Purple Martin Update 3…March 1, 2008

[Steve Kroenke]

Purple Martin Update 3…March 1, 2008

Purple martins continue to arrive at Bob’s colony and mine in northwest Louisiana and March is the big month for the ASYs. I have studied my colony and believe I have around 55 to 60 ASY males in residence and most are paired. I estimate that I probably have about 100+ martins in. Bob probably has around 40+ ASY males and many of his have mates, too. So we may have close to 170 martins in both our colonies at this time. During the next three weeks of March, we should see a huge influx of ASY martins pouring into our personal and satellite colonies. I attracted 254 pairs of martins in 2007 and Bob had about 130.

So far, I am not seeing any trends relative to housing preferences though my various gourds have a higher occupancy level than my multi-compartment houses. I am observing that there is little difference in occupancy levels between natural gourds and my plastic ones. My Troyer Horizontals with cling plates and those with tunnels/porches are well liked by the martins. Though I will always like natural gourds, I have decided to start phasing them out and substituting Troyer Horizontals with tunnels/porches. In fact the other day I replaced 24 of my natural gourds, including traditional ones and those that maximize vertical/horizontal depth, with Troyer Horizontals with tunnels/porches. Guess what? The martins accepted the change though some of the martins did seem to have a puzzled look on their faces and were thinking, “What the…!” This may be my last season for natural gourds in my colony as the artificial gourds are so easy to take care of, last longer and are well accepted by martins. If folks use plastic gourds, I would recommend the high quality ones like Troyer Horizontals, Super Gourds, Excluder Gourds and Naturelines. The cheaper plastic gourds are often translucent and allow too much light to penetrate and heat up the interiors.

Starlings and house sparrows have not been much of a problem. I shot one male house sparrow and two male starlings in February and I don’t consider that an uncontrollable situation. I usually eliminate only one male sparrow each year and they are largely absent in our immediate area. Starlings are stronger flyers and some do visit from time to time and not all leave alive! I shot five starlings and trapped one for a total of six in 2007. I don’t know what 2008 will bring relative to starlings, but they will be shot on sight if I get the chance.

The biggest threat to our colonies is predation from Accipiter hawks and merlins, not starlings and house sparrows. In February we had some unsuccessful attacks by merlins and I thwarted several of these by intercepting the falcons as they entered my colony. The Accipiter hawks have been unable to sneak up or dive down on the martins as I have confronted the hawks directly under our colonies. The sharp-shinned and Cooper’s hawks will usually not enter our colonies when they can clearly see me. They often just turn away or circle for a while and then move on. The deadliest month for migratory hawk and merlin attacks is April and we often experience several a day. We are apparently located on a major migratory flyway for Accipiters and merlins and I have never seen so many raptors in my life. These predators are flourishing and growing in population! Though I stop probably 95% of these attacks, the Accipiters do succeed at times when they achieve total surprise and I am not ready. I observed five successful kills by migratory Accipiters in 2007 though I forced two of the hawks to drop the martins which were dead. If I wasn’t on constant guard, we would probably lose at least one or two martins to Accipiters and merlins a day throughout much of March, all of April, and early May. It would be a martin feast for these raptors. The resident Cooper’s hawks start predating the martin fledglings almost the day the first ones leave the nest. I observed 59 direct kills by Cooper’s hawks on martin fledglings in 2007 and easily two or three times that many occurred outside my observational range. The hawks seem to eat nothing but martin fledglings and feed them to their young.

Stay tuned for more purple martin updates from northwest Louisiana.

Steve

[Guest]

Hey Steve, I really enjoy reading your updates. I saw your pictures you posted of your housing. Really great setup.
Quick question for you. What percentage of my gourds should be occupied before I put up another rack?
Thanks,
Adam

[Steve Kroenke]

Hey Adam,

I am glad you like the updates. I try to provide one every week or so and will start including more pictures as more martins arrive.

Gourd racks can often achieve 100% occupancy levels because gourds provide territorial privacy for martins and give them "their space". However, you may still have martins that will dominate more than one gourd.

There is probably no specific occupancy rate below 100% that would signify it may be time to erect another gourd rack. However, if you have the room in your yard, I would consider adding another gourd once your set-up achieves a 75% occupancy level. At that level, you may have some martin pairs controlling more than one gourd and offering additional gourds on a different rack will make it easier for newcomers to move in to your colony.

Also, having several gourd racks spread out in your colony offers a "multi-cavity stimulus" and may attract many martin visitors, including territory seeking male martins. Martins "like their space" and will often disperse out into a colony among several gourd racks or houses. Then females may be attracted to all these males and their various cavities. So it can be to your advantage to offer at least two separate gourd racks.

I hope this information has been helpful. Good luck.

Steve

[Tim Mangan-Kansas]

Steve:

Always nice to read your updates. I have had martins visiting everyday since the 19th. One or two would show up and spend an hour or two just sitting on the perch's. Had a migrant female that spend several nights here waiting for the weather to improve before she continued her journey.

Yesterday morning, "my" birds arrived. About 8:00 AM, I heard the unmistakable call and saw I had 5 males and one female out on my housing. The males were going in and out of the gourds trying to get the lone female to come visit "their" place. There was even a fierce fight between two males for a compartment in my one of my Coates houses. (With my extra Troyer gourds available, I am going to say these are not two of my "brightest" males that I currently have on site.) This activity went on all morning and then off to feed all afternoon. Gosh, it's nice to have them back!

Just like last year, I am now submitting my official request to you to send me up some of your extra females. I could use four right now, thank you very much.

Tim

[birdy girl]

I like reading your updates also. It is always nice to know how other folks are doing with their martins. Keep us informed.

[Steve Kroenke]

Hey Tim,

I am glad you are seeing more martins. Yes, I will see if some of my love sick females who have rejected all those Louisiana males will head north for some Arkansas testosterone!

My martins are fighting, too, and the males are dominating multiple house compartments and gourds. It is most frustrating to watch at times! But that is part of martin behavior to control territory to reduce competition for mates and provide females with a variety of choices.

We are getting a lot of southern wind today so I expect more martins to be arriving in my area and possibly yours. But it will get a little cooler after this front passes through.

Steve

Hey Birdy Girl,

I am glad you enjoy the updates and I have enjoyed reading about your colony site and looking at the nice photos. Martins should be arriving in your area in larger numbers soon.

Steve

[Guest]

Thanks for the help Steve. One more question, Where do you find the tunnels with porches with round holes for the troyer gourds. I found only excluder entrances with the porches at the pmca store.
Thanks
Adam

[Guest]

Steve:

Just one good dog if your area can be fenced or partly fenced will scare those hawks off. Size may not be important but vocal. Probably would need to have a smaller area fenced for him/her during fledging.

Enjoy and learn from your comments.

[Babsi]

Thanks for the advice on Gourds, Steve. I am going to get the Troyer Gourds with the tunnel, I lost a lot of Martins to Owls last year. I found the gourds at http://www.cuent.com/troyergourdtunnel.htm.
Barbara