Billinge 22/07/15

The days may be getting shorter but dawn is still a bit too early for my liking. However, I managed to drag myself out of bed at 05:30, after snoozing the alarm a few times, and made my way up to Billinge. There wasn't a breath of wind and it was nice and overcast so I was able to put up 3 nets in the willows on the higher part of the site. This area can be really good for warblers at this time of year and is also favoured by flocks of Goldfinches now the Knapweed is going to seed.

The first couple of hours were really busy and as soon as I had ringed the birds from one net round it was time to go and check the nets again. Willow Warblers featured with 12 ringed and this brings the total ringed at the site over the past ten days to 30. Some of the Willow Warblers have completed their post juvenile moult and could be on their way south. Other signs of juvenile dispersal/early migration also came in the form of a Sedge Warbler and a Garden Warbler, neither of which breed at the site.

This Willow Warbler may reach the south coast by the end of the month.

Sedge Warblers are another early migrant.

If looks could kill. The Garden Warbler didn't want to pose for a nice photograph and just gave me dirty looks.

Goldfinches were ever present and a flock of up to 50 fed in the vicinity of the nets with other smaller parties and family groups coming and going. The morning turned out to be a bit of a finch-fest with 32 Goldfinches being caught along with a supporting cast of 9 Linnets and singles of Greenfinch, Chaffinch and Bullfinch.

26 of the Goldfinches caught were juveniles like this one. Goldfinches seem to have had a fairly good breeding season and this species clearly benefits from the proliferation of garden feeding.

There seem to be fewer Linnets about compared with the same time last year which is probably a result of increased failures among the early broods.

The lack of roving tit flocks continues and only one group of 6 Long-tailed Tits and 2 Blue Tits were seen all morning. Large and noisy tit flocks are usually a feature at this time of year but their low numbers or complete absence shows what a terrible breeding season they have had in this area.

Ringing totals (retraps in brackets) were: Willow Warbler 12; Chiffchaff 5; Blackcap 8; Whitethroat 1; Sedge Warbler 1; Garden Warbler 1; Robin 1; Long-tailed Tit 1; Goldcrest 1; Goldfinch 31 (1); Linnet 9; Greenfinch 1; Chaffinch 1; Bullfinch 1; Yellowhammer 1; Reed Bunting 1. Total 75 (1).

Unusual retrap

I have been neglecting the blog a bit recently but hopefully there will be regular updates now that autumn migration is gathering pace. I have been out and about whenever time and the weather have allowed and have caught 127 new birds and 18 retraps of 22 species since my last post. It is not a big total but its not bad considering the way the weather has been up here. The top five species ringed over the period (14th - 20th July) with retraps in brackets were: Swallow 24; Willow Warbler 18 (1); Chiffchaff; 18 (2); Goldfinch 11 (2); Tree Sparrow 9 (1).

The most unusual capture was an adult male Kestrel that was caught in a mist net at Crawford. I don't catch Kestrels very often and I have often gone years without catching one but this was even more unusual because it was a retrap. It was a bird that had been ringed at the same site a few weeks earlier, on 21/04/15. This year has been very poor for voles, their main food, so I can only assume this particular Kestrel has taken to feeding on small birds coming to the feeders at Crawford or the population of small mammals is doing better in the vicinity of the feeders because of the constant supply of seeds. Perhaps it is a combination of the two factors but it certainly is an unusual recapture.

Adult male Kestrel recaptured 20/07/15

This and that

It has been a couple of weeks since my last post so I thought I should cobble something together by way of a catch up. There hasn't been one stand out thing to write about but there have been some bits and bobs worth mentioning. On the birding front I have had Common Crossbills flying over Billinge and Crawford on a total of 4 occasions with most heading west. There have also been some unusually early flocks of Siskins moving south which are likely to be the forerunners or foreflyers of a large scale irruption this autumn. 

Sitka Spruce produced a bumper crop of seeds last year which meant few Crossbills, Siskins and Redpolls migrated in search of food and led to an almost complete absence of Siskins on garden feeders this spring. A bumper crop generally results in better survival and a good breeding season but is often followed by below average seed production and so provides the circumstances that can lead to large scale irruptions of the associated species.

