Three High Quality Plastic Gourds

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Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Three High Quality Plastic Gourds

Though natural gourds have their special appeal to purple martins and their human landlords, there are high quality plastic gourds that come close to the outstanding attributes of the naturals. I have used a variety of commercial plastic gourds in my martin colonies and there are three designs which have proven to be highly attractive to martins. I would not hesitate to recommend any of these gourds as I have used them for years with excellent results.

I like and use three plastic gourds: Super Gourd, Troyer Horizontal, and Excluder. All these designs have important characteristics which increase their attractiveness to martins and provide a safe home for them. The PMCA sells the gourds mentioned above.

There are a number of factors to consider when evaluating the quality of a commercial plastic gourd and folks often have their own opinions. I look at such key attributes as the opaqueness of the plastic, gourd size/shape, entrance hole types, ease of cleaning/checking nests and ability to modify the gourd as necessary. Though I consider cost of the gourd, this is not as important to me as the quality of the product. I would prefer paying a little more for a high quality commercial gourd rather than purchase a cheaper one that may have problems in the future.

Opaqueness

One of the most important factors to consider in buying a plastic gourd is the quality of the plastic. The same quality principle can apply to natural gourds and most landlords prefer thick shelled ones. You want your plastic gourd to be durable and provide a reasonably safe home for the martins.

I only use an opaque (non-translucent) plastic gourd so that light will not penetrate the plastic and possibly heat up the interior to dangerous levels. This is called the “greenhouse effect”. Also, translucent gourds allow light to shine through the plastic and increase the brightness inside the nesting chamber which can make the martins more easily visible to predators through the entrance hole. This can reduce the seclusion factor that may be attractive to female martins which select the cavity. The three gourds mentioned above are largely opaque. Some of the cheaper gourds on the market are constructed of low grade plastic and have translucent walls. I have held these gourds up to the sun and could see my hand silhouette against the gourd. I would not use any such gourd in my martin colony; unfortunately, you often see these cheap types being sold on the Internet, in discount stores, garden centers, and home improvement businesses which increase the chances of “impulse buying” by the public because of the low price. Also higher quality plastic will resist UV rays from the sun better and last longer; sunlight can destroy plastic without UV inhibitors.

Gourd Size/Shape

Purple martins are not large birds and do not need gigantic nesting cavities to successfully raise a family. Martins need safe cavities where access to the nest from the entrance is made difficult for predators by vertical/horizontal depth or internal/external barriers. A secluded nesting area minimizes chances that predators will be able to see the martins inside and reach the contents. Additionally, deeper cavities may reduce rainwater intrusion into the nest bowl and be attractive to female martins that actually select the male and his territory. Female martins are looking for the safest nest cavities for their young and deeper nest sites are safer.

There are two main commercial gourd types: vertical and horizontal. The vertical design is the traditional type where the entrance hole is cut on the front of a generally round shaped gourd. The entrance is usually cut several inches from the bottom depending on the curvature of the gourd. The vertical gourd emphasizes a wide and round shape where the entrance hole immediately opens into the nesting chamber area. The Super Gourd and Excluder are examples of verticals.

The horizontal design emphasizes horizontal length where the entrance hole is placed far from the nesting bowl area to create a long internal nesting environment. Horizontal gourds may have a tunnel like entrance area which restricts visibility and access by predators to the nesting chamber. The Troyer Horizontal is the best example of this gourd design.

If you like round shaped gourds, then a ten inch diameter design works well for martins and the Super Gourd and Excluder meet that size. This size provides plenty of room inside for a family of martins and there is no need to use much larger gourds though about an inch below or above the ten inch range also works fine. Martins never had huge cavity dimensions for thousands of years when martins nested in vertically deep and narrow woodpecker cavities. On the Super Gourd and Excluder, you could attach a tunnel to create horizontal length around the entrance hole and provide more protection from owls. The tunnel addition works well with smaller diameter gourds and creates significant horizontal depth from the entrance hole to the nesting chamber and I have used such a design with some of my naturals. I have used Super Gourds for many years and the Excluder in 2009 and both have been well occupied by martins and raise many youngsters each season.

