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

[brent]

Hi everyone,
I completed a nest check today and had my normal mix of hatchlings and eggs. One exception is that what should have been a nest of 5 hatchlings there was nothing. Last nest check there were 5 eggs that were to hatch April 26th. Not long ago I saw what I thought was a parent removing an eggshell from that nest but perhaps it was a full egg. I do have a SY male around and it could have been him removing the egg but not 100% sure. I would say a snake but I have electric pole protectors that I don’t think a snake could have breached but I could be wrong. Do parent birds remove whole eggs if they are determined infertile? Brent

[C.C.Martins]

Hey Brent. Sorry about that, dont think it was a snake.
had the same thing happen last year. 2 layers of snake netting, separated by 4 feet and sandwiched between both, a predator guard. No way a snake got up there. Only cavity to loose eggs. I didn't see say other birds but subbies were around. They did have 3 chicks eventually. Yesterday, one of the eggs was off color, doesn't look viable. Ill see what they do with it.

[Thomabear]

Agree with Tom... If it had been a snake, I don't think it would have stopped after 5 eggs. It likely would have raided several nests and your martins would have been on edge afterwards. Are they acting normal?

[brent]

Yes, Thomabear, they are acting normal. I’ll be doing another nest check Wednesday or Thursday. But everything seems fine. Parents are feeding chicks as normal. What do you think of the eggs being removed by the SY or even the parent birds? I did not find any eggs below the house so they would have had to be taken away from the house. What do you think? Has that ever happen to you? Brent

[Thomabear]

Brent, I’ve never had that happen. I’ve had the occasional egg or two go missing but never all of them out of one nest. It’s definitely a head scratcher. Please do let us know how the next nest check goes. I’m definitely interested in what you see. Hopefully it’s just a one off occurrence.

[Martintown33]

That is a quandary, Brent! Let us know if an answer reveals itself.
Rob

[brent]

Hi everyone,
I wanted to follow up on my report and questions in regards to discovering that all the eggs in one nest were gone. I’m sad to report that after today’s nest check I found a second nest with all the eggs gone. Nothing there and nothing looks disturbed. That’s a total of 11 eggs. The adult pair just looks inside and sits on the porch perch. I really think it’s SY males. I also discovered a small chick at the inside entrance of another compartment. Nothing apparently wrong with the chick so I placed it back with the others. Later I checked and the female parent stayed in the nest as I looked in. It was as if she was protecting the chicks. I must have at least 3 very active SY males. They are lurking around and the adults are constantly fighting them off. I check the electric post guards everyday and there is electric pulse so I can’t imagine a snake or something else getting the eggs. I have two nests left with eggs that are going to hatch on the 4th and 5th of the month. I don’t know what to expect. I know SYs can cause problems but this is really something else. The chicks in the other nests seem fine and the parents are feeding them regularly. Keeping my fingers crossed. Nothing much I can do. I’ve been doing my nest checks every 4 days. I feel helpless. Any thoughts? Thanks, Brent

[Martintown33]

Man Brent that is tough. Sy males could be the problem, but I’ve never seen them completely wipe out nests before, but doesn’t mean that it couldn’t happen. It’s going to be hard to solve the mystery without some 24 hour surveillance.. may want to try mounting some blink cams in the 2 remaining nests, or security cams viewing the entrances of those 2 nests, and see what shows up… I wonder if it’s possible some type of predator has figured out how to jump pass the shock box… so sorry this is happening..
Rob

[defed]

i don't have a lot of experience, but last yr, i had a nest w/ 4 or 5 eggs (can't remember w/o looking at my notes) and only 1 hatched. they just left the other eggs there. after a wk or 2, i took them out. not saying the never remove bad eggs, but mine didn't.

[brent]

Not a happy landlord here Rob. I think I’ll put up the snake netting just to see but it would be difficult for a climbing predator to get past the electric guard. I’ve attached a picture of the guard. If anyone sees a way a predator can breach this let me know. There is a one half inch space between the guard and the post. Brent

IMG_0827.jpeg

(2.32 MiB) Not downloaded yet

[SSMartin]

How many volts are you reading on your setup there? How deep is your ground rod and how dry is your soil?

When my sandy soil is dry my livestock will walk right through my electric wires. After a rain they won’t even make eye contact with them.

Just a thought. Also check out Parmak 12volt chargers if you ever need a replacement. They can push 13-18 volts.

