About 25 members gathered for a Sunday morning stroll around Ardingly Reservoir, a 5km walk that included a detour over the River Cuckmere. The weather forecast indicated wet periods, but the precipitation was minimal for a short period. The event was led by Mark Wright who recorded 34 species, the full list of which can be found in our Recent Sightings.

There were significant numbers of hirundines (mainly Sand Martins but some House Martins) feeding up before their journey south.

The star birds of the day were a party of Spotted Flycatchers, three or four, obligingly sitting still between catches, in the field borders near the village of Arlington.

Check out the walks schedule on our Events page for more autumn birding around the county, including walks in these locations:

• West Rise Marsh, Eastbourne
• Birling Gap, East Dean
• Cissbury Ring near Worthing
• Cuckmere Haven
• Selsey/Church Norton
• Dell Quay Fishbourne

All photos by Jonathan Cook.

The colony of Kittiwakes nesting at Seaford abandoned their nests during the June heatwave this summer, with the population present in mid-June vacating before the first of July. We hope to see the Kittiwakes return in future years, though rising summer temperatures might not bode well for the colony. 

Colony history 

Kittiwakes are a Red-listed cliff-nesting species typically found in the north of the UK, and Sussex is toward the southern edge of their range. “This is the biggest colony on the south coast, and the only remaining one in the southeast,” explains Alison Giacomelli, a member of our Scientific Committee and the leader of our annual Kittiwakes survey. 

We have been monitoring the Kittiwakes in Sussex since they first nested in the county in 1976. Initially nesting in Newhaven, they gradually moved to Seaford, with the majority nesting there beginning in 1996. 

In 2016, when the Kittiwake population was declining at an alarming rate in southern England, this colony was one of only seven to buck that trend. Unfortunately, the last ten years have not been kind. In 2016, we recorded 1,120 nests in the colony. By 2024, we recorded only 202 nests. An increase to 364 nests in 2025 had given cause for optimism about the colony rebounding. 

What happened this year? 

The summer of 2026 brought record-breaking heatwaves to the UK. The Kittiwakes weathered the first heatwave in May, but based on the timing of the abandonment, we hypothesise that they were unable to withstand the second one in June. 

“The south-facing chalk cliff must have been unbearable for them,” says Giacomelli. When she visited Seaford in mid-June, she had counted 200 nests – a promising start, given that the full colony would not have been visible from land. When she returned on the first of July for the official survey, accompanied by a representative of the South Downs National Park Authority and their drone pilot, the site was quiet, with no Kittiwakes on the cliff or nearby on the water. 

While Kittiwakes have also struggled globally with warming seas impacting the food web they rely on, given the timing, Giacomelli believes the most likely explanation for their departure is that the eggs did not survive the heatwave. This would have left the adults with no reason to stay. 

What does this mean for the kittiwakes? 

Kittiwakes raise only one brood a year. If nests fail, the adults cannot lay eggs again, and they would have gone out to sea to start their winter period early. 

This species lives around twelve years, first breeding around age four, so a colony can withstand poor breeding years. “But this is now a colony that has lost an entire breeding year,” notes Giacomelli. 

This year’s abandonment of this Kittiwake colony is a stark reminder of how populations struggle in the face of climate change. The Met Office recently conducted a rapid climate attribution study, concluding that the UK’s record-breaking mean temperature was made around 130 times more likely by human-induced climate change. Climate projections indicate that summer temperatures will continue to rise.  

With warmer summers likely in the future, it remains to be seen whether the Kittiwakes will have better luck on the Seaford cliffs in the coming years. They are likely to visit again in future breeding seasons because of their site fidelity, says Giacomelli, while adding that it is also possible that they could avoid Seaford because of the catastrophe this season. “We’ll have to wait and see,” she says. “Here’s hoping for a better year next year.” 

This is a good time of the year to consider taking part in the BTO Breeding Bird Survey (BBS), because if you take on a square you will also have the option to take part in the Sussex Winter Bird Survey (SWBS) (starting 1 November 2026) by surveying the same square over the coming winter. Some squares have recently become available and there are plenty of squares available right across the county; some of these squares are accessible if you have limited mobility or if you are reliant on or choose to use public transport.

This national monitoring scheme is administered by the BTO and jointly funded by the BTO, JNCC and RSPB. It has been running since 1994 and its primary aim is to provide population trends for common and widespread bird species in the UK. Population trends for Sussex are also produced and published in the Sussex Bird Report. Survey plots are randomly-selected 1-km squares and the same squares are surveyed each year. Volunteers visit their squares three times each year during the breeding season, once to record simple habitat data, and twice to walk a fixed route, recording birds seen and heard. There are more than 200 BBS squares across Sussex, covering every type of habitat, and new volunteers are always needed.

Volunteers must be able to recognise common and widespread birds by sight and sound, and must be able to physically get around a survey route reasonably early in the morning, but beyond those requirements absolutely anybody is welcomed into this survey scheme. Previous experience of survey work is not necessary and help and support from experienced volunteers can be arranged if required; there will also be some informal practice sessions arranged in Sussex in March and April 2027. Finally there is no requirement to conduct surveys alone – take a friend with you!

