Wednesday, 31 January 2018

Savvy Siskins and Sneaky Snipe

In an previous post I mentioned how Siskins had started visiting the feeders in my garden much earlier than usual this winter and that the first two seen in late November were already ringed. I speculated that both were likely to be returning birds rather than having been ringed elsewhere and I thought I would be able to confirm that by retrapping one or both of them within a relatively short space of time. I have caught 11 Siskins in the garden since then and over 100 Goldfinches but haven't caught either of those ringed Siskins, both of which were adult males, or any others that had been ringed prior to this winter, let alone ringed elsewhere. Now that I have ringed some Siskins this winter it isn't possible to say a bird could be a returnee by the mere presence of a ring as I was able to with those first two males.

It is fair to say that I am both surprised and disappointed that I haven't retrapped either of those ringed Siskins and that disappointment has been compounded by two I have photographed recently. I have got loads of photos of Siskins, some of which are really quite good, but that doesn't stop me from trying to take more, and I have done a bit of 'snapping' over the last week or so. When I review photographs I always look to see if I can read any rings, if present, and I managed to read part of the ring numbers of a couple of Siskins and, surprise surprise, they weren't birds I had ringed this winter. The first, a male photographed on 24th Jan, was wearing ring that started Z0..... which is the start of a sequence that I was using in the garden 2 to 3 years ago and certainly not this winter. The second was a female with a ring inscription that started with the letter S...... and another photo showed more of that ring number which pointed to it having been ringed in the garden last January.

Z0........ male Siskin

The other photos of this bird revealed more of the ring number which, by a process of elimination, is almost certainly a bird that was ringed as an adult female on 22/01/2017
I have no way of knowing how long they have been visiting the feeders but there is a chance the Z0....... ringed bird could have been one of those initial males. What I can say is that at least 3 Siskins, ringed prior to this winter, have visited the feeders and that all 3 have evaded recapture to date. Their ability to avoid being caught strengthens my view that they are all returning birds and that they are quite savvy when it comes to avoiding a mist-net in my garden because they have seen it all before. Net shyness, as it is sometimes referred to, is not unusual and is most common in resident birds or at times when a population becomes relatively static such as birds visiting feeders in winter and is something I try to minimise in various ways, so it is interesting that these Siskins appear to have remembered or perhaps I should say retained that level awareness despite being away from the garden for over 7 months. Obviously there is still a chance that these birds will end up being caught at some point later this winter but I wouldn't like to bet on it.

Regular readers of this blog may remember some photographs of Snipe roosting in a field of winter cereal that I posted on the blog last winter (link here). Snipe roosted in this field from November (when they were first found and up to 29 were counted) through to at least mid-January (when the crop started to grow and made the birds harder to see). I had never seen Snipe using an arable crop as a daytime roost site before and, knowing how traditional Snipe roosts usually are, I wondered if they would use the field again, especially if the type of crop changed. As things turned out the field was sown with rape in the autumn and I thought that change, and the fact that rape has a different structure, can get denser and a bit taller than autumn sown cereals during the winter, may put the birds off.

I didn't spot any birds using the field during November and the density of the crop meant any birds, if present, had a much better chance of remaining unseen, especially if they had chosen a different part of the field to roost in. It started to feel like I was looking for the proverbial needle in a haystack but I continued to scan the field from time to time. I probably could have got permission to do a walk through survey but it would have been very difficult to find a time when other people weren't around and I was concerned it may have drawn others to think it was OK to do the same, so I decided to stick with observations from the adjacent public footpaths to be on the safe side. Unfortunately there is trend for people in this area to think it is OK to walk around the headland of just about every field and even walk through crops with their dogs rather than sticking to the numerous public footpaths and public open spaces.

Anyway, I happened to be scanning the field about a week ago, on one of this year's rare sunny days, when I noticed a Snipe amongst the rape and it was in the same part of the field that the birds used last winter. Further observations revealed a few more and I eventually counted 10. A few days later I could see a similar number in the same area when a loud bang and some crashing from a building site about half a mile away caused a few more birds to pop their heads up and I ended up counting a minimum of 19. Unfortunately I didn't have my camera with me on either occasion but I have managed to get some images since.

The images above give you an idea of how difficult the are to see but it gets a bit easier once you get your eye in. I am sure they have been using the field all winter and that I have simply overlooked them until recently. If you think they were quite difficult but want a real challenge have a look at the series of images below. 

Spot the Snipe, not that you have any chance of finding it in this photo.

