Purple Martin Nests
July 8, 2024
This morning at 11:30, following a special Backyard Birding presentation by Ken Wiersema on Purple Martins, 12 of the 14 participants in the class assembled at 3 Crabs Beach to visit the Purple Martin colony. The minus tide and beautiful, calm morning made for a great fieldtrip. When we made it out to the three pilings that support 18 Purple Martin nest boxes, I climbed the ladder and used the endoscope to peek inside each box. Fifteen nests had a total of 64 eggs. The other three boxes had nesting material but no eggs yet.
To see the egg count from this survey in a new window click: 2024 Purple Martin Census. Hint: If possible, drag the new window to the side so you can see the table while you look at each photo.
The 18 nest boxes are mounted at the top of the three pilings, about 15' above the sand.
Purple Martin Colony 3 Crabs Beach
To inspect a box, I lean a ladder against the piling, climb up about 10', and insert an endoscope through a small hole in the front of the nest box. I can view what the camera shows on my cell phone, and Ken can view it on his tablet on the ground below. If I place the ladder correctly, I can insert the endoscope into all six nest boxes on the piling. I quickly take pictures, then move to the next piling. So we only disturb the birds for five minutes at each piling.
To see a short (and silent) video of this process in a new window in your web browser click here. The video is 59 MB, so I don't recommend trying to play it on your cell phone. It takes about 15-20 seconds to load.
The "tri-plex" boxes are labeled nA, nB, nC, from top to bottom, so the first piling has 1A, 1B, 1C, 2A, 2B and 2C. The second and third pilings continue the numbering system. We write the box numbers at the back of the nest box to make it easy to identify the box from the photo.
Purple Martins typically lay 4-6 eggs, one per day, generally in the morning. Incubation starts with the second to last egg, so the chicks all hatch within a day or two of each other. Eggs range from 0.8 to 1.1 inches long and 0.6 to 0.8 inches wide. Incubation takes between 15-18 days. There were no eggs when we checked the boxes on June 22nd, so these eggs were all layed in the past 16 days. We anticiate seeing some chicks when we conduct the second census in a couple weeks.
Below are the endoscope photos of each nest.
Purple Martin Box 1A at 3 Crabs. 7/8/2024
Note the green leaves under and around the eggs in this nest and all the other nests with eggs. For some reason the Purple Martins start lining the nest with fresh green leaves, or sometimes seaweed, a few days before the female starts laying her eggs.
Purple Martin Box 1B at 3 Crabs. 7/8/2024
Purple Martin Box 1C at 3 Crabs. 7/8/2024
Purple Martin Box 2A at 3 Crabs. 7/8/2024
Purple Martin Box 2B at 3 Crabs. 7/8/2024
Purple Martin Box 2C at 3 Crabs. 7/8/2024
Purple Martin Box 3A at 3 Crabs. 7/8/2024
Purple Martin Box 3B at 3 Crabs. 7/8/2024
Purple Martin Box 3C at 3 Crabs. 7/8/2024
Purple Martin Box 4A at 3 Crabs. 7/8/2024
Purple Martin Box 4B at 3 Crabs. 7/8/2024
Purple Martin Box 4C at 3 Crabs. 7/8/2024
Purple Martin Box 5A at 3 Crabs. 7/8/2024
Purple Martin Box 5B at 3 Crabs. 7/8/2024
Purple Martin Box 5C at 3 Crabs. 7/8/2024
Purple Martin Box 6A at 3 Crabs. 7/8/2024
Purple Martin Box 6B at 3 Crabs. 7/8/2024
Purple Martin Box 6C at 3 Crabs. 7/8/2024
If you have Internet Explorer 10 or current versions of Chrome, Firefox, or a new iPad, you should be able to play a short video covering one season (2018) of Purple Martin nesting at 3 Crabs.
Click Here to play the video in your web browser (requires an HTML5-compliant web browser). When you finish, click the HOME button at the bottom left edge of the page, or click the picture of me in the upper left corner of the page, to return to this page.
If the video won't play click here to try it with your system software.
Purple Martins
3 Crabs Colony
2024 Season
This year the first Purple Martin returned to 3 Crabs on April 14th. Others arrived over the next several weeks. After their 8,000-mile flight from the east coast of southern Brazil they spent a good month feeding, resting, and negotiating for ownership of the various nest boxes. (For a fascinating documentary on the migration route of our Western subspecies of Purple Martin, watch this short video, On the Wings of Roxa.) Given the very cool spring, they didn't start actively working on their nests until June. Since dragonflies are the preferred food for feeding their young, the PUMA have to time laying eggs so that when they hatch two weeks later there will be an abundance of dragonflies.
We monitored their nest building and when we observed prolonged periods when adults stayed in the nest boxes we scheduled our first nest box check. We ended up checking the nests four times, coinciding with the minus tides that allowed us to walk out on the tide flats. The report from the final box check on August 16th is in the center pane to your left. Click the links below to open the reports for the first three surveys. Each link opens in a new tab, so you can easily compare nest photos from each inspection if you wish.
Here is a table showing egg and chick counts for each census. There were no chicks on July 8th so that column is not included.