It really looks like we are heading for one of those autumns/winters where the irruptive species come to the fore and steal the birding headlines. I don't think these irruptions will be confined to a few seed eating species either as I also think the conditions are developing for a good arrival of Waxwings. It may not be quite on the scale of the 2012/13 irruption but I certainly think it could be a good one. Why do I think it could be a Waxwing winter and the simple answer is the cold spring and its impact on pollinators and berry production across much of northern Europe. If the Rowan and Hawthorn in this area are anything to go by the berry crop could be down by at least 50% on last year if not more.

So there are some predictions or perhaps I should say educated guesses based on recent observations. Make of them what you will but right or wrong I will refer back to them later in the year when we know what has actually happened. I certainly think it is a year where some big irruptions are on the cards. One thing we don't have to wait for is to know that it has been an abysmal breeding season for many insectivorous species. I have never known so many warblers singing so late in the season such has been the level of nest failure so far and the woods and scrub near me are what you could call almost titless. 

So what have I been ringing? Well I am still catching Redpolls and Goldfinches coming to the feeders at Crawford although Tree Sparrows have dropped off now that winter cereals are starting to ripen. My last visit to Billinge on the evening of the 9th produced a few Willow Warblers, Chiffchaffs and Linnets along with a fairly good catch of 21 Swallows that came to roost in the willows. As for the garden my local Starlings seem to have gone on their summer holidays and have largely vacated the area despite the constant supply of food. However I have caught a few Woodpigeons in the garden including two that needed fishing line removing from their feet. One of these Woodpigeons also happened to be an unusually dark individual.

Adult male Lesser Redpoll

A duskier than normal Woodpigeon and it does stand out as looking dark in the field.

This Woodpigeon was lucky to be caught and have the fishing line removed before any permanent damage was done.

Moth catches have remained below par to say the least and are a fraction of what they should be at this time of year. The only species that seem to be present in near normal numbers are Buff Ermine and perhaps Ghost Moth. Not much else I can say about the moths or lack of them other than it was nice to catch two Garden Tigers today. Garden Tiger is a declining species that is less than annual in the garden despite its name. However, Poplar, Elephant and Eyed Hawk moths are regular in the garden although they have generally emerged later and in smaller numbers this year.

Garden Tiger 12/07/15

Garden Tiger 12/07/15

Poplar Hawk Moth

Poplar Hawk Moth

Elephant Hawk Moths

Eyed Hawk Moth

Finally, an odd looking Blackbird appeared in the garden earlier today. It looked like it was carrying something until I realised it had a huge growth in its bill. It turned out it was a bird that had been ringed in the garden on 9th May when it showed some signs of a problem with the upper mandible but nothing on the scale of its appearance today. I was surprised to see that it was still able to feed with such a large mass growing from the roof of the upper mandible but it managed to pick up some food from the bird table. However, the growth is clearly taking its toll on the bird's ability to preen and clearly limits its forward vision. It is a surprise it has managed to survive thus far and shows how resilient some birds can be.

No it isn't carrying anything it is a growth on the underside of the upper mandible.

The same bird when it it was ringed on 9th May

Sunbathing Blackbirds

With  long spells of strong sunshine dominating yesterday's weather I wasn't surprised to see a Blackbird sunbathing on the lawn in the afternoon. However, what was a surprise was seeing five sunbathing at the same time with 4 of them close together on the lawn. The sunbathing was interspersed by bouts of preening and birds repositioning themselves to get the best of the sun's rays. Also, there was some coming and going amongst the birds that meant there was a minimum of six different birds involved and there could have been as many as eight. This is the first time I have seen so many Blackbirds sunbathing together and there was clearly a social element to the behaviour with birds choosing to sunbathe in close proximity to each other.

It was interesting that 2 adult females settled down to sunbathe so close to each other. They were joined by a juvenile soon after as can be seen in the next photograph.

With a mini heatwave forecast for next week there will be a lot more opportunities for the garden Blackbirds to indulge in more communal sunbathing.

Crawford 23/06/15

The number of birds using the feeders at Crawford has been growing judging by the speed they have been emptying and I have had to fill them every other day just to keep pace. I don't normally carry on feeding such sites into summer but the potential to catch good numbers of Lesser Redpolls , Goldfinches and Tree Sparrows has tempted me to do so.

