Large scale forest restoration treatments are currently underway to treat the ponderosa pine forests on Camp Navajo using restoration prescriptions to restore ecosystem function to the ponderosa pine forest community. Forest restoration treatments involve removing accumulated leaf litter and reducing density of over-stocked forest stands through prescribed burning and mechanical thinning. Thinning and burning operations may alter species richness and density of certain wildlife species. Bats serve important ecosystem functions in ponderosa pine forests, (e.g. bats are predators of forest insects) but the effects of forest restoration (i.e., changes in resource availability) on forest dwelling bats are poorly understood. It is critical that we understand the effects of forest restoration prescriptions on these species before decisions are made to restore large areas. The purpose of this study is to collect pre-treatment data for eventual post-treatment comparison in order to understand the affects of ecosystem restoration on forest dwelling bats within ponderosa pine communities.
The study is restricted to the western portion of Camp Navajo Army National Guard Depot near Flagstaff, Arizona.
We currently have 8 groups of artificial roosts in each of three forest treatment areas (thin, thin and burned, and no treatment). Each group contains 6 trees with artificial roosts. An equal number of roosts have been attached on the north, east, south, and west sides of trees giving us a total of 576 artificial roosts. Roost construction enables an observer to count the number of individual bats using the roost, and to determine their species. To determine bat box use, boxes were checked weekly starting in May and monitored until late October. Bats were removed from boxes and banded using colored aluminum bird leg bands. Color band combinations allowed us to visually confirm the species and the treatment areas where bats were originally captured. In addition to bat box captures, bats were also trapped with mist nets. Radio transmitters were placed on mistnetted bats to locate natural roosts in the treatment areas. Standard forest vegetation structure was sampled at both artificial and natural roosts. From 2005 to 2009, 948 bats consisting of seven species were captured from bat boxes. Bat box use peaked in mid-August and bats selected east and west facing boxes more often. During mistnetting, we captured a total of 503 bats consisting of 15 species. Preliminary analysis suggests thinning may have an impact on bat box use, however, more treatments will need to be finished before clear results are seen.
The primary benefit of this study is developing baseline empirical data on select bat species diversity and relative abundance for the subsequent comparison to post-treatment ponderosa pine forests. These results will suggest how forest management restoration prescriptions affect forest dwelling bats. Such information could influence future prescriptions, or alleviate concerns about the impacts of forest restoration prescriptions on these wildlife species.
For more information contact:
Michael Ingraldi, Ph.D.
Arizona Game and Fish Department
5000 W. Carefree Highway
Phoenix, AZ 85086-5000 .
Phone: (928) 523-5625 E-mail: email@example.com