Trio's thoughts on enlarging compartments

[Matt F.]

I read this on Trio's site, and am interested in other's thoughts on the matter.

From Trio:
"In recent years the thought that larger nesting compartments for purple martins allowed them additional protection and better egg/fledgling production has become somewhat popular. Because their nest would be farther from the entrance, a predator reaching inside the nest compartment would not be able to reach birds in the back of the enlarged area as easily as in a standard 6"x6" compartment.

By enlarging compartments on Trio or DuraCraft aluminum martin houses, a dark cavity is created instead of the shiny interior of a 6"x6" compartment. This invites starlings, so a starling-resistant door must be used instead of a standard door. While this will prevent starlings from entering the compartment, sparrows can and will enter, and herein lies yet another problem. You must monitor houses that have been modified to 6"x12" compartments very closely (daily). It was soon discovered on our testing grounds that a sparrow will build a nest in front of an active purple martin nest trapping the martins in the compartment until they are discovered or die from starvation.

Supporters of large nest compartments claim a higher percentage success rate in fledging nearly all eggs that hatch. This can also encourage martins to lay more than the average of 4-5 eggs, to as many as 7 or 8 eggs. While we want to help the purple martin species flourish, two or three extra mouths to feed can overwork parents that sometimes struggle to keep a nest of four or five babies well fed, especially during inclement weather.

There are pros and cons to using enlarged compartments. Nature Society does not necessarily endorse the use of larger compartments, but offers instructions below to modify Nature House martin houses for those that prefer enlarged compartments. It should be noted that purple martins will rarely use starling-resistant doors on a standard house. Crescent doors will not be needed unless you have modified your martin house."


Thoughts? Input?

[Emil Pampell-Tx]

Sounds like they are defending their old product. I disagree with most of what they say. But then again, I don't use their products, so what can I say.

[John Miller]

It's encouraging to see that Trio is addressing this issue more -- although apparently with some reluctance, in response to a more enlightened marketplace. They've been making blank doors and crescent SREH doors for some time to help in reconfiguring their houses. I've reworked several.

I think the statements about risk of large clutches is just odd. I find it hard to believe that modifying these houses triggers larger clutches of eggs of 7 or 8. This is something that needs more study -- maybe by PMCA. Is it a larger compartment area or is it seclusion and darkness that stimulates larger clutches? I suspect we don't know for sure, nor whether larger clutches are more or less likely to fledge higher overall numbers.

In my modified Trios, sparrows build in the back compartment (until torn out). I've not had experience in observing sparrows trying to overtake a martin nest that's in the back -- might happen in an unmanaged site.

A little off thread, but I do like that Trio's crescent doors retain a little lip across the bottom -- being more blunt and structurally less flimsy across the bottom than some aluminum crescents.




John Miller,
St. Louis, Mo

[RC Moser]

I have had Trio style house since the I started Purple Martining. IMO I don't like them. I will phase them out completely one of these days.

The reasons I don't like them are"

--They leak, any little rain storm soaks the nest chamber weather it's expanded or not.

--They are like little ovens or freezers when it's hot or cold.

--The thin al. door crack easily at the hinge point.

--Round holes invites trouble in any form or size compartments

IMO some of the good things:

--They are easy to modify

---expand the compartments, repair any cracks or add perches too. Even making doors or of stronger material relatively easy.

--The PM's like them

--Easy to shoot sparrows off if you turn you house with the side to you, this limits the colateral damage or possible punchure a nest compartment.

--Easy to lower and raise and they are a cheap set up cost wise and last for ever if taken care of, some of mine have 9 years on them.

[Guest]

Personally, if I bought the 24 compartment castle, I would only put it up with 12 enlarged compartments. I would never install it as is from the factory. That house needs to be modified, period. I do like it though, it is a classic, no doubt.

[Donnie Hurdt MN]

I have always liked the looks of them too, but I cant justify the expence of buying one untill I get a coloney of martins started.

[Guest]

I just wanted to remind everyone that they sell the Trio Castle in the PMCA Shop.

This photo is "Img" tagged from the PMCA Shop and should not give anyone any trouble with popups.

The house is $369.95 (PMCA member price) for the entire assembly. The savings you receive from buying this house as a PMCA member will practically pay for the membership.

I like this house. I might get it and make the modifications because it is such an icon in Purple Martin houses.

[Guest]

I have a 24 Castle that my grandfather purchased in 1965. It has been mine for 7 years. I have painted it all white and installed crescent openings on all 24 doors. Despite what they say, my colony seems to love them. I just can't bring myself to cut on the house that has raised literally thousands of fledglings, especially since it houses well over 12 pair a year. I have gourds and Martin Suites as well, and the occupancy and fledge rates are about the same as my old castle.

[Emil Pampell-Tx]

J., the martins are so loyal to a site that they do not care what you put up, they will use it, so undoubtedly you are very successful

I had a lot of gourds with round holes, and the martins loved them. I did change that for the benefit of the martins. I put up sreh entrances, tunnels to protect them from the owls, and am presently making gourds with the side entrances for more protection from owls. I know what you are saying and I respect that very much, as it is your decision. I do wish that you would also consder the fact that if you can make it more appealing for the martins, make them safer with deep compartments, and use whatever it takes to make their housing more safe. I was stubborn for a long time, did not make any changes, but now I am so happy that I gave in to make it safer for my martins. I think deep compartments are safer for martins.

good luck next year

[Guest]

J Gragg, I understand what you mean by wanting to keep your Trio Castle all original. I am thinking real hard about gettting the Trio Castle. However, I am really liking the Alamo house also.

[Guest]

Indeed Emil-don't we all do that stuff in the off season-and I agree. On tap for this winter is Owl guards on the castle (I have not had an attack by owls or hawks on the house itself, but have had attacks in the area, so just a matter of time). I'm also going to add Sandy's tunnels to my super gourds with modified excluders. I think the Coate's Water's Edge suites are safe enough, except for the door latches which I will fortify somehow.

I think the castle with crescents with the addition of owl guards this year will provide as safe a home as can be. But as my colony keeps getting more crowded I'm attracting more attention predator wise, and I'll have to keep an open mind on housing to try to stay a step ahead of them. It's no fun basing modifications on actual losses to the colony.

[John Miller]

J Gregg

Sounds like you are digging in your heels on not modifying the castle to deeper compartments, as you said, because you don't want to cut on a venerable old house that your grandfather purchased.

But you really should, especially since you already have the crescent openings on. Now, I don't like the look of the old doors with plugs in them, but Trio now sells blank doors that would do your house proud. Tip: you can easily open these with a paint can pry.

I've modified several old Trio pioneers that also are from the 1960s. One thing that I was struck by this past summer during nest checks was to find brooding females still on the nests in the back compartments after the house was lowered. They just like being back there out of sight, and with good reason. Even with owl guards, the owls can still look right into an unmodified house and see them, and will attempt to reach through and pull the doors off.

Anyway, just some thoughts from a Trio guy.

John Miller,
St. Louis

[Guest]

Everyone is off base here. Trio has already made all the money they need. Why else would they not double the size of the compartments so they could sale more houses. Many years ago I asked these same questions and their response was they liked their current system. I have been surprised that they are offering entrances other than round.