Pre-Christmas Oxford Birding

BTO Darvic-ringed juvenile Peregrine

Another fairly interesting week on patch, and whilst I haven't seen anything particularly exciting in terms of rarity value there have been a few moments which were really worth spending all those hours in the field for! I managed to see last week's Little Gull a couple more times although views have been quite brief - I'm glad that a few more people managed to catch up with it but also quite pleased to not have thousands more photos to sort through!

There have been a steady stream of Caspian Gulls hanging around during the day and in the roost - I think I am now up to eight or nine birds on the meadow for this autumn. 15th December was particularly memorable with five birds present, including the splendid adult male pictured below, which arrived mid morning with a small group of large gulls. An adult Mediterranean Gull also roosted that evening, which was the first that I'd seen for a few weeks.

Adult Caspian Gull

2cy Caspian Gull

Adult Mediterranean Gull

With the amount of flooding recently there has been a lot of wildfowl movement but despite going through all the ducks every day I've failed to turn up anything interesting other than a few Shelduck. When the floods are this large, we occasionally get diving ducks like Tufted Duck, Pochard and even Goldeneye and Smew on the meadow - in fact I had a large flock of Tufted Ducks go straight over one evening which really indicates the level of wildfowl movement around the county at the moment. I did manage to jam in on a female Ring-necked Duck which was found by Stuart Thomson at Dix Pit whilst I happened to be there - one of those on/over the meadow would be amazing, and I did think to check all the ducks in the photo below quite carefully!

Tufted Ducks - this flock of 24 going north was the largest I've seen on patch

The ringed Siberian Chiffchaff has been continuing to show well both in the ditch bordering the floods and in the bushes at the south end of Burgess Field. On 16th December I found a second individual which is a bit more brown and "dusky" than the other one, but seems to have the green and beige tones in the right places with an absence of yellows throughout the plumage.

Siberian Chiffchaff PHX356 in the ditch

The second Siberian Chiffchaff

That transition from beige/brown mantle into the greenish fringe to the edge of the wing and tail feathers is very typical of tristis

As part of our winter Chiffchaff project we carried out a ringing session on 20th December to try and ascertain the number of individuals present in the area. Prior to this I had estimated that there were around ten colybitta with the two tristis - so it was quite a surprise to catch 18 colybitta plus a retrap from last winter. There are still loads of unringed birds around so I think there are probably 30-50 wintering just in this small area of bushes, which is pretty extraordinary for a site that isn't a sewage works. I'd like to try and find out if there is a lot of turnover of birds throughout the winter or whether it will simply be a case of the proportion of ringed birds increasing with the number of ringing sessions - I guess we would need to catch enough to have some sort of mark/recapture population estimate in place for this to work.

colybitta Chiffchaff in the hand

Based on this success I had a quick trip off-patch to check out the Chiffchaff situation at Abingdon Sewage Works and had another Siberian Chiffchaff and two Blackcaps amongst the hordes of Chiffchaffs and tits. I wouldn't be at all surprised if there's something rarer from the east (or west, given the Kent Yellow Warbler...) wintering there this year, so I'll make sure to check it after the cold snaps that tend to bring more birds in.

tristis Chiffchaff at Abingdon STW - a classic site for them

On 22nd December I was walking back towards the southern entrance of Port Meadow when I noticed a commotion on the floods. All the ducks suddenly rushed together as a juvenile Peregrine began stooping over them, and I hurried towards the edge of the flood to get in position for photography. I initially wasn't sure what the bird was going for, thinking that it was maybe trying to harass the ducks - but then noticed that there was something floundering in the water in front of the flock. Viewing through the camera's electronic viewfinder was difficult and I couldn't quite work out what it was. I actually thought it was a lapwing, as I could occasionally see the black and white tail poking out of the water, and only realised that it was a Black-tailed Godwit when I saw it flap its wings. I hadn't seen this bird on the floods when I arrived and its odd position in the water makes me suspect that it was flying over and then been knocked/forced down onto the flood by the Peregrine.

The Godwit was swimming frantically and kept diving under the water to escape the Peregrine - really odd behaviour to observe in a wader.

On its next pass the Peregrine was successful in capturing the Godwit, initially lifting it out of the water whilst the bird was struggling before biting down on the back of its head and dispatching it, presumably by breaking its neck. It then carried its kill out west over the sailing club towards Binsey. I have included as many photos as possible from this crucial moment and I think they illustrate the sequence of events quite well. All over in just a couple of minutes.

A sad end for the Godwit but a real privilege to watch - I hope the Peregrines continue to perform like this over the winter! Unfortunately, the Darvic ring on the Peregrine's left leg isn't legible in any of the images, but it is a BTO scheme so I wonder if it's a locally-hatched bird.

Continuing with the raptor theme, the next morning I had an adult female Merlin zip across the floods, flying east into Burgess Field. One of those moments where you subliminally know what the bird is almost as soon as setting your eyes on it - I didn't even bother with bins, just reached for the camera and even then only managed to get photos once it was already past me. Merlin is recorded very infrequently on Port Meadow (and within the city in general), with the last being in January 2019, hence this is a very welcome patch tick (number 159). I have also seen one over the Wytham Field Station, where the lab/office is located - it was trying to take a Skylark in song-flight. I believe this dubiously made it on to the Port Meadow year list that year, and indeed was on my patch list for a while before I decided to be a bit more strict with the boundaries. More on this in a future post.

Adult female Merlin

Now that I'm away from Oxford until the New Year it looks like that's patch birding for 2024 wrapped up - the next blog post will therefore be a review of the year and targets for 2025.