DOI: 10.5061/dryad.xd2547dr3
title: Dataset: Thermoregulation of understory birds in lowland Amazonia

description: Understanding the capacity for thermoregulation is critical for predicting
 organismal vulnerability to climate change, especially in lowland tropical
 rainforests, where warming conditions combine with high humidity and
 limited elevational or latitudinal refugia. Here, I focused on nine
 species of ground-foraging insectivorous birds in the genus Myrmoderus,
 Myrmornis, Hylopezus, Myrmothera, Formicarius, and Sclerurus—sensitive
 forest specialists characterized by recently documented population
 declines in both disturbed and undisturbed forests. Using high-resolution
 data from loggers deployed on birds and their environment, I examined
 whether and how birds used thermoregulation and whether ambient water
 provided cooling opportunities. Variation in the rate of temperature
 change over the diel cycle suggested that all species employed behavioral
 and physiological thermoregulation, but some patterns differed by species’
 phylogenetic relatedness. All species warmed hours before their
 environment at sunrise, then experienced lower temperature increases at
 midday relative to the ambient thermal flux. These morning warming periods
 peaked around sunrise for all but Sclerurus rufigularis and constituted
 the diel temperature change maxima for five of the nine species. Six
 species exhibited pronounced oscillations in temperature change consistent
 with regular bathing around sunset, possibly for thermoregulatory or other
 purposes. This oscillation was the most prominent feature in the diel
 thermal flux for all three Sclerurus species and, to a lesser extent, for
 Myrmoderus ferrugineus, Myrmornis torquata, and Myrmothera campanisona.
 Local rainfall reduced ambient temperatures, and birds experienced
 stronger cooling in the wet season and with higher rainfall intensity.
 However, rain-induced cooling events were markedly absent in all three
 Sclerurus spp. These results highlight the fundamental role of water in
 avian thermoregulation and suggest that terrestrial insectivores attempt
 to maintain thermal homeostasis throughout the diel cycle. The observed
 thermoregulatory behaviors highlight a potentially critical aspect of
 their vulnerability—thermal regimes are profoundly altered by forest
 disturbance, climate change, and their combination.
description: # Dataset: Thermoregulation of understory birds in lowland Amazonia
 [https://doi.org/10.5061/dryad.xd2547dr3](https://doi.org/10.5061/dryad.xd2547dr3) ## GENERAL INFORMATION Principal investigator contact information Name: Vitek Jirinec Institution: Integral Ecology Research Center Address: Blue Lake, CA, USA Email: vjirinec@iercecology.org Date of data collection: 2017 to 2019 ## SHARING/ACCESS INFORMATION NA ## DATA & FILE OVERVIEW Please see related data at: [https://doi.org/10.5061/dryad.c866t1g84](https://doi.org/10.5061/dryad.c866t1g84) [https://doi.org/10.5061/dryad.5qfttdz7z](https://doi.org/10.5061/dryad.5qfttdz7z) ### DATA-SPECIFIC INFORMATION FOR: temperature\_lag1\_dataset.csv 1\. Number of variables: 10 2\. Number of cases/rows: 10485575 3\. Variable List: * group: binary category (bird, ambient) for logger data source * sp: if bird, scientific name for species * bn: if bird, band number * id: unique individual/logger identifier * t.AMT: local timestamp * time.HM: local time * time.H: decimal hour * degC: temperature reading (degrees Celsius) * d.degC: temperature change at lag 1 (degrees Celsius) * n: sequential observation rank per logger (2:n) ### DATA-SPECIFIC INFORMATION FOR: analysis\_dataset.csv 1\. Number of variables: 10 2\. Number of cases/rows: 10147 3\. Variable List: * sp: scientific name for species * id: unique individual identifier * site: study site (Cabo Frio or Km41/Camp41) * date: date * d.degC.max: maximum logger temperature change for that individual at lag 1 (degrees Celsius) * d.degC.min: minimum logger temperature change for that individual at lag 1 (degrees Celsius) * season: wet, dry * degC.mean: mean temperature recorded by the nearest weather station (soil) transect (degrees Celsius) * degC.max: maximum temperature recorded by the nearest weather station (soil) transect (degrees Celsius) * rain.intensity: maximum change in soil moisture at lag 1 (percent volumetric water content) recorded by the nearest weather station