The Troyer gourd is a horizontal design with a tunnel like entrance area that opens up into an enlarged nesting chamber. This design emphasizes long and narrow rather than wide and round. Think of the Troyer gourd as a vertically deep woodpecker cavity turned on its side to create horizontal depth. Martins do exceedingly well in the Troyer Horizontal gourd and the martins are offered more protection from avian predators like owls. The martins are deep inside and the narrow entrance area reduces visibility and access to the nesting chamber. The actual nest site is reached through a tunneled foyer. You can even buy an add-on tunnel with a porch to increase the horizontal length by about two inches. The Troyer Horizontal is about 13 inches in length and with an add-on tunnel the depth increases to around 15 inches with a narrow entrance area. I have many Troyer Horizontals and the martins thrive in them.

Entrance Holes

There are two basic entrance hole types that folks can use in their martin colonies: round holes and sreh holes. Both are appropriate choices depending on the landlord’s preference and the starling competition dynamics at the colony site. What works for one site may not work for another and every situation is different. Some folks have major starling problems and other landlords have few or none. At my personal martin colony I have minimal starling problems which are easily controlled via shooting/trapping and I use round holes that are preferred by the martins. We use only srehs in our various satellite martin colonies because of greater starling problems in urban/suburban areas where these sites are located and we are not continuously around to shoot/trap starlings.

You can purchase these gourds with round holes or srehs depending on your preference and/or starling competition issues in your area. I prefer commercial gourds that give the landlords a choice in entrance holes rather than the manufacturer “deciding” what is best and then the landlord has to modify the gourd to meet his/her preference. The only person who can decide what is best for his/her colony is the landlord, not the manufacturer who knows nothing about what is happening in colonies in every location in North America.

Nest Access

All quality commercial plastic gourds have easy access to the nesting chamber usually via a twist off access door cap. The three gourds mentioned above have this feature.

Ability To Modify As Necessary

Even though the Super Gourd, Troyer Horizontal and Excluder are well designed high quality commercial plastic gourds, you still may want to make personal modifications to them.

Ventilation is an important concept of purple martin housing and this includes commercial plastic gourds. The Troyer Horizontal has two “bump indentions” in the upper back where air vent holes can be drilled. I have drilled either ¼ or 3/8 inch vent holes in all my Troyer gourds at the indention points. This procedure has worked fine in providing ventilation in my Troyer gourds.

The Super Gourd and Excluder do not have vent holes and I have successfully used these gourds in the Deep South with our hot humid temperatures without adding ventilation holes. However, ventilation is definitely a good thing and may minimize heat build up inside plastic gourds. One positive manufacturer modification to these two gourd designs could be “factory installed” ventilation ports/indentions on the gourd backs/necks. If indentions were added, then the consumer could drill appropriate vent holes in a similar fashion like can be done with the Troyer gourd.

If you ventilate these gourds, you can drill holes and insert PVC elbows in the upper back/neck to help vent rising hot air out the gourds. Also, vent holes can be cut in the upper back/neck and these holes can be covered with aluminum canopies to prevent rainwater intrusion.

Another modification concerns porches. Porches usually help martins to enter restrictive srehs. A porch allows a martin to approach the entrance in a horizontal physical profile which facilitates entry into a sreh. Porches also aid parent martins in feeding their large young when they cluster around the entrance hole. The parents do not drop as many dragonflies at the entrance when a porch is provided because the parents can sit on the porch and easily transfer food to their babies. Additionally porches allow the martin fledglings to more easily return back to their nests to roost. Fledglings are not initially skilled in landing on cavity entrances so the porches make it easier for these youngsters to enter their nests to roost. The fledglings can first land on the porches and then more easily slip through the entrances to their nests.

The Excluder comes with outside and inside porches and this works well with both round holes and srehs. For the Super Gourd with crescent entrances, there are add-on metal porches which fasten to the bottom of the crescents. You could also use a tunnel insert with a porch. The Troyer Horizontal can be fitted with a tunnel/porch combination.

There are many opinions on the various commercial plastic gourds and everyone probably has their favorites. I think anyone would do fine with Super Gourds, Troyer Horizontals and/or Excluder Gourds and all these gourds are available from the PMCA. The PMCA is the most important organization for the study and preservation of the purple martin and the PMCA is concerned about the quality of purple martin products it offers for sale to the public. These three gourd designs have been available from the PMCA for many years and that tells me these commercial gourds are quality martin products.

