Data from: Ageing gracefully: physiology but not behaviour changes with age in a diving seabird

A higher proportion of long-lived animals die from senescence than short-lived animals, yet many long-lived homeotherms show few signs of physiological aging in the wild. This may, however, differ in long-lived diving homeotherms that frequently encounter hypoxic conditions and have very high metabolic rates. To examine aging within a long-lived diving homeotherm, we studied resting metabolism and thyroid hormones (N = 43), blood oxygen stores (N = 93), and foraging behaviour (N = 230) of thick-billed murres (Uria lomvia). Because murres dive exceptionally deep for their size and have a very high metabolism, we expected that aging murres would show signs of physiological senescence. We paid particular attention to resting metabolism as we argue that these maintenance costs reflect those experienced during deep dives. Blood oxygen stores (hematocrit), resting metabolic rate and thyroid hormone levels all declined significantly with age in incubating murres 3-30 years of age. In birds measured longitudinally three years apart, thyroid hormone levels and hematocrit were both significantly lower, suggesting progressive changes within individuals rather than selective disappearance of individuals with high metabolic rates. Within our longitudinal dataset, we found no effect of age on dive depth, dive shape, or behavioural aerobic dive limit. A meta-analysis of changes in resting metabolism with age across 15 animal species demonstrated that such declines are pervasive across most of the kingdom. The rate of decline was highest in species with high energy expenditure supporting a linkage between metabolism and senescence. Physiological changes occurred in tandem with advancing age in murres, but offset each other such that there was no detectable decline in behavioural performance.Time-depth recorders attached to chick-rearing murres in 2004Raw text files generated by Lotek download software. After a preamble including the logger serial number (8XXX), the data file presents three columns: the time & date, the temperature in degrees Celsius and the pressure in psi. To convert psi into approximate depth, multiply by 0.705. The text files are organized into three folders representing the three deployments. Each file name also has the last five digits of the band number of the individual bird to whom the TDR was attached (the total band number is 996XXXXX, where XXXXX is the unique identifier of the bird and included in the title of the file). The band number serves as the identifier to relate it to the meta-data file that includes sex, age and other attributes of the bird.2004 Chick-rearing.zipTime-depth recorders attached to chick-rearing murres in 2006Raw text files generated by Lotek download software. After a preamble including the logger serial number, the data file presents three columns: the time & date, the temperature in degrees Celsius and the pressure in psi. To convert psi into approximate depth, multiply by 0.705. The text files are organized into two folders: FW and DLW. The FW folders include all those birds that were observed during feeding watches. The DLW folder includes all those birds that were injected with doubly-labelled water (except controls labelled as "CON"). There was no statistical difference in the behaviour of DLW-injected and control birds (for more details, see: http://datadryad.org/resource/doi:10.5061/dryad.23td2). Each folder then has a number of subfolders representing the different deployment dates. Each file name also has either all eight digits of the band number (if the band number started with 785) or the last five digits of the band number (if the band number started with 996, which was dropped for simplification in the field) of the individual bird to whom the TDR was attached. The band number serves as the identifier to relate it to the meta-data file that includes sex, age and other attributes of the bird. In some cases, additional information (e.g. site location) were included in the file name to simplify work in the field, but that is not needed to uniquely identify the bird.2006 Chick-rearing.zipTime-depth recorders attached to chick-rearing murres in 2007Raw text files generated by Lotek download software. After a preamble including the logger serial number, the data file presents three columns: the time & date, the temperature in degrees Celsius and the pressure in psi. To convert psi into approximate depth, multiply by 0.705. The text files are organized into three folders representing the different deployments. Each file name has the last five digits of the band number (the band number started with 996, which was dropped for simplification in the field) of the individual bird to whom the TDR was attached. The band number serves as the identifier to relate it to the meta-data file that includes sex, age and other attributes of the bird. In some cases, additional information (e.g. site location) were included in the file name to simplify work in the field, but that is not needed to uniquely identify the