Extended incubation recesses in Sanderlings are impacted by temperature and body condition
Data files
Feb 01, 2024 version files 3.06 MB
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README.md
3.62 KB
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Recesses.txt
2.96 MB
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Script_transmission.R
15.18 KB
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TDR.txt
85.81 KB
Abstract
Complex incubation strategies have evolved to solve the trade-off between parent survival and care for their eggs with often brief departures (recesses) that maximise egg survival or infrequent extended recesses maximising adult condition. Here we examined incubation behaviour of Sanderlings (Calidris alba), a species that exhibits both bi- and uniparental incubation behaviour. During 11 breeding seasons in Greenland, we have quantified incubation variability with thermologgers placed in nests. We estimated the impact of environmental conditions and individual characteristics on the occurrence and the duration of recesses. We found that extended recesses are a unique feature of uniparentals, and their frequency and duration increased in colder temperatures. The relationship was mediated by body condition, with individuals in poor condition performing longer extended recesses in colder temperatures. This suggests that extended recesses may represent a shift towards self-maintenance at the expense of the egg care, allowing birds to continue incubating under unfavourable conditions. Our study illustrates how extended recesses may be a key breeding strategy to overcome high energetical costs associated with incubation. Quantifying such behavioural flexibility paves the way for tracking future behavioural responses of individuals in the face of changing environments.
README: Extended incubation recesses in Sanderlings are impacted by temperature and body condition
https://doi.org/10.5061/dryad.v41ns1s3q
Description of the data and file structure
We collected behavioural information on Sanderlings' incubation ecology. We collected information on their incubation recesses at two different time scales. Firstly, we collected information at the recess scale: the recess is the statistical unit. Secondly, we pooled these recesses at a daily scale. For that, we focus on the Total Duration of Recesses (TDR), summing all the recesses during a 24h period. Therefore, we obtained two datasets; "Recesses", at the recess scale, and "TDR" at the daily scale.
Description of the column names:
‘Recesses.txt’ dataset.
· date: date-hour of each recess performed YY-MM-DD HH:MM:SS.
· recess_size_max: duration of each recess in minutes.
· recesslong: 0/1 for each recess, to describe if this recess is extended (≥ 120min) or short (<120min).
· strategy: description of the nest’s status; UNI if the nest is uniparental since the beginning of the incubation; UNISWAP if the nest started the incubation with both parents incubating and switch strategy during the incubation to become uniparental (see Methods).
· year: Year of data acquisition
· nest_id: unique combined ID of the nest, composed of the first four letters of the species name (SAND), the year, and the field nest ID.
· sexe: sex of each individual. Cells containing *NA *are individuals for which the sex was not available due to lack of morphometric measures.
· body_condition: body condition of each individual calculated with the Peig and Green’s index (2009) (see Methods). Cells containing *NA *are individuals for which the body condition was not available due to lack of morphometric measures.
· nest_age: incubation stage. The first day of incubation is assigned day 0, the second day of incubation is assigned day 1, third day 3… to keep track of the incubation advancement.
· previous_temperature24: Ground temperatures (ºC) averaged during the 24 hours preceding the hour of the recess. If one hour or more was missing during the previous 24h, the mean could not be calculated, and *NA *was assigned to the cell (see Methods).
· previous_temperature12: Ground temperatures (ºC) averaged during the 12 hours preceding the hour of the recess. If one hour or more was missing during the previous 12h, the mean could not be calculated, and *NA *was assigned to the cell (see Methods).
· previous_temperature6: Ground temperatures (ºC) averaged during the 6 hours preceding the hour of the recess. If one hour or more was missing during the previous 6h, the mean could not be calculated, and *NA *was assigned to the cell (see Methods).
· previous_temperature2: Ground temperatures (ºC) averaged during the 2 hours preceding the hour of the recess. If one hour or more was missing during the previous 24, the mean could not be calculated, and *NA *was assigned to the cell (see Methods).
· previous_temperature1: Ground temperatures (ºC) of the hour preceding the hour of the recess. NA was assigned when the preceding temperature was not available.
day: each recess classified as being during daytime (9h-17h) or night time. Despite permanent light, most Arctic species keep a diurnal rhythm.
Code/Software
We used R to process the data, R version 4.3.0. All packages used are described in the R code.
Methods
This dataset (2011-2021) is a long-term monitoring based on fieldwork in Greenland. The field team collects behavioural data at Sanderling nests by putting thermologgers in the nest cups during the incubation period. Loggers are then retrieved at the end of the breeding season and data is processed with TinyTag Explorer Software. One dataset is at the recess (departure from the nest to forage) scale, and the other is at the daily scale (see Methods). Datasets are used in conjunction with the provided R code.