Reproductive success of three parid species in managed boreal forests
Data files
Feb 11, 2026 version files 1.86 MB
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BT_data.csv
187.15 KB
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BT_R-script.R
45.55 KB
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GT_data.csv
732.78 KB
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GT_R-script.R
41.75 KB
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README.md
22.53 KB
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WT_data.csv
783.58 KB
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WT_R-script.R
50.36 KB
Abstract
Anthropogenic impacts, such as forestry and land use practices, can deteriorate habitat quality, affecting reproductive success and leading to population decline. The boreal willow tit (Poecile montanus) population has dramatically declined in Finland. In contrast, great tits (Parus major) and blue tits (Cyanistes caeruleus), both of temperate origin, have expanded their ranges and increased in numbers in Northern Finland. It has been suggested that the decline in the willow tit population is mainly caused by the reduction of breeding sites and wintering areas resulting from habitat loss and degradation. We investigated whether forest management influences the reproductive success of willow tits, great tits, and blue tits, including recruitment across years, while considering other factors such as possible intra- and interspecific competition. We combined long-term breeding data (1990-2020) from Oulu, Finland, with spatial data on forest management activities and analysed the data using (generalized) linear mixed-effect models. Results varied depending on the breeding parameter, species, and forest management method. Forestry had no significant effect on clutch size. We found negative effects of thinnings on nestling survival and growth in great and blue tits, with clear-cuttings negatively affecting blue tit nestling growth. However, recent clear-cuttings had positive effects on willow tit nestling survival and growth. Despite these benefits, clear-cuttings near nesting sites were associated with reduced willow tit local recruitment probability, leading to an overall negative impact on the population. These findings may arise from forest management influences on food availability; certain stages following clear-cutting may improve the food availability for boreal willow tit nestlings, yet thinnings may reduce foraging opportunities for great tits and blue tits. While some positive effects of forestry on willow tits were recorded, they may not be enough to offset the well-established negative impacts of forestry on the loss of optimal wintering and breeding habitats.
Dataset DOI: 10.5061/dryad.9ghx3ffz4
Description of the data and file structure
This repository includes the data and R scripts required for analysing and creating figures presented in the original research article, "Reproductive success of three parid species in managed boreal forests."
All CSV files (=the data) were generated with similar column names in English (Table 1). They are the variables also used in the analysis. See the original research article for further explanation of the methods and more detailed variable descriptions.
Table 1. Explanations of the data column names in files BT_data.csv, GT_data.csv, and WT_data.csv.
| Column name | Explanation | Unit |
|---|---|---|
| row | row number | |
| location | location in the study area | character |
| year | study year | |
| fring | female ring number (ID) | character |
| 0-30v.cc57m | 0-30 years from clear-cutting (57 m) | % of coverage |
| 0-30v.cc113m | 0-30 years from clear-cutting (113 m) | % of coverage |
| 0-30v.cc329m | 0-30 years from clear-cutting (329 m) | % of coverage |
| 0-30v.cc500m | 0-30 years from clear-cutting (500 m) | % of coverage |
| 0-30v.thin57m | 0-30 years from thinning (57 m) | % of coverage |
| 0-30v.thin113m | 0-30 years from thinning (113 m) | % of coverage |