bird.2007 Chick-rearing.zipAccelerometers attached to chick-rearing murres in 2010, Part 1Accelerometer files produced by Little Leonardo accelerometers. Each subfolder has the last five digits of the band number of the individual murre to whom the accelerometer was attached, and serves as the unique identifier to cross-reference with other information (sex, age, etc.). Within each folder, there are five files: the raw data (obj) file and a text file for the temperature log (in degrees C, every 1 s), depth (in m, every 1 s) and acceleration in the X and Y directions, in 32 Hz increments.2010 Accelerometers, Part 1.zipAccelerometers attached to chick-rearing murres in 2010, Part 2Accelerometer files produced by Little Leonardo accelerometers. Each subfolder has the last five digits of the band number of the individual murre to whom the accelerometer was attached, and serves as the unique identifier to cross-reference with other information (sex, age, etc.). Within each folder, there are five files: the raw data (obj) file and a text file for the temperature log (in degrees C, every 1 s), depth (in m, every 1 s) and acceleration in the X and Y directions, in 32 Hz increments.2010 Accelerometers, part 2.zipAccelerometers attached to chick-rearing murres in 2011Accelerometer files produced by Little Leonardo accelerometers. Each subfolder has the last five digits of the band number of the individual murre to whom the accelerometer was attached, and serves as the unique identifier to cross-reference with other information (sex, age, etc.). Within each folder, there are five files: the raw data (obj) file and a text file for the temperature log (in degrees C, every 1 s), depth (in m, every 1 s) and acceleration in the X and Y directions, in 32 Hz increments.2011 Accelerometers Chick-rearing.zipTime-depth recorders attached to chick-rearing murres in 2013Output from LUL TDR recorders sent to France for downloading. The Excel worksheet includes a tab for each individual bird. Each tab shows the last five digits of the band number of the individual the TDR was attached to. The total band number is 996XXXXX where XXXXX is the last five digits and uniquely identifies the bird. Each recorder was attached to multiple birds, and downloaded at the end of the field season (it was not possible to download the TDR in the field, so it had to be sent to France to be opened, downloaded and destroyed). Each tab presents four columns: date-time, temperature in degrees C, pressure in mbar (note that surface pressure is ~1040 mbar [but varies among loggers] and should be subtracted to determine depth. To convert mbar into depth, divide by 1000) and luminosity in lux. As the TDR was attached to the leg via tape over the logger, the luminosity readings are not representative. The first data file shows that meta-data. As several of the TDRs quit part way through the season/never started, many of the birds for which the TDR was attached have no associated data.TDRFiles_2013.xlsxTime-depth recorders attached to chick-rearing murres in 2009Output from Lotek LAT program for Lotek time-depth recorders attached in 2009. There are two folders: TDR_ACC_H2O and TDR_rearing. The birds in the folder TDR_ACC_H2O were injected with doubly-labelled water, which does not statistically affect their behaviour (see Elliott et al. 2013. PNAS). For the first 24 h, they were also equipped with an accelerometer (see http://datadryad.org/resource/doi:10.5061/dryad.40gk7 for details of deployments). Accelerometers were also attached to some of the birds in the second folder, which were observed for feeding watches. The meta-data file has details on which had accelerometers attached. Within each folder, there is a subfolder with the band combination (9 digits beginning with 1186 or 5 digits). For band numbers with 5 digits, the prefix was 996 so that the total band combination was 996XXXXX where XXXXX is the band number provided in the subfolder heading. The band combination for each individual ties the TDR recording with the meta-data (sex, age of the bird). Each folder includes two binary files (which can be read into the Lotek program) and a text file. The text file has four columns: the record number, the date-time, the pressure in dBar (converts directly into depth in m) and temperature in degrees Celsius.2009 Chick-rearing.zipAccelerometers attached to chick-rearing murres in 2009Raw binary (obj) files from Little Leonardo loggers and the text files output from the Little Leonardo software. In addition to the attached file, all of the files in the data appendix here: http://datadryad.org/resource/doi:10.5061/dryad.40gk7 were included in the analyses (those birds were injected with doubly-labelled water, but doubly-labelled water does not statistically influence behaviour, Elliott et al. 2013 PNAS), except for the incubating birds: 65548, 62706, 69971 and 81061. Those files were not duplicated here. The file names have the five digit band number (prefix 996 so that the total band number is 996XXXXX where XXXXX is the five digit band number included in the file name), for cross-referencing with