Purple Martin Occupancy Levels By Gourd Type

[Steve Kroenke]

Purple Martin Occupancy Levels By Gourd Type

In my current purple martin colony I have 324 plastic gourds and 80 Trendsetter compartments for a total of 404 cavities. I am using 36 Excluder Gourds, 36 Super Gourds, 48 Troyer Vertical Gourds, 64 Troyer Horizontal Gourds with cling plates and 140 Troyer Horizontals with tunnels/porches.

I have completed a detailed review of all my gourds which includes close observations and nest checks to try to determine occupancy levels by type. Here are the stats and I believe these are reasonably reliable though I could be off by a few pairs:

Excluder Gourds: 36 occupied out of 36 for 100% occupancy level

Super Gourds: 32 occupied out of 36 for 89% occupancy level

Troyer Vertical Gourds: 42 occupied out of 48 for 88% occupancy level

Troyer Horizontal Gourds with cling plates: 64 occupied out of 64 for 100% occupancy level

Troyer Horizontal Gourds with tunnels/porches: 133 occupied out of 140 for 95% occupancy level

There are 324 gourds with 307 occupied by martins for a total occupancy level of 95%. Any gourds not occupied are being dominated by another pair of martins and though it is late in the season for us some of these dominated gourds could still be claimed by SYs if they fight the dominating pair hard enough.

I am most pleased with the occupancy level of my plastic gourds and this level is about comparable to my natural gourd level years ago when I used naturals.

I haven’t completed a thorough review of my five Trendsetter houses comprising 80 cavities. The occupancy level in the houses will probably be overall lower than the gourds as there are generally more nest domination issues with houses than gourds in most cases in my martin colony. However, I still believe my three 12 room Trendsetters and the 16 room house may have 75% occupancy levels or better. My large 28 room Trendsetter is more dominated than the smaller houses due to its design and vertical/close entrance hole placement. The smaller houses have staggered holes which help to minimize long term nest domination issues from aggressive martins.

In many cases landlords can achieve higher martin occupancy levels by using gourds with entrances facing different directions and using a variety of gourd styles to provide martins with more territorial privacy. Though martins are colonial nesters, they still defend their territories and these territories can sometimes encompass multiple gourds or house compartments when certain martins exhibit significant nest domination behavior. Gourds are usually spaced farther apart than house compartments and this spacing configuration can reduce nest domination issues.

Steve

[cajun]

I am surprised at how martins go to gourds so readily. I don't see many gourds in my area but I put them up and bam they took to them. I still have 1 a pair in the trio minis. I am thinking about getting the gourd rack that holds 16 for next year. Great report Steve, I hope everything is going well. Tim

[Steve Kroenke]

Hey Tim,

Up here in northwest Louisiana, most folks have houses for martins rather than gourds. However, martins LOVE gourds in this area and the martins filled my gourds when I first started by colony in 2005. I also had gourds in north Florida where I previously lived and the gourds were often almost 100% occupied each season while my houses were much lower.

I believe gourds offer the territorial privacy that martins like and this helps "keep martins out of each others' feathers"!

It is getting "down to the wire" in our area to attract breeding martins, but I am still seeing SY males and some females trying to find a nest site in our colonies. There are even some ASY males that seem to be looking for a nest. These ASY males may be from other unmanaged sites that have been taken over by competitors or attacked by predators.

I hope your martin colony continues to do well. Yes, I would encourage your to erect another gourd rack for next season. The Troyer Horizontal Gourds are such excellent cavities for martins and I would highly recommend them.

Please keep us posted on how your martin colony is doing.

Steve

[Okie]

Steve would you recommend all THG or a combination of different styles? Glad to have my idea that martins prefer the gourds confirmed. Thanks
My goal is to have a gourd rack up next year but only get 6 gourds to start & was trying to decide which kind to get. Your stats help.

[Steve Kroenke]

Hey Okie,

I would select the Troyer Horizontals with a tunnel/porch if you decide to go with one gourd design. These are my favorite gourds and martins thrive in them in my colony. This gourd is deep and the martins way inside and more protected from predators.

I like gourd racks with a variety of gourd designs as they have a more diverse look and may help to minimize nest domination issues. Martins tend to dominate gourds that are similar.

