I read with great interest the paper on the population of Peregrine Falcons Falco peregrinus in north and west Cornwall (Watson & Sale 2020). The paper concentrated on the period 2015 onwards (and sometimes 2016 onwards) relative to the period 2008–14. It put forward three main propositions: that there was a statistically significant intensification of a decline in fledgling production after 2016; that the population decline is due to increased juvenile and adult mortality; and that increased mortality may be due to marine pollution, climate change or agricultural contamination but probably not due to persecution. I will look at each of these propositions in turn.