Steve Kroenke
e p jones
Posts: 91
Joined: Thu Nov 13, 2003 7:41 pm
Location: Cincinnati

First, I'd be interested in your evaluation of the new Natureline II plastic gourds--molded of UV-inhibited Polypropylene.

Also sold by PMCA.

There are a number of entrances options, a new porch option, and a Viewing Port w/ snug-fitting cover.

The "cap" that slides up and down the stem allows for either ventilation or heat retention as well as reducing water intrusion.

Second, to help with keeping nests dry, we plan to install "nest trays" in the plastic gourds at Grand Valley Preserve (see recent PMCA Update Magazine).

After consultation with Louise, we have settled on galvanized 1/4" screen (sometimes called hail screen or rabbit screen).

Our idea is to bend down (90-degrees) each of the 4 edges to give about 1/4" elevation off the floor.

We will secure the trays to the gourd bottom with plastic ties thru the drain holes to prevent fighting PMs from tipping up the tray and potentially blocking the entrance.

Your perspective appreciated.
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Your description of the new Natureline II gourd is most interesting and exciting! I have never used Natureline gourds so have no direct observations of these gourds and nesting martins. I may order one and check out the features. Since this gourd is sold by the PMCA, I am sure it is a quality product and designed for the benefit of both martins and their landlords. Thanks for sharing the information about the Natureline II gourd.

The use of "nest trays" in martin cavities is important relative to keeping nests dry from rainwater intrusion. In plastic gourds, using a sufficient number of drainage holes does help drain rainwater out. I have used a layer of broken twigs occasionally at the gourd bottom to provide some elevation/barrier between the nesting material and the bottom and faciliate rainwater drainage. The twigs may provide an "open" barrier between the regular nesting material and the gourd bottom and this can help to drain water out. However, rainwater can still blow in through the entrance hole and soak nests. The use of "wire mesh" or a similar product sounds like a good option to keep martin nests elevated off the gourd bottom and drier.

One way to keep a lot of rainwater out of the nesting chamber of gourds is the use of a long tunnel which traps rainwater there. Drilling some drainage holes in the tunnel can help to expel rainwater. I have also used downward pointing PVC tunnels on my natural gourds and these gourds were often dry inside even after heavy blowing rain storms.

Steve
John Miller
Posts: 4771
Joined: Mon Mar 22, 2004 9:11 pm
Location: St. Louis, MO

Hi Steve

Thanks for posting this. It gives me an opportunity to comment regarding Excluder gourds. Of course I don't need much of an excuse to comment about martins (grin), but here goes.

I really like using Excluder gourds at public locations on a rack. they are the heaviest gourd out there, so I think would survive being hit by the occasional rock from a kid, and they don't much move in the wind.

I used to put PVC elbow vents in all my gourds, but last season just began dilling two upward slanting holes in the upper neck of the excluder gourds. I put two holes, about 1/8 inch, on a line on opposite sides from the hanging holes. This is not a big big air vent, but probably adequate and easy. It works well in the excluder gourds because they are thick plastic.

Porch placement has been discussed a lot. Suggest placing the porches no more than one-fourth inch below the SREH openings..maybe 1/8 inch...for best ease of martins entering and restriction of starlings. The excluder gourds have indentations to set the porch lower, but suggest higher.

I like to reduce wing entrapment risk in all my housing. I cut an inch wide section from a 3 inch drain pipe, and then use tin snips to cut out an arch that I glue on the Excluder porches on the inside, making a bit of a tunnel. Also, I sand off any rough edges and I make sure it's not obstructing the entry at the top or sides. My glue, liquid nails, is not pretty, but I think this small tunnel maximizes safety and martins don't care if it's not neat. A photo is attached. S&K has begun adding something similar inside their snap-on tunnels, and sent me a sample recently.

One concern with Excluder and Super Gourds is lack of traction inside. I squirt in a blob of liquid nails and smear it around with a piece of terri cloth. Or you can literally comb through it. When dry it leaves enough residue to provide good traction to help hold nests in place, or provide foot traction to prevent leg splay in nestlings should the nest wear through.

