For Hume the bell tolls

 

I was toying with the idea of driving over to the east coast on Friday to see a Falcated Duck which would have been a new UK life tick for me. Why toying with the idea? Well it was almost certainly an escape from a collection rather than the genuine article and so would only have been an insurance tick just in case it was accepted as wild. Being commonly kept in collections, this particular duck of the far east has had a most troublesome history with UK birders, almost all birds seen in the wild are actually escapes or what we call plastic birds. Indeed it is only comparatively recently that the BOU acknowledge that it could occur here as a genuine vagrant.  The problem is that to be absolutely sure of a wild origin it either needs to carry a ring placed on it in its natural breeding ground or have had isotopic analysis performed on a feather which can show where it has been. I was hence very 50/50 on a 7 hour return drive for an insurance tick. In the event it was all academic as it did the decent thing and buggered off overnight so I defaulted to my original plan for Friday of going to see a rare  Hume’s Leaf Warbler somewhat closer to home near Bristol.

 

As I’ve explained before, see here, the seemly unattractive location of a sewage works can be a magnet for overwintering insect eating birds. The microclimate here is warmer than the surrounding countryside and a plentiful supply of food is available right throughout the winter. Every year some of these sites hold onto a few Warblers such as Chiffchaffs which normally migrate to warmer climes for the winter. Sometimes though something much rarer decides to overwinter in these microclimates rather than migrate, a case in point being the Pallas Leaf Warbler that was at Abingdon Sewage works last year. Recently an even rarer warbler, namely a Hume’s Leaf Warbler, was found just outside a village called Compton Dando near Bristol at a small sewage works. 

 

I’ve seen Hume’s Warblers before in the UK but only badly. Not so much because they are shy by nature but rather that their insect food tends to be deep within the hedgerows. Hence the attraction of seeing one of these little gems out in the open.

 

Hume’s Leaf Warbler rates as a two star rarity in the Colins bird bible equating to one or a few records per annum. It is very similar to the scarce but more common Yellow-browed Warbler and has only recently been split as a full species. In worn spring plumage it can be almost impossible to tell the two apart but in fresh autumn plumage the Hume’s is said to be slightly more dull and greenish above with bill and legs somewhat darker than its cousin. The best way of telling them apart, however, is its very distinctive loud disyllabic whistling call. It is a common bird in its  mountain woodland breeding range of central and southern Asia. Luckily, there were said to be no Yellow-browed Warblers at Compton Dando so identification should be quite straight forward.

 

The treatment works were located down a very small country road just outside of the village but my OS locate app, armed with the exact map reference, took me to the exact spot. I set up my camera on my tripod at a promising looking spot the other side of a mesh fence from the works and soon enough the bird flew into the works in the fliting hyperactive manner of a Phylloscopus Leaf Warbler. The whole area was teeming with swarms of small invertebrates and the Hume’s had no difficulty in finding plenty to eat. It was joined by other birds enjoying this mid-winter feast, Chiffchaffs, Grey and Pied Wagtails, Long-tailed Tits, and feisty Robins. The industrial scenery could hardly be called  photogenic but with lots of patience and a little care it was possible to get acceptable shots of the bird on the ground and on support wires.  For 4 rather cold hours I had the bird to myself except for two brief visits by other birders.

   

A bit of technical info on the photos. It was overcast with light cloud most of the time I was there resulting in comparatively low light levels. I used my 500mm lens with a 1.4x converter on the R5 to get these pictures – I find the autofocus can struggle with the 2x converter on this lens in low light levels on small subjects. In order to get the shutter speed up and ISO speed down as far as possible the lens was wide open at F5.6. The disadvantage of this is the very small depth of focus at 720mm resulting in the whole bird not being sharp unless it is completely at 90 degrees to the lens. I aways focus on the eye in this case as I find that an out of focus eye ruins the shot. I was using a shutter speed of only 1/125 sec most of the time to bring the ISO speed down to around 800. This means that there would be noticeable motion blur unless the bird was absolutely still which probably happened one shot in 50.  Given the distance of the bird the shots had to be heavily cropped, something that the large pixel count of the R5 sensor can cope with. I always shoot in RAW to give me the maximum post processing flexibility. The unprocessed cropped photos were still quite granular. They were hence post-processed as follows, some basic white balance and exposure editing using Lightroom then exported again in RAW format firstly to Topaz denoise and then into Topaz sharpen before finally reimporting into Lightroom for any final adjustments such as spot removal etc.

 

 

 

 Footnote – my blogs are posted with sometimes rather imaginative spelling and grammar due to my extreme dyslexia!