DOI: 10.5061/dryad.5mkkwh73v
title: Urban / rural acorn ant metabolic rate and running speed

description: Metabolic rates of ectotherms are expected to increase with global trends
 of climatic warming. But the potential for rapid, compensatory evolution
 of lower metabolic rate in response to rising temperatures is only
 starting to be explored. Here, we explored rapid evolution of metabolic
 rate and locomotor performance in acorn-dwelling ants (Temnothorax
 curvispinosus) in response to urban heat island effects. We reared ant
 colonies within a laboratory common garden (25 °C) to generate a lab-born
 cohort of workers and tested their acute plastic responses to temperature.
 Contrary to expectations, urban ants exhibited a higher metabolic rate
 compared with rural ants when tested at 25 °C, suggesting a potentially
 maladaptive evolutionary response to urbanization. Urban and rural ants
 had similar metabolic rates when tested at 38 °C, as a consequence of a
 diminished plastic response of the urban ants. Locomotor performance also
 evolved such that the running speed of urban ants was faster than rural
 ants under warmer test temperatures (32 and 42 °C) but slower under a
 cooler test temperature (22 °C). The resulting specialist-generalist
 tradeoff and higher thermal optimum for locomotor performance might
 compensate for evolved increases in metabolic rate by allowing workers to
 more quickly scout and retrieve resources.
description: Acorn ant running speed and
 metabolic rate meta-data   <b>Running speed
 (AcornAntRunningSpeedDryad.csv)</b> Colony – a unique, alphanumeric
 identifier for each colony Individual – a generic numeric
 identifier for each individual tested within each colony; the identifier
 is the same for a given individual across the multiple test
 temperatures TestTemperature – a numeric
 vector corresponding with each of the temperatures at which running speed
 was tested, including 22, 32 and 42 °C SourcePopulation – a character
 vector for whether the ants originated from an urban site or a rural
 site Site – a
 character vector indicating the site name from which the ants
 originated RunningSpeedmmPerSecond – a
 numeric vector indicating the running speed in units of mm per second for
 an individual at a given distance interval and at a given test
 temperature DistanceInterval – a numeric
 vector indicating the distance interval over which the running speed was
 recorded; distance intervals are 20 mm each, over a span from 0 to 100 mm;
 possible distance interval values include 20 (indicating the distance run
 from 0 to 20 mm), 40 (indicating the distance run from 20 to 40 mm), 60
 (indicating the distance run from 40 to 60 mm), 80 (indicating the
 distance run from 60 to 80 mm), 100 (indicating the distance run from 80
 to 100 mm) NumberWorkers – the number of
 workers present in a given colony at the time of running speed
 testing NumberBrood – the number of brood
 present in a given colony at the time of running speed testing
 NumberQueens – the number
 of queens present in a given colony at the time of running speed
 testing   <b>Activity within the
 metabolic chamber
 (AcornAntRespirometryActivityDryad.csv)</b> Colony – a unique, alphanumeric
 identifier for each colony TestTemperature – a numeric
 vector corresponding with each of the temperatures at which activity in
 the respirometry equipment was tested, including 25 and 38 °C
 SourcePopulation – a
 character vector for whether the ants originated from an urban site or a
 rural site Site –
 a character vector indicating the site name from which the ants
 originated NumberWorkers – the number of
 workers present in a given colony at the time of activity
 testing NumberBrood – the number of brood
 present in a given colony at the time of activity testing NumberQueens – the number of
 queens present in a given colony at the time of activity testing
 ColonyMassInGrams – the
 total biomass of the colony in grams NumberActiveWorkers – the number
 of workers actively moving around the respirometry chamber during a given
 time interval TimeInterval – the number of
 seconds elapsed since the beginning of activity monitoring   <b>Metabolic rate
 (AcornAntMetabolicRateDryad.csv)</b> Colony – a unique, alphanumeric
 identifier for each colony SourcePopulation – a character
 vector for whether the ants originated from an urban site or a rural
 site DecimalLongitude – a numeric
 vector indicating the decimal degrees of longitude for the colony
 collection site DecimalLatitude – a numeric
 vector indicating the decimal degrees of latitude for the colony
 collection site Site – a character vector
 indicating the site name from which the ants originated ColonyMassInGrams – the total
 biomass of the colony in grams TestTemperature – a numeric
 vector corresponding with each of the temperatures at which metabolic rate
 was tested, including 25 and 38 °C CO2 – carbon dioxide
 concentration in ppm NumberWorkers – the number of
 workers present in a given colony at the time of metabolic rate
 testing NumberBrood – the number of brood
 present in a given colony at the time of metabolic rate testing
 NumberQueens – the number
 of queens present in a given colony at the time of metabolic rate
 testing