Try again in this zoomed and cropped image but I wouldn't waste too much time trying.

Same image again but even with a nice red arrow pointing it out you will probably struggle to see anything identifiable as a Snipe.

.....and here is a tighter crop of the same image and you can just see the distinctive crown stripes of a Snipe's head. Now that was a difficult one.
I certainly believe the use of this field by Snipe in successive winters qualifies it as a traditional roost site (and Snipe could have been using it prior to last winter) but it remains to be seen how long this particular winter roosting tradition can survive in the face of modern agricultural practices and crop rotations.

Sunday, 21 January 2018

Garden Ringing: 20th January 2018

The weather hasn't been suitable for mist-netting over the last week or so but yesterday morning presented a brief opportunity ahead of a belt of rain that was due to move in. I set up the usual 6 metre net in the garden shortly after first light and caught 22 birds in just over an hour before the forecast rain put a halt to proceedings. The catch was much as expected with Goldfinches accounting for the majority of birds caught and another 2 new Siskins continued the early presence of that species in the garden.

The light was shocking yesterday (that is why it was so good for mist-netting) so this and the following photos of finches were from a few days ago.

Female Siskin being photobombed by a Goldfinch (also a female).

........and again.
That could have been that but the rain stopped towards mid-afternoon when I caught 2 Starlings in the manually operated bird table trap with one being a new bird and the other a retrap. I try to avoid recapturing colour-ringed birds but now and again the opportunity to catch a new bird takes precedence. The new bird had a full yellow bill which was well ahead of a lot of the other Starlings seen or caught recently. This bill colour change often goes unnoticed but the predominantly yellow colour of the adult bill changes to black towards the end of the breeding season, generally starting in late June or July, and juveniles start life with an all dark bill. The change back to the yellow bill of the breeding season can begin as early as November in the British population and generally a bit later in migrants from the continent and there are also differences between age classes with older birds generally changing first.

Male Starling ringed 29/11/17. Note the bill is starting to change from black to yellow and the base is becoming blue, showing it is a male. The uniform eye colour also indicates this bird is a male.

Female Starling ringed 20/01/18. The bill is all yellow and the base is turning pink showing this bird is a female. The pale eye ring also confirms the sex as female.
The ringing didn't end with a couple of Starlings as I decided to put the net up again because the weather conditions were perfect (very overcast and no wind) and the forecast for the next week was looking pretty dire. The net hadn't been up for more than ten minutes before another 10 Goldfinches had been caught and another half hour saw the afternoon total rise to 17, all Goldfinches (16 new and only 1 retrap). I could have carried on but I decided to call it a day as I was more that satisfied with a day total of  35 new birds and 6 retraps plus I had other things to do. Final ringing totals for the day (retraps in brackets) were: Goldfinch 29 (4); Chaffinch 2; Siskin 2; Greenfinch 1; Starling 1 (1); Coal tit (1).

Now you may have noticed that the ringing totals aren't listed in any sort of species order but my thoughts on that and recent changes to the British List can wait until another day, but the one thing that should really stand out is the lack of tits. There are very few Blue, Great and Coal Tits visiting my feeders and it has been pretty much the same all winter, but more so since the turn of the year. I don't know if it is because their populations are particularly low or if there is plenty of natural food that has allowed them to stay closer to their woodland breeding sites but there is no doubt that my garden is generally devoid of tits, apart from periodic visits by the Long-tailed variety. I am not complaining as I am not what you would call a tit man (can you say that anymore in these overly PC days) but Blues and Greats seem to have been unusually scarce in the garden this winter.

Tuesday, 16 January 2018

Long-tailed Tit feeding behaviour.

Way back in December 2013, the 24th to be precise, I was watching birds visiting the feeders in the garden when I noticed a Long-tailed Tit hanging from a twig by one leg whilst holding a sunflower heart in the foot of the free leg and feeding on it. I had never seen a Long-tailed Tit feeding on a sunflower heart in this manner before and I couldn't find any descriptions or reports of this behaviour in the literature I had to hand or from internet searches. I posted a brief account of what I had seen on the blog at the time and a link to that post can be found here.

It didn't appear to be common behaviour amongst the many Long-tailed Tits visiting the garden back then and although I observed this feeding behaviour on more than one occasion later that winter it may have been limited to just one individual. This was one of those situations when it would have been really informative if the Long-tailed Tits were colour-ringed as I would have been able to establish how many individuals were involved but what I can say is I didn't see more than one bird feeding in this manner at the same time.

