No, this isn’t the recipe for the world’s largest Yorkshire pudding (though I wouldn’t mind giving that a try). Instead, these were the ingredients for the annual census of Forvie’s Black-headed Gull colony, which took place a few days ago – a big landmark in the bird breeding season on the Reserve.
Actually, the full recipe would also include six intrepid observers, each armed with a tally counter, and a seventh person acting as timekeeper and lookout. Plus a selection of overalls, old clothes and battered hats. The birds make it clear you’re not welcome, and use everything in their armoury to try and drive you off – including well-directed ‘whitewash’. The Forvie gull census is not a job for your best togs.
So what’s with the flour then? Well, if you’ve got one-sixth of a massive Black-headed Gull colony to census, it can be difficult to know where you have and haven’t been. All the nests look much the same. The simplest way of knowing if you’ve already counted a particular nest is to mark it with a generous pinch of flour – ideally next to the nest, not all over the eggs, of course. It’s a cheap, non-toxic, biodegradable and very effective way of making sure you have a 100% accurate count. But the amount of flour required is considerable. I am therefore known to the staff in our local supermarket as ‘the weirdo who comes in and buys twenty bags of flour and nothing else’. I don’t usually even try to explain to the checkout staff what it’ll be used for, as I’m sure they already think I’m off my rocker in any case.
The gull nest census is timed very carefully so that it takes place immediately before the first chicks are due to hatch. This, in theory, is when the number of nests containing eggs is at its highest. Also, once the chicks start hatching, they quickly become mobile and disperse into the rapidly-growing vegetation in the colony. This would make them difficult to count – and more importantly, vulnerable to getting trodden on. So we don’t want to be traipsing through the colony once they’ve started hatching en-masse.
Of course, some gulls will continue setting up home and laying eggs even after the first of their neighbours’ chicks have hatched, and we just have to accept that we won’t be able to quantify these late nesters. Consequently, the number of nests recorded by the census represents a minimum population size only. But our methods are consistent, and the results comparable from one year to the next – so the science is sound.
During last week’s count we didn’t see any chicks, but we did find a couple of nests with the eggs ‘chipping’ – where the chick just begins to break through the eggshell at the start of the hatching process. This told us that our timing for the census was spot-on.
Of course, with hatching imminent, this is a critical time for the gulls. As a result, all the work we undertake within the colony – including the nest census – is subject to a strict set of ‘house rules’. We get a maximum of 20 minutes at a time in the colony, after which we have to depart for at least an hour (to allow the birds to settle and incubate their eggs) before we return. Likewise, if the weather is cold, wet or excessively windy, we won’t enter the colony. At all times, the welfare of the wildlife must come first, and our primary concern is allowing the birds to breed successfully. For this reason, we didn’t census them at all last year – the weather was just too cold to risk it. Thankfully, though, this year’s weather was kinder to us.
So, what of the results then? Well, it was a big effort by the team to get the work done, with some sections of the colony requiring three 20-minute sessions during the day in order to cover all the nests. One particular section contained a dense sub-colony of some 900 nests, which was a challenge for the observer! In the end, the total for the whole colony was a whopping 2,265 nests containing eggs – a new site record for Forvie. This beats the previous record of 2,124 set in 2018.
Late in the day, Patrick ventured back into the colony to survey a sample of nests in order to ascertain an average clutch size – the number of eggs per nest. A typical complete clutch for Black-headed Gull comprises three eggs, though some stop at two, and others – rarely – will lay four. Patrick’s sample count of about 160 nests produced an average clutch size of 2.7, meaning the whole colony would have contained upwards of 6,000 eggs. Quite an establishment.
To put our numbers into context, the last UK-wide census of Black-headed Gulls revealed a total breeding population of 138,000 pairs. This means that Forvie holds over 1.6% of the entire UK population of Black-headed Gulls. And this is why we take their wellbeing so seriously!
Black-headed Gulls are considered to be a common and widespread species in the UK, and 138,000 pairs probably sounds like quite a lot, right enough. But consider that the human population in that same area is around 70 million, and suddenly the gulls don’t seem so abundant after all. All things are relative of course – but I can’t help thinking how accustomed we’ve become to being wildlife-impoverished, when we ourselves outnumber even common species by several orders of magnitude.
Wider context aside, the gulls here have been doing very well. In my early years working at Forvie – back in t’day, when I were a lad – the breeding population comprised 600-800 pairs. So in fifteen years, the colony has trebled in size. This could be due to a number of factors (including good wardening, obviously…). For example, other local colonies have died out in recent years, with the ‘refugees’ perhaps relocating to Forvie. Meanwhile, behind its protective electric fence and free from disturbance, ‘our’ colony’s productivity has been consistently high, meaning lots of new youngsters recruited into the population – and many of these later settle and breed here themselves. Also, the habitat within the electric fence has gradually become more gull-friendly, with former areas of sand and shingle reverting to grass and vegetation – the sort of places the gulls love to nest.
As we finished the census, the weather threatened to close in on us, with menacingly dark skies heralding torrential spring showers. A good time to be leaving, then. But the black clouds and low sun gave a brief opportunity for some dramatic photos of the white gulls against the dark backdrop.
I have always thought Black-headed Gulls to be underrated birds, possessed of a simple elegance that most of us probably overlook – most likely because they’re relatively commonplace. In addition to their natty dress sense, they have a lively social life at their colony which further adds to their appeal. The sound drifting from the colony across the river to Newburgh speaks of vitality, energy and new life. And wherever you are in the local area, you can see the gulls plying up and down between the colony and the fields and the estuary, gathering food for their chicks – a lovely reminder that here, on our doorstep, is something special.
Here’s raising a toast to Forvie’s Black-headed Gulls then. Long may they require me to buy the supermarket out of flour.