All eggs from one nest gone. Any idea what happened?

[Martintown33]

Brent, by what you’ve observed it does seem like the SY’s are the cause. I guess I’ve been lucky, in 25 years of hosting martins, I’ve never had SY get that aggressive. I’ve seen them fight ASYs to try to overtake their compartments, and i see them suspiciously peering into occupied compartments, as you describe, but I’ve never had one get that violent. As I recall, I think you had some aggressive SY issues in previous seasons, but not to this extent, I don’t believe.. Well, I hope that your affected pairs start over, there’s still time.. sorry this has happened..
Good luck,
Rob

[brent]

Hi everyone. Terry you have a good point. The only thing is it happened to two nests. But I’m sure it’s possible. Rob, I hope this doesn’t happen to you or anyone but apparently it’s not uncommon. I will check on Wednesday. I think I’ll find new eggs in one or even both of the nests. I’m hoping that little one that had head injury and possibly eye injury is doing well. Since it was as healthy looking and as big as the others I think it’ll be fine. But I have a nest with real little ones, only hatched on May 5th. I hope they were left alone. I’ll follow up and let you all know. Thanks for the replies. Brent

[birdman in buckhead]

Brent - Fortunately, I've never had the problem that you are currently having, so I can't answer the question that you have asked, but I don't see an answer in this thread. What do SY males do to eggs if they invade a nest? Do they smash them in the nest, carry them off, or throw them out on the ground under the housing?

Do any flying predators remove eggs from nests? I can't think of any besides the normal culprits like sparrows, but I think they typically break the eggs in the nest.

I'm leaning towards the parent birds. It would crertainly be highly unusual, especially occurring in 2 units, but it can't be considered impossible. Any landlord who's had a colony for a few years has seen birds do head scratching things! Like a few years ago when an ASY female removed half of her nest from a house unit, then put it all (same nesting material) back in. I'll never forget her male mate and a female in the unit below, both looking at the situation and cocking their heads - in my mind, thinking what the heck is she doing????!!! LOL!

[Martintown33]

Terry, it is funny when they cock their heads to the side, similar to the way a puzzled dog does…
Rob

[birdman in buckhead]

Brent - I now have the same problem! I guess I jinked myself (or as they say down in New Orleans, I put a gris-gris hex on myself) when I wrote "fortunately I don't have the same problem". One nest had 3 eggs in it 8 days before the last nest check, then they were gone! I don't have the electrified defenses that you have, but there are 2 SY males hanging around. I've closely watched them for the last few days, and I have never seen them enter an occupied gourd or house unit. They look inside, but never enter that I know of. I see the pair of ASY birds going in and out of the gourd. I assume they will lay more eggs and will verify during this weekend's nest checks.