Pictured: purple hairstreak, Favonius quercus
200-year trend in Cambridgeshire: Little change, possibly a slight increase.
Modern records
From Jenyns’ notes it is hard to deduce how common the species was but this and other historical accounts show it was known from at least a few locations across the county. Today it is quite widespread and relatively common, but it often goes unnoticed as it spends much of its time up in the canopy of oak trees and the same may have been true in Jenyns’ time. However, many woods are now left to form closed-canopy mature stands, which probably support larger populations of this species than in the past, when timber was harvested for local use. The purple hairstreak can now be found within the city boundary in Cambridge wherever mature oaks are found, but patient observation is required to detect this small butterfly in the tree canopy.
National records map
Purple hairstreak national records map:https://species.nbnatlas.org/species/NHMSYS0021002801