Just sharing,
thanks Steve,
John Miller
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Hey John,

Thanks for sharing your observations concerning the Excluder Gourd. The Excluder is my favorite vertical plastic gourd.

I have thought about using downward pointing ventilation holes in the necks of both Super Gourds and Excluders since these gourds are constructed from thick plastic. Since you have had success with this approach, I may try it in 2010.

I have written in the past about the slick plastic of various commercial gourds and problems with the “shifting nesting syndrome”. Here is a link to a relevant posting:

http://purplemartin.org/forum/viewtopic.php?t=4400

In 2009, I tried a “new” pre-nest in my Excluder and Super Gourds in hopes of minimizing the problem of spreading nesting material. This is what I did. I created a “clay soup” in a bucket of water. Then I took a handful of full length pine needles and soaked them in the water. The clay is sticky and clings to the pine needles. Then I created a thick foundation of clay laden pine needles in the bottoms of my Excluder and Super Gourds. The pine needles would bind together to create a mat that would adhere better to the plastic than plain nesting material which more easily separates. I kept the drainage holes clear of clay. After positioning the pine needle clay foundation on the gourd bottom, I would then put a substantial layer of dry pine needles on top, fashion a nest bowl and add dry oak leaves to the nest cup. The thick clay pine needle foundation seems to do a pretty good job of holding nesting material together on the slick plastic once the clay dried. The key is to create a solid foundation of clay bound pine needles which may adhere better to the plastic. I checked many of my Excluder and Super Gourds during the nesting season and most of my pre-nests with the clay soup pine needle foundation held up well and did not separate significantly and the clay did not clog the drainage holes. I plan to use the same process for 2010.

Steve

Hey Ronnie,

Unfortunately it seems that many martin housing products, including quality ones, may require some additional modifications. I don’t mind building good pre-nests in my Super Gourds and Excluders using the process I described in my response to John M. If you build a thick pre-nest, this may minimize traction problems with nesting material in slick plastic gourds.

While tunnels probably provide more protection to martins should an owl try to cling to a gourd, the tunnels do nothing to stop an owl from grabbing martins off gourd porches or crossbars. All of our owl attacks are on visible martins sitting in the entrance openings, on house porches, on gourd crossbars or on gourd porches with or without tunnels. If folks use exterior barriers on their gourd racks to keep owls from reaching gourd entrances/porches, then many owl attacks can be thwarted.

I use both tunneled and non-tunneled gourds and see no difference in martin occupancy levels, eggs laid or young raised. I like both styles of gourds and have not arbitrarily added tunnels to all my gourds and have no plans to do so in the future.

Steve
e p jones
Posts: 91
Joined: Thu Nov 13, 2003 7:41 pm
Location: Cincinnati

On both Naturelines and Natureline IIs, we use exterior porches and individual (for each gourd) hawk/owl guards (See recent PMCA Update magazine for guard design).

We are looking for the "hail screen" (aka rabbit screen) from most hardware stores to significantly help with reducing all wet nests issues.

Also, we believe the "traction issue" will be eliminated when these trays are installed atop the relatively slick gourd floors; then secured.

Big advantage, as always, with galvanized or aluminum trays anywhere is they can easily be removed season's end and cavity cleaned.

Expect these "homemade" jobs will cost only 5-10 cents!

The installation of secured screening in plastic gourds will be our first.

Porched Natureline gourds had 100% occupancy last season, compared to 15-20% for a Trio castle and a cedar house--all had SREH.

If these work as expected, we will strongly consider 100% housing implementation in the growing colony, as much better drying air flow is assured.
Emil Pampell-Tx
Posts: 6743
Joined: Tue Nov 11, 2003 1:26 pm
Location: Tx, Richmond (SW of Houston)
Martin Colony History: First started in Gretna, La in 1969 with a small homemade house, have had martins ever since at 2 different homes in Texas

I have purchased a few of most of the plastic gourds, and after I modified them with tunnels & porches, it makes no difference to the martins as to whom made them or whom sold them.

