Data from: Factors affecting the nesting success of Swainson's thrush (Catharus ustulatus) along an elevational gradient
Data files
Jul 06, 2023 version files 310.56 KB
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NestData_21.xlsx
13.32 KB
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Nestinit1921.numbers
254.50 KB
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README.md
3.06 KB
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realtemp.csv
6.50 KB
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weatherdata.csv
33.18 KB
Oct 12, 2023 version files 310.57 KB
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NestData_21.xlsx
13.32 KB
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Nestinit1921.numbers
254.50 KB
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README.md
3.07 KB
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realtemp.csv
6.50 KB
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weatherdata.csv
33.18 KB
Abstract
Montane birds face several ecological challenges during the breeding season, including nest predators, competition for territory, and food availability. The continuing effects of climate change are causing shifts in these plant and animal communities, as well as changes in abiotic factors such as increased temperature and precipitation effects, adding additional stressors that could affect nest survival, putting their populations at risk. The Swainson’s thrush (Catharus ustulatus) is migratory songbird which is moderately common and breeds along a wide elevation gradient within this system (200-1,250m). Populations of Swainson’s thrush were once declining, though recent research shows their ranges to be shifting downwards, potentially as the result of increased precipitation and temperature at higher elevations. Although lower elevations might be more favorable in terms of climactic conditions, nest predation is higher at lower elevations in other systems. Thus, this species might be faced with the opposing pressures of adverse climactic conditions at higher elevations and increased predation at lower elevations. Nest survival is a fundamental process to population size, and therefore, is important in evaluating how montane breeding birds are adjusting to the changing climate. We monitored nests of Swainson’s thrush along an elevation gradient in the White Mountain National Forest in New Hampshire in 2016, 2018, 2019 and 2021 at two sites: Mt. Jefferson (500-1,250m) and Bartlett Experimental Forest (200-300m). We found a significant negative effect of rain intensity (millimeters per hour per day) as well as a negative interaction effect of elevation with minimum daily temperature and average daily temperature, on the daily survival rate of Swainson’s thrush. Our results provide evidence that nesting survival of montane breeding birds could be at risk as heavier precipitation events become more frequent and intense, a likely outcome due to the changing climate within the White Mountains and other montane ecosystems, putting other passerine species at risk in this system.
Data contains appropriate contexts used for rMark daily nest survival analysis. There are several data files within this dryad: an excel file (NestData_21.xlsx) that is the nest data for all years collected (2016-2019, and 2021). We also have a separate nest survival data set that includes nests from years we collected weather variables (2019 and 2021; Nestinit1921.numbers). There are also two .csv files included: one has all weather data (weatherdata3.csv) and the other is the predicted data used to create the figure necessary to describe the interaction effect (realtemp.csv). Lastly, there’s a rmarkdown file labeled (NestSurvivalAnalysis_Deckel.Rmd) which outlines the code used to run the analyses. Finally, we’ve included a few potentially helpful supplementary documents (Supplementary_Material_SWTHmanuscript.docx)
Description of the Data and file structure
Nest survival data for all years (NestData_21.xlsx) and just for 2019 and 2021 (Nestinit1921.csv) is organized to include all information needed to determine daily probability survival, including site (JEFF = Mt. Jefferson, BEF = Bartlett Experimental Forest), FirstFound (date the nest was first found), LastPresent (last known date the nest was active), LastChecked (last date the nest was checked), Fate (0 or 1; successful/failed nest), elev_bin (grouped data to include the year and elevation bin) Year (the year the nest was monitored), elevation (in meters), AgeFound (the age, in days, the nest was found), NestAge (approximately how old the nest was when we found it), and init_jul (nest initiation in julian date).
Temperature and precipitation data (weatherdata.csv) have columns that include date, group (year and elevation bin, i.e., BEF2019 = Bartlett experimental forest in 2019), bin (i.e., “BEF” = Bartlett experimental forest), precip (i.e., daily precipitation in mm), elevation (in meters), year, julian date, time (a covariate used by rMark to match weather data with daily survival), mean daily temperature, minimum daily temperature, and temperature range (all in celcius), and m_per_hour (mm of rain per hour, i.e., daily rain intensity).
Predicted temperature variables for the interaction effect model are in the (realtemp.csv) file. This includes the elevation when held constant (in meters), the minimum daily temperature variable (0-26 degrees celsius), the daily survival rate estimate (i.e. real), and the standard error (se) and upper and lower confidence intervals for these (lcl and ucl).
We’ve included an rmarkdown of the code we ran to complete the analyses (NestSurvivalAnalysis_Deckel.Rmd). All files included here should be what users need if they want to replicate the code. Users will need to have R studio and rMark install in order to run code. Required information needed for rMark nest survival can be found in Appendix C in the nest survival guide here: http://www.phidot.org/software/mark/docs/book/pdf/chap17.pdf
R studio is needed to open the file(s), but RMark is needed to run the code.