The BBS squares (asterisks indicate priority squares that have been surveyed before) in Sussex which currently need volunteers for this coming winter and the 2027 breeding season are (updated 16/9/2026):

SU7907 near Funtington*
SU8102 near Bosham Hoe*
SU8307 near West Stoke*
SU8404 Fishbourne*
SU8909 Goodwood Park*
SU9729 near Northchapel*
SZ7996 East Wittering*
SZ8199 near Birdham
TQ0124 near Kirdford*
TQ0205 near Lyminster*
TQ0322 near Codmore Hill*
TQ0324 near Wisborough Green
TQ0601 East Preston*
TQ0826 Billingshurst
TQ0918 West Chiltington*
TQ1031 near Slinfold*
TQ1038 near Ewhurst (Surrey)*
TQ1323 Dragon’s Green*
TQ1531 Broadbridge Heath*
TQ1636 Kingsfold*
TQ2536 Gossops Green
TQ2638 Langley Green*
TQ2733 Tilgate Forest*
TQ4716 near Isfield*
TQ4922 near Buxted
TQ5023 Buxted*
TQ5026 High Hurstwood
TQ5128 near Crowborough*
TQ5130 central Crowborough*
TQ5212 Golden Cross
TQ5228 near Crowborough*
TQ5312 Golden Cross
TQ5435 near Eridge Station*
TQ5639 Tunbridge Wells*
TQ6000 Eastbourne Upperton*
TQ6414 Bodle Street*
TQ6419 Earl’s Down*
TQ6817 near Penhurst
TQ7811 Hollington*
TQ8013 Baldslow*
TQ8413 near Three Oaks*
TQ8613 Guestling Green*
TQ9217 near Winchelsea Beach*

The following BBS squares may be accessible to you if you have limited mobility (including using a wheelchair) as the survey routes are entirely on pavements and minor roads:

SZ7996 East Wittering
TQ0601 East Preston
TQ2638 Langley Green
TQ5639 Tunbridge Wells

The following BBS squares may be accessible by train as they are close to rail stations (other squares may be easily accessible by bus):

SU8404 Fishbourne
TQ0205 near Lyminster
TQ5023 Buxted
TQ5228 near Crowborough
TQ5435 near Eridge Station
TQ5738 Tunbridge Wells
TQ6000 Eastbourne Upperton

For further information, please contact Helen Crabtree at hcrabtree@gmail.com.

Back in the spring, one lucky birder at our conference’s silent auction won the chance to spend a morning bird ringing with SOS Chair Clare Buckle. On the 22nd of August, our winner joined a team of four ringers – Clare Buckle, SOS Database Manager Dr John Newnham, Knepp Lead Ecologist Matt Phelps, and Becky Parangi-Sayers – for a sunny session at the Knepp Wildland.  

What is bird ringing, and why does it matter? 

For anyone new to it, ringing involves carefully catching wild birds in fine-mesh mist nets, fitting each with a uniquely numbered and lightweight metal ring around its leg, recording a set of measurements, and releasing each unharmed. Every ring carries a unique number so that, if the bird is ever caught again, its movement can be traced. This gives us valuable insight into lifespans, migration, and how well the population is faring. 

Knepp is a particularly rewarding place to do this work. The estate’s rewilding project has transformed former farmland into a medley of scrub, wetland, and wood pasture that supports a diverse population of birds. 

An early start and a busy morning 

The team met at 6am to put up five mist nets. They targeted passerines, or perching birds, to see which species were using Knepp during their migration journey. It was a productive morning with 65 birds caught in total. 

Willow Warblers were the most numerous species, with a total of 29 birds ringed. One was a paler adult, and the rest were all lemon-yellow juveniles. 

Common Whitethroats and Lesser Whitethroats passed through the site, along with plenty of Blackcaps. But the star of the day was a beautiful juvenile male Redstart, with its rust-red tail on full display. 

These species travel incredible distances as they migrate. Redstarts head for the Sahel region of Central and West Africa for the winter, while the Willow Warblers and the Common Whitethroats face an even longer journey. Some travel as far as South Africa before returning to Sussex to breed in the spring. That’s a round trip of about 8,000 miles! 

Along with these migrating birds, the team also caught a stunning male Bullfinch, Blue and Great Tits, and a Goldcrest – Britain’s smallest bird. 

Hands-on science 

Throughout the morning, the ringers talked our winner through the techniques used to age and sex each bird – from plumage details like the juvenile Willow Warblers’ yellow wash, to more subtle clues in feather shape, wear, and signs of moult. They took biometric measurements, including wing length, weight, and stored fat. Our winner also got the chance to handle and release several birds themselves. 

A huge thank you to Clare, John, Matt, and Becky for sharing their expertise, and to Knepp for hosting. Sessions like this are more than a memorable day; the data collected builds up our understanding of how Sussex’s migrant birds are faring, at a time when many species are under real pressure.  

Keep an eye out for our 2027 conference – we hope to offer a ringing session at another silent auction next year! 

All birds ringed and released under licence by BTO ringers.

We sent out over 1200 emails to members yesterday from our mail.newsletter@sos.org.uk email address giving you the opportunity to sample a couple of versions of our annual Sussex Bird Report in digital formats that can be seen via computer, tablet or smartphone. We are aware that a proportion of these landed in recipients’ SPAM in boxes. If you are a paid up member of SOS, and have provided us with your email address, you should have received this email. Please can you check your SPAM if nothing arrived.

The email asks if you would prefer to receive this publication in digital format in the future and email Mark Mallalieu (Chair, Scientific Committee, SOS), know your preference of the two formats linked in the email. Please forward your reply to mallalieum@gmail.com and NOT to mail.newsletter@sos.org.uk.

The sharp rising cost of printing and postage is eating into the money that SOS can reinvest in conservation and people engagement activities.  Every member that chooses the digital version will save SOS approximately £5.

We will continue to publish the Sussex Bird Report in book format and there is absolutely no pressure to convert. Simply do nothing and the report will land on your doormat as usual.

Jonno Cook, (Chair, Membership and Publicity Committee, SOS)

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.