2023 Earthwatch Arizona Expedition Part 1 - Owls

After a long exhausting junior year of high school, an Earthwatch Expedition to conduct field research on owls in the Chiricahua Mountains was just the thing I needed. I was looking forward to seeing all the unique wildlife the Chiricahuas had to offer, and they certainly did not fail to deliver. This time, we had a lot more participants and researchers, going from 9 people to a total of 18 researchers, techs, students, and coordinators combined! With increased numbers, we were able to complete plots more efficiently and trap more owls as multiple teams surveyed different areas.

The major five owl species that we were looking to trap were Elf Owl (Micrathene whitneyi), Flammulated Owl (Psiloscops flammeolus), Northern Saw-whet Owl (Aegolius acadicus), Western Screech-Owl (Megascops kennicottii), and Whiskered Screech-Owl (Megascops trichopsis). Of these, the most common was Whiskered Screech-Owl, quickly followed by the Elf Owl and Western Screech-Owl. We caught these three species, however, for the Elf Owl, forgetting my camera that night, I wasn’t able to photograph it. We did hear Northern Saw-whet Owl once or twice, but it was relatively uncommon, and we did not trap any. Also not caught nor heard was the Flammulated Owl. In the past, these birds have had territories in the Chiricahuas but none have been found in the last year or so. For descriptions of specific methods and techniques used to research the owls, please see my previous post about this expedition from last year.

Here we have a pair of Mexican Spotted Owls (Strix occidentalis lucida) attempting to sleep in a tree (the second bird is to the left and partially obscured by the trunk). As seen here, these birds usually breed in high-altitude mixed coniferous forest. Being one of our larger owls, we are unable to capture them because they would simply tear through our mist nets. We actually do have Spotted Owls back in California, but they are of a different subspecies and also are getting pushed out of their range by the larger and more aggressive Barred Owl (Strix varia).

Again, we have a pair, this time Whiskered Screech-Owls (Megascops trichopsis). The Chiricahuas and a small collection of other mountains known as sky islands in Southwest Arizona and Southeast New Mexico are some of the only places you can find Whiskered Screech-Owls in the United States. As with many birds of Southeast Arizona, they are primarily a Mexican species, with the typical US Screech-Owl species being Western (M. kennicottii) and Eastern (M. asio). Telling the species apart can be incredibly difficult, but thankfully we don’t have Eastern here. To tell the difference between Western and Whiskered, the call is the most reliable determining factor. The call of a Western is most similar to that of a ping-pong ball dropping onto the floor. The Whiskered is the opposite. Also, hence the name, the whiskers on the Whiskered Screech-Owl are slightly longer than that of its Western counterpart

From the same pair, we have two fledgling Whiskered Screech-Owls perched high in an Emory Oak (Quercus emoryi). These birds fledged recently and during that process, one of them missed the branches and fell to the forest floor. However, baby owls have the remarkable ability to climb trees. Using their beak, talons, and wings, these birds can scale almost any tree. So, if you see a young owl on the ground, chances are, it can get back up, it just hasn’t done so yet, so the best practice would be to leave it be.

Here is a different pair of Whiskered Screech-Owls, this time at night and in hand. This particular pair was very aggressive, and for this, was relatively easy to catch. However, the female was quite an escape artist, managing to free herself from the mist net three times before she finally was caught for good.

If you look at the feathers of a bird under a blacklight, certain feathers may appear reddish. This coloration denotes that they are new and the old ones have just molted. In the case of this Whiskered Screech-Owl, most of its wing feathers have recently gone through the molting process.

Unlike last year, this year we caught a Western Screech-Owl (Megascops kennicottii). Like the Whiskered, they prefer lower elevations, and we didn’t hear either species when we conducted our high altitude searches at 9,000 feet, instead getting them on surveys closer to the research station, located at 5,400 feet. They also tend to enjoy more riparian areas, which are closer to the station, as a creek does run nearby.

Lastly, we have a Whiskered Screech-Owl perched in a tree right after being released. These owls tend to act like flycatchers in their feeding patterns. As sit-and-wait predators, they often take up a perch and wait for things to pass them by, occasionally making forays to grab at insects, fish, or whatever other creature catches their attention. Here in the Chiricahuas, most owls subsist on insects, although, based on the number of mosquito bites I had by the end of the trip, they probably could be doing a better job.

This concludes part one of a two-part series of my 2022 Earthwatch Arizona Trip. See here for part 2!