Continued from Purple Martins 1 of 3
Remember when we talked about monitoring? What exactly does that mean? In the beginning, after you have opened the houses but before the martins arrive, it means checking them every day to see who’s trying to move in. If it’s a House Sparrow, you can’t let them get even an idea that they’re going to nest in your martin house. Do a daily “walk-under” to see what’s going on. If a native bird (Eastern Bluebirds, chickadees, titmice, wrens, etc.) shows interest in your martin housing, they should be discouraged from nesting.
All native birds are protected by law and we can never remove eggs or completed nests. If a native bird begins building a nest, temporarily close the martin entrance & put up a single house nearby to attract the bird away.
What are 'walk-unders'? This means studying your colony without actually getting into the housing and observing their actions under normal circumstances. You aren't directly involved and you get to see the normal happenings when they aren't being directly interfered with. A good pair of binoculars might come in handy if you want to study from a longer distance. Every day a landlord should walk under his colony to see if anything unusual can be detected from the ground. No, these walk-unders will not drive your martins away and in fact, after a short time, they won't even pay any attention to you. from—chuckspurplemartinpage.com
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1. Now the fun part. Start looking at the calendar! Around the first part of March you might see some advance scouts (ASY). They may stop at your new housing, but will go on to where they nested successfully the year before (“site fidelity”). Toward the end of March, first part of April, the subadults (SY) will begin to arrive. Open your houses! Cross your fingers and your toes that some PMs will stop by!
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“Upon arrival, males spend a great deal of time exploring cavities at the colony site. Following selection of one or more nest cavities, the males await arrival of females. Males advertise their selected cavity by performing the “claiming-reclaiming” display. This display involves flying from the cavity, gliding around, re-entering the cavity, turning and singing in the entrance. Although this activity stimulates the interest of arriving females, the female actually selects the cavity, thus inheriting the male whose cavity she chooses. Pairs become established after a few hours to a few days.” TP&W—The Purple Martin and It’s Management in Texas – 3rd Edition 2007
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2. Nest building. Ok, the PMs are here and you can see them building their nests. After the nest is complete check the box every week on the same day. Keep a nest record chart. Note the date of the first egg (very important) and add 28 days. Continue to check the nest every week, but when the young get to be about 22-23 days old, direct nest checks should cease. Why? Opening the nest box may cause the immature birds to “jump” before they can fly. From this point on, check the nests only by walking under them. For detailed instructions on how to do nest checks, refer to this website: http://www.chuckspurplemartinpage.com/
3. Nest replacement. This is not an absolute requirement but George recommends that when the nestlings are 10-14 days old, we clean house! Remove the babies to a temporary box and clean out all used nesting material. Replace with shredded pine straw and or corn stalks available from PM web sites. Do not do this in the 20+ day range after the first egg is hatched, because the immature birds may fly out. This helps control blowflies and/or mites.
4. What else can I do to help my PMs? Martins love eggshells and will devour them during the nesting season. Early in the spring, if we have a cold spell that lasts several days, the PMs are going to need some help. They can survive 3-4 days without food (on days below 45 degrees few/no insects are flying), so when this has happened, George suggests offering crickets and boiled egg yolks, chopped and put in an open tray. We know our Texas weather, and the lower temps resulting from a Blue Norther shouldn’t last more than a few days.
5. What happens when the PMs fledge? They fly away to a nearby tree or shrub! A day or two later after fledging, they’re doing aerobatics! What a sight! The martins spend 4-5 months in the U.S., arriving in March and are all gone by the end of July. Where do they spend the rest of the year? Brazil! These guys really know how to commute.
6. So now my martins are all gone. Now what?? Wait, that’s what. Leave everything alone until Labor Day, then bring down the houses. Wash them out with a solution of 10% vinegar/90% water (no soap), dry thoroughly, close off the entrances and leave the houses lowered until next March.
The link to Chuck’s Purple Martin page (web link at end of article) has a FAQs section where someone asked how the returning PMs choose their nesting cavity. Chuck says he doesn’t really know, but the funny thing is that year after year the first gourds/nesting cavities chosen are the ones facing his house. Maybe those beautiful little birds just want to look out their front door to see who is taking care of them.
A big thank you to George Vickrey for giving up two hours of his Sunday to talk with me about his Purple Martins. He doesn’t know it yet, but I’m going to ask him if I can come back and take more photos when his martins return in March, and if it’s OK with him, would like to follow his Purple Martin families all summer long and report back to our Mystic Shores residents. Everybody loves baby pictures, right? I already know of several folks who are interested in becoming a landlord. It is surely a gratifying endeavor. I asked George just what it is that makes it so special and he said, “Just knowing that I’m helping that species survive. Their loyalty to humans…it’s very rewarding.”
Did You Know?
Native American tribes hung clusters of hollowed-out gourds to attract PMs long before the first European settlers arrived.
Loss of habitat and competition from the European House Sparrow and European Starling has caused a complete “tradition shift” of the PM and the entire species, especially east of the Rocky Mountains, is entirely dependent on humans for nesting cavities.
An estimated 1 million North Americans provide housing for PMs.
Banding shows that most PMs live one to two years. The record longevity for PMs in the wild is 13 years. The annual mortality rate is 50 percent for adults and 60-70 percent for juveniles.
PM Myth: They eat large amounts of mosquitoes. Not true because mosquitoes are mostly low-flying, nocturnal insects and PMs feed during the day and fly high!
PM Myth: Scouts return to South America to guide their colony back to the site. Not true! Scouts are just the first birds to arrive each year and are looking to claim the best nesting cavities.
*Information courtesy of Texas Parks and Wildlife
HELPFUL LINKS:
http://www.tpwd.state.tx.us/publications/pwdpubs/media/pwd_bk_w7000_0254.pdf
http://www.chuckspurplemartinpage.com/
http://purplemartin.org/update/StarlImpact.html
The Stokes Purple Martin Book: by Donald and Lillian Stokes
Contact for more PM info: annconner@gvtc.com
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