This summer I am working with a team of college students studying Flammulated Owls in the Manitou Experimental Forest (MEF), west of Colorado Springs, under Dr. Brian Linkhart. Since 1981, Linkhart has been carrying out a long term study of Flammulated Owls concerning various aspects of demography. This year we are collecting data on an additional study site, a forest which will be thinned in 2010. Expect an owl post about once a week…
Pike's Peak as seen from the Manitou Experimental Forest (yes, those are cows in the field)
The MEF, dominated by large stands of ponderosa pine, has been an optimal site for numerous studies in Colorado, including studies on the impact of land management such as prescribed burns. Both students and alumni of Colorado College form the Flam Crew and are housed in a spacious lodge. The Flam Crew sets out in the afternoons, returns for a dinner which we cook as a group, and then we work until midnight. This week, our duties consisted of locating and tapping cavity trees in four study areas. A few students check the most promising cavities with a peeper, a camera on a long, adjustable rod. A “good” cavity is big enough for a sapsucker and fairly deep.
My first day (and everyday) in the field proved extremely exciting. We began tapping aspens along a creek bottom, a habitat type I will be overwhelmingly familiar with by the end of this summer. Unmarked cavity trees are flagged with a neon-colored tape and given a round metal tag with an ID number. In this way all potential nesting cavities are kept track of and easily spotted at night. The nest site in this particular territory, however, was found through peeping and not by tapping. After poking the camera through the cavity, the crew gathered around an eye level screen. The female sat, snuggly tucked at the bottom of the cavity, peering up at the camera with ghoulish black eyes.
At night we use lure nets to capture territorial, testosterone-pumped males. We arrange mist nets in a V-shape and place a recording of territorial calls in the center. Sometimes a nearby male will respond, and hopefully fly into the net. Immediately after being snagged, we check the owl for a brood patch. Females are released ASAP in case they are incubating. Otherwise, we take wing and tail measurements, band the bird if not previously banded, and bleed the bird for genetic analysis. Holding a Flammulated Owl is a unique experience. Most raptors have powerful, scythe-like talons for tearing into prey. But the talons and beak of a Flammulated Owl are for catching insects. Nonetheless, their talons feel like cactus-needle pinpricks to human skin. From a distance, their eyes appear a bottomless black. In the hand, the eyes are a deep, chocolate brown. Upon release, they do not always fly away. Instead, they sit in a kind of torpor. We are instructed to gently drop our hand in order to wake them up. The first time I did this, the owl woke up and pooped, letting me know he did not appreciate my handling him.
We also check cavity trees at night, leaving one person at the mist net. Dropping into the creek bottoms, we use headlamps and flashlights to thoroughly check flagged trees. This week, I was also instructed in the art of hooting. Single hoots are territorial calls. If two hoarse, short notes are tagged onto the front it becomes a territorial encounter call: who-who-hoot. Making a territorial Flammulated Owl call is simple: position your lips as if you were about to say “boop”, but don’t utter the consonants. It helps to open the back of the throat and blow a directed stream of air upwards, toward the roof of your mouth. If a male responds to our hooting, we chase it and mark the tree from which they are calling as a songpost. During one such chase, I got to see a male give location calls to a female. These calls are his way of asking “Are you hungry?” The female usually responds positively. This female gave several soliciting calls, hoarse “whoots”, which was quickly followed by copulation. This bird was probably still finishing her clutch and not yet incubating.
Week one has raced by and I have already learned so much. I cannot imagine a summer job I would enjoy more than this!