I'm sorry to hear that Liza! We have too many of them here! The blues have 1 or rarely 2 pairs locally seen and then we get a swarm (5-6 TRES) near a box with the main pair defending it's box and territory. And Kendra, at my paired sight there is a lake on the next property over and 3 on the property behind it. Site #2 has lakes but you have to move a few properties away. Okay so I was there again today. Swallow pair #1 has a completed nest so that box is locked up. At box #2 I approached to see Mr and Mrs. blue perched on the fence behind it. But of course later on I was again dive bombed. (so annoying! I just stood there in protest) Only a couple of pieces of grass in the box. I still haven't decided. Do I wait to see if the blues win out or double it up? I like the TRES, but it's really irritating that everywhere I go for bluebirds the swallows want every box and always seem to outnumber the blues. It doesn't make any sense. Even Dorene Scriven's "bluebird trails" mentions bluebirders giving up hope of having boxes only for the bluebirds. Ever since waging all out war on the HOSP the TRES have shown up. They can't steal a box from the HOSP but if it concerns the bluebirds, of course! They decide to come take it. UGH! The things just irritate the heck out of me! And this property has hardly any space for multiple boxes. There's too many trees and a fence in my way. Ugh. rather depressing nesting season. I've had enough of these TRES.

Hi Jann, Crazy old me. Please forgive me? Living over here where I do, I am thinking of way south Florida for zone 10. Gosh, you are a lucky duck then. I obviously don't anything about either of those species. I do know though that some of my neighbors to the north say that their Chickadees (which would be Black-capped)are not nesting in their boxes. Our Carolinas nest easily in the boxes. Conversely, our Carolina Wrens do not tend to use boxes, while I understand that the pesky House Wrens further north won't stay out of people's bird houses! So, I assume that there are regional differences in their nesting preferences. I would think that someone who lives in your immediate area would really be able to help with the nestbox placement, since they would know what is characteristic of the wonderful birds that you have. I hope that person shows up here to help you. Good luck to you!!

Kathy -- when I went back out, I decided that BOTH nests look like they are primarily twigs, though there certainly are some more grass-like pieces as well as a few small seedheads (maybe dried sedum?) in the second one (it's also not as deep). I pulled out the one that was clearly all twigs (had a very deep "cup" in the middle but no eggs), but I left the other because I just wasn't sure. Here are the two pictures: first is the all-twig one that I removed today (how well do I need to clean out the box? I think there are a few twigs on the floor since I didn't have a brush with me). The second is the other box. Just a note: these two boxes are fairly close together because last year we had tree swallows and I had read that tree swallows and bluebirds will "share" space if there are two boxes. Swallows won't let another swallow pair nest nearby but will leave the bluebirds if they want the other house. I think what I read (on Audubon site or somewhere) was to put the two boxes about 10-15 feet apart. I know that's not what you do if you want actual bluebirds to use them both, but we were hoping to keep a pair of bluebirds in the one if the swallows returned this year (those swallows are GORGEOUS birds, too!)

My husband thinks if we plug up the hole, the wrens will go to the other bluebird box so we'll just keep taking out the twigs. She builds a perfect circle of twigs morning and night. As I walk back from destroying her work if just look over and say, "Sorry little bird." I know it's for the best. I've figured out a way to stop feeling guilty about it; I just have my husband do it! Plus I keep picturing the destroyed bluebird eggs I've seen from what the Wren's can do. Thank you all for your advice. Now we just need our Blue's to start building!