Prior flood flags gave no clear later catch link in four English and Scottish beetle samples in 1993-2015

We tested whether a flood flag predicted recorded beetle catch in the next unflagged trapping interval. Four collection and fixed trap models used 4,019 events in 456 collections in England and Scotland in 1993-2003 and 2004-2015. The log(1 + catch) estimates were +0.040, +0.012, -0.017 and -0.044. All four-test adjusted intervals included zero. All sensitivity intervals also included zero. The evidence does not show a repeated later catch difference. The response excludes Pterostichus madidus because source subcategories can overlap. Selected consecutive records, explicit zeros, few year groups and conditioning on an unflagged later trap limit inference. Capture loss, reporting rules and local biological change cannot be separated. This is not evidence of trap recovery or a causal weather effect. The package gives code, source hashes, aggregate evidence, numerical checks and a figure. External source records stay outside the package.

observation bias · flooding · carabid beetles · pitfall traps · lagged response · regional replication · null result