| # | County | Records since 2000 | Species recorded | Area |
|---|---|---|---|---|
| 1 | Gwynedd | 577,110 | 8,784 | 2,535 km² |
| 2 | Pembrokeshire | 544,235 | 7,633 | — |
| 3 | Powys | 488,445 | 7,731 | — |
| 4 | Ceredigion | 333,948 | 6,870 | — |
| 5 | Carmarthenshire | 316,087 | 6,632 | — |
| 6 | Isle of Anglesey | 268,317 | 7,213 | 711.3 km² |
| 7 | Conwy | 265,633 | 5,145 | — |
| 8 | Swansea | 181,185 | 6,451 | — |
| 9 | Monmouthshire | 146,912 | 5,551 | — |
| 10 | Wrexham | 115,231 | 4,514 | — |
| 11 | Denbighshire | 87,983 | 3,675 | — |