2024 PUMA Census at 3 Crabs. (click to see larger image)
Here are a few pictures from this season:
Purple Martin carrying nest material. 6/18/2024
Purple Martins claiming nest boxes. 6/23/2024
Purple Martins claiming nest boxes. 6/23/2024
Purple Martins claiming nest boxes. 6/23/2024
Purple Martins on nest boxes. Total of 61 chicks with 8 eggs remaining. 8/4/2024
Purple Martin fledglings. 8/5/2024
Feeding time. 8/7/2024
Feeding time. 8/7/2024
Feeding time. 8/15/2024
Feeding time. 8/15/2024
Learning to fly. 8/16/2024
As reported in the census table, Box 4B did not produce any chicks. On the first census there were 2 eggs, then only one egg for the next two surveys, and finally yesterday there were no eggs but lots of feathers. Adult PUMA begin molting after their chicks fledge. The following image shows a male and either female or fledgling looking out of Box 4B. The male has a feather or two protruding from its breast. Perhaps he is using the protection of this empty nest to groom the feathers off?
Male PUMA beginning molt. 8/17/2024
Still a few chicks being fed. 8/23/2024
History
Efforts to establish a Purple Martin (PUMA) colony at 3 Crabs Estuary in Dungeness, WA began in the mid-1990s. Volunteers from the Olympic Peninsula Audubon Society (OPAS) constructed four simple nest boxes and hung them on old pilings that they accessed by boat. By 2005 PUMA were returning regularly and OPAS began adding more boxes. Instead of using a boat at high tide, volunteers monitored the nests at minus tides when they could walk out on the tide flats and raise and lower the boxes with a 10' pole.
Purple Martin nest boxes at 3 Crabs, 5/16/2010
For more information on the history of the OPAS Purple Martin project, see: Purple Martin Nest Box Study,
There are also some excellent blog posts about the PUMA outings here: OPAS Blog,
I joined the other volunteers in 2009 and have helped build, maintain, and monitor the nest boxes ever since. Every fall, after the Purple Martins head south, we bring in the nest boxes to clean, repair, and store until spring. The goal is to put the boxes back up shortly before the PUMA return in early to mid-April. The challenge is that we have to do this task when we have a daylight minus tide. The PUMA do not read our tide charts so sometimes they arrive while we are putting up the boxes, and sometimes we put the boxes up a week or two before they arrive.
Newly retired, young and fit, I took over the task of lowering the nest boxes on a 10' pole, so we could hang them on a nail at eye level. Then we would remove the door, insert a mirror, and take a picture of the reflection of the nest in the mirror.
Checking a Purple Martin nest box at 3 Crabs Beach, 6/22/2009
Finally we replaced the door, raised the nest box on the pole and hung it up again. This was somewhat challenging on a calm day and very challenging on a windy day. After a wind gust nearly caused me to drop a box containing eggs I proposed screwing a board to the feet of an extension ladder so it wouldn't sink in the mud, and inspecting the boxes from the ladder. This created new challenges but over the years we have modified nest boxes, the ladder, and the method of taking photos. Here is what that process looked like:
Checking a Purple Martin nest box at 3 Crabs Beach, 7/12/2018 (by Sally Harris)
In 2018, the Washington Department of Fish and Wildlife, North Olympic Salmon Coalition, and about 28 other organizations completed a major project to restore the Dungeness Estuary at 3 Crabs. This effort included removing the 3 Crabs Restaurant and an old bridge over Meadowbrook Creek, rerouting the road and constructing a new bridge, and removing several hundred old creosote-covered pilings left over from the Dungeness Wharf. Yes, including the pilings that we hung the Purple Martin boxes on. To understand the scope of this project, watch the excellent 8-minute documentary produced by local cinematographer John Gussman, titled 3 Crabs, 5 Salmon, 30 Partners.
You may also enjoy my 4-minute video of the piling removal, which happened from October 12-17, 2018. NOTE: this is a 65MB file so it may take a minute to load before it starts playing. For those of you who are fact-checking me, be aware that the Purple Martins you hear singing in this video were half-way to Brazil, having left town in early September. Chalk this up to poetic license on my part.;)
Fortunately, OPAS negotiations resulted in three new steel pilings placed where we specified on the tide flats where we had been hanging the boxes on about ten pilings. If you watched the above video of the piling removal, you will see that they installed the three steel pilings before beginning to remove the old pilings. In 2012 we began experimenting with a new box design, using 6" PVC pipe mounted on a 1x6" backboard and then attached to piling.
New PVC nest box design at 3 Crabs, 6/21/2012
The Purple Martins seemed happy with this design and we slowly started replacing old wood boxes with these new, lighter boxes. In June 2018, with permission from the Washington Department of Fish and Wildlife, we mounted two duplex nest boxes in the tidal lagoon adjacent to the parking lot at 3 Crabs.
New nest box installation at 3 Crabs, 6/26/2018
Since we now only had three pilings, we spent the fall and winter designing and building six Purple Martin triplexes using the 6" PVC pipe. Here is a photo of the new boxes ready to install. What looks like a nose is a handle for pushing the door in or pulling it out. A small nail on each side secures the door. The hole near the top on the right side of the handles is an access hole for inserting an endoscope camera to photograph the nest. So we no longer have to remove the door, which is safer for the birds and for the person on the ladder.
New triplexes ready for installation, 3/17/2019
We also added a stand-off to the ladder. The photo below shows Alex inserting the endoscope into Box 5A while looking at the image on his cell phone. When he gets the image focused on the nest with the showing the box number on the back of the box he presses a button on his screen to take the photo. Len is on the ground holding the ladder steady while our fearless leader, Ken, views the endoscope image on his tablet. We can now photograph all 18 nests in under 20 minutes, vastly reducing the annoyance factor for the birds. At this first check of the season, most of the boxes had fresh nesting material, but no eggs.
Checking a Purple Martin nest box at 3 Crabs Beach, 6/22/2024
