Finally had an couple discovered eggs on the ground

[BHULL]

I've been trying to attract martins for years and finally had my third couple in 9 years set up shop.This morning I was reading about egg and nest checking rules and so with eggs laid last week decided to nest check and (3) found the eggs on the ground and very upset to say the least.These two birds are sub adults and for the last week I finally won the sparrow battle by closing off the remaining holes in housing unit and putting up a bluebird house which they went to.I'm not sure a predator did this and was reading that if they lay infertile eggs they will get rid of the eggs.Questions arise Will they possibly lay more eggs?Should I open up the other holes and gourds?I was just getting ready to order a predator guard for the pole.The two other couples in the past eggs disapeared and them as well(snake possible)the other couple raised 4 fledgings successfully and never came back the next year(probably died)My site is not the greatest located in a valley and have large trees within a 100 ft of housing.The martins are still here and came as I was looking at eggs and I quickly put housing back up and they seem comfortable with me with my battles with the sparrows.I thought I had done everything to protect them.Very bummed out person from Ohio

[Mary Dawnsong]

Hi Bruce,

I am so sorry you lost those eggs.
There is a good chance the martin pair will lay another clutch, especially since they are still around.

The most likely culprits are non-native House Sparrows.
If you are not using Starling Resistant Entry Holes (SREH), then European Starlings are also a good possibility. Both species will toss out eggs and may also peck them. Both species will kill martin babies and even martin adults.

SREH entries on your housing will take care of any starling problem.
A strong trapping and/or shooting program can control House Sparrows (HOSP). If your martin house is a Trio brand, then the Spare-O-Door fits and is an extremely effective HOSP trapper.

I think you should open all the holes in your martin housing immediately.
When the only holes open are occupied by martins, then the martins are at extreme risk from HOSP and Starlings. That's because the martins' compartment becomes the focus of those non-native pest birds.

Good luck, Mary

[Guest]

I finally won the sparrow battle by closing off the remaining holes in housing unit and putting up a bluebird house which they went to.

I am not clear. Did you put up the BB house and let the sparrows nest? Or do you use it to trap and ...dispose?
IMO: If you are letting them have a nest in the hopes that that will placate them and leave the PM alone, don't think that will work.
Kinda like playing with fire.

If I misread please forgive me.