Birdfy Nest Duo Review: My Own Private Nature Documentary

Even though I've been a bird-watcher most of my life, nothing prepared me for the experience of witnessing—on my phone—the entire process of birds being born in my own backyard.

I’ve maintained a regular “dumb” nest box for years, the birthplace of generations of black-capped chickadees. I’ve seen them going in and out, but I always wondered what was happening in there, especially the year I opened up the box in the fall and found five deceased fledglings at the bottom. How could this have happened? I wondered.

Thanks to the Birdfy Nest Duo smart nesting box and its built-in thermometer and hygrometer, I now at least have an educated guess. (The poor things likely overheated during an early season heat wave.) Being able to watch the entire nesting operation from all angles, starting with excavation and egg-laying and ending in hatching and fledging, has been one of the most educational and entertaining bird-watching experiences I have ever had, and something I'd recommend to anyone interested in birds, nature, or just life science in general.

Birdfy makes three smart nest boxes in addition to the Duo. The original, the Birdfy Nest , has one camera—located inside the box—and can only hang from an eye hook screwed into the top. There's also a version made out of solid fir in contrast to the others’ lightweight bamboo. I have also tested Birdfy’s artful Polygon , but persistent connection issues prevented me from using it this season.

I have not tested the first two single-camera versions, but I can't imagine not having a second camera outside the hole to see who's unexpectedly poking their head in. (At one point in my testing, it was a confused flicker; another, a curious starling—this is when I learned chickadees can hiss). It's also critical to be able to pole-mount the box to keep it away from predators.

The Nest Duo is substantial—16 inches tall and about 8 pounds—with one 1080p HD camera facing the nest entry hole on the exterior and another tucked discreetly inside the nest box itself. There's also an internal hygrometer (humidity) and thermometer (temperature) that show readings on the live view in Birdfy's easy-to-use app. There are four easy-to-install, screw-on entry hole sizes for different species, from 0.9 inches for wrens up to 2 inches for starlings or bluebirds, along with corresponding metal predator guards to prevent chewing. The entire side of the box opens with a latch for easy cleaning and access.

In the app, each screen capture appears as a split-screen image, which you can tap to view 20-second videos (with audio) of both the inside and the outside of the box. The videos are immediately downloadable and shareable—no subscription is needed.