meta-data (sex, age). For each individual, there is a text file for temperature (in degrees C) and depth (in m) in 1 s increments and acceleration in the X and Y directions in 16 Hz increments (arbitrary units).2009 Accelerometers Chick-rearing.zipTime-depth recorders attached to chick-rearing murres in 2008Output of Lotek Tagtalk program for time-depth recorders attached to the leg band of murres in 2008. Each file name includes the logger serial number (5XX) and 8-digit unique band number for cross-referencing with metadata (sex, age, etc.). For each logger deployment, there were two files: a 'basic log' ending in _00 that recorded temperature and pressure every 30 s and a 'conditional log' ending in _01 that recorded temperature and pressure every second when dbar was above a critical value. For the loggers with serial numbers 505, 510 and 511, that value was 28 "dbar". For the loggers with serial numbers 509 and 518, that value was 18 "dbar". For the logger with serial number 512, that value was 4 "dbar". Note that there was a flaw in the loggers and every pressure value needs to be divided by 4 to convert the reported dbars to actual dbars. As dbar = m, to convert pressure into depth in m, divide the recorded number by 4.Chick-rearing 2008.zipTime-depth recorders attached to chick-rearing murres in 2005Raw text files generated by Lotek download software. After a preamble including the logger serial number, the data file presents three columns: the time & date, the temperature in degrees Celsius and the pressure in psi. To convert psi into approximate depth, multiply by 0.705. The text files are organized into folders representing the deployments. Each file name also has the unique eight digit band number of the individual bird to whom the TDR was attached. The band number serves as the identifier to relate it to the meta-data file that includes sex, age and other attributes of the bird.2005 Chick-rearing.zipTime-depth recorders attached to chick-rearing murres in 2009Output from various Lotek time-depth recorders. Refer to the same folders from each year for chick-rearing birds for information on the format of each file type. In 2004, some birds had handicaps attached and 2004 data were therefore excluded from analyses. In 2008, because of an error in the programming of the tag, the actual pressure reading is 1/4 the reported reading and therefore the conditional log filled rapidly.Incubating.zipTime-depth recorders attached to incubation birds in 2004-09Output from various Lotek time-depth recorders. Refer to the same folders from each year for chick-rearing birds for information on the format of each file type. In 2004, some birds had handicaps attached and 2004 data were therefore excluded from analyses. In 2008, because of an error in the programming of the tag, the actual pressure reading is 1/4 the reported reading and therefore the conditional log filled rapidly.Incubating.zipAccelerometers attached to incubating birds in 2009Binary (obj) files and text files (depth in m every 1 s; temperature in degrees C every 1 s; acceleration at 16 Hz in both X and Y axes) for incubating birds in 2009. The band numbers, in the title of each file, provide the unique identifier to associated the dive file with the metadata.Incubating Accelerometers.zipTime-depth recorders attached to birds simultaneously with GPS units in 2010-11Time-depth recorder files generated by Lotek download program for recorders attached to birds that also had GPS units on their backs. Because the GPS units likely also altered behaviour, and due to the small sample size per year, these data were excluded from the dataset analyzed within the manuscript but are included here for completeness. The 8 or 9 digit band number is in the file name and uniquely associates the individual with the meta-data. The data files include columns for date-time, temperature (degrees C) and pressure (in dbar, which is equivalent to depth in m).GPS + Time-depth recorders.zipMeta-data and dive summaryThis file has two tabs. The first tab provides the meta-data collected along with each deployment, such as sex and age of each bird. The second tab tabulates the depth and duration of all dives completed by chick-rearing birds within the dataset that were >5 m in depth. We assumed that the pressure sensor of all Lotek TDRs were comparable. However, as we deployed Little Leonardo and Lotek TDRs simultaneously, we were able to demonstrate that they agreed on dive duration but not dive depth. All Little Leonardo depth values in this spreadsheet have been converted to their equivalent Lotek depth using the equation given in the manuscript: Lotek Depth = 0.897*(Little Leonardo Depth) + 0.781 (R2 = 0.998). Care should be taken when comparing different devices because of differences in the calibration of the pressure transducer and because larger devices impact the dive behaviour of murres (Elliott et al. 2007. CJZ).AllDivesover5m.xlsxHematocrit, T3 and Metabolic Rate dataExcel spreadsheet with two tabs: one with hematocrit data and the other with T3/metabolic rate data. Headers are provided for each column