Winter really isn’t as interesting as the breeding season – but it’s quite interesting.
Most resident passerine species have very similar distributions in the winter to those in the summer. That may sound obvious, but it needn’t necessarily be so, need it? Our Jackdaws and Chaffinches could all move to different areas of the country seasonally but it appears that, generally speaking, they do not.
Pied Wagtails are quite interesting; their relative abundance looks quite different in winter and summer (at least in Britain – less so in Ireland). Basically, there are fewer Pied Wagtails, relatively speaking, found in cold places in winter – hardly surprising but very obvious now that, for the first time, we have relative abundance mapped for the same species in both seasons. Pied Wagtails are less keen on living in the north and the uplands in winter and become relatively abundant in some lowland areas that they do not greatly favour in summer. Grey Wagtails do something similar too.
Snow Bunting is a breeding species, but I think of it as a wintering one. And I think of it as a coastal species because when I see them they tend to be on shingle beaches in Norfolk. Come to think of it, I’ve rarely seen Snow Buntings anywhere else. And that shows what a sheltered life I have led – they are all over the place inland in north Scotland in winter. I must get out more.
The difference in relative abundance of Fieldfares and Redwings is interesting. Where I live, and in all the places I’ve lived, they seem to come along pretty much together and they are treated almost as a single species; ‘Fieldfaresandredwings’. The Atlas shows that Fieldfares have a much more easterly centre of gravity of their distribution, with fewer getting to Wales, the southwest and Ireland in comparison with Redwings. You’ll see them both, in the same field, in Ireland and Norfolk, but their relative numbers are likely to be different. I hadn’t really appreciated that – and now it interests me. That made me look more closely at Blackbird and Song Thrush; to my eye the Blackbird resembles the Fieldfare and the Song Thrush resembles the Redwing in terms of winter relative abundance.
It’s not just Ireland that Bewick’s Swans eschew these days. Their range has contracted by around a half in Britain and Ireland since the first winter Atlas. We still hold about a third of the world population of this species but they seem to be more and more concentrated into the Fens – especially around the Ouse and Nene Washes. It’s a good job that both areas are SPAs and under sympathetic management but what if the fens are filled with wind turbines? Or if the land use changes to grow elephant grass on a large scale? ‘All your eggs in one basket’ is rarely a good strategy for any bird.
No, the winter maps are not as interesting as the breeding maps – partly because a lot of the interesting wintering species are coastal (ducks and waders), but that’s not to say that they are uninteresting. Maps of bird distributions, but particularly these maps of relative abundance, are interesting enough for anyone.
By the way – this is the 1000th post on this blog.
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Got my atlas in the post today. I knew it was going to be something special but I was still shocked at just how impressive it is and I’ve barely scratched the surface.
Congratulations on 1000 posts Mark, here’s to 1000 more.
I think one of the most interesting aspects of winter distributions is the difference from the breeding maps in ‘resident’ species. Many of them move away from higher ground. The national Atlas shows that Skylarks move out of many northern Scottish areas, for instance, and for Meadow Pipit, the abundance maps (in Britain) for breeding and winter are almost the opposite of each other. Linnet is, as everyone knows, among the most interesting of all species and in winter clearly quits the upland areas in the Scottish Borders, the Pennines and central Wales.
Many of the more subtle changes, however, only can be seen at the finer scale exemplified by county (tetrad) atlases that complement the national picture. In Cheshire and Wirral, for instance, whose recent atlas is now freely available on the internet, the very interesting Linnet was found in winter in only half the number of tetrads occupied for breeding, and in only two of the county’s 50 tetrads above 150m in altitude while Dippers moved a few km down their rivers.
But these are just initial thoughts and I am sure the national Atlas will repay many hours of study.
Your blog is as stimulating as ever. You got me googling my way to the BTO Migrating thrushes’ page. To see whether it was just the apples in my garden that kept all those black meatballs of sparrow hawk fodder in the East of England. Song thrush don’t seem to migrate in in big numbers unless it is bad weather. They “leave Britain for Ireland, France or Iberia for the winter, although most show little seasonal movement unless prompted by severe weather. Hard winter weather can also bring birds from the Netherlands and Belgium into Britain.” Blackbirds come regularly from guaranteed colder climes and obviously stop when they reach my apples!
Interestingly, Chris Packham did a short piece for the One Show (I think!) but he messed it up a bit by trying to generalise in such a short piece. Our robins generally hold territory throughout the year although the most dominant of the sexes will turf out the other partner in leaner times. Continental robins do not hold territory throughout the year and arrive in the UK in good numbers during the winter. Most will stay in coastal areas and thus do not compete with the resident birds inland. Continental robins also tend to be shyer than our own birds probably because they never get a chance to familiarise themselves with people in their territories. It is similar with blackbirds but the difference is that continental blackbirds will move inland. UK blackbirds remain territorial and they can often be distinguished from their continental cousins by the fact that they chase the latter around. The continental birds tend to be a bit more tolerant of each other and can lead to some really interesting garden behaviour. As Mark mentions, it is a little more complex with finches and all have slightly different strategies, none of which, is fixed.
Your comment about Bewicks and having everything in one basket reminded me of the black necked grebs on Kinnordy being the majority of the Scottish breeding population.
The Westmuir Village website gives suggested reasons for the decline but not Otters. Ok I am harking back to that but when I think about it I cannot see Black headed gulls deterring otters. The only other lowland Black Headed Gull site I know is Minsmere and that had predator fencing (against foxes) before otters arrived so they never knew what they were missing.
There must be a reason that the gulls like (not necessarily floating) bogs on the high moors away from anywere, or one I know near the road that has army protection.
OK it is anti Otter but are a lot of nests any different from the classic fish in a barrel comment thrown at people who loose a pond full of carp to Otters.
Rewilding is a lovely idea but does that mean we stop managing the countryside eg.Minsmere takes down its anti predator fence and we make do with the scattered nesting population that escapes from and is too few to attract to much attention from a predator?
Just started reading through the Atlas, yes it is mightily impressive but what I have not seen commented on is its ability to inspire the next generation. My daughter (22 months old) got very excited by short eared owls and scaup! 🙂 She’s in training for the next Atlas!
By the way Dr A, Winter is far and away the most interesting season – all those waders, geese and wildfowl – fantastic. Jog on up to the Black isle and I’ll show you!
Callum – hi! and thank you. Enjoy as much wildlife as you can in the forthcoming short days!
Think the 1,000 blog deserves many congratulations,feel sure lots of us have enjoyed your blogs and comments and raised many issues that have made us think,really well done.
dennis – that’s very kind of you to say so. Thank you.