Semi-Arid Shrublands Require Little On-Going Management to Remain Suitable for Black-Capped Vireos

• DOI: 10.1637/19-027
• Publication Date: 2020-01-01
• Authors: Charlotte M. Reemts; C. Craig Farquhar; Jacqueline R. Fer...; Richard M. Kostecke
• Keywords: Shrubland; Cowbird; Larrea

The recently delisted black-capped vireo (Vireo atricapilla, hereafter “vireo”) nests in shrublands from south-central Oklahoma to southwestern Tamaulipas, Mexico. Vireos are considered be “conservation-reliant” because they require on-going habitat maintenance and control of brown-headed cowbirds (Molothrus aster, “cowbird”). Most long-term research has been conducted comparatively mesic parts the range, but more arid comprise larger proportion their distribution. Our study area is a Nature Conservancy preserve Texas (Val Verde County), which does not manage or cowbird populations. We examined change characteristics (2002 vs 2017) bird detections (1997-2001 2013-2017) at two sites: alluvial terrace an adjacent semi-arid canyon. site recovering historic flood 1950s that scoured vegetation bare ground; canyon experienced any major disturbance time frame. Vireo declined site. Several important changed significantly: density leaf cover lower heights (<1 m) decreased, number shrubs increased, tree height increased. At site, increased all classes above 0.5 m, shrub width While become less suitable for vireos, supported breeding vireos throughout our period despite lack landscape management control. data suggest undisturbed persist as mature viable extended periods, possibly perpetuity, with little no need management. These low-maintenance will especially persistence