Purple Martin on nest box. - Photo by John Gussman

Story by Dow Lambert

Following Ken Wiersema’s July 12th presentation on the OPAS Purple Martin Project, a dozen of the participants joined Ken and I at 3 Crabs to inspect the 18 nest boxes hanging from three pilings out on the 3 Crabs mud flats.

OPAS field trip to view Purple Martin nest boxes at 3 Crabs. *Photo by John Gussman.*

The tide was just starting to rise after hitting its low of -2'0" at 11 a.m. The temperature was 55 degrees and the wind was gusting from 14-18 mph—less than ideal for climbing the ladder, but with two people holding it I felt comfortable at the top while using the endoscope to peek inside each box.

Dow Lambert checks Purple Martin nest boxes using an endoscope. Video by Dee Renee Ericks

Fourteen nest boxes had a total of 43-50 chicks and 15-19 eggs. A more accurate count was impossible because the chicks were all piled up on top of each other, perhaps hiding an egg or another chick.

None of the chicks have opened their eyes yet, and appear to be from 1-6 days old.

This year, the first Purple Martin returned to 3 Crabs on April 17th. After 4-5 weeks resting, feeding and selecting their nest boxes, they spent several weeks gathering grass, sticks, and mud to build their nests.

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.

Egg size: 0.8-1.1" long; 0.6-0.8" wide
Incubation: 15-18 days
Fledging: 26-36 days

After laying eggs, the parent birds really object to other birds getting too close. Belted Kingfishers frequently perch on the two supports where we mount six nest boxes over the tidal pond by the parking lot at 3 Crabs. But after the Purple Martins take control, they don't let the kingfisher hang around.