Non-native saltcedar (Tamarix ramosissima) and giant cane (Arundo donax) have invaded major rivers of the arid Southwest U.S., with profound biological implications.
Saltcedar and giant cane alter structure and composition of riparian vegetation, river channel dynamics, soil chemistry; and negatively
affect aquatic and terrestrial wildlife populations.
The Rio Grande river has been heavily colonized by saltcedar and giant cane.
In response, Big Bend National Park (BIBE) actively removes the invasives and is attempting to restore native vegetation along the river.
These activities are historic in scale, affecting large portions of the river riparian habitat within BIBE.
Treatments include large-scale prescribed fire, manual removal, and biocontrol agents (northern tamarisk beetle, Diorhabda carinulata).
This project is to determine and monitor the response of migratory and breeding birds and butterflies to BIBE exotic species removal and native species restoration efforts.
A diverse bird community relies of the river as important habitat throughout the annual cycle.
The Yellow-billed Cuckoo (Coccyzus americanus), listed threatened under the U.S Endangered Species Act uses riparian vegetation in the region and could benefit by the treatments.
Migrating Monarch butterflies, (petitioned for listing in U.S; listed threatened in Mexico) regularly use the habitat.
Butterflies are excellent indicators of restoration success, and many butterfly species likely utilize the BIBE riparian habitat.
This project will conduct bird point counts and butterfly line transect surveys during spring migration and summer breeding seasons of 2016 and 201 7. The project will also census the population of threatened Yellow-billed Cuckoo.
NPS has established vegetation and river channel monitoring protocols at multiple sites along the river.
This study design will coordinate with these efforts, including control and experimental (treated) sites.