Data from: High atmospheric temperatures and ‘ambient incubation’ drive embryonic development and lead to earlier hatching in a passerine bird

Tropical and subtropical species typically experience relatively high atmospheric temperatures during reproduction, and are subject to climate-related challenges that are largely unexplored, relative to more extensive work conducted in temperate regions. We studied the effects of high atmospheric and nest temperatures during reproduction in the zebra finch. We characterized the temperature within nests in a subtropical population of this species in relation to atmospheric temperature. Temperatures within nests frequently exceeded the level at which embryo’s develop optimally, even in the absence of parental incubation. We experimentally manipulated internal nest temperature to demonstrate that an average difference of 6°C in the nest temperature during the laying period reduced hatching time by an average of 3% of the total incubation time, owing to ‘ambient incubation’. Given the avian constraint of laying a single egg per day, the first eggs of a clutch are subject to prolonged effects of nest temperature relative to later laid eggs, potentially increasing hatching asynchrony. While birds may ameliorate the negative effects of ambient incubation on embryonic development by varying the location and design of their nests, high atmospheric temperatures are likely to constitute an important selective force on avian reproductive behaviour and physiology in subtropical and tropical regions, particularly in the light of predicted climate change that in many areas is leading to a higher frequency of hot days during the periods when birds breed.

Usage Notes

Experimental chambersThis file contains the temperature data for the experimental chambers used in the study. The column headings are all very self explanatory. Temperature is degrees Cexperimental chambers.csvIncubation lengthThis file contains the data regarding the incubation duration of clutches in the experimental treatment. Column headings are self-explanatory. The locations given in 'Colony' are all found in the Gap Hills area, as described in the paper.locationThis file contains the data for the descriptive component of the paper, characterising temperatures in different types of nest and locations in vegetation as described in the paper.Natural nestsThis file contains the data that describes the variation in temperature for natural nests at Fowlers Gap with respect to environmental variables such as location, height and orientation as described in the papernatural nests.csvNormal - LethalThis data set looks at the time that the experimental nests spent at normal or lethal incubation temperatures during the experimental period (as described in the paper).normal-lethal.csvTemperature Fowlers GapThis file contains the data on maximum daily temperature from the Fowlers Gap automated weather station run by the Australian Bureau of Meteorology. This data is presented in Figure 1.temperature FG.csv