4/8/15: Kate Stone helps with the observation efforts at the Pygmy-owl nest. She searches for male #960 at 6:20 am. The bird appears to be north of the nest, across a large drainage. At 7:00 am Kate hears soft high trills that we correlate with the female vocalizations, but she cannot pinpoint its exact location. The female continues to vocalize intermittently until the male starts hooting in the vicinity of the nest at 7:16 am. This spectrogram taken from the nest shows the typical male hoot and the female’s higher trill.
At 7:35 am the female perches east of the nest tree in the branches of a nearby Douglas-fir (see picture below).
At 9:30 am Kate tracks the male to a large Douglas-fir, almost a kilometer north from the nest, across Baldy Draw.
4/13/15: Kate is back at it. The male and female are going in and out of the cavity and begin hooting and trilling at 6:39 am. The spectrogram below shows the male hooting from the cavity entrance at 7:06 am, recorded by our automated recording unit (ARU).
4/17/15: As soon as I arrive at the nest at 6:15 am, I start filming and swap the ARU batteries. I see no activity, but when I review the footage later I find the female sneaking into the cavity at 6:18 am. The exact time I was changing the batteries. The entrance is so small that she gets stuck in the hole for 5 seconds with her legs sticking out.
At 6:20 am the male’s telemetry signals are getting stronger. He is flying closer to the nest, and at 7:51 am I start hearing male hoots. At 9:25 am, I leave after failing to pick up any female activity.
In the afternoon I review ARU recordings from earlier that morning. I witness peaks in Pygmy-owl vocalizations, as male #960 and its paired female copulate twice between 5:58 and 6:11 am. Numerous copulation events indicate courtship or laying stages. The ARU spectrogram below depicts the copulation vocalizations. The yellow and white lines depict the female and male range of vocalizations during copulation.
4/20/15: At 6:00 am Kate detects the male far to the northeast of the nest. It is still dark, but she hears the female softly trilling for ten minutes east of the nest. Between 6:20 and 8:24 am, the video recording confirms no activity at the nest entrance. From 7:44 to 8:24 am, Kate hears three copulation vocalizations and we speculate that the female might be laying eggs. In the picture below, #960 looks straight at Kate, with his antenna still secured to his back.
4/22/15: At 10:15 am, Kate, Sarah Norton and I go swap in a new battery for our recording device and also peep into the cavity. The male transmitter signals suggest #960 is away from the nest. At 10:38 am we observe three eggs in the cavity!
Did you know that Pygmy-owls have a mean clutch size of 5 eggs, but they can lay from 2 to 9 eggs? It takes on average 28 days for the eggs to hatch.
4/24/15: On another exciting note, Lewis’s Woodpeckers are returning from migration. At 8:32 am our first Lewis’s Woodpecker of the year is caught on camera thanks to Philip Ramsey.
William obtained an MS in Wildlife Biology from the University of Montana in 2018 focused on the influence of habitat selection on reproductive outcomes of Lewis’s Woodpecker in the Bitterroot Valley, MT.
William coordinates the “Intermountain West Collaborative” Motus project. Motus is an international collaborative network that permits tracking migration of small wildlife by using telemetry and automated receiving units. In addition to Motus, William also leads various banding operations at MPG Ranch, including the capture and tracking of Lewis’s Woodpecker, Northern Pygmy-owl, Flammulated Owl, Common Poorwill, and Common Nighthawk.
Outside of work William enjoys everything outdoors, team sports, and traveling.