09-08-15 Field Note

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09-08-15 Field Note

September 9, 2015

Kate Stone compiled this week's bird field note. The note shows bat trapping, songbird banding with UMBEL, and Osprey tracking from RVRI.

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Bird Field Note Kate Stone 9/04/15

The bird crew transitioned into “bat mode” for three nights of bat trapping with Lewis Young, a volunteer for MT Fish, Wildlife, and Parks. Carrie Voss, Debbie Leick, and Kate Stone joined Lewis in the field and contributed pictures to this update.

We trapped bats in three locations. We chose sites based on trapping success in previous years (Davis Creek Seep), and high levels of recent bat activity detected on acoustic monitors (Floodplain Channel, Tongue Creek Pond). The three sites also differed in surrounding plant communities and water availability.

We set all of our nets over water, taking advantage of a bat’s need to drink upon waking in the evening.

We captured 48 bats of six different species*. As in previous years, the Davis Creek Seep yielded the most bats. This seep concentrates bats into one spot because it is the only water source in the area. Debbie recorded numerous bat calls on the floodplain before trapping, but the number of alternative water sources nearby made them less likely to catch in any one spot. Bats may not use Tongue Creek Pond much yet because it is new, or because tall vegetation surrounding the pond limits the area of open water.

Lewis used a light to illuminate the joints in the wing of a Long-legged Myotis. Adult bats have rounded, knobby joints, while juveniles have narrow, tubular joints.

We captured more Long-eared Myotis (top) and Long-legged Myotis (bottom) than any other species. Most Myotis bats weighed between four and nine grams.

We also caught two Big Brown Bats (top) and one Hoary Bat (bottom). A 16-inch wingspan makes the Hoary Bat the largest bat in Montana, but they weigh less than birds with comparable wingspans. Our Hoary Bat weighed 25 g. In comparison, Hairy Woodpeckers have a 15-inch wingspan and weigh 66 g, Northern Saw-whet Owls have a 17-inch wingspan and weigh 80 g, Common Poorwills have a 17-inch wingspan and weigh 50 g, and American Robins have a 17-inch wingspan and weigh 77 g.

UM Bird Ecology Lab: Songbird Banding 24-28 August 2015

We added a species to the MPG Ranch species list: the Canyon Wren. We captured it at the Ridge station.

The Western Wood-pewee, a small tyrant flycatcher, migrates to South America each winter. We caught 10 Western Wood-pewees last week, but only one this week.

Raptor View Research Institute Rapunzel Update Rapunzel settled on a territory with an adult male Osprey this


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09-02-15 Bird Field Note