The forecast for this morning was near perfect so I decided to go and put up a couple of nets for a few hours. I opted for a leisurely start rather than getting up a stupid o'clock and arrived just after 6:30 a.m. I soon had the nets up and started catching straight away and it was clear that a good number of juveniles were now using the feeders. The first couple of hours were quite busy but the catching rate then slowed as the sun burned off the cloud cover and made the nets more visible. I packed up by 10 a.m. having caught 59 birds comprised of 44 new birds and 15 retraps.

Juvenile Lesser Redpoll

Juvenile Goldfinch

Juvenile Tree Sparrow

Ringing totals (retraps/controls in brackets) were: Goldfinch 15 (6); Lesser Redpoll 4 (3); Greenfinch 5; Chaffinch 1 (1); Bullfinch 1; Tree Sparrow 10; Great Tit 1; Long-tailed Tit 1 (1); Blackbird 1 (1); Robin 1; Dunnock 2 (1); Magpie 1; Chiffchaff 1. Juveniles made up just over half the catch with a total of 30 and included 9 Goldfinch, 8 Tree Sparrow and 3 Lesser Redpoll.

A few new adult Goldfinches were caught and provided more examples of variation in plumage. Both of these birds are males (age code 6) with the bird on the right having a less extensive red mask than some females.

This female Chaffinch had a quite a bad a case of scaly leg which is caused by an infection of mites. This bird was released unringed because of the severe encrustations. Chaffinches seem to be particularly prone to this condition and infected birds are encountered fairly regularly.

Sexing Goldfinches: easier said than done.

My previous posts on this subject are still attracting a lot of interest and my original photographic guide (link here) has been viewed thousands of times. When I put that guide together I was dealing with birds that had been caught in autumn and winter and consequently were not of known sex. However, that post illustrated the problems that can be encountered when trying to sex birds from the extent of the red mask, appearance of the lesser coverts and the colour of the nasal hairs. Around a third of the birds couldn't be sexed on plumage with a sufficient degree of certainty as they had one or more feature that was intermediate in appearance or they had what appeared to be contradictory plumage features.

I managed to catch a few birds last summer that I was able to sex from the presence of a brood patch in the case of females or a cloacal protuberance in the case of males. Although the sample size was quite small they threw a bit more light on the plumage features and on the extent of the red mask in particular. These birds confirmed that there is an overlap in the extent of the red mask between males and females and perhaps far more than is generally realised.

Bringing matters up to date I have caught more Goldfinches so far this breeding season than I have ever done before and I have been able to confirm the sex of these birds by checking them for the presence of a brood patch (female) or a cloacal protuberance (male). Being able to handle and photograph more birds of known sex has confirmed that there is a significant degree of overlap in the appearance of some males and females and others are what might be considered borderline. So lets have a look at some of these recent birds.

Z414635 was retrapped and photographed on 16/06/15                   Z414932 was ringed on 16/06/15                   

Z414933 was ringed on  16/06/15                                       Z414934 was ringed on 16/06/15    

Z414921 ringed and photographed 12/06/15.                   Z414888  retrapped and photographed 12/06/15  

The images above show 6 of the 13 adult Goldfinches that have been caught on my last two visits to Crawford. These birds are broadly similar in appearance but having said that there are some differences in the extent of the red mask with Z414934 (middle right) having the most extensive and Z414921 (lower left) having the least extensive, both above and below the eye. All have some greyish or greyish white nasal hairs or greyish feathers at the front of the crown except for Z414934 (middle right). Some readers of this post may be happy to suggest the sex of some or all of these birds and there is certainly no harm in giving it a go. They represent almost half of the birds caught recently so they are not unusual examples by any means.

So what sex are they: well Z414635 and Z414932 (top left & right) are females and both had very good brood patches; Z414933 and Z414934 (middle left & right) are males and each had a bulbous cloaca; Z414921 (bottom left) is a male and also had a bulbous cloaca while Z414888 (botton right) is another female that had a very good brood patch. Had I caught these birds outside the breeding season I would have probably left several unsexed based on the extent of the red mask and colour of the nasal hairs. In fact  Z414635 (top left) was originally ringed on 18/01/15 and I left it unsexed at the time and that was using all the plumage features including the appearance of the lesser coverts. However, I did make a note that I thought it was possibly a male so it was a really useful to retrap this bird and find out that it is a female and that I nearly got it wrong. 

