Program and Agenda

Abstract

RESPONSES OF RIPARIAN BIRDS TO (MOSTLY) PASSIVE RESTORATION OF MONO LAKE TRIBUTARIES

Riparian ecosystems of three major tributaries of Mono Lake, CA, USA have been subjected to decades of cumulative ecological damage caused by water diversions, water impoundments, and livestock grazing. Negotiations leading up to a landmark 1994 legal decision and a 2011 settlement agreement initiated restorative processes on these streams as early as the mid 1980’s. Some active restoration has taken place (e.g., plantings, channel reopenings, and large woody debris placement), but most restoration has been passive (namely returning minimum requirement water flows and the cessation of livestock grazing). Court-ordered restoration plans did not prescribe bird population monitoring as a means by which to measure restoration progress. Nonetheless, interested stakeholders, including non-governmental organizations, academic institutions, and governmental agencies undertook sixteen years (1998-2013) of riparian bird research and monitoring to assess avian responses to restoration efforts. The comparison of contemporary bird species composition data to historic accounts and environmental impact assessments provides evidence that restoration efforts have been generally successful in creating breeding habitat for an expected assemblage of riparian breeding birds. Relative densities of shrub and ground nesting birds versus canopy and cavity nesting birds differed among tributaries, however, suggesting variability in community responses to different restoration trajectories among sites. Research on species of conservation concern including the Yellow Warbler (Setophaga petechia), Willow Flycatcher (Empidonax traillii), and brood parasite Brown-headed Cowbird (Molothrus ater) revealed multi-scale stressors affecting population processes. We found that while some local stressors can be addressed by restoration plans and practices (e.g., vegetation and water management), larger scale stressors (e.g., distances to source populations, cowbird foraging behaviors) are often not.

Authors

Heath, S. K., University of California, Davis, USA, skheath@ucdavis.edu

McCreedy, C., Point Blue Conservation Science, USA, cmccreedy@pointblue.org

Latif, Q. S., Rocky Mountain Research Station, U.S. Forest Service, USA, qlatif@fs.fed.us

Tonra, C. M., Migratory Bird Center, Smithsonian Conservation Biology Institute, TonraC@si.edu

Details

Oral presentation

Session #:S16
Date: 9/25/2014
Time: 13:45
Location: Longs Peak - Diamond West

Presentation is given by student: Yes