Purple Martins Attracted to a Typical Suburban Backyard in Pennsylvania. 2009

Ken Kostka
American Swallow Conservancy
Pittsburgh, PA

          I have been trying to establish a colony of Purple Martins at my place of residence in Natrona Heights, PA since 1981 without success. In 1999, I adopted a strategy of attracting martins to the marginal habitat of my typical suburban backyard by first establishing them at an ideal location about a mile away, reasoning that once they were thriving at the highly desirable site on waterfront property, the overflow would spill into more marginal areas nearby, like my backyard! In 2009, this “indirect” attraction strategy really began to pay off for me.

LD4smallIn 1999, I began attempting to attract martins to the US Army Corps of Engineers Lock 4 facility in Natrona, PA, (see photo to left), an ideal site along riverfront property 1.5 miles from my home.  In 2005, I attracted one breeding pair to this river site. The colony grew to 3 pairs in 2006, 7 pairs in 2007, 9 pairs in 2008, and 20 pairs in 2009! (The colony would have grown faster but I had to relocate the housing several times.) In late May and June of 2009, I began to have multiple, almost daily, visits to the martin housing in my backyard (photo right). Although no martins stayed and nested, it was quite encouraging. I was often awakened by the sounds of investigating martins. They visited at all times of the day, sometimes several times a day. The fact that a 20 pair colony was located only 1.5 miles away was no doubt largely responsible for these frequent sightings. What follows is a list of all the Purple Martins sighted at my house on Painter Ave. in Natrona Heights during the spring and summer of 2009:

May 21, 2009. 4:00 PM. One adult male (ASY-M) and one subadult female (SY-F) land on house #1. They bill-wipe and fly around the yard, but do not enter any compartments. I get the impression they are established somewhere and just stopped by while out foraging.

June 5, 2009. 9:45 AM. One subadult male (SY-M) is present for 45 minutes. He is banded! His band number is Yellow K933. He was banded as a nestling at Lock 4 in Natrona, PA, 1.5 miles south of my backyard in Natrona Heights, PA.

June 6, 2009. 9:50 AM. One subadult male (I’m pretty sure it is K933 again) is present

red circle is my backyard where martin houses were located in 2009

when I leave for work.

 June 7, 2009. 7:00 – 10:00 AM. One subadult male is present off and on all morning. The yellow band on his left leg and the red anodized band on his right identify him as a 2008 nestling from the Lock 4 colony.

June 8, 2009. 9:29 AM. As if on cue, K933 (I’m pretty sure) swoops in and lands on compartment #1 (WH-1) and calls, then takes off moments later.
June 16, 2009. 9:00 – 10:00 AM. Three Purple Martins appear. Two banded subadult males (SY-M’s) Yellow X852 (who was banded as a nestling at Saxon Golf Course?) and K933 (I’m pretty sure), and a third martin that did not land. Yellow X852 was startled and jumped back when he looked into a compartment that actually had a mirror in the entrance hole. This shows that mirrors are very effective at deceiving martins into thinking that other martins are present since they obviously cannot recognize their own reflection. I once saw a starling react this way as well. At 2:00 PM, yellow X852 (pretty sure) brought 5 martins into the site. Some may have landed, but only briefly.

June 17, 2009. 7:50 AM. Two martins circling the site. Later, at 9:00 AM, there was just one martin circling.

June 19, 2009. 5:00 PM. An ASY-M swoops around the site for several minutes.

June 24, 2009. 2:00 PM. An ASY-M swoops around the site and vocalizes.

June 25, 2009. 8:00 – 8:30 AM. My neighbor says that two martins swooped around. One landed on WH-1 but was harassed by House Sparrows. I reinvigorate my House Sparrow trapping efforts, which have slacked off a bit.

June 26, 2009. 7:00 – 8:00 AM.: 2 martins present. 9:45 AM: 5 martins present; 12:45 PM: 3 martins present; 1:40 PM: 3 martins present. (one is an ASY-M that lands); 2:30 PM 1 ASY-M present; 3:30 PM: 1 ASY-M present.

June 27, 2009. 8:00 – 11:00 AM.: 3-4 martins present off and on all morning; they visited frequently; 3:45 PM: 4 martins visit. One repeated goes in and out of WH-1, apparently trying to get the attention of a female; 4:45 PM: 3 martins land on T-14 – 2 ASY-M and 1 SY-F. (1 or 2 other martins fly around but do not land.); The SY-F appears to be with the other ASY-M, not the ASY-M that is landing on WH-1 porch and vocalizing loudly.); 8:10 PM: 2 martins flew around, one vocalizing loudly.

June 28, 2009. 6:15 AM: 2-3 martins visit briefly; 5:22 PM: 2-3 martins visit briefly.

