Application of passive acoustic monitoring to compare avian populations in perennial grasslands and croplands in Nebraska

Perennial grasses, such as switchgrass ( Panicum virgatum ), have emerged as a promising and reliable feedstock for bioenergy production, offering a potential alternative to conventional feedstocks (e.g. corn). Incorporating perennial grasses into agroecosystems can also enhance biodiversity across multiple taxa, including providing crucial habitat to declining grassland bird populations. Understanding the habitat value of different bioenergy crops in relation to the surrounding landscape will require extensive data to assess the trade‐offs between bioenergy production and supporting grassland bird populations. We used passive acoustic monitoring (PAM) to compare bird communities in perennial grasslands and croplands in southwestern Nebraska. Species richness for grassland‐obligate species and species of conservation need (SCN) were consistently higher in grasslands than cornfields throughout most of the monitoring period spanning from March to September. Additionally, we found that the amount of grassland habitat around monitoring locations significantly influenced the effectiveness of field types in supporting avian populations. We found that PAM provided a more robust and detailed account of avian occupancy of perennial grasslands and croplands compared to point count surveys, but several limitations must be considered before the widespread application of this technology to answer ecological research questions. Practical Implication . Incorporating perennial grasslands into agroecosystems can not only provide an additional source of bioenergy feedstock but also support declining avian populations, contributing to the development and sustainability of the bioeconomy.