I have seen and photographed Long-tailed Tits using this feeding method each winter since that first encounter and it has gradually become more common amongst the birds that visit the garden. I haven't started colour-ringing my Long-tailed Tits (yet) so it is still not possible to be certain of the number of individuals involved but last weekend (13th & 14th Jan) at least 4 were using the 'hanging and holding' feeding method simultaneously out of a total of ten or so that were in the garden at that time. Establishing numbers is further complicated by the fact that more than one Long-tailed Tit flock may visit the garden over the course of a day and birds from the same flock may switch between feeding on sunflower hearts and fat cakes but there is no doubt it has become more prevalent amongst the the birds that visit my garden. This also begs the question as to what extent it is an innate skill as opposed to having to be learned. Again colour-ring could help answer that as it could show if there are any differences between age groups (potentially a nice line of research for someone).

There is a bit more to it than just hanging upside down and eating - a Long-tailed Tit will take a sunflower heart from the feeder and carry it in its bill to a suitable twig and then hang upside down before transferring the seed to one of its feet. Now I don't know if individuals have a preference over which foot they hang from and which foot they hold the seed in or if they can be ambipedal but I have seen individuals hang from either foot and photos in this post show that (now there is another research project for someone). The twig that an individual chooses to hang from may be near the feeder but is often one or two metres away, presumably to avoid disturbance from larger species that may come to use the feeder. The twig selected obviously has to be a suitable diameter to enable the bird to get a good grip and the way the tendons work in the birds leg and foot probably allows it to hang with little or no effort.

There are a couple of aspects of this feeding behaviour that I find really interesting, one is that they seem to be increasingly taking advantage of a relatively new food source in the form of sunflower hearts and the other is the question of how common and widespread it has become. With that in mind I contacted Kate Risely, who runs the BTO Garden Birdwatch project, to see if it was something she was aware of and if had been reported before. Kate wasn't aware of any reports of this behaviour and thought it was interesting enough to try and find out how common and widespread it is by putting a request out on Twitter (link here). 

Kate also did a little digging and kindly pointed me to some references in the literature on Long-tailed Tits feeding whilst holding food items in one foot and hanging from the other. Two of them were notes in British Birds, one from 1959 and the other from 1989, and related to food items that had been provided. Ornithologist Derek Goodwin commented on the latter report saying: 'this is normal and usual behaviour if a Long-tailed Tit finds an insect too big to be swallowed immediately'. This shows the feeding method itself is not that unusual, although I would say I think it is one that is easily missed or overlooked in anything other than a garden or feeding station setting as Long-tailed Tit flocks are usually always on the move. However, the use of this feeding method to exploit sunflower hearts taken from feeders does appear to be relatively new.  It remains to be seen how common and widespread it is or if it is an increasing trend as has been the experience in my garden. Early replies to the BTO tweet show it has been noted elsewhere but none make comment on how long it has been happening or if it is increasing at the locations concerned.

Hall-Craggs, J (1959) British Birds 52, 21-2.
Shackleton, K (1989) British Birds 82, 373-4.

Friday, 12 January 2018

Still here, and ageing.

Apologies for the lack of posts in recent weeks but there has been a lot going on on the domestic and family front to say the least. Added to that the birding has been fairly quiet around here so there hasn't been a huge amount of interest to blog about anyway. For what it is worth here is a summary of what I have been doing on the avian front over the last few weeks.

A total of 121 birds were ringed during December and another 68 were retrapped or resighted with much of that total coming from birds ringed in the garden. Goldfinches topped the totals with 36 ringed and Starling topped the retraps / resightings with 39 records, mainly resightings of colour-ringed birds. The only unusual ringing activity involved Siskins with a total of 7 ringed (6 in the garden and 1 at Billinge) which is an exceptional number for December.

Interestingly, the first Siskin was seen on the feeders in garden on 20th November and it was already ringed. A few days later 2 were coming to the feeders, both of which were wearing rings and both were adults so there is a chance they were returnees rather than birds that had been ringed elsewhere. I expected to catch one or both of theses birds as they continued to visit fairly regularly so it was a bit of a surprise when I caught 3 new birds in early December. A few Siskins continued to visit the feeders on a daily basis throughout December and at least 8 individuals were involved. In previous winters it has been mid to late January before they start coming to the garden on a regular basis so to have them start two months early is really unusual for here. This change doesn't seem to have been caused by any sort of food shortage as there are still plenty seeds in the alder cones. In fact Goldfinches were more hit and miss in the garden during December and this has continued on into January as they are spending quite a lot of time feeding in alders. This shows there is still an abundance of alder seeds to be had in the local area and it is probably also true of the wider countryside.

