DOI: 10.5061/dryad.4b8gthtkd
title: The effect of ambient temperature on bird embryonic development: A comparison between uniparental incubating silver-throated tits and biparental incubating black-throated tits

description: The temperature experienced by avian embryos during development has
 important impacts on their growth and post-hatching phenotypes. Ambient
 temperature can directly affect avian nest temperature and indirectly
 affect it through its impact on parental incubation behaviours. Because
 the nests of uniparental incubators are usually left unattended more
 frequently than the nests of biparental incubators whose nests can be
 attended by another bird when one bird leaves the nest, we predict that
 the effect of ambient temperature on nest temperature and thus on
 embryonic development (specifically, incubation period length and hatching
 success) and post-hatching phenotype (i.e. potential carry-over effect on
 nestling body mass and condition) should be greater in uniparental
 incubators than in biparental incubators. To test this prediction, we
 studied two congeneric species, the biparental incubating black-throated
 tits (Aegithalos concinnus) and the uniparental incubating silver-throated
 tits (A. glaucogularis). We found that although the two species’ embryos
 both developed faster (shorter incubation period length) when ambient
 temperature was higher, the slope was significantly greater for
 silver-throated tits than for black-throated tits, consistent with our
 prediction of a greater effect of ambient temperature on embryonic
 development in silver-throated tits. However, the result was not due to a
 greater effect of ambient temperature on nest temperature because nest
 temperatures of the two species had positive relationships with ambient
 temperature in a similar way. Therefore, it implies a greater response of
 silver-throated tit embryos to temperature change. In addition, ambient
 temperature during the incubation stage did not affect either hatching
 success or nestling body mass and condition in both species. Although our
 predictions were not fully supported, our findings highlight the different
 responses of embryonic development to environmental changes between a
 uniparental incubator and a biparental incubator and suggest further
 research to explore the mechanisms.
description: # Data from: The effect of ambient temperature on bird embryonic
 development: a comparison between uniparental incubating silver-throated
 tits and biparental incubating black-throated tits
 ##### **[Article link:
 https://doi.org/10.1111/jav.03168](https://doi.org/10.1111/jav.03168)**
 This dataset (Hu_2023_JAB_Tits_data.xlsx) includes the details of the
 "nest temperature (°C)", "incubation period length (in
 days)", "Hatching success", and "nestling body mass
 (g) & condition" of the silver-throated tits and black-throated
 tits, which were collected from 2008 to 2022 (except 2020 when COVID-19
 pandemic occurred) in the Dongzhai National Nature Reserve of Henan
 Province, located in central China (31.95 °N, 114.25 °E). It also includes
 related data about ambient temperature (°C), clutch size, brood size, etc.
 Nest temperature (Sheet 1): Nest temperature data (°C) were recorded by
 the temperature loggers. We used temperature data loggers to monitor the
 nest temperature (i.e. the temperature inside the nest bowl) of the two
 species for eight years (specifically, from 2008 to 2012 and in 2019,
 2021, and 2022). In the earlier years (2008–2010), thermistor probes were
 directly installed into the centre of the clutches. In the later years
 (2011, 2012, 2019, 2021, and 2022), the thermistor probe was enclosed in
 an artificial egg made of paraffin wax (of similar size to the eggs of the
 real eggs of the studied species) before being placed inside the nest. The
 temperature loggers were installed into the nests during either the
 egg-laying period or the incubation stage but were mostly installed on or
 before the day of clutch completion. The recording intervals of the
 temperature loggers were mostly set as 1 min, with some exceptions set at
 10 s, or at 0.5, 1.5, 2, or 2.5 min. Incubation period length (Sheet 2):
 Incubation period length (in days) was calculated as the number of days
 from the day of clutch completion to the day before hatching. Hatching
 success (Sheet 3): Hatching success was the proportion of hatched eggs
 relative to clutch size. Nestling data (Sheet 4): Nestling data mainly
 included the nestlings' body mass (g) and condition. Nestling body
 condition was calculated as the "scaled mass index" (see Peig
 and Green 2009 for details) using body mass and tarsus length, which
 provides a body condition index standardized by body size. ref: Peig, J.
 and Green, A. J. 2009. New perspectives for estimating body condition from
 mass/length data: The scaled mass index as an alternative method. – Oikos
 118: 1883–1891.