The other feature that is usually checked when using plumage to sex Goldfinches is the appearance of the lesser coverts. The images below show the lesser coverts of the birds above and in the same order.

female                                                                                   female    

male                                                                            male      

male                                                                                               female

Some ringers don't have much confidence in the appearance of the lesser coverts when it comes to sexing Goldfinches but I think they are just as useful as the extent of the red mask. The image of the lesser coverts that stands out to me is female Z414735 (top left) which is quite unusual as it has mainly black lesser coverts with very little in the way of brown fringes. I have never seen a female Goldfinch with so little brown in the lesser coverts before and that, in combination with the extent of the red mask, is why I even thought it may be a male when it was originally ringed in January. The other birds more or less conform to the general rule that females have mainly brown lesser coverts or very broadly tipped brown lesser coverts while those of males are black or mainly black with well defined and usually narrow brown fringes although Z414934 (middle right) has quite broad brown fringes for a male but they are really well defined. It is worth noting that the black portion of the lesser coverts is usually deeper black and glossier in males than it is in females but as with all Goldfinch plumage features there is some overlap.

There is one more confirmed sex bird that I should show in this post to illustrate another variation in the lesser coverts. I used photos of this bird (D954944) in a recent post because it was a control and I mentioned its appearance then. The bird is a male but it had lesser coverts that looked more female like. However, the lesser coverts were mainly a golden-yellow or broadly tipped golden-yellow rather than the usual brown. It was originally ringed on 09/11/14 as an adult but wasn't sexed at that time. I can only assume the unusual appearance of its lesser coverts played a part in the decision not to sex it when it was ringed. Some may see examples like this as a reason to treat the lesser coverts as an unreliable feature but I simply see it as another variation to be aware of.

Male Goldfinch D954944 photographed 27/05/15

I would love to be able to say that I have found a reliable way of sexing all Goldfinches from their plumage but unfortunately I can't. The more I look at the plumage of birds that have had their sex confirmed by other means the more overlap in the plumage features I see. It is far too easy to get overconfident when trying to sex Goldfinches from their plumage and I know I have been guilty of that in the past. I can't give a definitive figure for the proportion of birds that can't be safely sexed on plumage alone as the time of year will make a difference. Autumn birds present more problems than late winter birds as the protracted moult of the head feathers can make a difference to the appearance of the extent of the red and nasal hairs. Whatever the figure is it is likely to be significant and it could be as high as 30%.

Whatever your view is on this subject I hope you find the photographs of known sex birds useful at least. Some blogs and guides only show images of males and females that have very obvious differences in appearance similar to those below. Those birds are not the problem and simply making reference to the variability of the species doesn't show the points of overlap where accurate sexing starts to become more difficult or impossible using the plumage features discussed. I hope this post has gone some way to rectifying that.

I know it is obvious but Z192897 on the left is a male and D725790 on the right is a female. These images are similar to those that are often shown and described in sexing guides but they don't tell the whole story as they are not typical examples of most males and females.

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Starling RAS round-up.

My Starling RAS (Retrapping Adults for Survival) period has ended but the project continues with the ringing of adults and juveniles outside the main study period. The juveniles are being ringed to look at both dispersal and future recruitment into the breeding population and the later adults are being ringed to see if they are recorded in the main study period in future years. It may not sound the most exciting of projects but the more I have got to know my Starlings the more interesting they have become.

I have caught and colour-ringed or re-sighted nearly all of adult Starlings that have visited the garden since mid-April and the total currently stands at 160 individuals, which is far more than I had originally anticipated. Interestingly 60 of these adults were ringed in previous years with the 4 oldest retraps having been ringed in 2011. Next year should be even more interesting as the proportion of retraps should be much higher now that the majority of adults breeding in the area have been ringed.

The first juvenile was caught in the garden on 22nd May and a total of 154 have been ringed since then. It is hard to say if Starlings have a had a good breeding season from the number of juveniles caught in the garden but I suspect productivity may be down on last year. On the plus side the majority of juveniles have been good weights so at least they have got off to a good start even if overall productivity is down.

Some other species seem to be having a really dreadful breeding season and although the weather has warmed up during the day it is still quite cold overnight. There just aren't enough insects around and birds that mainly rear their young on caterpillars are having a particularly tough time. The numbers of moths and other insect attracted to the moth trap are still only a tiny fraction of what they should be at this time of year so it doesn't look like the situation is going to improve any time soon. It wouldn't surprise me if this breeding season turns out to be one of the worst on record for some species.