Signs of Spring

Currently, I’m very busy getting ready with colleagues to travel to Greenland next week. We have an extremely full programme of fieldwork activities covering oceanography, biology, sea ice, snow and glacier processes as part of our NCKF work. More on these no doubt in a future post…

Yesterday, one of my ace DMI colleagues (without whom most of the work we plan would definitely not happen) shared the first optical satellite image of the area this year – taken by ESA’s Sentinel 2 (a truly astonishing source of free imagery and everone should know about it). Because the area is very far north, it has been in the Polar night until now so we have been reliant on the ESA Sentinel 1 imagery based on radar.

First Sentinel-2 optical satellite image of the year downloaded from Sentinel Hub’s EO Browser today. Processing with Sentinel Hubs optimised natural colour filter has introduced some artefacts, notable the brigh white patches which probably represent areas of shadow due to the low solar angle. The area is blanketed in thin cloud and only parts of the glaciers, sea ice and icebergs are clearly visibe.

It’s a wonderful thing to see the first satellite image of Spring, akin to other signs like the first cuckoo (in the UK), the first peewit egg (in the Netherlands), and the timing of the cherry blossom in Kyoto.

The first lapwing (peewit) egg of the year was traditionally presented to the Dutch monarch – these days, given the

There was recently a very illuminating thread on phenology on mastodon in reply to a query by Pauline von Hellerman where the Diagram Monkey John Kennedy pointed out the existence of the Pan European Phenology network – not something I was aware of before (though I’d suspected it’s existence) – and who have all sorts of interesting data.

Where biology is clearly showing us earlier springs due to climate change, the date of the first optical image is unlikely to change any time soon due to climate change.

A newer updated version of the Economist’s cherry blossom flowering date plot provided by Datagraver after I posted the old one. See:

Nor are species assemblages (it’s not quite certain that it’s the same variety of cherry blossom for the whole 1200 year period), or biodiversity losses (the cuckoo is down 65% since the early 1980s alone in the UK, and heaven knows it was not particularly common then) likely to affect it. Not to mention human behaviour changes, the lapwing has gone from being a common agricultural bird to near threatened over the same period, which probably also affects the reliability of that data.

Of course, quite a bit of what you might call bulk phenology can be done by satellite too now…

Copernicus land dataset showing biological activity in Europe basedon satellite data available here

As for Qaanaaq, there is not much in the way of biological phenology, but a compilation and analysis of data on sea ice cover and thickness over the last 60 years would probably be as instructive. Do get in touch if you’re interested in doing this as a student project…

Garden birds

Female blackbird on a tree branch
Female blackbird waiting for food

At this time of year about the only thing worth going out into the garden for is to watch the birds. Even in the centre of town where the Sterna nest is located, we have identified 22 different species in the back garden (in no particular order: blackbird, starling, fieldfare, jay, redwing, robin, house sparrow, hedge sparrow, wren, greenfinch, goldfinch, chaffinch, bullfinch, hawfinch, willow warbler, great tit, blue tit, greater spotted woodpecker, magpie, crow, collared dove and pigeon).

As we try to garden for wildlife we’ve left seedheads on plants and I have sacrificed my winter brassica crop to the bloody pigeons (next year I will net them). We have bird feeders for fat balls, seed mix and sunflower seeds and we have also been putting out apples for species such as blackbird and fieldfare. Given the large numbers of birds we’re attracting, it’s no surprise that we have to replenish the food supplies every day or two, especially in the cold weather. I’m still surprised though at how quickly birds find new sources of food. A few years back when we lived in Scotland we put a nyjer seed feeder up in the back garden to attract goldfinches. I’d never seen a goldfinch there beforehand but within a couple of hours we had a pair feeding from it. It’s a mystery to rank with the famous blue tits learning to open milk bottle tops to get at the cream.

Feeding birds deliberately in our gardens is a pretty recent phenomenon, until large urban populations of humans, largely separated from their agricultural roots, were well established, birds were mainly seen as pests, especially species like sparrows which eat grain. It’s also hard to imagine that many of these species were also seen as a human food source until pretty recently. The masterful Birds Britannica book, informs me that goldfinches were almost hunted to extinction in Britain, being considered a food delicacy in the 19th century.  They were in fact one of the first birds the RSPB had on their list of concern. This is pretty incredible to me. They are extremely beautiful, but very small, not much more than a mouthful each and presumably several were needed in each portion. Its a familiar story, as the introduction of modern agriculture with pesticides and the shortage of weed seeds through the winter must also have taken a toll on goldfinches as on many other species, which now have their strongholds in towns rather than the countryside.

Goldfinch and Great Tit on bird feeder
Goldfinch and great tit on bird feeder

The habit of feeding birds has not only caused a shift in which birds live where, it has also apparently led to some species choosing to overwinter much further north than would otherwise have been the case, since there are now reliable food sources about and of course, a run of milder winters has helped. Given the hazards that many songbirds face abroad, for example Cyprus, where they are still eaten and where 1.4 million were taken this winter, this may perhaps be a good thing

Surprisingly though, a recent research study using radioactively labelled foodstuffs found that, in summer at least, bird food from feeders made up only around 5% of an individual bird’s diet. It appears that they see bird feeders as a sort of chip shop on the way home from the pub kind of food – just for a dip in when feeling peckish and not the main source of nutrition except during periods of food scarcity.

Greenfinch eating sunflower seeds while goldfinch looks on
Greenfinch eating sunflower seeds while a goldfinch looks on from above. Good hygiene is essential to prevent the spread of diseases at feeding stations like this one.

Unfortunately there is a dark side to feeding the birds in our gardens. It has been well known for sometime that birds can contract diseases such as aspergillosis, salmonella and e. coli infections as a result of the close contact that bird feeders necessarily encourage. Since 2005, trichomonosis has become an increasing problem too in the finch population, having apparently jumped species from pigeons and doves. It appears to affect greenfinches and chaffinches in particular, but also affects other species and although occurring mainly in the UK, has also been reported in Norway, Sweden and Denmark. The overwhelming popularity of birdwatching in the UK means that it may well simply be better reported than elsewhere.

Now that the snow has melted and the days are started to lengthen again, our feathered friends are bringing us much joy and even the recently hatched Arctic chick is starting to take an interest in their flutterings about the garden.

Apple halves in the frost
Apple halves left out for the birds in the frost