34 Years Trying

[cabin man]

Hello all. I have been reading posts on the forum for years. rarely posting anything. After all these years, I finally have a committed pair . I witnessed them bringing in leaves today, so I imagine they are close to egg laying. I need some advice, though. I had a pair of tree swallows nesting close by,(followed the protocal), and all were getting along just fine. I have had some really aggressive swallows over the years, but this male never bothered the martins. only other swallows. Well the swallows were due to hatch anyday, and I noticed them acting strange this morning. When I glanced over to their gourd, I saw a wren throwing out their feathers. I immediately opened the cap and saw that all the eggs were gone! Has this happened to anyone else? I am sooo worried that this could happen to the martins if/when (hopeful), they lay their eggs. I spooked the wren by opening the gourd, so he ended up on the gourd rack. (great,huh). I only have a four gourd starter rack up in this area, so there's not a lot of room. Last night there were 2 pairs of SY 's here. Do you extremely knowledgeable folks have any thoughts or advice for me? I read a lot about Martins, and have helped my friend get a colony started, but have never hosted them myself. Could it have been a sparrow that tossed out the eggs and the wren just followed up the opportunity? I need to try anything and everything to keep this pair. Please help with your thoughts. Thank you all for your time . Rob

[4th Gen Martin Fan]

Rob,
I am so excited about your nesting and visiting martins after 34 years. You seems very knowledgeable and conscientious so that is a plus. I would not consider you a naive landlord with the information you have provided.
I presume that the tree swallow gourd was mounted away from the martin's gourd rack from your description. The tree swallow's eggs were raided by something and you would presume by the wren. Others will have to comment whether a wren would take out the eggs. You relate the wren was taking away feathers from the tree swallow's raided nest. Have the tree swallow parents been seen lately around the nest both before and after the eggs were found missing?
Does the tree swallow gourd's pole have a pole guard to prevent a snake from getting the eggs and parents? Is the entrance hole starling resistant on the tree swallow gourd? What if the eggs/parents were already gone when the wren came to take advantage of nesting material for its nest elsewhere. In that case, the wren is an innocent suspect. Neither pole guard or starling resistant entrance hole would prevent a English house sparrow (HOSP) from raiding the eggs.
At this point I would make sure that the martin gourd rack has a pole guard to protect them from a climbing predator; snake, coon, etc. and starling resistant entrance holes to exclude European starlings.
As you know, none of these measures will exclude HOSP. Eliminate HOSP by any means if they are present.
I hope your martins remain safe from a similar tragedy.

[flyin-lowe]

While sparrows and starlings have a bad reputation I have lost more birds at my place to house wrens then sparrows and starlings combined. Mostly because I can shoot the sparrows and I use SREH. Fortunately I never lost martins, it was always blue birds. I noticed in my area that the wrens start nesting later in the season. I had BB boxes up and every year the second clutch of BB's would be killed or the eggs would be destroyed by wrens, and I would find twigs stuffed right on top of the BB nest. Depending on the size of the BB babies sometimes they would build right on top of the deceased BB babies. Fortunately I never had them attack a martin nest but I am assuming they would just the same.

Congrats on the nesting martins. I thought 5 years was a long time to wait.....

[4th Gen Martin Fan]

I appreciate that other Forum members have experience that I do not have and contribute to the knowledge base needed in these circumstances.
Now I am glad that I have never encouraged wrens close to my martin colony.
Each year I have a pair of Carolina wrens build a nest in open and random containers on the metal baker's rack under the back porch of my house. They provide entertainment for my wife. My house is in a forest of 40+ feet tall trees so martins are out of the question at home.
Do wrens prefer low lying nesting sites like a bluebird or tree swallow nest? Are they less likely to nest in a higher house if lower cavities are available?
The wrens select containers on my baker's rack which are chest to waist height. Thereby I would presume that they prefer lower lying cavities rather than 8' to 12' up in the air. Example: martin housing.

[Mhoover]

It is primarily the house wrens that do the damage to BB and Tree Swallow nests. I have never had any problem with the Carolina wrens. I ended up placing a nest box for the house wrens over a hundred feet from my martin racks and facing away from the racks and that has stopped the house wrens from bothering the martins. House wrens are extremely territorial and the one pair that I do have keep all of the other wrens away. It is not a perfect solution but in my case it has worked.

[Tengai]

Male House wrens will build dummy nests in any and all cavities in his territory. Filled to overflow with twigs The female chooses which nest is to her liking and line the nest with grass fur etc. He will also remove eggs and newly hatched chicks that are in those nest boxes. The further out in the open boxes are placed the less likely they will claim cavities. Had many a BB and TS nest taken over.

[cabin man]

Thank you all for getting back to me. Wow! I wasn't the only one that experienced this. I knew that I would get some answers from all of you. Thank you. I witnessed the tree swallow coming back this morning and being aggressive towards the Martin's, but thankfully, the Martin's held their own. I decided to put another tree swallow gourd out on a shepherd hook to accommodate them if they wanted to come back. I am hoping that the wrens move into either one of them. After reading the last post, it sounds like they could claim all of them. I am just hoping that they get out of the gourd rack. I have been dealing with issues for so many years, I will not let this deter me. I will surely try my best to keep the Martin's that I have. Thank you all again for your replies. And wish me luck! Rob