Volunteer Phil has written about a sighting of a rather special bird, seen and photographed whilst helping with essential wildlife monitoring work on the reserve.

Recent Sightings Thursday 7th January – A Marsh Tit in Fattengates Courtyard

Having been invited to help with the annual brown hairstreak egg survey I took advantage of free time on what may now become a rare visit to Pulborough Brooks in Lockdown 3 to drop into Fattengates Courtyard to check out reports of regular sightings of a marsh tit there. During the autumn there had been regular sightings of a marsh tit on the feeders behind the yurt but several attempts to see one on my part had failed. Now it seems that Fattengates has become a favourite spot.

On arriving there I duly found what seemed an almost tame marsh tit taking advantage of seeds and peanuts that had been scattered on a log by one of our local visitors.

These unusual tits live in small numbers on the reserve but can be hard to find.  I had not seen one here for a few years. They are in decline in the UK with numbers dropping by 50% in the last 50 years and the breeding population is now estimated to be 45,000 territories. If this sounds quite a lot compare it to 3.6 million for blue tits, 2.4 million for great tits and 680,000 for coal tits.  

Despite their name marsh tits are birds of mature woodland, usually with a shrub understorey. Studies have shown that the decline may be linked to deer browsing in the understorey. So, with no large predators in the UK to keep the deer population in check, they appear on the red list of highest conservation concern whereas in Europe they are still relatively common, classified of least conservation concern, and are presumably easier to find.

Marsh tits can be very easily confused with willow tits as the differences appear to be minute and would not necessarily be noticed in the field. So how did I know the Fattengates bird was a marsh tit? Principally because it had been called by other people as a marsh tit and because the willow tit, whose UK population is estimated at only 3400 pairs, was thought to be virtually absent as a breeding bird in Sussex in my 2014 Birds of Sussex book.   

This sounds a little like cheating, so I thought had better read up once again about how to tell the differences which are so small that it was not until 1897 that ornithologists realised that there 2 separate species.  Some finer points to look for are as follows:

  • the black crown and nape are glossier in the marsh tit – sooty in the willow tit;
  • the willow tit appears to have a big head and neck in relation to its body – the marsh tit proportions are more normal;
  • the willow tit has a noticeably paler panel towards the outer edge of its folded wings:
  • the marsh tit has a very small black bib, whereas the willow tit bib tends to be a little bigger and wider at the bottom.

Beware however as there are some natural variations so none of these are completely prescriptive.

With such fine details to observe it helps enormously to take photographs and study them afterwards. This photo shows a hint of gloss in the black crown,  

The first photo above shows that there is no paler panel in the folded wing. For comparison this illustration shows a willow tit. 

Willow tit illustration by Mike Langman (rspb-images.com)

More recent studies of birds trapped for ringing show that marsh tits have a pale edge to their bills which is absent in the willow tit, and it is now thought that this is a more reliable way of telling the difference between the species. This pale edge can be seen in both my photos.

Willow tits and marsh tits share similar woodland habitat, with plenty of dead wood to provide nesting holes, but willow tits appear to have a greater preference for coniferous woodland and for wet woodland with willow, alder and birch and associated scrub.

So, putting the various observations with the location and habitat I can be sure this is indeed a marsh tit.

One final observation of interest is that the Fattengates bird seemed to have no fear of my presence rather like a robin. My Collins Bird Guide describes marsh tits as “fearless”. Curiously, there was no sign of the robins that are usually to be found at Fattengates, as if they recognise marsh tits as being higher in the pecking order and therefore need to maintain social distance.

If Lockdown 3 rules permit you to visit the reserve and walk round the nature trail, which at time of writing is staying open, why not take a little bird seed into Fattengates, scatter it on one of the logs and wait to see what comes.

Anonymous