I have almost finished submitting my 2017 ringing data to the BTO and just need to do some final checks. Provisional totals for 2017 ended up at 4183 new birds and there were another 958 recaptures or resightings. The top 5 species ringed accounted for more than half the total as detailed below (again provisional totals for now):

Species        New Birds         Retraps/resightings
Goldcrest         669                            30
Starling            621                          567
Redwing          425                              0
Goldfinch         366                            41
Chiffchaff         295                            30

I have also been checking through the gulls and waterfowl that come to bread at Orrell Water Park (as usual) and have photographed the ring numbers of 3 Black-headed Gulls (2 from Germany and 1 from Scotland), a ringed Coot (from south Wales) and a Canada Goose (from Cheshire). All could be considered regulars to a greater or lesser degree as they were all recorded more than once during December and one of the German gulls, the Coot and Canada Goose have been recorded in previous winters.

EZ33149 was ringed as a chick at Elvanfoot, South Lanarkshire on 20/06/2017 which is 222 km NNW of Orrell Water Park.

Sometimes I only need to take a few photos to get the full ring number but in many cases I have to take dozens to be sure. While these are crops most of my photos of ringed birds are just of their legs rather that the whole bird.

Best foot forward. This is the German ringed bird from the Helgoland scheme. It has been recorded 11 times so far this winter but I still haven't received the ringing details so don't know when or where in Germany it was ringed.

I am spoiled for choice when it comes to photos of this bird, or at least its legs. IA141745 has been recorded 15 times so far this winter and over 70 times since the first sighting in October 2012. It was originally ringed as an adult in Bohmke und Werder, Mecklenburg - Vorpommern, Germany on 29/04/2012 and is pretty much a fixture at the park between October and February.

GR03863 is what you could call an old(ish) Coot as it was originally ringed as a first-year on 23/12/10 so is a little over 7 years old. It is well short of the UK longevity record for the species which currently stands at just over 15 years but it is probably older than your average Coot. It was ringed 236 km south at Comeston Lakes, near Penarth in the Vale of Glamorgan during a spell of very cold weather but has been recorded up here 17 times since, most recently on 27/12/2017, so was probably a cold weather refugee when ringed.

The New Year hasn't seen much in the way of change as yet. Both German ringed Black-headed Gulls were photographed on the 1st and both have been recorded since. A few Siskins continue to visit the feeders in the garden on a daily basis and another 2 have been ringed. I have also resighted 25 different colour-ringed Starlings at the feeders and caught and colour-ringed another 2.

7 of the 8 Siskins ringed this winter have been adults. This adult male was caught on 10/01/2018. All the wing feathers including the coverts were relatively fresh, the colours were intense so there was no sign of any moult limits

The tail was equally unworn and again the colours were intense but the shape of the tail feathers was at the more pointed end of the range for adults. Adults with a relatively pointed tail like this can catch out the inexperienced and unwary but close examination reveals a neat pale fringe to the edges of all tail feathers and no signs of wear. In this shot you can just see that the primary tips are similarly fresh looking so no doubt it is an adult.

N34 is a female and was originally ringed as a juvenile on 18th May last year.
One notable absentee from the garden this winter has been Blackcap. I usually get one or two over the course of a winter and the first sighting usually comes before the end of December so to not have seen one by now is bucking the trend of the last few years. While Blackcaps have been absent I have got 2 Goldcrests feeding on the fat balls and fat cakes. This is relatively new behaviour for Goldcrests in my garden and although I have seen it before it is unlikely to become common and widespread, as happened with Long-tailed Tits some years back, as they are not very social in winter or long lived so the opportunities for such behaviour to spread in the population are not there.

Not the best photo but it is what you might call a decent record shot. The tail shape is in the intermediate range but it could be an adult and is possibly an individual that came to the feeders last winter. In addition to feeding on the fat balls and fat cakes direct it also picks up tiny fragments that have fallen on to the wire mesh and branches below or on fragments that have been wiped on the wire mesh and branches by other birds when cleaning their bills.
Another even more notable absentee from the garden, and one that is getting increasingly easy to forget, has been the humble House Sparrow. I haven't seen one at the feeders this year and only saw one during the whole of December, which is a really sorry state of affairs. If records from my garden and the local area are anything to go by they are still in marked decline around here.

So that brings things up to date, more or less, and with a bit of luck it won't be the best part of 4 weeks before my next post.