California Condors
Background
The California condor is one of the most critically endangered and monitored species in North America. Historically, the species was distributed throughout North America but by the 1980’s, there were only 22 known individuals alive. Since then, the species has been supported by extensive captive breeding and management operations, as well as widespread legislative actions to support individuals and protect populations. Today there are greater than 200 condors in the wild and their range is expanding. Even as the population is in recovery, it still faces a number of anthropogenic threats. A major threat is lead poisoning from lead fragments in carcasses. Another threat to this obligate terrestrial soaring bird and may have a great potential to impact condors is collisions with wind turbines. Wind energy is among the fastest growing energy sectors in California and surrounding areas.
Research Methods
Telemetry
We began studying the movement of California condors within the Desert Renewable Energy Conservation Plan (DRECP) area, California. We worked with our collaborators to deploy telemetry units on Condors starting in 2014 which laid the ground work for future analyses. This initial study recorded movements to understand how their flight behavior (especially altitude above ground level) responds to variation in topography and weather. We were able to use this to predict risk to birds from existing and proposed individual turbines within existing condor range; predict risk to birds from existing and proposed turbines within the projected (and expanded) future range of condors; and to identify wind and/or topographic variables that may be preferentially used by condors.
Specific Studies
As condor populations increase, we have used resource selection functions to predict future distributions and movements.
Assess risk to condors from wind turbine development by understanding flight behavior.
We studied fine scaled movements by looking at the relationship between the distances condors travel in a day, demographic characteristics, and time of year.
We looked at feeding sites to investigate the characteristics of these ground sites to identify spatiotemporal trends.
Publications
Hall J., M. Braham, L.A. Nolan, J. Conley, J. Brandt, L. Mendenhall, M. Lanzone, A. McGann, and T. Katzner. 2019. Characteristics of feeding sites of California Condors (Gymnogyps californianus) in the human-dominated landscape of southern California. The Wilson Journal of Ornithology 131(3):459–471.
Hall, J.C., I. Hong, S.A. Poessel, M. Braham, J. Brandt, J. Burnett, and T.E. Katzner. 2021. Seasonal and Age-Related Variation in Daily Travel Distances of California Condors. Journal of Raptor Research 55(3):388–398.
Poessel, S.A., Brandt, J., Mendenhall, L., Braham, M.A., Lanzone, M.J., T. E. 2018c, Flight response to spatial and temporal correlates informs risk from wind turbines to the California Condor. Condor: Ornithological Applications Vol. 120: Pp 330–342.
Poessel, S. A., Brandt, J., Miller, T. A. and Katzner, T. E. 2018a, Meteorological and environmental variables affect flight behavior and decision‐making of an obligate soaring bird, the California Condor Gymnogyps californianus. Ibis, Vol. 160: Pp. 36-53. doi:10.1111/ibi.12531