Meeting Abstract
The developmental environment is known to have lasting effects on phenotype and fitness. In oviparous species, the thermal environment embryos experience during incubation has been shown to strongly determine a range of traits. However, the exact mechanisms by which temperature during development influences phenotype remain largely unknown, and this is especially true for environments that experience temperature fluctuations. In birds, eggs can experience large temperature fluctuations when parents leave the nest to forage or due to weather events. Additionally, a predicted consequence of global climate change is a higher degree of climactic variation meaning less stable and consistent temperatures. To evaluate how temperature fluctuations during development may influence organism phenotype at hatch and beyond, we incubated zebra finch (Taeniopygia guttata) eggs under one of three conditions; one that periodically cooled eggs five times a day, one that held a constant optimum control temperature (37.4°C), and one that held a constant low temperature (36.4°C), which was the average incubator temperature of the periodically cooled eggs. Embryonic heart rate was measured at two time points during development via a Buddy digital heart rate monitor. Incubation duration, mass change during incubation, hatching success, and hatchling morphology were also recorded. We are currently analyzing the effects of periodic cooling during incubation on embryonic development, as well as morphology at hatch, in order to assess the relationship between embryonic heart rate, hatchling success, and hatchling phenotype.
