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

Abstract

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.