Curbridge and my first young Blackbird of the year

The weather has been appalling this weekend with torrential rain and gale force winds throughout, which has completed flawed my plans to spend the weekend in search of Nightingales. Friday was the best day weather wise so I nipped down to Curbridge reserve before putting a net up in the garden.

The tide was low and therefore ideal for looking for waders, and I immediately located a single Whimbrel feeding at the mouth of the first creek. Two Common Sandpipers, fluttered along the waters edge away from me, landing on the other side of the estuary next to three Greenshanks and another Whimbrel. As I scanned down the estuary I noticed a flock of 17 more Whimbrel dropping out of the sky, bringing the total to 19, and two Oystercatchers were feeding on the inter-tidal.

Juvenile Blackbird

Returning home I decided to open the net in my garden and immediately caught a juvenile blackbird, which had only just fledged the nest. The wing and tail feathers had not fully grown...

Juvenile Blackbird

                                                             

                                                                   .....but I was still able to sex the bird due to the black tail feathers, as opposed to brown in a female.

Partly Grown Juvenile Blackbird Tail

Other birds captured included three new Greenfinch's and a new Robin, but that was about it. 


I am off to Turkey tomorrow, leading an Ornitholiday's trip, to the the same region as last year, The Goksu Delta, Cukurbag, Biricek and Gaziantep, hopefully I will get some internet access during the trip, and if I do I will try to keep you posted.

Partial Leucistic Nuthatch

I have previously posted on this blog about abnormal plumage in birds, in particular leucism, and posted pictures of a few species with varying plumage patterns. Well this previous article prompted Nick and Teela Spratts to send me these pictures of a partially leucistic Eurasian Nuthatch that has been visiting their Oakhampton, Devon garden.

Leucistic Nuthatch - N & T Spratts

At first glance this bird looks very reminiscent of the subspecies Sitta europaea asiatica or  S.e. europaea that occur in Eastern Russia/Siberia or Fenno-Scandia/Western Russia, respectively. But the pictures show that this bird lacks the rust coloured vent and slate grey mantle of those subspecies.

Leucistic Nuthatch - N & T Spratts

Comparing this bird with a typically plumaged S. e. caesia (the British and Continental European race) which I have previously ringed shows the extent of the aberration in the plumage. The slate grey mantle and warm peach coloured underparts are lacking, although it is still possible to see patches of rust showing through on the vent, which may indicate that this bird is a male.

Normally Plumaged Nuthatch

Thanks to Nick and Teela for sending these pictures and allowing me to post them, it is an interesting looking bird but I think I prefer the normal plumaged one!

Bird on a Wire....and a post....

Not much to speak of bird ringing wise this weekend, a couple of sessions in the garden was about it, so I spent much of the time birding. Saturday morning started with an early morning stroll around Botley Wood in search of colour ringed Common Nightingales. It was another cold start, with a heavy overnight frost but this did not stop the Nightingales singing. There appeared to be two new territories this week, one of which was in a remnant piece of vegetation that National Grid have left in place around their re-cabling works. The bird was showing very well whilst singing, so much so that I was able to get a great view of its legs and its colour rings. The bird was first captured last May as a first year male, meaning it was hatched in 2010, in the same location where it was singing this weekend.....during my studies I have found this species to be extremely faithful to a territory. I have watched one bird sing from the same branch 4 years running....no sign of my 8 year old bird yet though!

Yellowhammer on a Wire

After Botley Wood it was off to Old Winchester Hill in search of migrants, but I think it was too late in the day as not much going on. In fact, a flock of about 20 Yellowhammers was the most exciting thing. 

Years ago I used to catch quire a few Yellowhammers at Manor Farm Country Park, but in recent years they seem to have disappeared, which is such a shame.

The birds were feeding on a newly ploughed field, and occasionally flying up on to the boundary fence where they gave excellent views. One bird was eyeing up a passing fly that appeared to be putting its life into its own hands...

Female Yellowhammer eyeing up Fly

....despite several attempts it failed to catch it!

Male Yellowhammer

As I was watching the Yellowhammers I suddenly noticed two birds on a posts in the next field...a pair of Northern Wheatears were feeding within the nearby Vineyard. 

Northern Wheatear

At this time of year I would normally expect this species to be migrating, but this pair seemed very settled, and with the numerous rabbit burrows available I wouldn't be surprised if they were breeding.

Ageing Chiffchaffs in Spring

This weekend I re-trapped a Chiffchaff that I had originally captured at Botley Wood in April 2011, giving me the ideal opportunity to test my ageing skills on a spring bird. Published literature, including my trusty Svensson and Jenni and Winkler, suggest that it is possible to age spring birds due to the extent of wear on primary and tail feathers, and on the presence of contrast in the wing feathers. Although Svensson does warn that the flight feathers of the nominate subspecies Phylloscopus collybita collybita "on average appear to wear more" than those of the subspecies P.c. albietinus.

So armed with these facts, and knowing that this bird was ringed on 3rd April 2011, and therefore was definitely an adult bird, I set about my task. Svensson states that in spring adult birds have all wing feathers the same generation, the tips of the primary feathers still well kept and the tail feathers dark grey and glossy. In addition, the primary coverts are neatly edged greenish. In 2nd year birds though, there is often a contrast between moulted adult central tail feathers and rest of tail and both the tips of the primaries and tail feathers are worn. In addition there is sometimes a contrast between slightly duller and greyish greater coverts.

Adult Chiff Wing Feathers

The first thing to notice with this bird was the extent of wear on the tips of the primaries, particularly primaries four and five (the third and fourth from the top), and also the extent of bleaching where feathers have overlaid each other.

Tail of Adult Chiff Tail

The second thing to notice was the extent of wear at the tips of the tail, and interestingly the difference between the left and right side of the tail. The right side (top) is broad and rounded and in good condition, as would be expected in an adult, whereas the left side (lower) is more abraded, with the feathers appearing thinner and more pointed and browner, as would be expected with a 2nd year.

Greater Coverts of Adult Chiff

Finally, the greater coverts should appear uniform and all of the same generation in an adult bird, but interestingly the colouration of the fringing and the extent of wear on this bird seems to indicate two generations of feathers, although the ground colour of the each and their length, would tend to suggest that they are all the same age.

The moult strategy of adult Chiffchaffs is relatively straight forward, with a complete moult carried out post breeding, and a partial moult carried out on the wintering grounds, and yet the condition of the wing and tail feathers on this bird would tend to indicate a 2nd year bird. This bird could have lost half of its tail during migration or on its wintering grounds which would explain the difference there, but the extent of wear on the primaries seemed extensive for an adult bird. Svensson does warn that ageing on wear alone can be complicated due to the nominate race collybita returning from its wintering ground with more worn flight feathers, and I guess this bird is proof of that.