Saturday 17 September 2011

Numbers and garden birds

The news that a species of bird of non-UK distribution had turned up on a garden feeder in south Buckinghamshire, made me wonder about the dynamics of numbers in our feathered visitors. How do our gardens, and possible round-the-year feeding, affect both the populations of garden birds and their near neighbours in the countryside at large?

This seems like quite an important topic, certainly worthy of rigorous sampling, efficient data collection and critical analysis.

Does this sound like an Imperfect and Tense blogpost? Nah! So after a moment's thought (in lieu of any serious research), here's the lowdown on the mathematics of bird numbers in the Tense Towers garden.

0 (zero)

Although it means nothing, zero is an incredibly important number to a mathematician and it's also pretty high up any garden-gazing birder's agenda. For example, how many Nuthatches are seen within the environs of Tense Towers in any 365 day period? Or, I wish we had this many Wood Pigeons (the vegetation-trampling, profusely-defecating, feathered handbag-fighting, wastes of space that they are. I'm just saying, that's all).

1 (one)

If the song is to be believed, this would be a single partridge in a pear tree, but we have neither of those. We could possibly muster a Sparrowhawk in a Hawthorn tree? However, for the best bird-brained maths, count up all the visits to the peanut feeder by a Great Spotted Woodpecker, times this by the number of birds seen sharing said feeder during these visits and then divide by the number you first thought of. The answer will be one. Our GSWs do not like sharing, not with each other and certainly not with any of those upstart finches, no thank you very much.

2 (two)

Hold on, let me stop you before you ask... no, we haven't got any Turtle Doves either. Though we do have several Collared Doves, the only species on the planet to look good in beige. I guess that once you have two, then there's a certain inevitability that more will surely follow. It's not simple multiplication, I reckon it's a pyramid selling scheme.

3 (three)

Let's have some proper maths now. How about a bit of Trigonometry? I know what you're thinking, "What's his angle on this one?" Well, as it turns out, it's 120 degrees. All you need is one peanut feeder and 3 equally-spaced Blue Tits. No squabbling, each has enough room and valuable feeding time isn't wasted. And if you fill the feeder with a certain type of seed, your Blue Tits will be really spaced, man.

4 (four)

Multi-port feeders, they could be 6 or 8, but we'll stick with 4 for the time being. When they're full, peace and harmony settle over the garden and it is a relaxing place to be. The tranquillity is temporary, however, for when the seed falls below the level of the top ports, all hell breaks loose, as suddenly there's twice as many finches as full ports. It's a bit like a dual carriageway packed with nose-to-tail rep-mobiles trying to filter down into one lane to negotiate a caravan with a flat tyre. It is possible, but there's gonna be an amount of carnage and broken door mirrors along the way. The Goldfinches are in the BMWs, by the way.

12 (twelve)

Physicists would have us believe that there are 11 dimensions in the quantum world of String Theory. And if that's too difficult a concept to grasp, don't try counting a flock of House Sparrows during an RSPB Big Garden Birdwatch. Twelve is my limit, before my eyes start going in different directions and the balancing mechanism of my inner ear gives up on all the sudden changes of direction. That's also the real reason the BGBW is only supposed to be for an hour. The human mind isn't built to cope with a squabbling flock of finches for more than 60 minutes.

30 (thirty)

Imagine the scene... you're sat staring out of the window at the feeders, your brow furrowed in concentration, eyes darting to every fluttering movement. All your senses are switched to overdrive, as you watch intently for your quarry. But it's been half an hour now, thirty whole minutes, but no sign at all, perhaps it's not around today. Someone enters the room behind you and joins you at the window. After several seconds, they whisper excitedly, "There! Did you see it? Coal Tit!" Your answer is not printable.


Katie (Nature ID) said...

Is it already the Big Garden Birdwatch? Time sure is flying by. My memory seems to be condensing - what feels like only yesterday was months ago. This was a very entertaining read.

Imperfect and Tense said...

[Checks wristwatch and calendar] No, don't worry, Katie, that's not until the end of January. Could you tell it's been a low news week on the wildlife front? We've been out today, though, so stand by for normal service to be resumed...

Martin said...

Higgle, piggle, giggle! I was chuckling away happily and that was before drinking alcohol! Lovely sentiments.

Imperfect and Tense said...

Cheers, Martin. No seriously, Cheers!(clink)

Spadger said...

Hoopoe are beige and far cooler than collared dove! But they'd probably score zero in your garden :0( unless of course you join the ranks of the clergy! As according to Mr W. E. Oddie they are often found on a vicars lawn.

Imperfect and Tense said...

I'll give you that one, Hoopoe are pretty cool. In terms of the Tense Towers garden, they're not even zero, more like imaginary numbers.

Spadger said...

Yes but that's coz you're not a vicar and Tense Towers is not a vicarage!

Imperfect and Tense said...

Bless you, my son, we all have an altar upon which to raise our beliefs. Did I ever mention that the erstwhile alter ego of His Tenseness is a bit of the priestly persuasion? Canon Cameron Binns?

Katie (Nature ID) said...

Oh my! I'm starting to wonder about subscribing to your comments now. You may have become too popular a blogger for me to follow anymore. The first time I heard the word "vicar" was from Wallace and Gromit. Hey, my apologies, I'm an American now (shoot, that sounds bad already).

Imperfect and Tense said...

Popular, Katie? There's only 28 guys and gals in the Tense 'hood. I am heartened that you've heard of Wallace and Gromit, but what are vicars called in your neck of the woods? Should I presume that the "shoot" was suitably ironic? :o)

Martin said...

And two years on, my thoughts wander to the GSW.. and whether the rules dictate that since you can tell the sexes apart, but only ever see one at a time, whether the species goes down as a one, two or three when juveniles are spotted?
I guess human bias plays a role too.

Imperfect and Tense said...

By the time we arrive at winter bird feeding records, I think that the juveniles have moulted into adult plumage. So if we only see woodpeckers one at a time, we can only know whether they are a male or a female and so totals would plateau at 2. If we had seen both male and female birds, but then managed to see two of the same gender, we could nudge the total up to 3.