June 29, 2009. 9:30 AM: 2 martins visit. The ASY-M lands and calls loudly to what might be an SY-F; this bird almost lands but does not. 2:00 PM: SY-M lands on WH-1. He has yellow band on his right leg and an aluminum band on his left, indicating he is probably from the Saxon Golf Course colony site; 7:30 PM: 1 martin flying around vocalizing.

June 30, 2009. 8:00 – 8:35 AM: Two martins visit. One, an ASY-M, lands.

July 01, 2009. 9:00 AM: 3 martins land – 1 ASY-M, 1 SY-M, and 1 SY-M or SY-F. 11:55 AM: one martin flies around vocalizing.

July 13, 2009. 11:00 AM: 1 ASY-M circles the housing.

July 20, 2009. 9:30 AM: 4 martins flying around; at least 1 is an ASY-M; they fly over the neighbor’s yard also; none land. 9:50 AM; 1 non-ASY-M flying around the housing, almost landed; 10:30 AM: 2 martins flying around; 12:45 PM: 1 ASY-M flew around for 15 minutes and almost landed several times. He was swooping very low in front of the housing. 4:38 PM: 1 non-ASY-M swoops around but doesn’t land. He is present for about 5 minutes.

July 22, 2009. 12:30 PM: One ASY-M and 1 SY-M or SY-F landed on both houses and snooped around for about 10 minutes.

July 23, 2009. 1:30 PM: 1 non-ASY-M swooped around for about 1 minute.

July 26, 2009. 6:00 PM; 1 martin seen flying above site.

July 27, 2009. 8:00 AM: one pair of martins, an ASY-M and an SY-F, land on housing after swooping around and vocalizing.

July 30, 2009. 11:30 AM: 2 ASY-M’s and one SY-M fly around housing. Several minutes later, the SY-M (yellow band on left leg) lands on both houses and looks at mirrors. His reflection startles him!

Aug 3, 2009 11:22 AM: 2 martins (non-ASY-M’s) fly around, then land on the overhead wires nearby, then buzz the housing again.

Summary of sightings and analysis. There were a total of 83 visits between May 21 and Aug 3, 2009. Some of these were the same bird visiting on multiple days. There were a relatively large number of ASY-M visitors, which I thought was very encouraging, since unestablished sites are usually frequented by unpaired SY-M’s. It is interesting to note that 53 of these visits occurred in late June (between June 16 and July 1st), which is traditionally when most would-be landlords have just about given up trying to attract martins for the season. Although uncommon, martins can begin nesting as late as the 4th of July.
My site consists of two wooden T-14’s, with the dawnsong speaker attached to the roof of one of the houses. I also have mirrors and decoys attached to each house. Next year, I intend to keep one house free of all these social attraction tools, just in case an investigating female is “spooked” or overstimulated by them. Not coincidentally, the two nearest colonies also consist of two T-14s.

Incidentally, the next closest colony is 7 miles north at Saxon Golf Course near Saxonburg, PA. It has had about 28 pairs for the past 4 years. I took over management of this colony in 2001, when it was in danger of being lost, with dilapidated housing and only a handful of breeding pairs. It was a pair of martins from this golf course colony that started the river colony through a technique known as “forced dispersal”.
Conclusions. A large, thriving colony on waterfront property nearby has generated a lot of martin activity in my backyard, about a mile away. Prior to the establishment and growth of this Lock 4 Natrona colony, seeing martins in my neighborhood was uncommon. But in the spring and summer of 2009, five years after the Lock 4 colony was established, it became a common occurrence. Many of the martins that visited my backyard site were unbanded, indicating that they had not fledged from either the Natrona or Saxonburg colonies. So the presence of a large, thriving colony apparently served to attract martins from a wide area.
If you have tried unsuccessfully to attract martins to your marginally attractive property, and you don’t live near a robust colony, try establishing a colony at the nearest large body of water. Similarly, if you live near a faltering, poorly-managed colony, try “adopting” it and managing it for maximum reproductive success. The nestlings from that colony are the most likely to become your first martins! The most productive management techniques include supplemental feeding, nest replacements, use of predator guards, House Sparrow/starling control, and asymonperchreplacement of old-style housing with housing that can be raised and lowered vertically. Be careful to limit the housing at these nearby colonies. Otherwise, they will continue to grow rather than force overflow to your nearby housing.
Keep in mind that this indirect attraction strategy can require a substantial investment of money and time. It is not uncommon to spend at least several years attracting the first breeding pair to even an ideal site in areas where martins are scarce. It can also take several years to turn a dying colony into a thriving colony. I also recommend erecting ideal housing – manageable wooden houses and large, thick gourds.