Additional rare and/or scarce species and noteworthy totals in this period included up to 35 Purple Sandpipers at Lowestoft, three Grey Phalaropes, three Sabine’s Gulls (all off Landguard during 16th to 20th October i.e. in the immediate aftermath of the infamous hurricane), a peak of 35 Little Auks off Covehithe, 21st November, Dipper of unspecified subspecies, Minsmere, 5th November, four Pallas’s Warblers (of which three were at Landguard), three Yellow-browed Warblers, Red-breasted Flycatcher, Benacre, 3rd October and Little Bunting, Landguard, 19th October.
Rob Fuller, Director of Science, BTO
Ash dieback – what might be the consequences for birds?
M
any people are asking this question. It is just a few weeks since Chalara fraxinea was confirmed in ash trees in eastern English woodland and, as yet, it is far from clear what the implications are for our woods and hedges and the wildlife living within them. Much will depend on the speed with which the pathogen spreads, the geographical extent of the disease and whether there is substantial genetic resistance amongst our native ash trees. If the worst scenario unfolds, and we see similar levels of tree mortality to those experienced in the worst affected parts of mainland Europe (e.g. Denmark), then the consequences for woodland ecology will be massive. Initial thoughts are that relevant processes for birds might include the following: • An increase in fallen and standing dead wood, which could provide a temporary
The coastal region dominated the Suffolk birding scene in this period but there were some very noteworthy reports from inland sites. These included a Black-throated Diver at Lackford, 26th November to 26th December (the first record of this species in west Suffolk since 1973), single Red-necked Grebes at Cavenham GP, 18th October and 6th November and two on Redgrave Lake, 30th October, and moribund Little Auks picked up at Long Melford, Bury St.Edmunds, Ixworth and Thetford Forest during the period 21st to 26th November.
glut of resources for saproxylic invertebrates that should benefit woodpeckers, possibly including the increasingly scarce Lesser Spotted. • Canopy cover will decrease letting more light through to the woodland floor. This may result in greater regeneration of bramble and saplings that could be beneficial to a range of species that nest and feed in the field layer and low shrub layer. However, much will depend on whether this re-growth is heavily browsed by deer or not. We know, from work in Bradfield Woods, that intense deer browsing can severely reduce the quality of regenerating coppice as a habitat for some warblers, Nightingales and Dunnocks. There is a possibility that, if the dieback is really severe and we see massive regeneration, this could actually give a boost to deer numbers, thus creating even greater pressures on woodland habitats. Alternatively, if the open canopy results in a proliferation of grasses and sedges, this may inhibit regeneration of the complex vegetation structures that many birds depend on. • Large changes in the tree species composition of woodland are likely to occur. For example, will we see an increase in sycamore in many woods? This would not necessarily benefit birds, as densities of breeding birds tend to be low in pure THE HARRIER – December 2012
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