Flammulated Owlet


A diminutive owlet perches precariously at the edge of a cavity entrance. What does the world look like up there, 30 feet high in the tree? The tops of spruces, a star studded expanse above, the distant side slope with granite protrusions, and us, three field researchers sitting below, are all sights to be to be taken in by a curious owlet on the verge of fledging.


Rarely will a brood fledge together; their take-offs are often separated by a day. After 23 days in the cavity, they’ll wing their way into a wider world. The act is anything but graceful. The fledglings often fall to the ground, padded by their fluffy gray down, where the parents continue to feed them. This particular owlet has plenty of other options—several blue spruce surround the aspen in which he (or she?)* perches.


The cavity is too high for us to approach by ladder or for Dr. Linkhart to reach using his climbing spikes. Instead, three of us have been posted on a “fledge watch”. After the owlet makes his brave jump from the cavity we are to follow it, scoop it up, and take a series of measurements. Finding newly fledged owlets proves no easy task.


Our owlet took a flying leap into a nearby spruce where we lost it for an hour. Sitting in the thick vegetation below, swatting mosquitoes, we listened for the owlet’s raspy begging. We finally observed a prey delivery by an adult and located our Flammulated Fluffball. Unable to reach the owlet, we raised a peeper pole and began gently nudging it, hoping to knock it off the branch. We vigorously wiggled the bough and poked him with the tip of the pole. The owlet hung on tight, trying to stay balanced with panicky wing flaps. Resistance is futile. He finally dropped to the ground with a soft thud. So much for a poetic fledging.


a day before fledging 

A last look at an owlet the day before fledging


 All owlets are banded and bled. In addition, Linkhart asks us to take feather samples. These feathers will be incorporated in another method for pinpointing the wintering grounds of Flammulated Owls. The owlet feathers will be analyzed for their hydrogen isotope ratios. Like a signature, a unique ratio of hydrogen isotopes can be found in the precipitation that falls at every latitude. These isotopes are transferred to plant and animal tissue via the food chain (trophic energy transfer). This hydrogen isotope “signature” can be found in bird feathers as well. We know the owlets have grown their feathers on the Manitou Experimental Forest (meaning the hydrogen isotope ratio will be specific to our location). Linkhart also took feather samples from a few owls in Mexico. Flammulated Owls in Mexico are not long distance migrants and, more likely, are resident birds. Therefore, he knows those feathers have been grown in Mexico. Linkhart hopes to compare samples taken in Colorado to those he took in Mexico, as well as samples his colleagues in different locations across the owl’s range have taken (hopefully including some from British Columbia). Eventually, a gradient of hydrogen isotope ratios across the owls’ range will be developed and the ratios in the feathers can be matched to latitude.


Working on the Flam Crew has helped me grow and learn in many ways. For one, I have learned the importance of blending different disciplines. Using feathers to locate wintering grounds seems a clever method, one that blends biology and chemistry. And much of Linkhart’s research incorporates statistics. Broadening one’s mind to other fields of study is all part of an education at Colorado College. The owl diary itself may be a blend of art and science. Obviously, a diverse knowledge over many fields is required to better understand our world.


 *Differences in gender are impossible to tell by appearance.