Subadults in northern Illinois

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Posts: 17
Joined: Fri May 08, 2020 8:57 am
Location: Evanston, Illinois, USA

Like a lot of would-be martin landlords, I'm trying to figure out when to open my compartments. So far there are a only a scattering of subadult reports from all of Illinois, and none from my area, the Lake Michigan shore north of Chicago. We're in a rainy/cool period that will become sunny and warmer starting Wednesday, May 20. Do you long-time landlords expect that the subadults will come in then? Or maybe there are subadults near me already, and people just aren't reporting them?
Stuart C.
Ed Svetich-WI
Posts: 810
Joined: Tue Jan 13, 2004 10:05 pm
Location: Brooks, Wi (McGinnis Lake)
Martin Colony History: 24 Super and Excluder Gourds on two gourd racks, all SREH. Full occupancy. My philosophy is to maximize fledge % with existing cavities rather than adding gourds to grow colony, thus providing opportunities for new colony expansion. Fledge over 100 nestlings yearly from 24 gourds. Band nestlings in cooperation with state university. 2019 Adendum: Reduced colony size to 12 gourds to focus on more intensive management regimen.


Now is fine. I had an early confirmed SY male on April 26th.That was an exception. There are now 4 SY reported north of you in Wisconsin. There should be a wave of SY after this rain and cool temps passes. If you have either the DawnnSong or the Chatter tapes, begin to play them. Open a few cavities on the side you can watch in case sparrows are around. I assume you are using SREH so you do not have to worry about starlings.

Good luck. Be patient.

Posts: 3144
Joined: Wed Mar 29, 2006 8:49 am
Location: Indiana/Henry Co.

By the time the SY's arrive many landlords don't get excited about making the report. You can look on the scout pages and see the number of SY reports is a fraction of the ASY reports. I would open them now and if you get other species looking in it close it off for a day or two or until you see martins. Really it doesn't hurt to have it open early in the season if you can keep competitors out of it. Every year people start colonies with ASY birds who didn't return to last years site due to poor housing, predators, etc.
2021 Currently 62 nest 138 babies plus 110 eggs (6-317-21) HOSP count-9
2020 42 nest, Fledged 164 HOSP count-8
2019- 31 Pair over 100 fledged
2018- 15 pair 49 fledged
2017 3 SY pair nested, 12 eggs total, fledged 10. 4 additional lone SY's
2016 1 pair fledged 4
2015 Visitors
2014 Visitors
2013 Moved 6 miles away, 1 pair fledged 2.
2012 30 pair fledged 100.
2011 12 pair 43 fledged.
2010 5 pair 14 fledged.
4th Gen Martin Fan
Posts: 1497
Joined: Thu Jul 04, 2013 1:19 pm
Location: TN/Collierville
Martin Colony History: I have been exposed to purple martin sounds in utero when my mother went out to get my father away from his martin colony.
I played around the martin colony every summer and watched as my father maintained his colony. In the late 50's until the 70's he did not notice European Starlings in south Texas.
When old enough, I helped maintain his colony. My primary task was eliminating English House Sparrows with a 1956 Benjamin 317 .177 air rifle.
When I settled into my own home, I started my first colony with an original Trio Castle and Trio Grandpa. When I moved again, I did not put up any martin houses. Frustration with European Starlings in the Southeast US was overwhelming.
Found PMCA Forum and learned about modern enlarged compartments and SREHs.
Inherited my father's last martin house, a Trio Grandma, modified it to modern specifications and have had good results since then.

Since subadult purple martins are being reported around and north of your colony, I would open some compartments. You do not want to miss the new arrival martins, especially the subadults.
Firm believer in HOSP/EUST Control, Enlarged Compartments, SREHs, Pole Predator Guards, Owl/Hawk Guards, Mite/Parasite Control, Housing Insulation, and Vents for Compartment Cooling.
PMCA Member.
Posts: 17
Joined: Fri May 08, 2020 8:57 am
Location: Evanston, Illinois, USA

Dear Friends,
Thanks for the thoughtful and helpful advice!
Posts: 678
Joined: Wed Mar 16, 2016 9:17 pm
Location: Raymore, MO

I agree with opening up the cavities when the first scouts are seen in your area unless you have a hard time keeping undesirable birds out. A lot of colonies are started with ASY birds and you should take advantage of all possibilities when starting a colony.
Jeff Dean
Posts: 17
Joined: Fri May 08, 2020 8:57 am
Location: Evanston, Illinois, USA

Both the martin houses I'm managing are about a mile from my own home (in different directions, alas): one in a park and one on a golf course. So all I can do is visit daily and root out sparrow nests. At the golf course I've created a way to play back dawn song from an old phone, which I hope will help. There *are* established pm colonies nearby, which is a positive factor.


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