Bits and Pieces

 Apologies for the lack of posts recently-I've been a lucky boy and had a couple of holidays. I'd like to make a plug for one. It's a lovely place in the foothills of the Gredos mountains about 2 hours west of Madrid. Keith and Jane have Finca la Sayuela waiting for you so check it out on the internet. If waking up to the song of Golden Oriole and Nightingale doesn't do it for you then sitting in the garden watching 7 or 8 raptor species circling overhead--plus lots of butterflies and stunning plants should seal the deal. Wonderful!!

So what's been happening while I was away? Well not a great deal--this is the breeding season so we don't tend to get out that much--but I have a few snippets of random stuff to ( I hope) interest you.....

When the weather is cool ( below 10 centigrade), the Swifts tend to fly low enough for us to stand a chance of catching them. They are magnificent birds but in the hand the have lethally sharp needle claws which make life painful for the ringer--but they also hold another less obvious surprise.....

But first here is a study of the head of a Swift....

For a fast flying bird which catches insect food on the wing big eyes are essential. But how small is that beak? What you can't see is that when the bird opens it's beak, it's mouth opens really wide-almost from the eye--giving it a very large gape to catch flying insects.

The surprise item is a particular blood sucking parasite called a Hippobscid fly--or a flat fly to us. They are presty gross but wonderfully evolved parasites. We collected a few in jars to send to someone doing a scientific study of them....

Gorgeous aren't they............

Hirundines ( Swallows and Martins), also come down low like this House Martin. In this side view you can see again a very small beak....

But the same bird from the front gives you an idea of how wide the mouth is again in order to help it catch flying insects....

This time of year also sees us checking all our nestboxes. Blue and Great Tits are far and away the most regular occupiers of boxes but this year they are about 10 days ahead of where they usually are so we have missed being able to ring the chicks as they are too big. Pied Flycatchers seem to be on track and we will report back on their success next time--checking is this coming weekend.

Here's a couple of recently fledged birds which show some interesting features; first a very recently fledged Great Spotted Woodpecker.....

The key feature here is that very young Great Spots have a red cap. This sometimes confuses folk into thinking they are the much rarer Lesser Spotted Woodpecker. Just be wary of this --Lesser Spots are only about sparrow size--much smaller that Great Spots. The Great Spot juveniles gradually lose the red cap over the first few months out of the nest.

This baby Robin is also a classic confusion species when so young....

The red breast only develops over the next few months--the dappled brown breast is supposedly designed to avoid aggression from adult Robins during a time when the youngsters need to be protected. As soon as the red comes through however, the adults use this as a sign that their babies are ready to look after themselves and drive them out of the territory.

New Arrivals!

 There's all sorts of bird movements going on at the minute-but here's two examples of completely different movements that we have encountered in the last few days......

Over the last few weeks, hirundines ( Swallows, House and Sand Martins ) have been arriving in their thousands. Many observers are reporting for the second year running, much fewer birds around than even a couple of years ago. However, on cold/damp mornings in our summer/late spring; these birds find it more difficult to find their staple food--flying insects. This is when sewage works can come into their own. The filter beds are breeding grounds for many insects and as they hatch and fly off, they provide good feeding or hirundines--which come down low enough to be caught for ringing. There haven't been many suitable days recently, but Paul managed a short session before the sun came out and the birds disappeared. He caught a few Swallows and House Martins--and here are a couple of pictures to illustrate one or two points........

Here is the tail of a Swallow showing the long outer tail feathers or 'streamers' as they are called. Research on this species suggests that the longer the streamers are as sign that birds are male--and furthermore, the longer the streamers, the more successful a male is in attracting a mate.........we measure the length of the streamer back to the other tail feathers to determine the sex.

Here is a House Martin ( not a very flattering pic but taken to show a couple of features. Firts, we often get asked about how to tell the difference between hirundines--in the UK, House Martins are the only species with a white rump as shown here. This picture also shows the complete uniform blue back typical of a bird having just completed a pre-breeding moult in it's African wintering grounds. As we'll see later in the year, juvenile birds have mixture of blue and grey brown feathers here.

So, here we have some new arrivals from thousands of miles away which have come here to breed during our summer. Now lets jump across to Pat's garden in mid Wales, and some new arrivals have been ringed--but from a very different source......

Here is a newly fledged ( recently left the nest) Siskin. Presumably just arrived from an egg in a nest not too far away from Pat's garden. You can see how generally speckled it is, and a closer look at the stripes on the wings there is quite a bit of buff colour--here's a picture of the wing in close up....

