An insight into winter feeding strategies

 Sorry if the title sounds a bit pompous--but the idea is quite simple and I hope demonstrated elegantly by these two very recent examples:-

Over the past two days we have had reports back from the BTO of two birds, a Linnet and a Yellowhammer which have been shown by ringing to visit winter feeding stations at two farms which are just over a mile apart. So what? This doesn't sound too important given that we got really hot under the collar a few months ago when one of our Redwings was found thousands of miles away. 

The Linnet was an adult male back in February 2019, when it was first ringed at one farm--and recently recaptured in April 2021 at another nearby. We don't know where the bird's breeding site is but we do know that it clearly has a knowledge of the area around Pattingham in south Staffs, and in particular the areas where farmers are putting out winter feed.

The Yellowhammer was first ringed in November 2020, at one farm, and retrapped at the other in April 2021.

By analysing lots of what at first sight appear to be unremarkable retraps scientists have built up a picture of how birds best utilize the food we put out. Essentially, they very cleverly spend their days during winter visiting several feeding stages in a sort of circuit; rather than spending all day at any one site-- even if it is permanently well stocked with seed. This may sound like a waste of time and energy, but a minute's reflection shows what a sensible strategy this is. To coin a very inappropriate saying--they don't put all their eggs in one basket!! Simply, by having a range of feeding sites which they move between, they don't get caught out if one of the feeding stations runs out of food--pretty simple really! The same happens in our gardens when the birds you see on the feeders at one time in the day are probably not the same as those at another time...........aren't birds brilliant!!!

What a Beast!!

 When you're as old as me, you can look back on years of birding and see that quite a lot of things have changed. Goldfinches and Long Tailed Tits feeding in gardens, Buzzards everywhere, Cuckoos and Turtle Doves getting scarcer and so on.

One very large and obvious bird which has gone through a massive change in (positive) fortunes is the largest European crow, the Raven. Until quite recently, this was a very rare bird in this area-you had to go the wilds of Wales, the Peaks, Dartmoor and wild coastal islands to see them. No-one is sure exactly why but they are now relatively common almost everywhere, and any area with a decent patch of mature tall trees is likely to have a pair of breeding Ravens. Even if you aren't sure what they are to look at , their deep, resonant 'cronking' call ( impossible for us to mimic), gives away their identity.

We know of a nest locally and have been monitoring it over recent years. As restrictions have relaxed in time, Kev managed to get friend Jim to dust off his tree-climbing kit and he went to the nest for us so that we could ring the chicks.

As it turned out, the 4 chicks were at just the right stage for ringing. Jim was also able to perform a simple but crucial act of cutting two of the chicks free from some twine in the nest which would probably have prevented the birds leaving the nest, great stuff.

You can see what a beast this species is!! The beak is massive and strong--as are the claws (which you can't see). You can also see the inside of the beak area is quite bright red in colour. The chicks of many species have either colours, structures or marks in or around the beak which provide strong signals to the parent about where to stuff the food they have just brought back to the nest. It looks like these 4 chicks will safely fledge now and continue the successful growth in population numbers of Ravens in the West Midlands.

You never stop learning!!

 This is a mantra of ours because even those of us who have been ringing for 40+ years can find new things to learn, new techniques and new skills.

So it was that Jen asked our good friend Paul if she could visit his site where there was a chance of some new species and a new skill for her to learn. Specifically, Paul has been colour ringing House Sparrows for some time now, so it was a great opportunity for Jen to learn the technique of fitting these plastic rings which can be seen and read in the field--thereby enabling data about the birds to be generated without the need to re-catch them.

Here's one of the colour rings which Jen applied--as you can see its much easier to read in the field than conventional metal rings ( these are also fitted -usually to the other leg.

One of the male House Sparrows showed a slight bill deformation with the upper mandible longer than the lower--we see quite a bit of this in a range of species but it doesn't seem to affect the birds too much--this one was perfectly healthy as far as could be seen.

Jen also managed to handle three other relatively unexpected species:- the first was her first migrant Blackcap of the season--probably recently arrived back from southern Europe or north Africa.

As you can see it was a male bird. A bit of a kerfuffle at one net turned out to be a rather angry Sparrowhawk which had darted into the net on a hunting foray.

This bird is a male--the simplest way of telling is by measuring the wing length in particular. Males ( as in most birds of prey) being significantly smaller than the females. This is also generally a slim, not very bulky bird-again a male character. Ageing is by various plumage features as well as the yellow eye colour--both of which point to a bird hatched last year (2020). As males get older, the upper surface feathers of the wing are blue/grey, and the eyes become orange.

