The latest report from Michael Walter:

This spring’s bird populations have now been calculated and, of the 18 monitored species, four have increased (green woodpecker, stock dove, blackcap and jackdaw), three have declined (mistle thrush, tree creeper and bullfinch), while the remaining eleven have been about average.  I didn’t start monitoring stock dove and jackdaw until 2004, so have a much shorter run of figures than for the other species.  For stock dove there is a fairly consistent rise, whereas for jackdaw it is more like a recovery after an earlier rise and then fall.  Both species feed on farmland, so there may have been an increase in feeding opportunities there.  They are also both hole-nesters, so it is possible that nest predators, such as grey squirrel, have been scarcer this year:  all just surmise!  For the third year no marsh tits nested on the monitored plot.

Spotted flycatchers are perhaps the most uncooperative species to be found at Blean – arriving late, seldom singing their quiet, insignificant songs, and then simply melting back into the woodland.  Our last hope of finding them before they return to Africa is now, when flycatcher families become a little more conspicuous, emitting anonymous, decidedly unhelpful squeaks, but interspersed with occasional more distinctive disyllabic calls, as they prepare to sally forth in looping flights after insects.

Often, at this time of year, the sadness of passing summer is partially assuaged by an influx of brightly-coloured butterflies – peacocks, red admirals, commas and brimstones.  Not this year though, as the season fizzled out, with just a smattering of second generation heath fritillaries to buoy my spirits.  A few white butterflies were around in August;  most years these would be mainly green-veined, laying their eggs on lady’s smock, but this summer any whites seen have almost invariably been small whites, which are much more catholic in their choice of plants on which to egg-lay – almost any species of crucifer, the cabbage family, will do.

Still on the subject of butterflies, I was thrilled on 9th September by my first record of a small copper this year.  Formerly quite a common species nationally, and still widespread, it has always been extremely scarce in the wood, where it is no more than a vagrant – a rarity value that seems fitting for such an exotic, luminously orange butterfly;  so small yet so perfect.

 

Small copper

Pair of small whites mating

Michael Walter

michaelwalter434@gmail.com

  • Thank you, yes, that's helpful. What you need is a 'Seldom Seen' type map of the Blean.

  • Hi, Thanks for the interest, and yes, this is just for the RSPB managed land. We do use consistent survey methodology so we can compare breeding numbers from year to year - some of our surveys have been completed annually as far back as 1982! BBS is a one of the surveys undertaken in the woods, but also CBC (common bird consensus), both of which follow a set walking route and bird registrations by sight and sound are recorded on maps during the journey. As the reserve is so large (509 hectares!) we even use a third method called Point Counts, where we stand at set points in the woods and map activity and song for a period of time. It is impossible to know if every bird registration/song is an actual breeding bird, so we complete multiple visits throughout the spring to better define territories - for example, a nightingale singing from the same coppice plot on 2 of the 3 visits would be considered a breeding male. I hope this answers your questions. Many thanks

  • Thanks for this, it's good to get some actual numbers for each type of bird. If they are the number of birds you count on your surveys, then how would that relate to the actual (breeding?) population in the woods? And do all RSPB reserves use a consistent method to survey, so you can compare? Like BBS for example. And what area are you counting over? The reserve area presumably, not the whole of the Blean, which I believe is quite big.