Boulder Chickadee Study nest temperature data, Boulder County, Colorado, 2024.

Incubation is a crucial part of the avian life cycle; eggs must be kept warm enough for embryos to develop. As egg temperatures drop rapidly when not being actively incubated, birds must balance the thermal requirements of their developing offspring with their own energy requirements when deciding to make a feeding trip. Incubation behavior can vary with ambient temperature, and across the breeding cycle. Here, we examine the incubation behavior of black-capped (Poecile atricapillus) and mountain (P. gambeli) chickadees where they live together in the Front Range of the Colorado Rocky Mountains. We deployed iButton temperature monitors in and around chickadee nests to record nest and ambient temperatures during the incubation period. For each deployment, we visually inspected temperature data to determine whether incubation was detected. For each deployment in which incubation was detected we quantified incubation behavior using the incR R package. Across the four nests for which incubation was detected, females (the incubating sex) spent about 85% of the day incubating, and left the nest about 32 times per day for an average of 6.7 minutes. On average, nest temperatures were maintained around 35˚C.

孵卵是鸟类生命周期的关键环节：鸟卵需维持足够温度以支持胚胎发育。当鸟卵未得到主动孵育时，其温度会快速下降，因此鸟类在决定外出觅食时，需在发育中后代的热需求与自身的能量需求之间达成平衡。孵卵行为会随环境温度以及繁殖周期的不同阶段发生变化。本研究针对同域栖息于科罗拉多落基山脉前缘地带的黑顶山雀（Poecile atricapillus）与山地山雀（P. gambeli）的孵卵行为展开调查。我们在山雀巢内及周边布设iButton温度记录仪，以记录孵卵期内的巢内与环境温度。针对每一次布设，我们通过目视检视温度数据以判断是否成功检测到孵卵行为。对于成功检测到孵卵行为的布设案例，我们借助incR R软件包对孵卵行为进行量化分析。在成功检测到孵卵行为的4个巢中，作为孵卵主体的雌性个体每日约有85%的时间处于孵卵状态，每日离巢约32次，每次离巢平均时长为6.7分钟。巢内温度平均维持在35℃左右。