Last but not least, this re-trapped Rook bumbled into another net. This was an adult bird as can be seen by the pale area of bare skin at the base of the bill--in younger birds this is absent because it is covered with feathers for a year or two. This makes separation from Carrion Crow a bit more complex. As it is this one is an easy bird to identify--and a useful addition to Jen's experience since we hardly ever catch Rooks at our sites.  

Already thinking ahead at Belvide!!

 We are just coming out of the winter feeding station period, and just entering into the breeding season......BUT it's never too early to be thinking about our main post-breeding site at Belvide Reservoir

A few weeks ago we joined with a working party to bring down much of the overgrown willows around our net rides to ensure they would be the correct height for our nets later in the year.

Meanwhile we have been refurbishing the steps that we use to get into some of our net sites. These can get pretty dangerous when the steps wear away and leave slippery slopes which would fail H+S inspections.

Really pleased about the steps to access net site 9

Kevin has also produced a revised ( and laminated!!) information panel for the entrance board to the reserve--and we think he's made a superb job of it.

Unfortunately it's really difficult to get the detail to show clearly, but we think you can get the drift. Actually, better still join the West Midland Bird Club and visit Belvide to see the poster in all its glory!

 

Only about 11 weeks to go before we start ringing at Belvide again.......can't wait!!

'' I walked behind with me old cock Linnet''-----

---so goes the old Cockney song from back in the day when Linnets and other common finch species were regularly kept as caged birds by lots of people. Here's a close up of the head and breast of a cock Linnet in breeding plumage in case you have never seen one...

You can clearly see the two key features of a pink breast patch and plain grey cheeks. The area of the forehead just above the beak also has some patches of pink but they are often difficult to see as in this bird.

But why post material about Linnets? Well, we really are in the last throes of the winter feeding stations as birds gradually disperse and concentrate on breeding. But for some reason however, one of our farms is still attracting good numbers of Linnets which don't seem ready to breed. We only managed 3 short sessions this week because of unfavourable weather conditions but we still managed to ring 58 new Linnets along with 4 more Yellowhammers ( bringing this winters total of Yellowhammers to almost 100), 3 Great tits plus one each of Goldfinch, Reed Bunting, Chiffchaff, Robin and House Sparrow.

The total of Linnets ringed at this one site over recent weeks is now an incredible 137 and the lack of retrapped birds suggests that there is a constant flow of birds through the site. We just hope we can get some recoveries of our birds to give us some idea as to where they are travelling to in order to breed.

I mentioned we caught another 4 Yellowhammers and just had to show this picture of an adult male caught this week:-

There are two reasons for showing this picture. First they are gorgeous looking birds so why not show it!? But second, regular readers will have read me banging on about adult finches and buntings having muted colours on the outer edges of their feathers during winter in order to reduce aggression between males especially. These outer edges wear off as we move into spring revealing the bright breeding colours lower down the feathers--and that's beautifully illustrated by this bird. You can still see some dull feather edges round the head, but most have worn off showing this stunning yellow head to warn off other males and attract females--brilliant!! 

 

What do recoveries really tell us?

A couple of weeks ago I mentioned that we had caught a Brambling at a farm feeding site, which had been ringed originally in Norway. Since then we have had details back from the Norwegian ringing scheme.

The bird was ringed as a male hatched in spring/summer 2020, and ringed on 10th October almost in the southern tip of Norway. We can say that because Brambling don't breed in that area, that this was a bird which had been raised much further north ( and probably east) --and was on it's autumn migration to warmer south western parts.

164 days later on 23 March 2021, Paul caught the bird at the farm feeder. No Bramblings had been seen at the farm all winter so it is safe to assume that our bird had spent the winter further south and was stopping off to feed up on its way back to Norway or wherever it had been raised.

The ringing records will now show a bird recaptured 164 days after original ringing and 845 km from it's original ringing site. Now this is all great information and data that we wouldn't have had were it not for ringing. But it also shows shortcomings--we don't know where the bird originally came from; we don't know where it went between ringing and recapture, and we don't know where it will end up, and we don't know how much distance it covered during it's migratory journey.

So, what's to be done? Well two things really. This example shows the need for continuing to ring birds because although this one bird leaves questions--if we take the total number of Brambling which have been ringed and recaptured we can begin to fill in some of the gaps in our knowledge. Indeed this has been one of the great successes of ringing -- large databanks of bird movements which can be analysed to build up a good picture of migratory movements over the last 100+ years since ringing began.

The second thing calls on developments in new technology. Satellite tracking is developing at pace but as yet the most informative devices are too large ( and costly!) for use with the smaller birds.  However, I'm sure this will change fairly soon and the prospect of attaching these trackers to small birds and following their movements in detail and in real time will be an absolute thrill and a massive game changer--bring it on!!

The team goes March-ing on........

 I've just been reviewing progress in March 2021, and it's fair to say that I've been really impressed by the success that we have had. One of our key priorities is training new ringers--but to do so we need good totals of birds so that trainees get plenty of practice.

