Anthropogenic noise does not surpass land cover in explaining habitat selection of Greater Prairie-Chicken (Tympanuchus cupido)

Over the last century, increasing human populations and conversion of grassland to agriculture have had severe consequences for numbers of Greater Prairie-Chicken (Tympanuchus cupido). Understanding Greater Prairie-Chicken response to human disturbance, including the effects of anthropogenic noise and landscape modification, is vital for conserving remaining populations because these disturbances are becoming more common in grassland systems. Here, we evaluate the effect of low-frequency noise emitted from a wind energy facility on habitat selection. We used the Normalized Difference Soundscape Index, a ratio of human-generated and biological acoustic components, to determine the impact of the dominant acoustic characteristics of habitat relative to physical landscape features known to influence within–home range habitat selection. Female Greater Prairie-Chickens avoided wooded areas and row crops but showed no selection or avoidance of wind turbines based on the availability of these features across their home range. Although the acoustic environment near the wind energy facility was dominated by anthropogenic noise, our results show that acoustic habitat selection is not evident for this species. In contrast, our work highlights the need to reduce the presence of trees, which have been historically absent from the region, as well as decrease the conversion of grassland to row-crop agriculture. Our findings suggest physical landscape changes surpass altered acoustic environments in mediating Greater Prairie-Chicken habitat selection.

Temperature, wind, vegetation, and roads influence incubation patterns of Greater Prairie-Chickens (Tympanuchus cupido pinnatus) in the Nebraska Sandhills, USA

Avian incubation involves behavioral decisions that must balance trade-offs between the incubating bird’s survival and current and future reproductive success. We evaluated variation in incubation off-bout duration and frequency among Greater Prairie-Chickens (Tympanuchus cupido pinnatus (Brewster, 1885)) in the Nebraska Sandhills, USA. Greater Prairie-Chicken life history favors incubation behaviors that prioritize success of the current breeding attempt over adult survival. Previous observations suggest incubating females make these behavioral decisions based on ambient temperature conditions, their own body condition, and predation risk. We monitored nest attendance by females at 30 Greater Prairie-Chicken nests to identify proximate cues used to make behavioral decisions regarding incubation. We recorded 930 incubation off-bouts. Females took 1.9 ± 0.7 off-bouts/day (mean ± SD), each with a mean (±SD) duration of 43.3 ± 24.1 min. Off-bouts were shorter in duration at higher wind speeds, at lower ambient temperatures, at nests with less cover, and at nests closer to roads. Females were most likely to leave the nest during mid-morning and evening, as are most gallinaceous birds, and incubation off-bouts became less frequent later in the season. We did not observe differences in incubation behavior between nests that failed and those that successfully hatched one or more chicks.