September is another exciting month of the year for birding in Sussex.
Autumn migration is now in full swing, with birds arriving from the north and east while our own breeding birds head south towards their wintering grounds. Almost any day can produce something interesting, including passage waders moving through our wetlands, seawatching with the potential for exciting seabirds, and coastal bushes filled with migrant warblers, chats and flycatchers. It is also one of the best months of the year for finding a rarity, particularly after easterly winds or autumn gales.
Passage waders
September remains an excellent month for passage waders, with adult birds joined by increasing numbers of juveniles making their first journeys south. With some very welcome rain in the last few days, mudflats, shallow pools and flooded fields should be checked carefully for a variety of species including Black-tailed Godwit, Common and Green Sandpipers, Dunlin, Greenshank, Knot, Ringed Plover and Ruff. Curlew Sandpiper, Little Stint, Spotted Redshank and Wood Sandpiper are among the scarcer possibilities, particularly after easterly winds.
Migrant passerines
September is the month when Sussex’s coastal and downland bushes can become very productive. Birds migrating south from Britain may stop to feed on the prolific elderberries and blackberries before crossing the Channel, with the potential for even a small patch of scrub to contain a variety of species.
Chiffchaff and Blackcap are among the commonest migrants, while Common Whitethroat, Lesser Whitethroat, Garden Warbler, Reed Warbler and Sedge Warbler continue to move through.
The real excitement, however, comes when, on the rare occasion, the weather produces a fall. Pied and Spotted Flycatchers, Redstart, Tree Pipit, Wheatear, Whinchat and Yellow Wagtail are all species worth searching for, especially at some of the migrant ‘hotspots’ including Beachy Head and Seaford Head, while Cissbury Ring, Climping Gap and Pagham Harbour are also well worth exploring.
September is one of the best months of the year to look for Wryneck in Sussex. These beautifully cryptic woodpeckers are recorded every autumn in Sussex, but their camouflage makes them notoriously easy to overlook.
Wrynecks are especially associated with easterly winds and periods of migration activity. Areas of rough grassland and scrub at places such as Beachy Head, Cuckmere Haven, Newhaven Tidemills, Seaford Head, Sheepcote Valley and Church Norton all have the potential to hold this species. Wrynecks can sit motionless for long periods, so patience is essential. Don’t assume that a seemingly empty patch of rough grass is birdless – scan carefully and watch for movement on the ground.
Migration Spectacles
September can provide some of the most spectacular visible migration spectacles of the year in Sussex. Two movements are particularly worth noteworthy: the westward passage of returning Brent Geese along the coast and the spectacular movements of large numbers of coasting Swallows and House Martins.
The first returning Dark-bellied Brent Geese begin to reach Sussex from their Arctic breeding grounds during September. They can be seen moving westwards along the Sussex coastline, heading for the mudflats and surrounding fields of Pagham and Chichester Harbours where they spend the winter. Usually they are in small groups close inshore, but sometimes much larger flocks may be seen.
The middle of September can also bring impressive coastal movements of Swallows and House Martins. On suitable days, particularly when there is a stiff breeze, huge numbers can be seen streaming east or westwards into the wind. Beachy Head is one of the best places to witness this phenomenon, where on the right day you may be fortunate to witness a continuous movement along the cliff edge, often just a few feet away.
Remember, though, that the chalk cliffs in Sussex are precarious and that cliff falls do occur, so don’t be tempted to stand too close to the edge.
Seawatching
September is potentially an exciting month for seawatching. As seabirds move south through the North Sea and into the English Channel, strong onshore winds can bring them closer to shore and increase the chances of seeing species that are otherwise difficult to find from land.
Gannet, Kittiwake, Sandwich Tern, Common Tern and Arctic Skua should all be on the radar, while stronger winds can produce much scarcer species. Balearic Shearwater is one of the major targets. September is an excellent month to look for them as they move through the Channel, with exposed viewpoints such as Selsey Bill, Splash Point, Cow Gap and Langney Point all capable of producing sightings in suitable conditions. In September 2025, record-breaking numbers of this critically endangered seabird occurred at Selsey Bill, and it will be interesting to see if there is any repeat in 2026.
Scarcer species such as Long-tailed Skua, Grey Phalarope, Sabine’s Gull and Sooty Shearwater are other possibilities, particularly after autumn gales. A seawatch can be frustratingly quiet for hours, but a sudden movement of seabirds can make all that waiting worthwhile.
Ospreys and Honey-buzzards
September is a particularly good month for Osprey in Sussex as birds continue their autumn migration. Unlike spring migrants, which can pass through quickly, some autumn birds may stop at suitable wetlands and remain for several days.
Chichester Harbour is the most reliable location, especially Thorney Island, where up to seven birds lingered during September 2024. Pagham Harbour is another regular site, but inland reservoirs, lakes and larger wetlands can also attract migrating birds where they may linger for several days. Arlington Reservoir, Weir Wood Reservoir and other suitable water bodies are worth checking, particularly when there are reports of birds moving through the county.
September can also produce Honey-buzzard on migration, especially at Beachy Head. Some of these birds will have spent the summer breeding in the UK, as confirmed by photographs that have been linked back to known breeding pairs in Sussex.
Other raptors to look for include Hobby, Merlin and Marsh Harrier. September can also be a good month for sightings of Short-eared Owl, with early signs suggesting that this is likely to be a good winter for them following a successful breeding season.
Rarities
September is one of the best months for rarities in Sussex. Coastal bushes are perhaps the most obvious place to start. Wryneck, Red-backed Shrike, Barred Warbler and Yellow-browed Warbler are all exciting September possibilities, especially after easterly or southeasterly winds.
Wetlands are worth equal attention. Scarce waders such as Buff-breasted Sandpiper, Pectoral Sandpiper, Red-necked Phalarope or Temminck’s Stint are all possible while flocks of Eurasian Golden Plover have the potential to hold an American Golden Plover or Dotterel, as happened at Jury’s Gap in September 2025.
Tips for September Birding
• Check the weather: Easterly and south-easterly winds can produce falls of migrants and increase the chances of eastern rarities.
• Work every bush: September migrants can be hiding almost anywhere, so don’t ignore small patches of scrub, hedgerows and isolated bushes.
• Scan every wader flock: Scarce species can be tucked away among flocks of commoner species.
• Try a seawatch: Strong winds can produce Balearic Shearwaters, skuas and other seabirds close to shore.
• Watch for raptors: Ospreys and Honey-buzzards are both possible during September, particularly when conditions (settled weather with northeasterly winds) encourage migration.
For the Sussex birder, there are few better times of year to be in the field. Whether it is a flock of newly arrived Brent Geese, an Osprey circling over a harbour, a Wryneck hiding in coastal gorse or a Sooty Shearwater powering west through heavy seas, September offers plenty of exciting possibilities.