My primary objectives are owl protection (thats why I use and prefer long tunnels), and am experimenting with 2in x 4in wire owl guards on the tunnels. My second objective is price, if the cheap gourds last as long as the other gourds, then I will choose the cheapest gourds. Size doesn't matter to me, as the martins at our place prefer the 9in to 10in gourds. Something that does matter to me is the weight of the gourd, I like to put a lot of gourds on the rack, so I prefer the lightest gourds (that weigh about a pound is ideal for me.) The heavy gourds require stronger poles and stronger gourd racks, thus they increase the cost of the gourd rack.

I agree with Ronnie, that if you are paying Cadillac prices, then you might as well purhcase a gourd that does not require any modifications.

I also agree that the gourds that Steve mentioned are good quality gourds. I also agree that good air circulation is very important down South, but probably not desirable in the North country.
Brad-AL
Posts: 566
Joined: Tue Nov 11, 2003 2:00 pm
Location: North AL

e p,

The new Natureline II gourd is awesome. I live in the town where those gourds are made and have spend a good amount of time sitting in the offices talking with the folks that design and make the gourds. When I first saw the plans for the NL II several years ago, I really didn't like the concept, but when I got my hands on one my opinion changed. You remove the front the same as on the old gourd, and can see down into the gourd through the inspection port. You won't have to fumble around feeling for any eggs that get buried in the leaves, you won't need a mirror on a handle as some folks use, you can actually see what you are doing. If you don't use tunnels on your gourds, the Natureline II needs no modification straight from the box. No light penetrates through the plastic on them either. They also now make a textured porch that fits their gourd fronts. The only modification that is required to attach the porch is to drill out the two dimples below the new doors, insert the tunnel pegs, and attach the o-rings that hold the pegs in place. The porch is rigid, and fits very securely to the gourd. NL gourds are also considerably lighter than SG's or Excluder gourds. That is a pretty important characteristic when you have a rack full of gourds.
Guest

I'll agree with Emil stick to basics,keep'em dry,provide some security and a food source,they will do the rest.

They don't care if its a Ferrari or a 1920 Model A

dick
Peggy Riley
Posts: 885
Joined: Tue Nov 11, 2003 1:21 pm
Location: TX/Tolar

I do like the Troyer, the SG and the Naturelines. But I also like the BO11"s. I like the fact that I can turn the gourds around in any direction I need to do nest checks. I like to place the outer gourds facing out and this is made easy with these gourds. I don't have to drill more holes. I also like the insulation factor. My Troyer, SGs and Naturelines are all over 10 years old and are still in fine shape. The Naturelines need a paint job but other than that I think I'll get another 10 years out of them.

Peggy
e p jones
Posts: 91
Joined: Thu Nov 13, 2003 7:41 pm
Location: Cincinnati

The best paint we have found, so far, for the gourds--either external (refinishing) or internal (for cavity darkening) is Krylon Fusion; at most hardware stores.

On Naturelines and Natureline IIs, the stem is drilled to allow orientation in 4 different directions (90-degrees apart) depending upon your mountings.
If that is not sufficient, additional holes can simply be drilled in the stem.

The cap provides a rain cover for the vent holes and slides up and down to either hold in the heat, or allow convection cooling of the cavity.

So far, both PMs and TRES (round entrance reduced to 1 1/2") lay their eggs as far from the entrance as possible; believe the gourd diameter is 11".
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

I appreciate folks sharing their experiences with various plastic gourds.

Many of my Super Gourds are well over 10 years old and doing fine. I have left them out all year long in both north Florida and now in northwest Louisiana and the plastic is still in excellent shape in spite of heavy sun exposure. There are no cracks or crumbling of the plastic.

I have noticed that some "green mold/mildew" will appear on my plastic gourds and also my naturals. I sometimes clean it off, but in some ways it gives an artificial gourd a more natural look! I usually just leave it alone.

E P, I have used the Krylon Fusion paint made specifically for plastic for many years with good results. I have in the past darkened the interiors on some of Super Gourds with this paint and the paint holds up well though you may have to do some upkeep from time to time.

While some folks have referenced the weight issue with Super Gourds and Excluders as a possible problem, I like the fact that these gourds are constructed from thick plastic and a "little heavy". This increases the durability of the gourds, eliminates translucence, and helps to minimize swinging on the crossbars if you haven't rigidly attached the gourds. However, I can see how the weight could be an issue depending on the type of rack/pole used. I have successfully suspended a combination of 16 Super Gourds/Excluders and Troyer Horizontals on a 2 inch square high tensile aluminum pole and as many as 36 on a 3 inch square pole.

