Barred Owls in Louisiana

Collaborators: Sabrina Taylor, Phil Stouffer, Ashley Long

My very first publication detailed roosting behavior of diurnal birds in Jamaican coffee farms, and this interest in what (where) birds do at night continued throughout the years. It was only natural to move to nocturnal birds as this opportunity arose in 2017 at LSU, when Phil Stouffer and Sabrina Taylor inherited 10 tags from Bret Collier. These tags represented state-of-the-art technology, containing both a programmable GPS and VHF beacon for remote data download without the need to manually follow birds (as I had to do for my previous work on Wood Thrush and the Black-throated Blue Warbler). The latest generation of these devices also includes an accelerometer to measure activity.

Phil and Sabrina approached me with the idea to use these tags to study Barred Owl (Strix varia) movement in an urban setting, and together we developed the project. We secured the necessary permits and additional support from LSU’s School of Renewable Natural Resources, and then we needed to actually catch these large nocturnal raptors and attach the tags—a tricky thing to do, for several reasons. After early struggles, we have now honed our technique and can usually catch, measure, and tag an owl within a couple of hours, then enjoy months of automated data collection before we retrieve our device.

The project has now grown to include several collaborators, including Ashley Long. BREC Conservation has become a valuable partner that now provides most of our research sites. Last but not least, we have used this opportunity to provide a rare glimpse into a unique scientific research for LSU students.

The project should continue through 2021.

Above is a sample of data we are collecting to study owl movement around Baton Rouge. Locations that share color belong to a single owl

Bluebonnet Swamp

Meet “Dennis”, a male Barred Owl that resides at Bluebonnet Swamp. We caught Dennis on 18 January 2021, took various body measurements, fitted him with a tag, and released him back into his territory unharmed. The tag was tracking his whereabouts ever since. We will periodically update this section as more data come in (about once every two weeks). The first map shows Dennis’ locations, marked sequentially. The second map shows the same locations, but these are categorized according to whether they were recorded at night (moon) or during the day (sun). Let’s learn about where Dennis hunts, where he roosts, and why this might be so.

Final update: 20 April 2021

Legend: blue – sequential owl locations, green – nest boxes for Prothonotary Warblers, brown – Library Trail markers, moon – nocturnal owl locations, sun – daylight owl locations

See a “Historical Perspective” photo album on this owl pair by John Hartgerink.