On Mon, 7 Mar 2005 11:27:24 -0500, cjensen@dts9000.com <cjensen@dts9000.com>wrote:
> Below is the result of your feedback form. It was submitted on Monday, March 07, 2005
> ---------------------------------------------------------------------------
> First Name: Charles
> Enter your city : Knoxville, TN
> Enter your request : Due to full occupancy, I'm expanding my single
> pole w/16 gourds to an additional three poles with
> 48 new gourds. I was intending to go with either
> the Super Gourds or the Plasticraft units.
> However, in reading about the Troyer gourds, I was
> interested if there is a consensus opinion whether
> these gourds are better, or just different? And,
> if they have additional benefits, whether the
> round opening with the metal insert is preferable
> to the half-moon opening.
>
> Thanks
> ---------------------------------------------------------------------------

Our Reply...

We have used natural gourds, Super Gourds and the Troyer Gourds.

We had 142 fledglings in 2003, and currently have about 25 Adults spending the night every night so far this year. It looks like it is going to be a great year. The sub-adults have not arrived yet. From what I understand the Plasticraft gourds are not as durable as the Super Gourds or Troyer Gourds, although we have not used them on our site.

As to your gourd types question. This is what we have found:

Number one Purple Martin Preference:

Natural Gourds

When they are at least 32 inches in diameter or more, and are treated with copper sulfate to prevent rot and you add the entrance hole and the additional access hole with screw cap for cleaning and doing the nest checks.
After doing all of the above we have two natural gourds left. These are each 4 seasons old. We take all the gourds down, clean and store them for the next season in September.

Number two Martin preference at our site:

Troyer Gourds

With the half-moon entrance and aluminum porch. The Troyer Gourds allow for a longer distance between the entrance and the actual nest. The narrow neck and the longer distance to the nest helps fend off flying predators like Owls and Hawks. A bird unfamiliar with the entrance take a day or so to learn how to enter and exit, but once they do its just as fast as the gourds with the round entrance. We don't have a European Starling problem here, but it is said that the half-moon helps keep the starlings out as well.

Number three:

The Super Gourds are consistently used at about an 85% occupancy rate. They are easy to maintain and clean and the access opening is just as large as the Troyer Gourd for nest checks.

Make sure you attach a good predator guard to the pole. I use two homemade guards crafted from plans from the internet, and one predator guard purchased from the Purple Martin Association. It is just a couple of dollars more than making it yourself.

Two years ago we lost two fledglings from a Super Gourd to a Rat Snake before we saw it, captured it and relocated it away from our site. It was able to get through the predator guard because I did not check to make sure the plate around the pole was as tight to the pole as necessary. Now I check each predator guard every time I do a nest check to make sure each is as tight and snug any place a snake could wriggle through.

Number four:

Eight sided Metal Martin House bought from a Home Center. Our first season: The birds would investigate the house, but never stayed the night. 100% vacancy for two seasons, while our Natural Gourds filled up the second season.

For a wealth of good information visit The Purple Martin Association

"The Purple Martin Conservation Association is the only organization devoted exclusively to the scientific study of Purple Martins (Progne subis), their biology, and habitat requirements."

Thanks for your great question and for visiting the Central Florida Bird Watchers web site.