On two seperate occasions, in two different locations in the past couple of years, I have observed a pair of spotted flycatchers build a nest, lay eggs and then desert the nest leaving the eggs for no apparent reason. The parent birds were ok, and moved nearby to build another nest, and as far as I could tell the original nest had no obvious signs of disturbance or damage. Has anyone any idea why this would happen? The birds on the most recent occasion have been using the same site for about 5 years, and this has never happened before as far as I'm aware.
Hello there...and lucky you...spotted flycatchers!
Only a broad spectrum reply here, sorry! The parent birds seem healthy so that rules out abandonment due to physical weakness plus they went on to build another nest nearby. The close proximity of the new nest I guess rules out abandonment due to food shortage.
So, a factor could be nest disturbance by a predator or human ( not you of course!). This will cause the birds to abandon the nest quite rapidly. Another possible factor could be nest parasitism.
I know that spotted flycatchers used to host cuckoo eggs but evolved to get wise to that, but an alien egg again may be a factor, I'm not sure about that though.
Anyhow, hope this helps a bit,
Ange
Hi Ange,
Thanks for your comments. I don't think predators were to blame, as there were no signs of damage that I could see, but was interested in your suggestion that parasites could have been the problem, I hadn't thought of that. As no other cause was obvious, that seems a pretty good conclusion.
Thanks again.
Daydreamer