Hi Tim
The very truth and every Martin landlord knows this since the mid 60's those
trio units have been on the market. They are the main reason for the decline
of the species. The units are to small the company today makes them double size (that means 12 units are now six because people complained. Martins prefer large gourds or large double size aluminum houses. (not the six by six type)
they will use them if nothing else is around but prefer gourds most of anything
and sparrows prefer houses. The trio unit is a great trap. Order trap from the manufacturer www.naturesociety.org double size the house use starling resistant doors which can be bought from nature Society people. Make the change to larger units must take trio apart and drill out 3 inch holes but can be done. This town were i live now went from three pairs in 2005 to 35 pairs
in 2010. All because i placed gourds and double size the aluminum houses.
Plus with gourds and large aluminum houses the birds produce large numbers
of eggs. With Martins its all location. Another fact: to date not one martin
has nested in the old small trio units placed for them in this town and its been 10 years and there nothing but sparrow slums. This town Barrington
has almost 50 gourds four double size alunimum houses and every site is
almost all will be full this year. The purple Martin conservation Assoc did a study
on units and all the information is correct. There population is recovering
from this national mistake but people need to remove those old houses and
place correct homes for the birds or there population will never recover
in area's were the old units are replaced people are getting record numbers
of birds even way out on Cape cod Martins are making a comeback because
of gourds and large homes.....
Ray

Wow I never knew that. Yeah the only thing that's been in my neighbors' martin housing is HOSP and Tree Swallows.

I wouldn't wanna see Tree Swallows in them either because they already use my bluebird boxes and the population is already big enough (Twice that of the bluebirds or more)

Now, what I was reading is that you can make those compartments larger and decrease the number of apartments? Wouldn't be a bad idea to try. Anyway I want to help them succeed and trapping the HOSP in the boxes and martin housing would further extend my HOSP control. I'm hoping to attain a DRST ground trap because of the shear number of HOSP. Thing is, getting a male decoy would be much easier than getting a female.

But I think trapping the HOSP in my neighbors' martin housing is the next step. I know there's no way to get every last sparrow...we all wish we could just ship them back across the pond!

Then again they aren't as dedicated to birds and this would be the best favor possible. I've been removing HOSP nests in these houses for the last 2-3 seasons but the only way to really get rid of them is trap and euthanize them.

Spar-O-Door without a doubt! Works absolutely great! Won't get starlings though, they can't fit in it. Best solution for starlings is to convert to the double compartments and put on the SREH (starling resistant entrance holes) openings and they starlings will for the most part give up. Keep in mind if they convert them, they can keep the round hole doors on 1/2 the compartments and just plug those and them use the SREH doors on the front 1/2 of the compartment.

I've not had good luck with the Universal sparrow trap, tends to reset (fall down shut) when you raise the house.

A great trap for Starlings but you have to monitor closely because both martis and bluebirds can fit in it is the Super gourd with the insert trap.

As long as you only set it while you can watch and free any native birds immediately, it's fine.

I have several Trio houses and my martins do great in them. They are all converted to double compartments which the martins (and I ;-) love.

Teri

Hey Tim!
I am a Puple Martin landlord wannabe, so I am not an expert on the subject. However, I have educated myself fairly extensively on these birds over the past few years. I am in Georgia, and what I found here is that the Martins tend to prefer gourds over houses. It seems like the further south you go, the better luck you have with gourds. I did have a house up initially, and it seemed to be nothing but a HOSP magnet. I do not ever see them at my Troyer gourds. I agree with Ray and Teri. Enlarge those compartments, and also use the in house traps. Heck, at this stage of the game, I would just take the housing down to do the modifications and maybe some of those nasties would give up and leave. You'd be waiting for the subbies now, and they haven't gotten too far north yet.~~Angie

I'm in TX and don't find that martins won't use houses. Wooden houses might be preferred over aluminum by northern martins and certainly lots of martins like good gourds, but there are martins all over the South living in Aluminum houses. I have two types, my neighbor with an adjoining colony has two types of aluminum and one plastic. The only one the martins won't use is the one he has with round holes and the unexpanded compartments. Hawks visit our colonies regularly and I think the martins know those cavities are too vulnerable to predation.

I do have some Bo-11 gourds under the house as well and they love those too.

Since the OP isn't actually the martin landlord, all of this might be for naught but it is a good discussion.

I use a retired small (6 cavity) Trio as nothing but a sparrow trap. The trees encroached on it so it's too dangerous for martins because of the hawks, but I have two Spar-O-Doors in it and will often get both of the pair at once. Those small holes are sparrow magnets!

Incidentally, I do get the rare bluebird in there as well even though they supposedly don't fit and I've heard of people trapping both Chickadess and Nuthatches with them so I should have said in my earlier post that they need to be closely monitored as well. That said, it is less common to get native birds in the Spar-O-Door, very common to get them in the Super Gourd trap. Since the I put the SREH on the martin houses, I rarely try to trap with the gourd.

Teri

Thanks everyone! The shear amount of feedback is great and It's amazing how different the perspectives are with Purple Martin landlords. Most Bluebird land lords have similar experiences.

And Teri, I know why you might think that, but eliminating these HOSP will only HELP the entire neighborhood. Martin and bluebird landlords have the same problem - Those HOSP are tenacious killers that have to go down if our natives are to survive and thrive!

By the way, I happened to cap. a Male HOSP in the neighbor's martin housing! He got the housing from someone else but it doesn't have the containing bag (It's a Spare - O - Door trap. I had to VERY CAREFULLY transfer the HOSP from the hole into my drawstring bag that I use for nestboxes. The battle against HOSP at my nest boxes has slowed down, for now. Mr Blue was sitting atop the box pair today - but the forecast looks disgusting! We were near 70 here in Ohio a day or two ago and now the forecast says lower and middle 30's for the next 5-6 + days! Thunderstorms, Rain, light snow, and sunshine are in the forecast. But it looks like nesting may be postponed this year:(...UGH...I hate cold weather!

**And Teri, I know why you might think that, but eliminating these HOSP will only HELP the entire neighborhood. Martin and bluebird landlords have the same problem - Those HOSP are tenacious killers that have to go down if our natives are to survive and thrive!**

Sorry but you really lost me here. I just finished giving you advice on what sparrow & starling traps to use, why would you think I don't appreciate the danger they pose to my martins and my bluebirds?