Larry White
Wildlife Biologist
Bureau of Reclamation
Technical Service Center, PO Box 25007 (D-8210),
Denver, CO 80225, (303) 445-2239
Email: lwhite@do.usbr.gov

Abstract
WILDLIFE MONITORING AT SALTCEDAR LEAF BEETLE
RELEASE SITES IN PUEBLO COUNTY, COLORADO

There is concern over potential impacts to wildlife from the field release of the saltcedar leaf beetle (Diorhabda elongata). Biologists from the Bureau of Reclamation have been monitoring indicator species of birds, butterflies, and bats at the release site along the Arkansas River near Pueblo, Colorado. Data collection in riparian habitats dominated by saltcedar (Tamarix ramoisissa), plains cottonwood (Populus deltoides), and various willow species (Salix sp.) include breeding bird point counts, nest monitoring, constant effort butterfly surveys, and "Anabat" bat surveys. Our 2000 and 2001 data suggests that while saltcedar does provide habitat for breeding birds and butterflies, cottonwood and willow dominated habitat supports a greater abundance and species diversity, especially for riparian obligate species. Intense foraging by several species of bats within saltcedar stands was observed. With the anticipated spread of the saltcedar leaf beetle and reduction of saltcedar at the release site, we will track any changes to wildlife populations over the next several years. We anticipate that any local impacts from this biocontrol measure would be offset by increases in wildlife populations if replacement native riparian vegetation becomes established. If the objective of saltcedar control is to increase habitat value for breeding birds, project managers should support revegetation with native woody riparian plants followed by monitoring.