Data from: High flight costs, but low dive costs, in auks support the biomechanical hypothesis for flightlessness in penguins

Flight is a key adaptive trait. Despite its advantages, flight has been lost in several groups of birds, notably among seabirds, where flightlessness has evolved independently in at least five lineages. One hypothesis for the loss of flight among seabirds is that animals moving between different media face tradeoffs between maximizing function in one medium relative to the other. In particular, biomechanical models of energy costs during flying and diving suggest that a wing designed for optimal diving performance should lead to enormous energy costs when flying in air. Costs of flying and diving have been measured in free-living animals that use their wings to fly or to propel their dives, but not both. Animals that both fly and dive might approach the functional boundary between flight and nonflight. We show that flight costs for thick-billed murres (Uria lomvia), which are wing-propelled divers, and pelagic cormorants (Phalacrocorax pelagicus) (foot-propelled divers), are the highest recorded for vertebrates. Dive costs are high for cormorants and low for murres, but the latter are still higher than for flightless wing-propelled diving birds (penguins). For murres, flight costs were higher than predicted from biomechanical modeling, and the oxygen consumption rate during dives decreased with depth at a faster rate than estimated biomechanical costs. These results strongly support the hypothesis that function constrains form in diving birds, and that optimizing wing shape and form for wing-propelled diving leads to such high flight costs that flying ceases to be an option in larger wing-propelled diving seabirds, including penguins.

Doubly-labelled water data and energetics comparison used to generate figures: Includes several worksheets: (1) "Background" are the background deuterium and oxygen-18 measuremetns from thick-billed mures in 2006. (2) "DEE calculations" provides the raw ppm data and calculations made to estimate daily enegy expenditure in thick-billed murres. Each band number (ID) can be cross-referenced with the time-activity file. (3) "Activity costs" represents the average body mass, mass loss and activity budgets and total energy expenditure (from Part (2)) used to calculate activity-specific costs. (4) "Interspecies comparison" data used to generate figures in the paper. (5) "Morphological comparison" database used to generate the figures in the paper. (6) "PECO ppm and DEE": Pelagic cormorant ppm data and calculations used to estimate daily energy expenditure. (7) "PECOactivity": Pelagic cormorant activity budgets (derived from accelerometer files) and daily energy expenditure (from 6), along with mass and mass loss (from 6).
Supplementary_Materials_Appendix1_PECO.xls

Thick-billed murre text data files used to generate activity budgets: Dive data files from Lotek 1100 time-depth recorders recorded at 3 second intervals. Each file name has the five- or eight-digit band number that corresponds to the doubly-labelled water measurements, except for those birds that were not banded and only identified by colour marked on their chest. One recorder was also attached to the top of the blind to record ambient temperature and pressure. Each text file has, after, a pre-amble, the date-time, depth (in psi; multiply by 0.71 to approximate depth in m) and temperature (in degrees Celsius).
DLW.zip

CEFAS G6A pelagic cormorant files (Part 1a): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO1a.zip

CEFAS G6A pelagic cormorant files (Part 2): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO2.zip

CEFAS G6A pelagic cormorant files (Part 3): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO3.zip

CEFAS G6A pelagic cormorant files (Part 4): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO4.zip

CEFAS G6A pelagic cormorant files (Part 1b): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO1b.zip

CEFAS G6A pelagic cormorant files (Part 5a): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO5a.zip

CEFAS G6A pelagic cormorant files (Part 5b): Text files downloaded from the accelerometers attached to pelagic cormorants (first of five folders). Each folder refers to one individual bird (cross-referenced with doubly-labelled water data). The file name within each folder refers to the CSV file created by the CEFAS program and has the logger ID and the date the file was created (downloaded). The data file provides date/time, depth (pressure in dbars which is generally equivalent to depth in m) and acceleration in three dimensions at 25 Hz (in g), after a preamble generated by the logger that includes the daylog. Note that data is partitioned into two sections. The first section has data every 1 s, the second section has data at 25 Hz in the "fast log"; for five files, the fine-scale (25 Hz) data was only recorded when the bird was diving. The CEFAS G6A manual is here: https://www.cefastechnology.co.uk/downloads/file.aspx?file=33.
PECO5b.zip

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