Flammulated Fluffballs 

The three amigos, 17-19 days old


Flammulated Owls are unique members of the family Strigidae. Typically, we think of owls as powerful hunters of small mammals. But the Flammulated Owl feeds primarily on moths. Furthermore, they are migratory. Long before frigid winter grasps the Rockies, these owls are on their way to Mexico and Central America. Where exactly do they go? This question may be answered by the next breeding season. Dr. Brian Linkhart has invested in geolocators, a device attached to the bird’s back which records light levels and the time at which they are measured, essentially recording sunrise and sunset. This sunlight data will be unique to the bird’s location. In this way, we may be able to determine exactly where owls on the Manitou Experimental Forest (MEF) go each winter. Unfortunately, this information is not sent to a satellite continuously and thus the data can only be retrieved by catching the owl upon his return from the wintering grounds. Because of this limiting aspect, Linkhart has decided to attach geolocators to males. Remember that males show higher site fidelity than females, thus they are the ones most likely to return to the study site.


We continue to mass the owlets everyday and measure their primaries. This week, I bled and banded my first owlet. The owlets’ blood will be sent off for genetic analysis to determine parentage. A case of polygyny brought an added twist to the study in 2004. Students observed a case of two nests belonging to one male. The second nest suffered considerably, with only one young (out of three) surviving to fledge. In instances like this, bleeding as many of the owls as we can, adult and young, becomes crucial.


Practicing fledging 

Flapping wings at 18-20 days old


The following week will be a busy one as far as owlet monitoring concerns. Some of the Flam Crew will be posted on “fledge watch”. Around the time owlets are expected to leave the cavity, a few of us will monitor the nest site, ready to capture, bleed, and band newly fledged young at various nests. Usually they fledge straight to the ground, but who knows what wild goose chases are in store for us….


Female Flammulated Owl   

A female watches as we mass her owlets, photo courtesy of Andy Bankert