You could perhaps have several Troyer Horizontals with tunnels/porches and several Excluder Gourds which are my favorite verticals.

But a gourd rack with all the same gourds is still nice looking and I have two of these racks with all Troyer Horizontals with tunnels/porches.

Here’s a photo of one of my K-24 gourd racks with all Troyer Horizontals with tunnels/porches. I like this look and the martins do well in this set-up.



Here’s a photo of my 36 gourd Super System with a variety of gourd styles. I like this look a lot and the varied gourd designs may help to minimize nest domination issues as martins often dominate similar gourds on a rack.



Steve

[cajun]

WOW Steve that is some great pictures!!!! Impressive!!

[BobbyG]

Steve do you think that martins like the gourds because they look like a natural place to live or because of the spacing of gourd houses being further apart than houses ? I am asking because I have a few ideas rolling around in my head wether its looks or distance.

[Okie]

Thanks for the reply Steve
I see what you mean about the variety, looks nice. Maybe it's just when you took the pic but it looks like more birds like the rack with all the same type or maybe its like you said they like the THG.
You have an awesome site. Serious Purple Martin Man you are
Interested in your answer to Bobby G question also.
May you fledge them all

[Steve Kroenke]

Hey Tim,

I have a lot of photos of my martin colony on the Forum. I am glad you like them.

Steve

Hey Bobby,

Over the years I have usually had more martins nesting in my gourd racks than in houses. It may be a combination of factors with gourds giving that territorial privacy martins may like and gourds reducing nest domination behavior because of the distance between them. Natural gourds have that "rustic" natural interior that martins may like: remember, martins nested for thousands of years in woodpecker cavities and other rustic type sites. However, I am having just as good occupancy levels in my plastic gourds as my old naturals. And think of a gourd separated from others on a rack may somewhat replicate a solitary woodpecker cavity in a dead tree. The gourd becomes isolated from the others and martins can have that territorial privacy. So a gourd may have that "natural cavity" look to it.

Houses that provide territorial privacy between the compartments are often better occupied than houses that don't. Trendsetter houses with staggered entrances, separate porches and porch dividers help to minimize nest domination, particularly as the season progresses. My old Trio houses with entrances side by side and continuous porches were horribly dominated, often having only one or two pairs of martins per side and the domination lasted for a long time. Houses that emphasize separate porches, staggered entrances, porch dividers and greater distance between the entrances may be better occupied than those that do not. In fact such houses can have full occupancy just like a gourd rack.

I like to provide a variety of nesting choices for my martins including diverse gourd styles and well designed houses like the smaller Trendsetters. I have martins that select gourds initially and martins that select the houses at first.

Steve

Hey Okie,

Both those gourd racks are doing well. The variety of gourds may help sometimes in increasing occupancy levels by minimizing nest domination issues. But I have two K24 gourd racks with all Troyer Horizontals and both racks are almost full with maybe one or two vacancies.

I am glad you like my colony. It is a lot of hard work to keep a colony of this size going strong. But as long as I can handle it, I plan to continue on. But eventually as I get older, I will not be able to do it and I will have to start thinking about downsizing. I wonder what I will have then!

Steve

[Rodger Drye]

Hey Steve,
Been a while since I've talked to you. Glad to hear you and your Colony are doing so well.! I too like the Gourds best and I believe my Birds like them best also. Your pictures are excellent, and hopefully if we ever get through all these computer problems I will be able to post some pics on the Forum of my Colony.

I have 77 Plastic Gourds all of various sizes and styles. I have a Gemini Rack with 48 THG's I'm in the process of installing.
I had 2 Aluminum Houses of which 1 I gave away. I don't feel like my Martin's like the Houses as much as the Gourds. I have a new Sunset House but am reluctant to put it up. I've got about 50 Birds by now with this new wave of SY's coming in.
Last nest check yielded 115 eggs and 8 chicks hatched. I am well blessed and very Happy about my Martin's!!

Have lost 2 SY's, 1 found in a Gourd and 1 found on the ground. I can only figure that a dominant ASY must have killed them??

I had 12 THG's, 6 with porches and round hole and 6 with cling plates and round holes.. The starlings went crazy over them and killed a beautiful ASY male - in return I killed 6 Starlings.! Had to change all my THG's to Conley II entrances. This wave of SY's are taking right to them.

