| 2023-09-12 | Pink-footed Goose (a skein of 70) | 70 | bird | | First of the autumn |
| 2023-09-12 | Turnstone | 20 | bird | on local beach | |
| 2023-09-12 | Sanderling | 20 | bird | on local beach | |
| 2023-09-12 | Ringed Plover | 20 | bird | on local beach | |
| 2023-09-12 | Golden Plover (a single bird piping over!) | 1 | bird | | Uncommon |
| 2023-09-13 | Gyr Falcon/Saker (hybrid) | | bird | Caught in hotel beer garden with jesses around the village. | Uncommon, hybrid sighting |
| 2023-09-13 | Northern Deep-brown Dart | | insect | | Observed |
| 2023-09-13 | Black Rustic | | insect | | Observed |
| 2023-09-13 | Lunar Underwing | | insect | | Observed |
| 2023-09-13 | Autumnal Rustic | | insect | | Observed |
| 2023-09-13 | Angle Shades | | insect | | Observed |
| 2023-09-14 | Merlin (female) | | bird | through our cottage garden | |
| 2023-09-16 | Hen Harrier (ring-tail) | | bird | | |
| 2023-09-16 | Lesser Redpoll | 5 | bird | | |
| 2023-09-17 | Galerula tanaceti (a fat leaf beetle) | | insect | New for Coll! | |
| 2023-09-17 | Northern Deep-brown Dart | | bird | | |
| 2023-09-17 | Small Wainscot | | bird | | |
| 2023-09-17 | Lunar Underwing | | bird | | |
| 2023-09-17 | Autumnal Rustic | | bird | | |
| 2023-09-19 | Red-breasted Merganser (Merganseridae) | 6 | bird | | |
| 2023-09-19 | Curlew (Numenius americanus) | 12 | bird | | |
| 2023-09-21 | Snipe | | bird | | |
| 2023-09-21 | Dunnock | | bird | | |
| 2023-09-21 | Song Thrush (Turdus philomelos) | | bird | Fall of multiple individuals | |
| 2023-09-21 | Meadow Pipit (Anthus pratensis) | | bird | | |
| 2023-09-21 | Goldcrest (Regulus regulus) | | bird | | |
| 2023-09-21 | Chaffinch (Fringilla coelebs) | | bird | | |
| 2023-09-29 | Gannet | | bird | | |
| 2023-09-29 | Curlew | | bird | | |
| 2023-09-29 | Kittiwake | | bird | | |
| 2023-09-29 | Linnet (x40) | 40 | bird | | |
| 2023-09-29 | Twite (x70) | 70 | bird | | |
| 2023-09-29 | Pedunculate Oak (a cluster of tiny plants growing on a rocky outcrop out of the range of the local sheep) | | plant | Cluster of tiny plants growing on a rocky outcrop out of the range of local sheep. | Unusual plant distribution. |
| 2023-09-29 | _Isolepis cernua_ (Slender Club-rush) | | invertebrate | Slender Club-rush | |
| 2023-09-29 | _Isolepis setacea_ (Bristle Club-rush) | | invertebrate | Bristle Club-rush | |
