In reply to Robbo:
2013 photos & vids here
eff37 on Flickr
Contacted the rescue centre. All the young died. None lasted more than an hour after we left them.
On a more positive tone, here's one of their former, bigger neighbours. Took the photo yesterday. At least three in the nest and adults are currently trying to lure them out. As is often the case, young martins are very slow to want to leave home. They often come back to the nest for a few days/nights once fledged.
"Each kindness shown to birds or men is sure to flutter back again"
I am back to wondering whether a sparrow got in the nest as I found a nestling yesterday from nest 2. Its head had a central wound, where there was a hole down to the bone. No blood so maybe a slug or worm got to it after it fell and died. Bit strange though that two mud nests collapse but theirs doesn't even though all three were made at the same time with the same mud. The other photo is where the nest had been. Unlike nest 5, nest 2 still had the small amount of original mud left up, so the new mud failed.
In reply to HAZY:
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