My Purple Martin Colony For 2019

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Steve Kroenke
Posts: 4339
Joined: Fri Nov 28, 2003 6:49 pm
Location: Louisiana/Logansport

My Purple Martin Colony For 2019

The 2019 purple martin season for our two personal colonies, mine and my neighbor Bob, in northwest Louisiana was a good one for the most part. We attracted over 500 pairs of martins to our two colonies and fledged probably several thousand youngsters.

Our purple martin season began on January 31, 2019 with the arrival of the “scout”, an ASY male, at my colony and officially ended with the fledging of the last nest on August 5, 2019. However, at least one fledgling, which now flies like an adult, is coming back to roost and roosted the night of August 18. I wonder how much longer this will continue! This is the longest I have ever had martins still roosting in my colony after the season has “ended”. So we have had martins for about six months in 2019!

There was one unusual component to this year: a number of late nesting martins, some of which could have been second broods of earlier nesting ASY pairs. I had multiple ASY pairs that fledged their young around the middle of June and within three weeks or more there were newly hatched babies in several nests with ASY parents. It is possible the “new” ASY pairs arrived after losing their nests elsewhere and took over those cavities that late, but it seems unlikely. This year I had three nests that fledged during the first week in August and I have never seen that before!

This season I had difficulty trying to determine a definitive number of martin pairs that nested in my colony. There were a number of re-nests and late nesters which added to the difficulty but I believe the number does fall within a small range.

In spite of the confusion with all the re-nests and late nesters, I conducted one massive nest check over several days in June and counted the number of eggs/nestlings. I also carefully studied my various gourd racks and houses to observe as many active nests as possible.

Here is a detailed analysis of my 2019 purple martin colony.

Number Of Cavities

This year I had 17 systems erected: four aluminum Trendsetter houses, including three 12 room houses two of which had gourds underneath and one 16 room system and 13 gourd racks, including four Geminis, seven K24 racks, one 36 gourd Super System and one 24 gourd Super System.

The total number of Trendsetter compartments was 52.

I erected 310 plastic gourds including Troyer Horizontals with cling plates and with tunnels/porches, Troyer Verticals, Super Gourds with inside/outside porches, and Excluder Gourds with inside/outside porches. This total includes eight which I call SY male deflector gourds erected during the last week in May to help attract single SY males away from active nests with small nestlings. All these deflector gourds attracted single SY and even several ASY males. Most just “played house”, but three pairs successfully raised babies though it was late in the nesting cycle.

So the total number of cavities in 2019 was 362.

Number Of Pairs

Based on the extensive nest check conducted over several days in June and detailed observations of my gourd racks and houses, I believe my total number of martin pairs for 2019 was between 340 and 350. The ratio of ASY pairs to SYs was about 4 to 1. As mentioned earlier re-nests and late nests made it difficult to pin down the specific number of pairs.

Number Of Nestlings

Over a three day period in June I conducted a massive nest check of my colony and counted 1274 nestlings (this includes 18 nestlings I had counted in a “welfare” check due to possible bites from buffalo gnats and had fledged earlier). There were 114 eggs being incubated. Though I didn’t conduct any more nest checks, probably at least 100 of these eggs hatched.

I do believe that a number of small featherless nestlings were thrown out by single SY males seeking territory and mates as I found dead and live ones scattered under some of the gourd racks. I also saw these males carry out small nestlings and drop them in nearby hayfields. It was impossible to find these babies and return them to their nests. So the total number of nestlings at one time was most likely larger than what I counted. I believe between 1300 and 1400 martins were fledged from my colony in 2019.

We had a good year in 2019 and soon I will be taking down all my gourds/houses, cleaning them out, and start thinking about possible changes in 2020. I will be replacing two of my Trendsetters with two new gourd racks as I really prefer gourds over houses. In fact I have already given those two Trendsetters to a good friend who has a thriving martin colony.

PMCA Member
300+ pairs of martins each season
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