Tunnels and heat build-up in gourds

[ldybala]

I've installed tunnels on all of my gourds and was wondering if this might cause them to overheat in the summer. It looks as if the cooler outside air will have to travel much further through a narrow opening. Specifically I've got S&K clinger tunnels on Big Bo gourds.

[Guest]

If you have not vented your gourds in some way, because of your location I recommend you do so before nestbuilding begins, Like NOW. A simple PVC elbow at the top of the neck is easy to do or you can find other ideas like removing the entire top of the cap and replace it with a PVC adapter and cap. I recommend adding 3/8" or larger drain/vent holes in the bottom of the gourd to total at least 6-8.

What this will do is give convection a chance to pull in outside air from the tunnel and the base and vent it out the top. This will solve the problem you see brewing for this and all other gourds.

[Linda Reynolds]

Here is some information posed just this week about this topic...........

http://www.purplemartin.org/forum/viewt ... c8424fe309

[Joe Zorn]

ldybala,

Those tunnels should not post a problem with heat, but as Linda and Dwight have indicated, ventilation is the single most important thing you can do at this point.

We had a terrible experience with heat last summer across the Martin areas of the U.S. and we all got a good dose of what heat can do to the babies.

If you get nothing else done before the martins, install vents, or drill vent holes up high in the nest chambers to allow the hottest air up high to get out and draft cooler air in through the door opening.

There's a hundred ways of ventilating, and each of us has our favorite. But do it, if it's not already done.

Otherwise, I don't think you have anything to worry about with the tunnels.

[Emil Pampell-Tx]

I have a slightly different opinion about last years heat. I think there was a terrible shortage of insects, and that the babies starved. Its probably a comination, when it gets real hot, the bugs activity slows down, the martins cannot get enough food to properly feed the babies, and the heat causes additional stress, and that caused the babies to jump. All the babies that Jumped were extremely poor at our place. They literally starved to death. I had some nests that had only 2 babies, the parents feed them well, and they survived the heat. JMO. I do however know that some places get hotter than it gets at our place, but at our place, the martins starved.

Having said that, i do think that good ventilation helps a lot, and I have vents in all of our gourds.

[Joe Zorn]

Ain't that the truth, Emil.

Compound that with downright fatigue of the martins parents because of the heat, who finally just give up trying to keep up.

[ldybala]

Has anyone placed a PVC elbow vent in the lid of a gourd? It seems as if that would be an easy solution.

[Guest]

That would give you some movement of air of course but for max air flow you should put the elbow as high on the gourd as you can,if you use the screw in type(an elbow with an external thread) the labor and equipment to install the elbow would be exactly the same.

dick

[Emil Pampell-Tx]

Placing the the pvc elbow in a lid may be a good place, except that I like to put it higher. The heat collects in the top of the neck, so the best place to put it is at the top of neck, that would tend to give the gourd a little bit of a chimney effect. I have found that the gourds are so tough, you can put the elbow anyplace, and you will not hurt the structural quality of the gourd, so I have moved them & plugged the old holes, and it doesn't hurt the gourd to cut holes in them.

Also, the sun deterioates the lid, and they crack. so putting the elbow in the lid may hasten that process in some cases.

[Scott D.- La]

Ldybala,
I conducted many temperature test over the summer in 09. From those reading, tunneled gourds were only about a degree warmer in most cases. Like the other's have advised, vent your gourds, and the closer to the top, the better.