Recipient Organization
UNIVERSITY OF ILLINOIS
2001 S. Lincoln Ave.
URBANA,IL 61801
Performing Department
Natural Resources & Environmental Sciences
Non Technical Summary
Bats could be important for the control of crop pests, thereby reducing the need for pesticides. This has important implications for ecosystem health and the economics of large-scale production agriculture. The Midwest is a critical area for production of corn, soy, and other commodity crops. Understanding the potential for bats to serve as natural pest control in agricultural systems is essential. If I demonstrate that bats could be playing a major role in insect control over large swaths of crop land, then I will prioritize communicating that information to farm producers. If I find that bats are excluded from crop lands due to a lack of roost trees, then I will provide recommendations on suitable amounts of forest cover to support bat roosts near agricultural areas so that state biologists can incorporate this information into future iterations of state wildlife action plans.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Goals / Objectives
Working at sites containing a matrix of agriculture and forest, along a gradient from mostly forested to mostly agricultural land cover, we will:1) Describe the bat populations occurring in these landscapes. This will generate baseline data to show which species are most likely to forage in agricultural areas.2) Assess the relative activity levels of common bat species and model how activity levels vary as a function of spatial and temporal factors. Such data will help us to parameterize models that attempt to describe the potential contributions of bats to pest control in different landscapes or at different time periods. 3) Describe the diets of common bat species, comparing the relative frequency of crop pests vs. other insects. Describe foraging ranges of common bat species in the forest-agriculture matrix. These data will help us to understand the potential for bats to control crop-damaging insects and how pest control by bats may be constrained by bats' foraging behaviors.
Project Methods
We will work at sites in three midwestern states. In Illinois, surveys will take place near agricultural lands in the center (vicinity of Champaign) and the south (vicinity of Carbondale or Harrisburg). In south-central Indiana, we will work near the Yellowwood and Morgan-Monroe state forests east of Bloomington. In northeast Missouri, we will work near state-managed conservation areas surrounding Kirksville. Forest cover is prevalent in Indiana, changing to a mix of forest and agricultural landcover in Missouri and southern Illinois, and agriculture is the dominant landcover in central Illinois.1. To monitor bat assemblages, we will capture bats in mist nets set over streams or trails/roads that serve as corridors through forested patches. For captured bats, we will record species, sex, age (juvenile or adult), body mass, forearm length, and wing damage score. We will band bats with unique forearm bands, which allows us to identify recaptures. We will also conduct acoustic surveysin agricultural fields and in bordering landscapes (e.g., forest patches or river corridors) to gather additional data on the composition of local bat assemblages.2. Acoustic surveys will also provide information on the relative activity levels of bats; echolocation activity provides an index of abundance, but not raw abundance because the same bat can be detected multiple times. From capture and acoustic presence/absence points for common species, we will generate spatial models that test how species distributions or occupancy are affected by landcover composition, distance to water, and proximity to potential roosts. Further, we will assess how activity levels vary with environmental factors such as local-scale features (e.g., trails vs. fields), large-scale features (e.g., percent of forest in surrounding one-km buffer), and weather (e.g., nighttime temperature or amount of precipitation). We can also determine which weeks or months bats are most active.3. Diet analyses will help us to understand what common bat species are eating and their potential to control crop pests. We will collect guano samples from captured bats or from roostsfound via radio telemetry or opportunistically. We will extract DNA from samples and sequence the CO1 gene using next-generation sequencing technology. Blasting the CO1 gene sequences against the Barcode of Life Database (www.boldsystems.org) will provide fine-scale taxonomy (often species- or genus-level) for prey consumed by bats. Currently, it is impossible to determine abundance of prey items in the guano and it is also impractical to describe insect availability due to the difficulty in sampling all available insects and the time and expertise needed to identify samples. However, we can describe relative frequency of occurrence for crop pests vs. other insects and learn the proportion of individual bats sampled that are eating crop pests. We will use radio telemetry to track bats to foraging areas, focusing on species most easily captured (e.g., Eptesicus fuscus, Myotis sodalis, and Lasiurus borealis) to ensure sufficient sample sizes and replication across the study sites. For bats of sufficient body mass, we will apply VHF or GPS radio transmitters to their backs with surgical glue. Radio transmitters will last for one to threeweeks. By overlaying foraging home ranges with underlying landcover data in a GIS, we will be able to assess foraging habitat selection. For Eptesicus fuscus, which weigh up to 25 grams as adults, we may apply 1.6-gram GPS+VHF tags to gain more fine-scale location data than can be obtained with standard radio telemetry.