Black Holes (Under-recorded Areas)

Suffolk Butterfly Recording 2019-2023 "Black-Holes"

Although we receive many thousands of sightings from various sources there are still some tetrads where few, or even no, butterflies have been recorded.  These under-recorded areas are often known as "Black Holes"

2015-2019 and 2019-2023 "Black-Holes"

Below iare two maps of the Suffolk recording area which show the areas remaining with few or no butterfly records i.e. "black-holes".  These are shown by the blue spots. 

Two maps are shown, one for 2015-2019 and the latest for 2019-2023.  The latter shows more under-recorded areas in the North-west of Suffolk.  Are there now fewer butterflies there or are fwer people recording?