View From the Shed by Volunteer Shaun - HOW DOES THE COUNT COUNT?

HOW DOES THE COUNT COUNT?

Do you remember the Muppets? Of course you do, they’ve been on our screens for over 50 years. What about Sesame Street? My favourite character wasn’t Kermit or Big Bird or any of the other ‘star’ names. I loved Count von Count, the purple Muppet vampire and, with his great love of numbers, I’m sure he’d like this week’s blog. It starts off a little dry (as many reports of numbers do) but by the end you’ll have learned something. Every day’s a school day.

As of February 2024, there have been 634 different bird species officially recorded in Britain, ever. Many are still around, some came this way only once and some may even be extinct. You can hope to see around 250 different kinds of bird in our country each year; the rest are rarities. I’ve seen 338 different kinds of birds in my lifetime (at least, those were the ones that I could positively identify - there have been many others that have left me fuming in ignorant annoyance), including those recorded on my foreign jaunts. Probably the largest concentration of a single species I’ve seen was a flock of Pink-Footed Geese at RSPB Blacktoft Sands

I was alone on an isolated part of the reserve and it was getting late. I began to head back to my car when I heard a distant honking that was becoming less distant by the second. Shortly the skies were filled by wave after straggly wave of these blaring beauties as they fell into landing formation. Initially I stood with my mouth agape in wonder as they darkened the sky above me. Then I realised that there were many, many birds overhead and I was directly in their ‘firing line’ and settled for a closed-mouthed happy grin. Tens, hundreds, thousands of geese, all gliding down mere feet above my head, I didn’t even try to estimate how many there were. I gave up after “more than several” and just delighted in the rush of it all. ‘Live in the moment’ they say, and for once I did just that. And then, silence as they settled down for the night. 

The site warden later reported that there were over 12,000 but I’ll have to take their word for that. I’m rubbish at counting birds in large volumes. I’m very much from the simplistic school of counting and I tend to go, “One, two, three…   lots.” Our own head warden Dave here at RSPB Old Moor can be a little more accurate in his counting though. To watch him go, “One, two, three… 2,638” is little short of miraculous. How do you actually count a flock that large? 

Well, if the birds are flying overhead at a fairly constant rate you could try the POINT method. This involves counting how many birds fly over a single specified ‘point’ during a given time period and extrapolating that number to cover their entire length of passage. This method works well if you’re on a busy migration path but if you’re counting large numbers of static birds, on a lake for example or feeding in a field, then the BLOCKING method is for you.

Blocking isn’t some arcane multiplication system taught in schools, unfathomable to anybody over the age of fifty. It’s a counting system where you mentally divide a huge group into ‘blocks’ (for example, if there is a fence line that you can use as a guide, then use the space between individual fence posts as a ‘block’). Count or estimate as closely as you can the number of birds in each block and simply multiply by the number of blocks. 

Both of these techniques are difficult at first but you will get more accurate with practice. Small flocks are the easiest to count. Just count them. I’m sure that you can manage any number up to, say, 100 as long as they aren’t too mobile.

Why is all this counting important? Like all recording of bird populations, whether officially or of the ‘citizen science’ variety, any submitted information, when gathered together, forms an overall picture of the health of nature as a whole. How many creatures exist? Where are they found? Where do they move to? How long do they live? What do they need to survive?

The RSPB, the British Trust for Ornithology (BTO) and other organisations collate all this information and make it available to anyone who wishes to use it. You can contribute your own counts via recording apps such as Birdtrack. All of this information is useful. Knowledge, as they say, is power.

If we don’t know these things then we’ll never know where to concentrate our conservation efforts. We may be trying to “save” a bird when statistics show that it’s doing very well for itself, thank you very much. But another species might be really struggling and we could easily do something to help its decline if only we knew. 

If we aren’t aware that we now have approximately 600 million fewer birds worldwide than in 1980 then how can we feel motivated to help reverse this decline? 

Closer to home, we British are seeing around 72 million fewer birds in our gardens than we did in the 1970’s. Numbers of House Sparrow, Starlings and Greenfinches have plummeted with an over 60% decline in each species. If we weren’t aware of this then we couldn’t make attempts to reintroduce their lost habitats.

If we didn’t know that there were just 11 booming male Bitterns in Britain in 1997, we wouldn’t have known how desperately they needed help, and we wouldn’t have celebrated a little victory when there were around 80 recorded last year, including several here at Old Moor. There’s still a long way to go until they can be called genetically safe, but we’re moving in the right direction.   

That’s why these counts count and that’s why I and many others submit our personal records. But there’s still no way I’m dressing as a purple vampire.