DOI: 10.5061/dryad.pj3133r
title: Data from: Free‐moving artificial eggs containing temperature loggers reveal remarkable within‐clutch variance in incubation temperature

description: Incubation is a crucial aspect of avian parental care and measuring
 incubation temperature in the wild can improve our understanding of life
 history tradeoffs and inform conservation efforts. However, there are
 challenges associated with measuring the temperature of eggs in natural
 nests. Most studies to date have measured incubation temperature by using
 a single, stationary logger in each nest. However, real eggs are rotated
 and moved throughout the nest by the parent during the incubation period,
 and thus, a stationary logger may not accurately represent the temperature
 experienced by individual eggs within the entire clutch. We recorded
 incubation temperature in nests by using multiple, mobile artificial egg
 temperature loggers. We installed six mobile loggers and one stationary
 logger in wood duck (Aix sponsa) nests to compare the two logger types in
 the field. We found that at a given ambient temperature, mobile loggers
 recorded lower average and more variable temperatures than stationary
 loggers. Further, temperatures recorded by stationary loggers showed no
 relationship with clutch size, while mobile loggers captured temperatures
 that were lower and more variable as clutch size increased. Also, the
 multiple mobile loggers revealed that eggs within a nest experienced a
 substantial range of temperatures throughout the incubation period. We
 discuss potential limitations of this method, but believe that it is a
 promising way to collect biologically‐relevant incubation temperature data
 and provides an opportunity to advance our understanding of incubation
 temperature as a parental effect.
description: Incubation temperature
 in wood ducksData were collected from
 incubating wood duck hens nesting in nest boxes at the Savannah River Site
 in Aiken, SC, USA in Spring-Summer 2014. Two types of temperature loggers
 (6 mobile and 1 stationary) were installed into nest boxes to record egg
 temperature when hens were incubating. Both logger types were modified and
 inserted into artificial eggs filled with wire-pulling lubricant to mimic
 the thermal properties of real eggs. We also recorded ambient temperature
 within the nest box, and measured hen body mass and tarsus length.
 Averages and standard deviations in temperature were calculated for each
 nest from the entire incubation period (~30 d). Averages and standard
 deviations for the mobile loggers are averages of the 6 loggers in each
 nest. Logger type: M = mobile; ST = stationary. Clutch size includes all
 fake eggs (i.e., temperature loggers). All average incubation temperatures
 and standard deviations in temperature reflect a correction for slight
 differences between temperature recording devices. In three nests, one or
 two mobile loggers were pushed to the side of the nest either in the
 middle or end of incubation. 'Excluding pushed loggers'
 indicates that these pushed eggs were removed from the mean and standard
 deviation in temperature calculations for their respective
 nests.Hope_et_al_data.xlsx