at the birds in person. Regular Peregrine followers have entered a familiar routine of the birds returning each winter, mating and laying in March, followed by 31/32 days of anticipation, then chicks hatching by early May and then growing rapidly, finally fledging in the long days of summer. We’ve all become accustomed to the Peregrines’ success and we probably all expected it to continue….
Sheffield Peregrines 2019 has however rather bucked this trend. Whilst other well known and well watched urban Peregrine sites around the UK, such as up the road at Wakefield, seem to be business-as-usual it has been a turbulent year at St. Georges for both the birds and their followers alike. This blog is an attempt to summarise and discuss some of the goings on so far…
It all seemed to be going to plan in March with the birds occupying the nest platform, bonding and mating. The birds looked to be the same returning birds we’ve had for the last few years, everything was familiar. By the middle of the month the female was spending more time in the nest box and started to create a depression in the gravel. Based on this behaviour and lay dates from previous years eggs were expected any day soon. So far, so good. All running like clockwork.
Along comes the 21st March, in some previous years egg laying had already started by this date, but not yet this year. Webcam watchers communicated via twitter and were convinced there would be a new arrival any minute. However, what did arrive was rather unexpected, not an egg but an intruding Peregrine instead! This (third) bird appeared from nowhere and the resident female left the nest platform. Watchers on the ground noted definitely 3 individual birds simultaneously as the birds chased each other around, the 2 resident birds noisily defending their territory. From the cameras the intruding bird was judged by observers to be a female falcon due to its size and was said to have different markings from the resident female, plus she could be distinguished by a metal leg ring. Aerial battles ensued and at one point a bird thought to be the resident female, sat on the corner of the tower was dive bombed by the assumed intruder almost knocking her off, right in front of the webcam.
What happened next isn’t 100% certain. Despite the two camera angles and watchers on the ground it can be difficult to identify birds individually. Even with ringed and colour-ringed birds it is not always possibly to ID birds as rings get hidden by feathers, legs can be out of sight etc, as Osprey watchers will know it’s often very hard to view or photograph even the bigger rings those bigger birds carry. On top of that, ringed or not, Peregrines tend to move through the air at speed! All anybody had to go on was the discernible size differences between males and females, a small silver leg ring on one bird and subtle possible/perceived differences in the birds feather colour and/or patterns (something notoriously tricky with Peregrines)
The consensus at the time was that the intruding bird was a female, due to her size. This is undisputed. She appeared to usurp the resident female and very soon after (an hour at most) there were bonding and copulation attempts between her and “our” male. Nobody can be 100% certain that this was the intruding female without strong identifying features but were sure as we can be that this is what happened. All of this was unexpected and unsettling at a crucial time. Footage from @doggie3132
It perhaps seems strange to us humans that the male would copulate so quickly with another bird when he has such an (apparently) strong bond with his longstanding partner. It is in situations such as this that webcams on urban Peregrine nests come into their own. Few, if any, traditional rural Peregrine territories have been observed and recorded 24/7 in the way that urban nests have been in the last decade or so. Is this normal behaviour? Perhaps this is normal in the Peregrine world even if such haste might be frowned upon in the human world? Perhaps if one bird, male or female, proves itself to be strongest then the drive to copulate and breed is instant and irresistible in a world where survival of the fittest is the daily norm? The animal kingdom is not a world of sentiment or romance. Only continued observation and recording across the many UK nests fitted with cameras over the next few years is the key to having greater insight into these and other unknowns. Ultimately this is the purpose of installing them and in a way is a grain of new knowledge unfolding in front of us, live on camera.
But… everybody had expecting an egg any minute, what now? This is where it gets tricky. Those of us watching regularly think the interloper female did occupy the nest on the night of the 21st but by the 22nd the original female, “our” female, was back. It’s never particularly helpful to anthropomorphise the birds but animals do give off body language to communicate their health, state and condition and the body language of the bird which reappeared on the morning of the 22nd could perhaps be described as wary, uneasy or sheepish. Not the body language of a confident bird and the body language of the female seen the night previously was far more upright and confident. But again nothing is 100% certain with unmarked birds. Bonding and mating ensued. One way or another the male saw plenty of copulation in a 24 hour period, whichever female or females it was with….
An egg! Around midday on 23rd March the much anticipated first egg arrived and was spotted by various followers online. The egg was white whereas in previous years they have generally been brown. Theories speculated that this was the new female laying the egg, something just didn’t look or seem right but then again after the trials and tribulations of the previous 48 hours perhaps that was to be expected? No firm conclusion could be drawn.
It was another 7 days of anxious, unprecedented wait before egg number two arrived on the 30th. Then a more familiar pattern of an egg every other day, #3 on April 2nd and #4 on April 4th. Perhaps normality had been restored? A clutch of 4 eggs has been typical at St. Georges even if they haven’t all always hatched. Still questions remained – foremost being about egg colour. The first egg was white, the final 3 the traditional brown. Could the colour discrepancy be evidence to support the different mothers theory? Or was the lack of brown shell pigment in egg 1, then the long delay until egg2 down to the stress of the intrusion and fight? Full brooding never begins until the last egg has been laid but egg and eggs can stay in a suspended stage of development between laying and full brooding. Would a week be too long for the first egg? It had been left unbrooded for seemingly many and quite long periods of time over it’s week of solitude. Would it still be viable? Would it be this year’s unhatched egg? If so could it be taken for testing to determine and compare parenthood? What happened to the intruder and would she return?
There were so many questions but only time would tell.
To be continued…