Choosing the Right Housing for your Purple Martins

As I sat outside yesterday morning, reading the bands on my returning purple martins, my husband came out to tell me my sister had called.  “She has a whole bunch of new martins at her site and you really need to call her!” he said.  I had to laugh out loud.  I wasn’t laughing at her or his excitement; it was more of an outburst of relief that she is finally experiencing the joy of having martins not only visiting, but nesting in her housing this year. 

It has been 3 long seasons since I first gave my sister 6 Troyer vertical gourds for her birthday in 2012.  She lives in Louisiana which has quite a thick population of purple martins during the breeding season, so I thought for sure she would have at least a pair or two her first season. 

She went into her yard and dutifully measured off 40’ from each of the tree lines and her husband even removed a large, older pine tree at her behest.  So, I was quite disappointed to hear that she only had a couple of lookie loos her first year.   

Adult Purple Martin visitors checking out the Troyer Vertical gourds but never staying.

At the end of her first season, despite her being in LA, I realized that it wasn’t going to be that easy.  After confirming that all of her neighbors have the cheaper, plastic green and tan housing, I found a used one that she could use temporarily to attract her first pair.  The only problems were that it had the round holes already cut out and the plastic was starting to crumble from being baked in the sun.

As sure as the sun rises in the east though, starlings flocked to the round holes and kept her from getting purple martins her second year, even with active elimination, so the sub-adults moved on.  They were not going to take any chances with these native bird killers in their apartment building.

Prior to the start of her third season, I encouraged her to go buy a newer house with the crescent entrances intact and give it a try.  I instructed her on how to enlarge the compartments to make them safer.  She knew that meant less nest cavities in her house, but she also knew her martins would be safer from an owl’s reach, as well as experience more reproductive success.

This year, her third season, she had the house and the gourd racks up, but still no takers yet.  I couldn't believe it - with all my successes here in Missouri, I was failing my own sister who lived in a martin-rich area.  Only one thing left to do; after deciding she had nothing to lose, we made a decision to move both the house and the gourd rack to a different location in her yard (and when I say *we* made the decision, I mean her sweet husband had to go move the housing).  The gamble paid off.  She now has two SY male and female pairs completing nests; one pair in the house and one pair in the gourd rack.  

After modifying the cavities to be 6" x 12" and moving the house to a different location in her yard, the pair on the house is nesting.  Due to porch domination, the pair on the perches are nesting in a gourd on the closely-situated gourd rack.

Now this morning, she has even more sub-adult arrivals that may take up residence in her housing and she is walking on air.  This was a true reminder and lesson learned – purple martins, despite the fact that the gourds would be a safer and more productive option for them, prefer the style of housing with which they are most familiar. 

Housing for the Short Term

All new landlords should be aware that just because you put up purple martin housing, doesn’t mean that you will automatically get martins.  It makes sense then that starting out with the cheaper plastic houses is certainly a good way to see if martins will even be attracted to your site.  But being aware of the pros and cons of cheaper housing and what you can do to alleviate some of the cons will help you make good decisions and protect your martins.

The basic requirements you should start with, whether buying or building are pretty basic: the housing should allow for easy raising and lowering and nest compartment access for cleanout and checking on the eggs or young. 

There is lots of good information included in this article on the PMCA website:

http://www.purplemartin.org/main/housestandard.html

Pros:

-The initial monetary investment is very low.

-Cheap, easy way to find out if purple martins will even be attracted to your site.

-Easy to move around the yard with a smaller ground stake and sleeve to try out different locations.

Cons:

-Compartment sizes in these houses are only 6” x 6”.  Adult purple martins are 8” long and compartments must be large enough to accommodate 2 adults along with 4-6 nearly-grown nestlings.  Modifications to provide larger cavities and ensure your martins will be safe in that housing are required to enlarge the cavities to 6” x 12”.  This effectively reduces a 12-14 room house to a 6-room house. 

-Porch domination is an issue with these houses, so the landlord may need to install porch dividers.

-The telescoping poles are not very durable and will not stand up to strong winds.  Landlords should be prepared to reinforce the telescoping poles made for these houses.

-As we found out with the used house, they are not very durable and will not last through very many seasons.
-In warmer areas, the housing may need to have shade added as they can get quite hot inside.

Housing for the Long Term

Houses versus Gourds:

Once you have attracted martins to your site, it becomes a personal decision about what type of quality housing with which you choose to move forward.  After my first year with the cheap, plastic barn, I tossed it (frustrations with the pole, the house, etc.) and put in a Trendsetter house.  I had never seen any others like it in this area, but it attracted 10 pair during its first year.  Then I added gourds and the martins still kept coming, seemingly no longer caring about the style of housing offered.

Trendsetter-12, with Conley II entrances.

Buying housing:

There are many different types of commercial martin housing available for purchase.  They can be made out of plastic, wood or metal.  If you do plan on buying, I suggest taking a look at the Purple Martin Conservation Association (PMCA)’s website at http://purplemartin.org/shop/, or if you do not have access to the internet, call 1-814-833-7656 to request a catalog (this newsletter is also mailed out to local landlords via USPS).

If you decide to buy, purchase the best housing or gourds and the strongest pole you can afford and remember that cheaper is not always better and it will last a lot longer.  When reviewing your purchasing options, recall that the adult martin size is around 8” long and will have 4 to 6 young.  Martins will nest in smaller (6”x6”) cavities, but prefer larger 6”x10” or 6”x12” compartments, or a gourd diameter of 8” to 10”.  Deeper nesting cavities will also help keep your martins safe from predators that will try to reach into the nesting cavity to catch their prey.

My sister's second pair has taken up residence in the nearby gourd rack now.  They think my sister's husband is pretty cool.

The pole upon which you place your housing is just as important as the foundation of your own home.  If the pole for your martin house fails, all your efforts will be wasted and may result in the death of many martins and their eggs.  When selecting a pole, ensure that it can withstand dangerous winds and that you will be able to vertically slide your house up and down the pole.  Never use a tilt pole or you will not be able to lower the house to remove a snake or English house sparrow’s nest once eggs are laid without causing catastrophic damage.

Building your own housing:

There are lots of different floor plans available for building martin houses, or you can create your own.  Keeping the above space requirements in mind, ensure that you use materials that will not absorb moisture, paint the outside of the house white and build your house with the idea that protecting the martins is the highest priority.  Use cedar as it is a better, longer lasting wood from which to build birdhouses.  Do not use any chemicals inside the nesting chamber. 

T-14 plans available from the PMCA Shop here.

One particular style house called the “T-14” (the 14 represents the number of nest cavities) has been very popular lately and has been the winter project of many landlords. Plans are available from the PMCA.  Another house style that I like is the “Northstar” house.  Plans are available from the inventor for $20.00.

Growing & preparing gourds:

If you don’t have natural gourds available right now that you can prepare for housing, then there are online sources where you can order gourds in 8” to 10” size.  You can also order more “ready to hang” gourds from http://purplemartin.org/shop/.

I am no expert in the area of growing and preparing gourds, but I can certainly point you to some websites with terrific information and step-by-step instructions as well as point you to some forums (PMCA) where the experienced, gourd-growing members can help with your questions. If you have the time and would like the challenge of growing and preparing gourds, send an email or call me and I can point you in the right direction!

For the “Do It Yourself” types, here is a great page for “From Natural Gourd to Bird House” - http://www.purplemartin.org/update/NaturalGourd.pdf.