Data big and small

Magpie

After one of those nights when I only get to sleep just before 5am I wasn't really up for the planned early start (though given the weather it probably turned out to be no bad thing). An afternoon wander round my local patch started quiet and got considerably quieter as the sky turned black and it started pouring down.In the end it was just me, the gulls and a few of the magpies who'd noticed I'd put suet pellets in the usual feeding niches.

Lostock Park. Wet. Very wet.

I logged my sighting on BirdTrack as I always do. Why bother, just for a handful of birds you may ask. The answer's the same as the one I give when friends say: "There's no point, I don't see anything special." There's any number of places where you can find out about rarity sightings, where do you get to find out about distribution and numbers of common (or what used to be common) species?  We know the first Siberian accentor for Britain was in Shetland on 9th October 2016 but when did we stop getting hundreds of starlings in our suburban parks? The danger is that we may not know what we've got till its gone and we don't notice that species we take for granted have crashed like those of yellow-breasted buntings in Asia or, worse yet, like the passenger pigeon.

The fact I'm getting over a dozen sparrows in my garden every day lately is a fact but so what? A year's daily totals for my garden is interesting to me but who else? Ten years ago I routinely got twenty goldfinches in my garden every day, now I'm lucky if I get four, is it my garden? my feeding strategy? a crash in goldfinch numbers generally? does somebody else locally have my goldfinches? The numbers lack context.

Projects like Birdtrack, eBird and the RSPB's Big Garden Birdwatch collect and analyse big data on bird sightings. So, for instance, I can have a look at my figures for the day I did the Big Garden Birdwatch and compare them to the national results to see how unusual or not my sightings were. And researchers can use the 40 years' worth of data to see trends like the crash in the number of starlings and the rise in the number of coal tits. The Big Garden Birdwatch collects the data for a snapshot in time: one hour of one weekend each year. BirdTrack and eBird take this a step further, collecting data for any day any time (if you've still got your old notebooks you can add historical data, too). BirdTrack is mainly focussed on UK & Ireland (though you can add records for other countries), eBird is US-based but has a wordwide remit. I quite often review past years' data for particular species or locations to get a feel for how things are changing or what I should be keeping an eye out for on my next visit.

"Big data" is made up of huge amounts of small data, nothing is too small as it all gets aggregated and collated to make it useful. There are good reasons for submitting your sightings, even if it's just two woodpigeons. Yours may be the only data for that location that day (or at all), or the only sighting of woodpigeons at that location, so you're filling in a gap. I quite often find myself kicking my heels at a train station or a bus stop and my train into Manchester is routinely stuck at signals at Castlefield for five or ten minutes (the record is forty) so I've taken to doing a bird count while I'm waiting as it's better for my blood pressure than keeping looking at my watch; quite often it turns out mine are the only records for that location that month. Or your sighting could support and reinforce other people's sightings: six people in a hide, each doing their own bird count will have very similar but not identical figures — someone will be looking left when everyone else is looking right, or may have a better view of whatever was half-obscured behind a tree trunk or whatever.

So please submit your bird sighting records if you can. It's free, it's useful to other people and you're doing your bit for citizen science.