Add German ground-beetle traits and occupancy trends (Chowdhury et al. 2025)

Joins carabid (ground beetle) traits and modelled national occupancy trends to a taxify() result by accepted name.

Usage

add_chowdhury(x, cols = NULL, verbose = TRUE)

Arguments

x: A data.frame returned by taxify().
cols: Which columns to attach: NULL (default) all of them, or a character vector of names. See enrichment_cols.
verbose: Logical. Default TRUE.

Value

The same data.frame with chowdhury_ columns: numeric body_length_mm and occupancy_trend; categorical wing_morph, trophic_level, habitat_pref, red_list_germany, red_list_iucn, threat_status, trend_status, trend_significance.

Details

Source: Supporting Information Data S1 of Chowdhury et al. (2025), 383 German carabid species, 382 of them with traits. Ground beetles are one of the most intensively sampled insect groups in ecology, and this is the largest openly reachable block of carabid traits.

wing_morph is three-state – long-winged, short-winged, and the 83 dimorphic species that produce both forms. Dimorphism is the trait of interest in carabid dispersal ecology, so it is never collapsed into a flight-capable/flightless binary.

red_list_germany is the German national Red List code (*, 1, 2, 3, V, R, G, D). red_list_iucn restates that same national assessment in IUCN letter codes and is not a global IUCN assessment: it maps deterministically onto red_list_germany (* to LC, 1 to CR, 2 to EN, 3 to VU, V to NT), with no off-diagonal case in all 382 species. A species can be critically endangered at its German range edge and of least concern globally, so these columns stay on this door and out of the global conservation_status trait.

occupancy_trend is the paper's own result: the modelled change in occupancy probability over two years, negative for a declining species.

References

Chowdhury S, Jaureguiberry P, Rada S, et al. (2025) Widespread decline of ground beetles in Germany. Diversity and Distributions. doi:10.1111/ddi.70112

Examples

if (FALSE) { # \dontrun{
taxify(c("Carabus coriaceus", "Amara aenea")) |>
  add_chowdhury()
} # }