Monday, 25 April 2011

The Barley Bird has Returned - April 2011

Over the last week I have had the opportunity to carry out two ringing sessions, both at Botley Wood, and both carried out with the background accompaniment of common nightingale song. The first session was carried out on 17th April and ended with the grand total of 30 new birds and four re-traps. Two of the re-traps were great tits, that were captured on 31st May 2010. Other birds captured included two blackbirds, six blackcaps, two chiffchaffs, and a female bullfinch and a male song thrush.

The most striking bird captured was an adult Eurasian jay. It was aged by the broadness and shape of the tail feathers and the number of black bars on the outermost greater covert.

Adult Eurasian Jay, Botley Wood - April 2011 T. D. Codlin

The striking turquoise primary, alula and greater coverts, although visible in the field, are probably best appreciated when seen close up.

Open Wing of Eurasian Jay, Botley Wood - April 2011 T. D. Codlin

One of the target species for my ringing studies at Botley Wood is the marsh tit. This species is considered to be in decline, but at this site it is a species that I regularly capture. Individuals can be incredibly variable and subsequently can be difficult to separate from the closely related willow tit. Features such as the pale wing panel and glossy or matt cap, can appear regularly in both species. However, help is now at hand. A recent research paper studied both marsh and willow tits and identified two new features; the first being the contrast between the white ear coverts and brownish side to the neck, and the second being a white mark on the cutting edge of the upper mandible, near the base.......both features are clearly visible on the picture below.

Marsh Tit, Botley Wood - April 2011 T. D. Codlin

Only 22 birds were captured on the morning of the 21st April, but the numbers didn't matter as the highlight was the capture of my first two barley birds of the year. The first bird was an adult male that I first captured last year, when it was returning for its first summer. This bird was very vocal, and as well as its typical song, was emitting loads of croaking and wheeting calls. This behaviour is typical of a male which is courting a female, and sure enough, the second bird I captured was a probable female. This bird was a first summer bird with a maximum wing chord of 80mm; typically male birds have maximum wing chords of between 84 - 88mm, females are usually a couple of millimetres shorter, but as always there is some overlap.

Adult Male Common Nightingale, Botley Wood - April 2011 T. D. Codlin

The combination of the behaviour of the two birds, the soft contact calls and short wing length of the second bird are indicative of a female, but in the absence of any conclusive features, such a a brood patch, I could not be certain, so left the bird unsexed. 

Adult Male Common Nightingale, Botley Wood - April 2011 T. D. Codlin

The other species captured included more blackcaps, chiffchaffs, blackbirds, blue tits and great tits along with my first common whitethroat of the year. Common whitethroats are a regular summer visitor to the site; the captured bird was aged as a first summer due to its extremely worn wing and tail feathers and small amount of white in the outer tail feathers.

Common Whitethroat, Botley Wood - April 2011 T. D. Codlin

With ringing activities finished and all the nets down we headed back along the road towards our cars, and there in the middle of the road was an adder. Typically, it immediately coiled up and prepared to strike rather than run (well slither!).........

Adder, Botley Wood - April 2011 T. D. Codlin 

........but once it realised that we were not intimidated and only interested in taking pictures, it beat a hasty retreat back into the undergrowth.

Adder, Botley Wood - April 2011 T. D. Codlin

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