| 0-30v.thin329m | 0-30 years from thinning (329 m) | % of coverage |
| 0-30v.thin500m | 0-30 years from thinning (500 m) | % of coverage |
| 0-10v.cc57m | 0-10 years from clear-cutting (57 m) | % of coverage |
| 0-10v.cc113m | 0-10 years from clear-cutting (113 m) | % of coverage |
| 0-10v.cc329m | 0-10 years from clear-cutting (329 m) | % of coverage |
| 0-10v.cc500m | 0-10 years from clear-cutting (500 m) | % of coverage |
| 11-30v.cc57m | 11-30 years from clear-cutting (57 m) | % of coverage |
| 11-30v.cc113m | 11-30 years from clear-cutting (113 m) | % of coverage |
| 11-30v.cc329m | 11-30 years from clear-cutting (329 m) | % of coverage |
| 11-30v.cc500m | 11-30 years from clear-cutting (500 m) | % of coverage |
| 0-10v.thin57m | 0-10 years from thinning (57 m) | % of coverage |
| 0-10v.thin113m | 0-10 years from thinning (113 m) | % of coverage |
| 0-10v.thin329m | 0-10 years from thinning (329 m) | % of coverage |
| 0-10v.thin500m | 0-10 years from thinning (500 m) | % of coverage |
| 11-30v.thin57m | 11-30 years from thinning (57 m) | % of coverage |
| 11-30v.thin113m | 11-30 years from thinning (113 m) | % of coverage |
| 11-30v.thin329m | 11-30 years from thinning (329 m) | % of coverage |
| 11-30v.thin500m | 11-30 years from thinning (500 m) | % of coverage |
| 0-4v.cc57m | 0-4 years from clear-cutting (57 m) | % of coverage |
| 5-10v.cc57m | 5-10 years from clear-cutting (57 m) | % of coverage |
| 11-20v.cc57m | 11-20 years from clear-cutting (57 m) | % of coverage |
| 21-30v.cc57m | 21-30 years from clear-cutting (57 m) | % of coverage |
| 0-4v.cc113m | 0-4 years from clear-cutting (113 m) | % of coverage |
| 5-10v.cc113m | 5-10 years from clear-cutting (113 m) | % of coverage |
| 11-20v.cc113m | 11-20 years from clear-cutting (113 m) | % of coverage |
| 21-30v.cc113m | 21-30 years from clear-cutting (113 m) | % of coverage |
| 0-4v.cc329m | 0-4 years from clear-cutting (329 m) | % of coverage |
| 5-10v.cc329m | 5-10 years from clear-cutting (329 m) | % of coverage |
| 11-20v.cc329m | 11-20 years from clear-cutting (329 m) | % of coverage |
| 21-30v.cc329m | 21-30 years from clear-cutting (329 m) | % of coverage |
| 0-4v.cc500m | 0-4 years from clear-cutting (500 m) | % of coverage |
| 5-10v.cc500m | 5-10 years from clear-cutting (500 m) | % of coverage |
| 11-20v.cc500m | 11-20 years from clear-cutting (500 m) | % of coverage |
| 21-30v.cc500m | 21-30 years from clear-cutting (500 m) | % of coverage |
| 0-4v.thin57m | 0-4 years from thinning (57 m) | % of coverage |
| 5-10v.thin57m | 5-10 years from thinning (57 m) | % of coverage |
| 11-20v.thin57m | 11-20 years from thinning (57 m) | % of coverage |
| 21-30v.thin57m | 21-30 years from thinning (57 m) | % of coverage |
| 0-4v.thin113m | 0-4 years from thinning (113 m) | % of coverage |
| 5-10v.thin113m | 5-10 years from thinning (113 m) | % of coverage |
| 11-20v.thin113m | 11-20 years from thinning (113 m) | % of coverage |
| 21-30v.thin113m | 21-30 years from thinning (113 m) | % of coverage |
| 0-4v.thin329m | 0-4 years from thinning (329 m) | % of coverage |
| 5-10v.thin329m | 5-10 years from thinning (329 m) | % of coverage |
| 11-20v.thin329m | 11-20 years from thinning (329 m) | % of coverage |
| 21-30v.thin329m | 21-30 years from thinning (329 m) | % of coverage |
| 0-4v.thin500m | 0-4 years from thinning (500 m) | % of coverage |
| 5-10v.thin500m | 5-10 years from thinning (500 m) | % of coverage |
| 11-20v.thin500m | 11-20 years from thinning (500 m) | % of coverage |
| 21-30v.thin500m | 21-30 years from thinning (500 m) | % of coverage |
| richness57m | forest type gradient (57 m) | relative gradient value from 1 to 6 |
| richness113m | forest type gradient (113 m) | relative gradient value from 1 to 6 |
| richness329m | forest type gradient (329 m) | relative gradient value from 1 to 6 |
| richness500m | forest type gradient (500 m) | relative gradient value from 1 to 6 |
| clutch | clutch size | number of eggs in a nest |
| timing | date of the first laid egg | a continuos number of "May days", 1=1st of May |
