It’s 5am on Sunday morning; the day of the Wheatfen Bird Ringing demonstration, and an unhealthily early start on what used to be called the “day of rest”.
I’ve always been a grumpy zombie first thing, and after dragging my carcass outside to nod “good morning” to a freezing breeze, I was less than delighted to find the car refusing to start. Not easily beaten, I simply jumped into car number two, ignored the blinding glow of a beaming fuel warning light, and floated along the 40 miles to the reserve. I was actually very much looking forward to the day, being a licenced ringer myself – you can’t beat the anticipation of what you might catch – what species would we get? Any migrant birds? Any birds previously ringed? Perhaps even a rarity…
We are always fortunate to have the UEA ringing group with leader Dr Iain Barr along to run the session. This relationship and the annual event have stood for over a decade at Wheatfen. Within the dark woodland, the group quietly erected several mist nets around the bird feeders as a perfect ambush for the still sleeping birds. You never quite know what might be roosting in the shrubs and bushes and too much noise might well scare these birds away. Needless to say, to the keen ears of the birds, a group of well-meaning ringers bumbling around in a woodland in the dark is about as quiet as a herd of rampaging cows.
Mist nets are made of fine nylon, woven to appear almost invisible, with lots of cushioning give to safely catch birds without causing them any harm. Caught birds can then be extracted by the licensed ringers ready for processing. To keep the birds calm they are held for a short period of time in small cloth bags, before being carefully handled, ringed (or re-recorded if already ringed), aged and sexed where possible, with wing lengths and weights also measured and recorded.
As daylight broke and a swift round of bacon rolls was devoured by the ringers (we know how to live it up), visitors started to turn up for the event. It was great to have a good crowd, with people of all ages coming along for the morning to learn about bird ringing. And the birds didn’t disappoint, with a wide range of species caught, including blue tits, great tits, nuthatches, dunnocks, blackbirds and even a coal tit to name just a few.
Typically, after discussing the importance of minimising stress to the birds whilst being handled and ensuring their absolute wellbeing, what should be waiting in a bag for ringing but a great spotted woodpecker? The most careful, gentlest person in the world could not stop this particular species from quite literally screeching its head off. They simply love to make a commotion. Other species, such as Goldfinches, tend to be exceedingly calm and placid, perhaps simply bewildered by the experience. They all fly away just the same though, happy enough after their small ordeal, matter-of-factly shaking themselves down before carrying on with their day to day feeding.
We humans are all different – different in appearance, behaviour, and so on. And it is just the same with birds. One blue tit coming into your garden feeders may look the same as any other blue tit that visits, but the careful observation of bird ringing opens up a whole new world. By looking closely at often fine differences in wing colouration and patterning, as well as various anatomical measurements, it can be possible to determine an age and sex for an individual, or at the very least separate an adult from a bird born that year. Ringers need a reasonably good memory bank of geeky bird facts to reliably age and sex the many species that may be caught throughout the year within the UK. Alternatively, a wheel barrow load of incredibly dry but important books. Thankfully my memory is still reasonably sharp.
We have been ringing birds in Britain for over one hundred years, with the British Trust for Ornithology (BTO) running the scheme for most of this time. Many of the fascinating discoveries concerning bird migration, population dynamics and changes come down to the data gained from dedicated ringers, who in themselves are “mere” volunteers. The analysis of these data provides the science behind a lot of the wildlife conservation objectives that aim to protect and enhance populations of Birds of Conservation Concern. Through ringing, each year new discoveries are made as well as monitoring the successes and failures of that breeding season, linking this to potential environmental factors.
It was not that long ago in our history that it was widely believed that swallows spent the winter in the bottom of ponds. They were seen swooping low over the water and at the time it seemed a reasonable assumption that they should suddenly dive under into the mud below! The ringing scheme unlocked an insight into bird migration like never before, and of course due to this we now know swallows spend their winter south of the Sahara desert (not far off really).
But even in the 21st century there are still gaping holes in our ornithological knowledge. Considering we know so much about the life history of the swallow, in contrast we know very little about its cousins the swift and house martin, and their wintering grounds. Ringing schemes highlighted declines in raptor numbers during the DDT chemical age of the 60s, and have linked an increase in bird weights at that time to the lack of predators that would have kept the birds fit and nimble.
Many birds ringed, despite staying close to where they were born for many years, manage to avoid future netting attempts, and avoid being caught again. Others, however, are not so clever, and get caught time and time again. One particular dunnock back at home we used to catch on an almost weekly basis. It happened so regularly its ring number, NY45872 has become engrained in my mind and now makes a useful online banking password that I can actually remember. Needless to say that we were saddened to hear from the BTO that Mr NY45872 had been caught by a cat in the village, and been reported as deceased. There we are, one of those things…
Should you find any ringed birds, dead or alive, and you can accurately record its ring number, please do send the record off to the BTO via their ringing portal and they will let you know where and when the bird was ringed. You can also find more information about bird ringing and how to get involved on the BTO website too.
Many thanks go to the UEA ringing group and Dr Iain Barr for their much appreciated help. As for me, off to the petrol station with one car, and a mechanic with the other…