[Martintown33]

Man Brent, I’d be so curious to know what’s going on, I’d have to mount a security cam or 2.. your electric pole guard does look very hard to defeat. I was wondering, could a squirrel, (able to jump 4 feet straight up) jump pass the electric guard, and climb the winch cable to the housing, and get the eggs… but, on the other hand, if that was the case, seems like you would have empty, cracked eggshells and a mess inside the compartment..
Definitely frustrating!
Rb

[brent]

Well the voltage is high, not sure how high. I use the same energizer as Thomabear. It’s a Gallagher S12. The ground rod is 8 feet with at least 6 feet in the ground. No Squirrels around either. I put up snake netting trap but no snake. I still think it’s the SYs. Everything looks normal. Today they’re feeding as if it’s just another day. Tomorrow is a nest check day. The last two nests with eggs should have hatchlings. I hope I don’t find them empty. I’ll post my findings. I have a feeling that the pairs whose eggs where taken may lay again. I hope so any way. Hey, there’s one of those SYs causing problems as I’m writing. I’ll never understand that behavior. Thanks everyone.
Brent

[C.C.Martins]

Brent,
End of season ill ask both you and Thomabear for specifics, think we may go that route at our public site. While I like snake net, I hate that stuff.

[cabin man]

Hi Brent. We had similar issues last year and it even got worse. We were finding Nests with Young and that were pecked and pulled out . I lost over 40 Young last year this way. I thought it was a rogue sparrow, but there were none around. It was determined through my mentor, it was an SY bird. Maybe more than one. There were so many males at my colony last year and not enough females to go around. When I spoke to someone at the Pmca, they mentioned that the females are usually the ones to perish on the return trip home. I believe they were not enough females to go around and when the at males got there, they just were trying to break up the family units so they might be able to tenet with the female . It was horrible! I didn’t know how to stop it. Eventually almost all birds, reheated and fledged successfully. Just a thought. If there are not enough females to go around, the way males could be trying to break up the pairs . I hope that is not the case for you though. It was one of the worst things I’ve witnessed since becoming a landlord. Hoping things will be better this year, and again, really hopeful this is not the start of something like that for you. Fingers crossed. Rob.

[Thomabear]

Sorry to hear this Brent. I’m also seeing an abundance of Male SYs at my home location this year. I’m seeing more than normal “to the ground” fighting. All nests are taken so I’m sure thats part of the reason. I seem to be a little behind you because hatching for me just started on the 1st. I’ll be doing a nest check in a couple days and I’ll let you know what I find. BTW, the Gallager S12 puts out 9,200 volts and the milliamps varies at around ~30. When the air is humid you can actually get a shock just from placing your hand close to the box, within 1/8 inch or so. In south LA one ground rod is more than adequate since soil moisture is high, not to mention your ground rod being so close to the unit. I agree that SYs are likely the culprit. It looks like you have a very determined one.

[brent]

Hi everyone. Just finished my nest check. As Rob from New Jersey mentioned I did discover one of the chicks in the neighboring nest had it’s head pecked and looks like it’s eye might be affected too. It does look healthy and as big as the others in the nest. I’m hoping the best for it. No doubt it’s SY males. I must have 3 or more. The other birds are being very protective of the chicks/nests. I actually see some sitting at the entrance until their partner returns as if on guard. The baby chick I found inside the entrance of one nest is doing fine. Luckily I discovered it in time. Again, no doubt it was a SY that tried to pull it out. Thanks Thomabear for the information on the Gallagher S12. I took the snake netting down today since I’m convinced that the electric pole guard will protect the birds from ground predators. Sure CCMartin, I’ll be happy to help you with the electric pole guard. Thomabear walked me through the entire set up. It helps so much with nest checks since you’re not dealing with the baffle guard and snake netting.

On the bright side, I have 70 chicks, 2 eggs, and the 2 nests whose eggs were taken show signs (fresh leaves) of possible new clutches.
Good luck everyone. Brent

[birdman in buckhead]

My thoughts are, if it's SY males causing it, why aren't the ASY males putting the SY's in their place? 1 or 2 years ago I had a SY male acting up by going into places it shouldn't. After a few days of this, 3 ASY males took the SY to the ground about 10 feet in front of where I was sitting! A bluebird even got a few picks in! When the SY flew off, the 3 ASY birds were on its butt for 50 yards. No more problems from the SY after that! It roosted outside of all the occupied units for the rest of the season.

That said, it's a very strange thing happening and the only logical conclusion is to blame the SY males. But a quote from Spock "When you eliminate the impossible, whatever remains, however improbable, must be the truth". So, are there any other reasons that are truly impossible?

[brent]

I don’t know Terry. What else could it be???? Both male and female parents chase the SYs off. I just don’t know. The birds are acting normal in that they are feeding their young and the parents of the empty nests seem to be bringing in new leaves as if they plan on another family. Because I did not see it myself I cannot say just what happened. However, everything points to the SY. I have seen the SYs lurking and looking into the cavities mischievously. Brent

[birdman in buckhead]

Brent - I suppose birds act differently in different parts of the U.S. I don't know why, but I just watched 2 or 3 ASY males give a SY male a whole can of whoop a**! Then they all came back and the SY perched on a gourd like nothing happened.

Is it possible the entire batch of eggs were considered "bad" by the parent birds? Considering the pair are preparing the nest for more eggs makes me think that whatever the cause was they don't think there is a treat or that it still exists....? That's an extremely human way of thinking about the situation, and I'm sure birds don't think the same way as us. But it is a possibility.