| nndist | distance to the nearest intraspecific neighbour (either GT, WT or BT) | meters |
| gt_vs_wt | great tit distance to nearest willow tit neighbour | meters |
| wt_vs_gt | willow tit distance to nearest great tit neighbour | meters |
| bt_vs_gt | distance to nearest great tit neighbour | meters |
| gt_vs_bt | distance to nearest blue tit neighbour | meters |
| fage | female age | binomial (0=juvenile, 1=older, unknown) |
| dcentre | distance to study area centre | meters |
| hatched | number of hatched nestlings | |
| recruit | number of recruits (per nest) | |
| meanweight | mean nestling body mass | grams |
| meanwing | mean nestling wing length | millimeters |
| fledged | number of fledged nestlings | |
| measurer | name of the measurer | character |
Files and variables
File: BT_data.csv
Description: A CSV file containing the original data and variables used for blue tit analysis in the research article. Empty cells in the data represent genuine missing information, which can occur when collecting data from live birds. The missing data is typically caused by a lost or predated nest after nesting has begun. Other possible reasons include a bird caught for ringing that accidentally escapes before measurements are taken, or a parent bird that cannot be caught for ringing and measurements before the nestlings fledge.
Variables
- Please see Table 1 (above) for variable names and descriptions.
File: BT_R-script.R
Description: An R script for analysing (LMM and GLMM, depending on the response variable) and creating figures of the blue tit data provided in file BT_data.csv. The analyses should preferably be conducted in RStudio.
File: GT_R-script.R
Description: An R script for analysing (LMM and GLMM, depending on the response variable) and creating figures of the great tit data provided in file GT_data.csv. The analyses should preferably be conducted in RStudio.
File: GT_data.csv
Description: A CSV file containing the original data and variables used for great tit analysis in the research article. Empty cells in the data represent genuine missing information, which can occur when collecting data from live birds. The missing data is typically caused by a lost or predated nest after nesting has begun. Other possible reasons include a bird caught for ringing that accidentally escapes before measurements are taken, or a parent bird that cannot be caught for ringing and measurements before the nestlings fledge.
Variables
- Please see Table 1 (above) for variable names and descriptions.
File: WT_R-script.R
Description: An R script for analysing (LMM and GLMM, depending on the response variable) and creating figures of the willow tit data provided in file WT_data.csv. The analyses should preferably be conducted in RStudio.
File: WT_data.csv
Description: A CSV file containing the original data and variables used for willow tit analysis in the research article. Empty cells in the data represent genuine missing information, which can occur when collecting data from live birds. The missing data is typically caused by a lost or predated nest after nesting has begun. Other possible reasons include a bird caught for ringing that accidentally escapes before measurements are taken, or a parent bird that cannot be caught for ringing and measurements before the nestlings fledge.
Variables
- Please see Table 1 (above) for variable names and descriptions.
Code/software
- Microsoft Excel was needed to inspect and modify the Excel files.
- R 4.1.2 and RStudio were used to analyse the data and draw figures. The latest versions of the following packages were used:
- MuMIn
- car
- effects
- lme4
- lmerTest
- DHARMa
- weights
Access information
Other publicly accessible locations of the data:
- The data is otherwise accessible by personal request.
Data was derived from the following sources:
- A long-term research on breeding passerines was conducted by professor Markku Orell and his research group from Ecology and Genetics Reseach Unit, University of Oulu, Finland.