A very pleasant morning at Oxwich.  The skies were open and there was a barely discernible northerly breeze.  We put nets in the scrub around the feeders (200 feet), in the fen meadow (180 feet) and in a new net ride through semi-natural woodland and rhododendron scrub near one of the main channels through the marsh.  Only the feeder nets proved fruitful.

 

Of particular interest were the willow warbler , a re-trap chiffchaff (ringed on the marsh in September 2014 and either now on passage or back to breed [no brood patch or cloacal protruberance was apparent]) and a magpie.  We have trapped one magpie a year for the past three years.  Beautiful and feisty birds in the hand, they can be aged based on the shape and pattern of the first and second (pattern only applies) primaries.

 

We also controlled a siskin.  This bird had been initially ringed in Minehead, Somerset in 2012, and was also captured at the marsh in June 2014, so we already knew some of its history.  It will be interesting to see if the siskin numbers now start to build, as they did in 2014.  There is no evidence of it at present. 

 

The two Cetti’s warblers were re-traps from 2014.  More interesting news recently received from the BTO, however, concerned a Cetti’s warbler initially ringed at Magor Marsh, Monmouthshire in July 2012 and re-trapped at Oxwich in November 2014.  Clearly Cetti’s warblers disperse (as is demonstrated by the continued extension of their range in the UK), but to re-trap a bird that has moved almost 100km since ringing is great.

Any comparison between years must be very cautious.  We have put up more net in 2015 than we did last year (although returns from extra nets have been limited), have visited the site more regularly, and sessions have varied a little in length.  Weather plays a massive part in determining the size of catches on any given day.  We have had permanent feeders in place since 2013 (albeit these are moved around within the site / rides), but another significant difference is there has been no ground-feeding in 2015.  Pheasants have taken up residence around the feeders and have been hoovering up all spilt fragments of seed, so ground-feeding has been pointless.

 

Comparisons are therefore limited and qualified.  The most notable difference has been is in the number of reed buntings trapped.  This may relate directly to the lack of ground feeding.  Interestingly, chaffinch numbers are notably higher in 2015 than the equivalent months of 2014, however, and this bird also typically forages on the ground.  Overall, the number of birds per session is lower in 2015 than in 2014.  By this time in 2014 we had only completed 9 sessions (58 unique birds / session), whereas we have completed 14 to date in 2015 (39 unique birds / session).  So the higher number of birds relates to extra effort, not to any evidence that there are more birds in the marsh.

 

Many thanks to Heather Coats, Charlie Sargent, Keith Vaughton, Darren Hicks and Valerie Wilson for company and assistance this morning.

 

Some pictures of birds from the session are below.

 

Owain Gabb

07/04/2015