I am sure that most ringers will agree that 2012 has been one of the most difficult years, with the wet and windy weather restricting activities. The poor weather though does also seem to have had a detrimental effect on the productivity of many species and these two factors are certainly reflected in our ringing totals.
Our final total of 10,251 new birds is just over 4,000 down on 2011. The species with the largest decline was Sand Martins where we undertake a Re-trapping Adults for Survival (RAS) project on the colonies along the River Lune. From 2140 last year to just 462 in 2012. The poor weather was mainly to blame, not only did it cause problems on the evenings we planned to go out but with so much rain river levels were high and we could not access some of the colonies and some were completely flooded out. Counts of the nest holes though showed a decline from last years record population. By contrast Swallows were up from 556 to 1400 due to the formation of a workable reed bed roost at Middleton Nature Reserve.
Turning to the warblers, all species except Willow Warbler were well down. Reed Warblers, on which we run an RAS declined from 971 to 649, Sedge Warbler from 479 to 243 Whitethroat from 158 to 70, Grasshopper Warbler from 46 to just 11 and Blackcap from 163 to 102. Suggesting poor productivity in all these species. Willow Warbler at 507 declined only slightly, past recoveries suggest that most of our passage Willow Warblers orginate in Scotland where the weather was apparently better than ours.
Of the resident species all the tits were well down with the marked exception of Coal Tit which at 459 was 108 up. Coal Tits nest earlier than the other tits so they possibly escaped the poor weather and perhaps their coniferous habitat provided better conditions. Support for this latter view comes from another coniferous breeder the Goldcrest which increased from 185 to 314.All the finches except Goldfinch were down.
Perhaps the best evidence for poor productivity comes from the nestling ringing in our nest boxes. A project where effort was the same in both years. Blue tit nestlings declined from 908 to 505 this year. Great Tits from 507 to 368 and Nuthatch from 69 to 39. The later nesting Pied Flycatchers did better going from 515 to 451.
So rather a dissapointing year, let's hope that 2013 brings better things.
John
No comments:
Post a Comment