Do all your THG's have round holes or what? Do you have a lot of Starlings or Sparrows? I have 2 NBT's for Starlings and 1 Uncle Blain for Sparrows. And yes my traps are very effective - have eliminated over 100 S&S's since 01-01-2016....!!!!

Also have caught 3 large Black Snakes so far this season.!

I want you to know how much I appreciate all your efforts in providing homes (Cavities) for our Birds. They have so many things against them. Weather, Food, Predators, Housing, and that's not to mention their Migration... I mean Wow these poor Birds need all the help we can give them. I am trying to do my part - I sure do Love my Birds. I even play music for my Birds.
Some days Country and Western, other days oldies but goodies.! I think it really helps to put them at ease and make them Happy.

Rodger

P.S. I'll tell you a little story about the music thing some time...
Thanks again, and Good Luck at all you do!

[Steve Kroenke]

Hey Rodger,

I am glad your purple martin colony is doing so well with many new martins arriving!

We use both aluminum houses and plastic gourds and the martins do well in both in our personal and satellite colonies. I prefer gourds over houses and I think the martins "seem" to do so, too. But I still like to have a variety of housing types in my colony to add little diversity and give martins a choice.

If your dead SYs showed some kind of trauma to the head area, then perhaps they died in battles with other martins. I have never seen an adult martin kill another adult martin though I have seen many vicious battles. Of course, starlings could have killed the martins, but the martins would show some kind of injuries to the head area. The SYs could have died from some other cause such as illness. I do know that two martins will sometimes fall to the ground fighting and hit the ground HARD. Perhaps the martin on the ground sustained some kind of internal injury. I don't know about the one in the gourd unless he had some kind of obvious trauma to the head area. He could also have died from some kind of illness. Martins often "just die" and we don't know the reason! If the SYs were females, then they could have been injured by a gang of ASY males which were gang raping the females. Male mobs can seriously injure a female martin when they pile on her or strike her savagely and knock her to the ground or against a gourd/house. The female may die on the ground or manage to enter a cavity and die from internal injuries.

All my houses and gourds have round holes and I wouldn't have it any other way for now. Martins have nested in round holes cavities for thousands of years and if you don't have starling issues or you can control starlings, then round holes are perfect for martins. We have a minor starling issue that I control through trapping/shooting. I have been out here since 2005 and not a single starling has ever succeeded in establishing territory in our housing or harmed any of the martins or their eggs/nestlings. All martins easily enter round holes without struggling, I have no entrapment issues, and martins can quickly enter/exit when Accipiter hawks are attacking or threatening. Those are some of the reasons I plan to stay with round holes for now. I have well over 300 pairs of martins thriving in round holes cavities in my personal colony and not single starling!

I would have no problems changing over to srehs if starlings were a real threat or as I get older and can't continue the level of starling control I have now. I will deal with that issue as needed. We do use all crescents at our five satellite martin colonies because we are not there to monitor the sites daily and these colonies are located in more starling abundant areas. We have lost martins to entrapment at these colonies over the years but the problem has not been significant.

We have almost NO house sparrow problem with our personal martin colonies. I have shot only one male sparrow this year and he was in a nearby tree. I sometimes shoot several sparrows that show up. We do have more sparrow issues with our satellite colonies.

Rat snakes seem to be declining in population in our immediate area and we are not catching many in our net traps. I have only caught two since 2005 and Bob has caught a few more. I rarely see rat snakes killed on the roads around here and the man who cuts hay says in rarely sees snakes anymore. He used to see big rat snakes in the hay bales! Snakes are important for the environment but I prefer they stay away from our martin colonies!

I appreciate your kind remarks and also appreciate that you are doing a great job in providing good quality housing for your martins and protecting them, too. Martins need all the help they can get!

Please provide updates on your martin colony from time to time! I know all of us would enjoy reading them!

Steve

[Rodger Drye]

Hey Steve,

I hope you get this message. Have been trying for last 2 1/2 hours to post you a reply. Part of the issue is my server on my I-Pad is Safari and everyone seems to be having trouble. Tried posting on the Lap Top with Google Chrome and it said the PMCA Forum took to long to respond and would not send my post.
Still trying.
Rodger