I bought some at Wild Birds Unlimited.

I just purchased one also at WBU. Vanessa

I use Bird watchers general store. They mail out quickly and dont rape you on shipping. Nice people.

Pam

Here is a link that might be useful: hole reducer link

So they do have restricters to keep out bluebirds but HOSP can still get in? I have decided that is what i need. War is waging at my house in tenn.-------bonnie

Just be sure to monitor. Our male bluebird actually once squeeeeeeeezed himself into a 1.25 entrance and was trapped.
Bluebars

Thank you bluebars i will monitor.----bonnie

Lots of sources at links below. Some folks call them squirrel tooth benders or hole guards.

Also a link on using therm here: http://www.sialis.org/holereducer.htm

Here is a link that might be useful: hole restrictor suppliers

Glad to see this posting still here. Last year I took down the damaged boxes with the woodpecker enlarged entrances and never did get around to fixing them. I just had put up new boxes.

I just ordered those hole restrictors now, better late than never. Am going to fix those boxes and put them up again this spring.

I am sorry to say that I never get bluebirds. I have never even seen one around here. I do see tree swallows flying over all the time but haven't had them come to my nestboxes. Birds nesting here in boxes are house wren, chicadee and downey woodpecker.

bonnieblueyes...The guy at Gilbertson Nestboxes sent me two hole reducers with my order. They had made extra this year. It has two holes...one that is small enough to keep out the BB and then one smaller to keep out the HOSP but allow the smaller birds...I will add the link below...I don't know how much he would charge. He is really nice...and you do have to call. I don't think he has them for sale on the site itself.

I am going to put them on an extra BB house and then attach a permanent inbox trap that I got there that is held in place by a wire which allows the HOSP to get used to it being there and then once that happens, you take the wire off and the HOSP doesn't notice anything different, and boom, trapped...I am going to get that done today... I also purchased that type of inbox trap for the reason that sometimes I had a hard time with a really smart HOSP, catching it with the Van Ert because he was wary of the new "thing" in his box...but Van Erts do catch a lot of HOSP and work where you don't want to leave a trap in the box...

Hope this link helps!

Diane

Here is a link that might be useful: Gilbertson Nestbox Co.

I see I am going to have to buy at least one and probably more hole restrictors. Either Woodpeckers or Flying Squirrels have worked on some of my boxes. Most boxes worked on, I could see woodpeckers using for roosting. But the smaller box that I had a small 1 1/8 inch hole for chicadess that they nested in last year has been pecked (or chewed) up into the vent slit so that its a large oval hole. I need to fix it in case they want to try that box again. I hope they do because the placement is great, I can see it from my back kitched door or back stoop. I could see all the nestbuilding activities and feeding last year and even saw the four babies fledge.

1 1/4" won't keep out HOSP. 1 1/8" will on a dee box but still allow HOWR entry.

Generally, EABLs prefer 1 1/2".

The best restrictors I have bought, so far were from Duncraft but they only have 1 1/4" & 1 1/2".

Linda

Maybe my house sparrows are fat but I have never seen them be able to get into a 1 1/8 inch entrance. Even the 1/14 seems to keep most out. My chicadees used a house sold as House Wren/Chicadee house last year with a very small enrance hole. Other years they used bluebird boxes with 1 1/2 inch entrances.

Of course if the House Sparrows stick around then I trap them so they don;t get much chance to take over the wrong box (or any box).

I just ordered those toothbender hole restrictors from Bird Watcher Genewral Store. I got two one inch and two 1 1/8 inch so that I can have a choice which to use.