Rachel Bru


My interests include exploring habitat associations of en route migrating songbirds using remote sensing tools. I am part of an effort granted by the United States Geologic Survey that will examine seasonal nocturnal songbird migration over the southwestern United States as detected by Doppler weather surveillance radar. We will be looking at archived data from fourteen NEXRAD stations beginning with Brownsville, TX, extending in a swath to San Diego, CA.

A NEXt generation weather surveillance RADar emits a pulse of longwave electromagnetic radiation that intercepts a target at a specific pulse volume (a 3-Dimensional position) and a portion of the pulse is reflected back to the same antenna, where it is received and interpreted. Properties that differ between the outgoing pulse and return pulse (at each pulse volume) contribute to 3 types of data: reflectivity, the overall size/density of the target; radial velocity, the target’s change in position relative to the radar; and spectrum width, the similarity in movements of multiple targets per pulse volume. These properties are evident from migrating birds aloft. Considering the vast scale of bird migration, these three types of data from the NEXRAD archives will efficiently provide information on a migration event that would be extremely daunting if collected by other means. By examining archived data in a Geographic Information System, I will tackle these questions:

• How does migrant density vary regionally across the southwest?
• What habitat preferences or associations do migrants exhibit during stopover in the southwest, and how may these patterns of habitat use be shaped by regional variations in migrant density?
• To what extent does radar beam obstruction limit application of radar for bird studies in mountainous terrain?
• How do migrant flight altitude distributions vary across the southwest?
• How do migrant directions of travel vary across the southwest?

The above are images from ArcGIS software showing the incorporation of Digital Elevation Models (left) and archived NEXRAD data and land-use/land-cover data (right), both of the Tucson, AZ area.

Department of Biological Sciences
The University of Southern Mississippi
118 College Drive # 5018
Hattiesburg, MS 39406-0001



The University of Southern Mississippi. Last modified: 11 June, 2009 . Questions and Comments?
URL: http://www.usm.edu/mbrg/rodney.htm