1 are called median coverts, 2 are called tertials and 3 are called greater coverts--and their edges are all creamy/buff with just a hint of green.

Over the next few weeks many of these feathers will be moulted and replaced with completely different coloured feathers as shown by this older bird....

As you can see, many of the buffy feathers have been replaced--but not all--the outer greater coverts as indicated are shorter with white tips, then the older more adult like greater coverts to their left. 

In stark contrast is the wing of an adult Siskin---

( Please ignore the number!!) Here you can see all the feathers mentioned earlier are brightly coloured green and yellow, with no sign of any remnant juvenile feathers. Here's an adult male Siskin to compare with the fledgling above..

Also at this time of year we often get birds showing signs that they are/have been actually breeding. Female birds develop what is called a 'brood patch' which is where they lose their belly feathers in order to have bare skin with which to keep their eggs warm. The skin becomes wrinkled to increase its surface area, and engorged with blood vessels for added heat. Here is a brood patch shown by one of the Siskins recently ringed in Pat's garden.

When you see birds settling down onto the nest you often see them wriggle about a bit--that's their way of ensuring their feathers have parted to ensure the brood patch is in touch with the eggs..... aren't birds brilliant!!

 

 

 

Snippets fro Demon.......

 'Demon' is the name for the database on which all our ringing records are stored by the BTO--and also where any already ringed birds are reported if they are found again. This type of record has been the mainstay of the ringing scheme since it started just over 100 years ago; and from it we have built up a picture of the migration patters on our birds. Each record is a tiny bit of info--but by pooling lots of records we can find patters.

I've selected a few from the recent batch of reports--just to try to illustrate the kinds of ideas we can derive even from individual records--these are in no particular order of significance.

I've reported regularly on the big numbers of Siskin and lower but significant numbers of Redpoll ringed in Pats garden in mid Wales. These birds move around a lot and are relatively easy to catch so as expected we get lots of reports. For example, from the birds Pat ringed in March and April 2021, he has had Siskins retrapped by ringers in.....Wirrall, Cumbria, Gwynedd and Angus and Bute--mostly in April 2022. This clearly shows a complex dispersal of these birds which can turn up anywhere. It feels like this is an area ripe for someone to study in more depth to try and get to the bottom of why these birds find the need to disperse in such a way.

Beautiful male Siskin-- but where will it be headed??

We ring several hundred Chiffchaffs at Belvide each year, such as a bird ringed in September 2020, which was retrapped by a ringer last month ( April 2022) in North Yorkshire. Now was this a bird which bred in Yorkshire and we caught it en route to it's winter quarters; which has now found its way back to the breeding area--or is it a random event??

A Chiffchaff

Our new project at Patshull is already starting to generate some recoveries such as:-

A Fieldfare ringed in November '20 recovered in Mons, France in October '21--this bird will have returned to breed in northern Europe/Asia in Spring '21, after which it will have joined a migrating flock which decided to avoid crossing the North Sea and spent the winter in France. This is quite typical for this species and the other northern thrush we get, Redwing.

The Robins we see in winter are mostly British bred birds, but there are also some visitors from the continent; which are more prone to wandering than out own fairly static birds. This could be the Robin we caught at Patshull in March '21 which was recaught in N. Nidely, Glos.in December '21

A Robin--British or Continental....??

Just to prove that Pat's Siskins aren't the only wanderers, a Siskin caught in Abi's garden at

 Patshull April '21, was recaught in Cumbria in January '22.

Sometimes it can also be very useful to record birds again, showing that they DON'T move. This helps us build a picture of good breeding areas among other things.

So the Yellowhammer ringed at Brewood Park Farm in November '18 and recaught in March '22 at the same site clearly demonstrates the success the bird is having at the farm, and pleases the farm owners that they are helping such endangered species.

One of our regular Yellowhammers at BP Farm

Finally--a matter of chance always plays a part in such matters. What are the chances of this happening?

Paul ringed ( among other things) 2 juvenile Blue tits and an adult male Chaffinch at Brewood Park on 14th December 2018--nothing particularly remarkable about that....until last week on 27th April 2022, when the same three birds turned up in the same net almost 3.5 years later!! Isn't birding great......

Thanks mainly to Sam for his regular reports from Demon--and other team members who feed me the data to generate these blogs.