Photo of Purple Martins on nest boxes by Dee Renee Ericks

Article by Dow Lambert and Dee Renee Ericks

On an early morning last week, with cooperative low tides, Ken Wiersema, assisted by Dan Wilson, Len Zeoli and Dow Lambert, arrived at 3 Crabs to conduct the fourth and final census on the Purple Martin (PUMA) colony. Breaking fog, bright sun and 5-10 mph winds greeted them as they walked out onto the tide flats.

Dow sets the ladder against the first piling. *Photo by Dee Renee Ericks*

The 18 PUMA nest boxes are mounted at the top of the three pilings, about 15 feet above the sand. To inspect a box, we lean a ladder against the piling. Dow climbs up about 10 feet and inserts an endoscope through a small hole in the front of the nest box. He can view what the endoscope’s camera shows on his cell phone.

Dow uses an endoscope which has a small camera to view the occupants of nest boxes. He uses his cell phone (not in view) to check placement. *Photo by Dee Renee Ericks*

At the same time, Ken is monitoring below and can view and photograph the nest box contents on his cell.

On the ground, Ken views a live image of the nest box interior on his cell phone. He takes a photo of the endoscope’s image through an app. *Photo by Dee Renee Ericks*

If the ladder placement is correct, the endoscope can be inserted into all six nest boxes on the piling. A running dialogue occurs between Ken and Dow as pictures are quickly taken. They then move to the next piling. The birds are disturbed for only about five minutes at each piling. The challenge is to visualize and count all the chicks as they are often piled on top of one another.

Endoscope image of Purple Martin nestlings in nest box 1C. *Photo taken by Dow Lambert*

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. Chicks are fed and cared for by both parents and typically will fledge after 27-36 days.

Endoscope image of nest box 6B. How many nestlings do you see? *Photo by Dow Lambert*

On this day’s count we found 9 eggs and between 57-71 chicks. This range of of chick numbers is based on examining data from that particular nest box in the previous census, and attempting to count individual birds viewed by the endoscope’s last image.

See chart below:

**3 Crabs Census Report July 1- August 1, 2023** *Compiled by Dow Lambert*

Ken Wiersema says, “So far we are having an excellent breeding season!”