I recently replaced all my remaining natural gourds with Super Gourds and Troyer Horizontals. I still like the naturals a lot, but these plastic gourds are easier to maintain and the martins do exceedingly well in them.

Steve
Guest

steve, i am curious why you do not have any s&k bo 11s' . they seem to be the best on the market in my humble opinion. aaron
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Hey Aaron,

I don't use any S&K purple martin gourds at this time. The few brands I looked at were translucent. I could see the shadow of my hand through the thin plastic when the gourd was held up to the sun. These were older brands so perhaps the newer ones are now opaque and if so that is a good improvement. Plus I try to support the PMCA as much as possible through my membership, donations, and buying martin products offered through them. All the gourds I use are sold through the PMCA.

I am sure everyone has their favorite commercial plastic gourd or house.

Steve
PMCA Member
300+ pairs of martins each season
msalcido
Posts: 254
Joined: Thu Jul 14, 2011 3:25 pm
Location: Texas/Mineola

Thanks for posting this Steve. I'm in the market for new martin housing and I've been leaning towards gourds, but there are so many types on the market that I have been confused. The whole horizontal/vertical didn't make sense to me until you broke it down and described it.

Very helpful information for a new landlord!

Thanks! :wink:
Mike

Fifth season of being a landlord! :) and a PMCA member!
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Hey Mike,

I am glad you found this posting of interest. The Super Gourd, Troyer Gourd, and Excluder Gourd are excellent plastic gourds and I have used them with success for many years.

When I wrote this original article, the new Troyer Vertical Gourd was not on the market. It is now available and it is a high quality plastic gourd, too. I have a bunch of them. You can get the Troyer Vertical Gourd from the PMCA.

Here is a link to an article I wrote about the Troyer Vertical Gourd; you might find it of interest:

http://purplemartin.org/forum/viewtopic.php?t=15120

Steve
PMCA Member
300+ pairs of martins each season
Sandy - NC
Posts: 617
Joined: Tue Nov 11, 2003 6:40 pm
Location: Rocky Mount, NC

Steve, your assessment is right on. One thing you didn't mention is that the gourds you discussed are made in the USA, thus creating American jobs. Gourds that were discussed by others are not, thus creating Chinese jobs. And, people want to know there are no American jobs. Well, when you prefer to support Chinese made products, then you can't complain about No Jobs here. And, if the manufacturers support employeeing Chinese workers, well, they won't get my business so that they have a larger profit margin.
Don't ever, ever give up. It will happen.

sbunn1@suddenlink.net
Emil Pampell-Tx
Posts: 6743
Joined: Tue Nov 11, 2003 1:26 pm
Location: Tx, Richmond (SW of Houston)
Martin Colony History: First started in Gretna, La in 1969 with a small homemade house, have had martins ever since at 2 different homes in Texas

The S&K gourds are made in the USA, not in China...Many years ago there was one batch made in China, but it was quickly discovered that they were not meeting expectations, and its my understanding now that none of their products are made in China, nor have they been made there for several years.

I agree with you however, that I don't like to buy things made in China, the quality just doesn't seem to be there when made in China.
PMCA Member, 250 gourds, 6 poles, 2traps
Guest

Do any of you have any picks of were exactly it is best to attach ventilation pipe on Troyer excluder SuperGourds. I have 6 horizontal and 6 vertical, with crescent entrances as there are many starlings in my neighborhood. I am not very handy and I just don't want to place it in the wrong spot. Thank you!
Steve Kroenke
Posts: 4342
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

Hey Leila,

I vented many of my Troyer Horizontals with two 3/4 inch PVC 90 degree elbows in the upper back where the "bumps" or "canopies" are located. This has worked well.

Here is a link to an article describing what I did:

http://purplemartin.org/forum/viewtopic.php?t=17788

I vented many of my vertical Super Gourds and Excluders with one 3/4 inch PVC 90 degree elbow in the upper neck. This has worked well, too.

Here is a link to an article describing what I did:

http://purplemartin.org/forum/viewtopic.php?t=17694

Steve
PMCA Member
300+ pairs of martins each season
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