Wildlife Network open data release 5 (2026-10-30): weekly bird, bat, amphibian and insect records, effort and arrival dates on a 5 degree grid

Weekly records of birds, bats, amphibians and insects on a 5 degree grid, with the observation effort behind them and seasonal arrival dates, built from openly licensed occurrence records (CC0 1.0 or CC BY 4.0) published through GBIF.org. Weeks covered: 27 October 2025 to 12 October 2026. New in release 5: methods version 0.16. An arrival now needs a real absence: a species still recorded in at least 70 percent of the weeks before its arrival, at a mean of at least 2 percent of its seasonal peak, gets no arrival date, because that is a resident gone quiet rather than a bird that left. A date is also dropped when its 90% interval is wider than 8 weeks or does not contain the estimate. Arrivals fall from 4,724 rows in release 4 to 4,399; the weekly records and effort are built as before, over the same weeks. Earlier releases keep the old rule, so use this version for arrival dates. Every arrival date keeps its 90% interval (arrival_low, arrival_high) and support (arrival_support, below 0.5 is weak). Files: weekly_records.csv (352,350 rows), effort.csv (15,986 rows: all records of a class per cell and week, for effort correction and judging coverage), arrivals.csv (4,399 rows: arrival, peak and departure per species and cell, with intervals), taxa.csv (16,765 species with GBIF keys), datasets.csv (284 contributing GBIF datasets with DOIs, for citation), README.md (every column, the arrival rule, the known limits and how the release was made) and CITATION.cff. Only records individually licensed CC0 or CC BY 4.0 are counted, including from datasets whose overall licence is stricter (for example iNaturalist, where each observer chooses a licence). Counts are records, not animals: they follow where and when people look and report, and coverage is strongest in northern and western Europe and North America. Acoustic detections from BirdWeather, shown on the Wildlife Network map, are not included. Made by Wildlife Network (wlnw.org), methods version 0.13. Code: github.com/wlnw-org/wildnetwork. Please also cite the GBIF datasets listed in datasets.csv.