Overview

This data package contains arthropod community data collected from bird nesting boxes, together with breeding performance data for the European pied flycatcher (Ficedula hypoleuca). Data were collected from eight woodland sites in England and Wales and are intended to support analyses of nest box ecology, nidicolous arthropod communities, and host–associate interactions.

Arthropods were sampled from both occupied and unoccupied nest boxes using different extraction methods, and breeding metrics were recorded for occupied boxes. The datasets can be linked at the individual nest-box level.

Data Files

arthropod_data.xlsx

This file contains arthropod records collected from nest boxes. Each row represents an individual arthropod specimen identified to family level where possible.

Key variables include:

• Order: Arthropod order
• Family: Arthropod family
• Subfamily: Arthropod subfamily (where identified)
• Genus: Arthropod genus (where identified)
• Species: Arthropod species (where identified)
• Lowest_taxon: Lowest taxonomic level confidently assigned
• Count: Number of individuals recorded for that taxon
• Site: Woodland site identifier
• Capture_method: Method used to collect arthropods (e.g. sticky trap or NaCl flotation)
• ID_no: Nest box or sample identifier

These data allow calculation of arthropod abundance, family richness, diversity indices (e.g., Shannon diversity), community composition, and functional group structure at the nest-box level.

nest_success.xlsx

This file contains breeding data for European pied flycatchers monitored in the same nest boxes. Each row represents a single breeding attempt per nest box.

Key variables include:

• Site: Woodland site identifier
• Trap: Trap or nest box identifier
• Nest: Nest presence or status indicator
• Notes: Additional observational notes recorded during monitoring
• Outcome: Nest outcome or breeding result as recorded in the dataset

These data enable analyses of reproductive performance and allow linkage with arthropod community metrics from the same nest boxes.

functional_groups.xlsx

Functional groups reflect dominant ecological roles, and thus niche occupancy. Where taxa exhibit multiple feeding strategies, the most commonly reported or ecologically dominant role was used, based on order- and family-level ecological traits reported in the literature.

Key variables include those as in arthropod_data.xlsx with one extra variable:

• Functional Group: ecological role assigned to taxonomic level

Sampling Design and Methods

A total of 120 nest boxes were sampled across eight woodland sites during the breeding season.

Arthropods were collected from nest boxes using two methods depending on nest occupancy. Unoccupied boxes were sampled using modified sticky traps, while occupied nests were sampled using NaCl flotation to extract arthropods from nesting material. Arthropods were identified to the lowest taxonomic level possible, and counts were recorded for each taxon.

Nest box entrances were not physically secured during sticky trap deployment. Of the bird species using nest boxes at the study sites, European pied flycatchers are the last to initiate breeding, with other species completing clutches and incubation earlier in the season. Sticky trap boxes were therefore selected from the nearest available unused boxes adjacent to actively building flycatcher nests. With one trap placed on the base of the nesting box, one on the rear wall.

While occasional ad hoc avian visits cannot be ruled out, the likelihood of sustained visitation was considered low unless birds were prospecting for replacement or second clutches. Consistent with this expectation, many sticky traps showed no evidence of contamination by feathers or debris, and there were no impressions in the vaseline indicating repeated bird contact. Traps were therefore left unsecured following reasoned consideration of likely disturbance and contamination risk.

Sampling took place during the 2024 breeding season. Site visits occurred on multiple dates between April and July to coincide with nest establishment, incubation, and chick rearing stages.

Visits were conducted on:

- 19, 22, and 28 April

- 1, 8, 16, 22, 27, and 30 May

- 4 and 9 June

- 14 July

Additional visits on 2 June, 14 June, and 2 July involved only selected nest boxes rather than full site coverage. All other listed dates involved visits to all nest boxes at the site. Nest outcome data were collected through routine nest monitoring conducted during the same period as arthropod sampling.

Data Integration

The two datasets can be linked using the following variables:

• Site
• Nest box or trap identifiers (ID_no in arthropod_data.xlsx; Trap in nest_success.xlsx)

This allows arthropod community data to be linked directly with breeding performance data for the same nest boxes.

Geographic Coverage

England and Wales. Data were collected from eight woodland sites. Site names are coded or anonymised within the datasets.

Temporal Coverage

Data were collected during a single breeding season. See associated manuscript or metadata for the exact year.

Intended Use and Reuse

These data are suitable for:

• Analyses of arthropod diversity and community composition in nest boxes
• Comparisons between occupied and unoccupied nest boxes
• Studies of nidicolous arthropod assemblages
• Investigations of relationships between arthropod communities and avian breeding performance
• Meta-analyses of artificial nest structures and associated invertebrate fauna

Notes and Limitations

• Arthropods are identified to family level; species-level resolution is not available.
• Different sampling methods were used for occupied and unoccupied boxes and should be accounted for in analyses.
• Functional group classifications are based on current ecological knowledge and may vary among studies.

Citation

If you use these data, please cite the Dryad data package and the associated publication.