Wednesday, 9 June 2010

Wednesday 9th.June 2010

Back on the 15th.April , I posted pictures of a pair of Nuthatches , which had decided to nest in a bird box on the side of my Warden's house , up on the Greensand Ridge . I managed to get plenty of shots of the pair , and looked forward to following the nesting story . All seemed well for a week or so , then just and odd view of a single bird at the entrance hole , but not entering the box . There followed weeks of no sightings , and it was obvious something had gone wrong . The last few weeks of volunteering has been mainly in the yard , working on the new shed , giving ample views of the nest box . Admittedly , last week and this , a male has returned to the garden , and has been calling from the Oak , but nothing at or near the box .
Today , before coming home , I decided to open the box and see if the mystery could be solved . With trepidation , I unscrewed the front of the box and slid it down . My worst dread of a dead female didn't materialize , just about 22cm./3 inches of bark , like that in the bill of the bird above , with a depression in the middle . Nuthatches lay their eggs in late April / early May , just after the pictures were taken , and obviously too late to do so now . So we decided to clear out the box , save doing it in the Autumn . I started clearing out the fragments of Scots Pine bark , then stopped when I felt something down at the bottom . That something turned out to be a dead Blue Tit , still in very good condition , but very stiff and flattened . Right on the floor of the box , were three eggs , without any nesting materials , and obviously the 3 inches of bark above them , before I started removing it . The eggs of both species are very similar , and my Observers Book of Bird's Eggs , states that the size and markings of both species are very variable , so they could be either .
I opened the box to get an answer , but have only finished up with even more questions . How did the Blue Tit die and finish up under 3 inches of bark ? Who's eggs were they under the bark ? Whichever species laid the eggs , why were they laid on the wooden floor ? Why did the Nuthatches carry on collecting nesting material when the Blue Tit was lying dead in the box ? All questions that I will never find the answers to .
Hope to get out tomorrow , weather permitting .


Warren Baker said...

Id say they were Nuthatch eggs Greenie, although its hard to judge the size in your pic. Blue Tit eggs are smaller. Id say the blue tit died of natural causes, and the nuthatches were put off by the Tits body, but did try to nest over it :-)

Greenie said...

Warren ,
I too think at least one of them could be a Nuthatch egg , but they were below the Blue Tit and without any nesting material below them .

ShySongbird said...

How very odd! Yet another mystery of Nature, Greenie. The more we look the more there is to learn but what a fascinating subject it is!