We ringed just over 900 birds, of 34 different species during March--thereby providing our smashing trainees with plenty to keep them going. This has been even more important given that lock-down arrangements have meant access to training events for most trainees has been difficult to say the least.

Rather than set out a potentially tedious list of all our species caught-I thought it might be better to take each active team member and briefly set out their highlights:-

I have mentioned Pat quite a lot recently mainly because his rural Welsh garden feeders have played host to lots of birds including many Siskin. This has continued during March at what Pat now calls  ''Siskin City'' returning a total of 179 Siskin plus a good supporting cast including 44 Goldfinch.

Like Pat, Jenni has recently achieved her 'C' permit and is using it enthusiastically, with several farmland and garden feeders on her patch. One garden feeder in particular has begun to attract good numbers of Siskin, and Jen has ringed 73 plus 41 Goldfinch. In her small home garden she managed to catch a beast of a bird as shown below:-

Woodpigeons are beefy birds which often simply roll out of mist nets so not too many actually get caught ( certainly compared to the number of them there are around!!). Novel species like this provide a welcome variation from the many many Blue and Great tits we catch....

Gareth has had his licence for a bit longer, and he is pressing ahead trying out some new sites. He has been rewarded, not by large numbers of birds--but by some quality in having the group's first migrant Blackcap and Chiffchaff on return from their winter quarters either in southern

Europe or north Africa.

Kevin is an experienced ringer and is pushing on with some new sites also. One garden in particular is showing great promise for the future even though it's been a bit late for him to start this winter. He has ringed 25 Siskin there but the most significant species has been the 6 Brambling he's ringed. The garden is part of a mature woodland with some ancient Beech trees. Brambling love beechmast so we are hoping in future years ( especially when there is a good beechmast crop) Kev will catch more of this splendid migrant finch which I featured in a recent post.

At the other end of the experience scale, Paul has been ringing for almost 40 years!! For those of us who are a bit long in the tooth, new kit, new trainees and new species all help to keep us enthusiastic. This no more evident than at Paul's main farm site, where he installed with the support of the farm manager a ''spinner'' continuous feed dispenser:-

You can see the seed hopper at the top and the small motor at the bottom with a spinner device between the two. It's also pretty 'green' --you can see the small solar panel to keep the mechanism working. The regular supply of seed has attracted good numbers of birds, and Paul has managed, by regular visits, to ring 108 Linnets, 84 Yellowhammer, 33 Goldfinch, 24 Chaffinch and 24 Reed Bunting, among other species. It's given all us old timers a boost!! 

 

 

108 Not Out !!

 Team members have been hard at it over recent weeks, as I will report next--but for now I'd like to share with you our success with one species in particular-the Linnet. This is a small finch which was commonly kept as a cage bird back in the day, and one which as a group we have rarely handled in the past. However, one of our farm feeding sites has attracted a regular feeding flock and during the last few weeks we have managed to ring a substantial total of 108 Linnets!! And when I visited the feeder yesterday afternoon, there was a group of 20+ still actively feeding.

What is intriguing is where these birds are headed. There isn't any suitable breeding habitat on the farm ( this species love nesting in gorse bushes), so they must be feeding up ready for a movement to breeding grounds elsewhere. Very few of the birds are in breeding plumage-but here is an adult male which is ready to breed:-

As you can see it is a male which has a bright red breast, and a grey head. Most of the males we have been catching are juveniles ( less that one full year old), and they have not yet aquired their full breeding colours. But this next picture illustrates a more general point -especially about the way finches and buntings finally get their breeding colours:-

This young male has actually grown breast feathers which are red--but the tips of the feathers are white-why? Well most finches form gregarious feeding flocks during the winter, and juvenile ( males especially) have pale tips to many of their feathers to hide the underlying colour, to reduce aggression between males. As the Spring wears on, so these pale tips wear off to expose the colour and -hey presto!!, let breeding behaviour commence!

Just a couple of pictures to show some other features. Males and females are easy to tell apart in breeding plumage because the females don't have the red breast, but in winter plumage they are a bit more tricky. However, the colour of the wings when folded are a really good clue, as you can see in the following picture:-

The bird on the left is a male with a russet brown back, the female on the right has a streaked, grey brown back.

Finally ageing can be interesting......However, juvenile birds tend to have pointed tail feathers while adult tail feathers are slightly more rounded. Both can be seen in this picture:-

You can clearly see that most of these feathers are pointed because this is a juvenile bird. However, a closer look at the two outer tail feathers between the fingers, shows a couple of feathers which are subtely more rounded--how come? The likelihood is that somehow the juvenile outer two feathers have been lost and the bird has regrown them  and, as expected they have grown through as adult looking feathers.

More about the rest of the teams recent success soon........