A Study of Lowestoft’s
Kittiwakes (Rissa Tridactyla)
Julie Martin and Steve Piotrowski
Introduction
An annual tally of the number of Black-legged Kittiwake (hereafter referred to as Kittiwake) nests and their whereabouts within Lowestoft was carried out by the late Brian Brown, with papers published in Suffolk Birds in 1986 and 1990. However, since his death in 1999, only ad hoc records have appeared in Suffolk Bird Reports. There has been no recent comprehensive study of Lowestoft’s Kittiwake population, which has increased significantly in recent years. In response to this, a breeding bird survey was carried out in Lowestoft during 2023 by Julie Martin.
Background
The British Trust for Ornithology (BTO) estimated the UK population of Kittiwakes in 2015 to be in the region of 205,000 pairs, but there have been substantial declines (BTO, 2024). Nationally, the Kittiwake breeding range has contracted by around 10%, with a population decline of over 40% during 1986-2011 (Balmer et al. 2013). This trend has been proven more recently by the Seabirds Count 2023 (JNCC, 2023). Declines of Kittiwakes in Britain can be attributed to fewer than 0.8 chicks fledging per pair at many monitored sites (Coulson, 2017). This is thought to be in response to over-fishing and changes to sea surface temperatures due to climate change. Sandeels are the Kittiwake’s preferred food item in northern waters, but stocks have severely declined to the extent that industrial sandeel fishing will no longer be permitted in the North Sea from April 2024 (BirdLife, 2024).
Suffolk has two Kittiwake nesting areas: the urban colonies at Lowestoft and the now-redundant offshore cooling towers at Sizewell. These are the only east-coast colonies between Bempton Cliffs, East Yorkshire and Dover, Kent (Balmer et al. 2013). The Kittiwake is now on the red-list of Birds of Conservation Concern and is listed as a vulnerable Species of European Conservation Concern. Therefore, looking after our Kittiwake colonies in Lowestoft is important for the conservation of the species within the UK.
Nesting Kittiwakes have been a part of Lowestoft’s heritage for 65 years since two pairs attempted to breed on the South Pier Pavilion in 1958. Numbers slowly increased and by 1970, 32 pairs were present. During the 1970s, the colony spread onto buildings surrounding the harbour area but the South Pier was the preferred site. By 1979, 86 pairs were nesting. Many of the favoured buildings were then demolished and birds were dissuaded from nesting on others by a variety of measures; cementing ledges, fixing netting and, more recently, installing spikes. Whilst increasing incidence of poorly installed and maintained deterrents posed a threat to the birds, through entanglement in the netting or being killed by the spikes, the greatest threat to Lowestoft Kittiwakes came in the late-1980s when the main nesting site, the South Pier Pavilion, was demolished. The final year of breeding at that site was in 1988 when 107 nests were noted, but the birds soon became accustomed to a purpose-built wall on the northern side of the harbour entrance. The colony increased very rapidly and a peak of 259 nests (producing 303 young) was reached in 1995. Kittiwakes began nesting on Claremont Pier in 1996 where numbers have since multiplied steadily.
Anti-gull measures employed by businesses in the town generally restricted Kittiwake nesting to the harbour area, but disaster struck in 2006 when urban foxes found the wall and predated many of the nests. Thereafter, nesting numbers in the harbour plummeted although, almost certainly, displaced birds from there were recruited to the Claremont Pier colony, which peaked at 47 nests in 2020. Predation by Red Fox (Vulpes vulpes), Common Rat (Rattus norvegicus) and Herring Gull (Larus argentatus) severely limited nesting success in the harbour area.
Nesting was noted for the first time to the town centre on Boots The Chemist and on Our Lady Star of the Sea Roman Catholic Church in 2014. The latter site proved to be a most favourable nesting location with numbers increasing rapidly to 62 pairs (raising 63 chicks) in 2015, 145 pairs in 2016 and 151 in 2018. A total of 36 nests (producing 36 young) were on the BT building, and Boots The Chemist hosted 22 nests (16 young) in 2016. Predation at the port continued, which probably explains the subsequent diverse spread of locations within the town. The purpose-built wall was abandoned by Kittiwakes in 2017. Lowestoft nesting totals have increased steadily in recent years from 200 in 2013 to 408 in 2017 and c.650 in 2021.
It is an obvious question to ask why Kittiwakes have chosen to breed in Lowestoft. Traditional nest sites are usually found in dense colonies on steep cliffs with narrow ledges, surrounded by other seabirds. What is it about urban Lowestoft that appealed so strongly to those Kittiwakes in 1958? We can only assume that access to suitable food sources played a key part. During ringing of Kittiwake nestlings between 2008 and 2013 regurgitated samples were collected and submitted for scientific analysis of contents. Of the total 123 samples tested over the six-year period, an average of 55% of samples contained sand eel. The proportion of sand eel varied between years with as few as 4% of 26 samples containing sand eel in 2010 to a whopping 91% of 32 samples in 2013. The remaining percentage was supplemented mainly with Clupeids such as Sprat and Herring (Carter, 2014). It is likely that these food sources are within a close range to Lowestoft and that competition at the feeding grounds is relatively low. This would go some way to explaining why Lowestoft’s Kittiwake population has continued to expand, although more work needs to be done to confirm this.
Winter Distribution and Movements
At the beginning of the 20th Century, the Kittiwake was seen off Suffolk solely as an autumn and winter visitor arriving in September and leaving in spring (Ticehurst, 1932). The Kittiwake is a surface feeder and is the most abundant gull in Britain and Ireland (Wenham et al. 2002) and in the world. The thriving fishing ports of Lowestoft and Great Yarmouth would have provided ample foraging opportunities for the species. However, with the subsequent demise of the fishing industry, Kittiwakes now compensate for low food availability by increasing their foraging range and devoting more time to foraging. Numerous studies show that the species is essentially oceanic outside the breeding season with populations from many breeding localities wintering in the North Atlantic and North Sea. Some birds from British and Irish colonies, especially first-winter and immature birds, spend time off the eastern seaboard of North America (Wenham et al. 2002).
Lowestoft’s ornithologists have had a long-term interest in Kittiwakes and regularly search for ringed birds. Two individuals ringed in Brittany, France, have been logged at Lowestoft (Andrew Easton, pers com). From 2004, licenced bird ringer Colin Carter began ringing Kittiwake nestlings at the purpose-built wall in Lowestoft outer harbour and at the Claremont Pier. This led to a long-running colour ringing project as part of the BTO’s Re-trapping Adults for Survival (RAS) scheme, later continued by Kessingland Ringing Group (KRG). Over 1,400 new Kittiwakes have been ringed since 2004 with a hiatus from 2020-2023 when access to the nest sites became problematic. There have been almost 3,400 re-sightings of the colour ringed birds since the project began. These re-sightings have proven that the vast majority of surviving Kittiwakes of breeding age return to their natal site to breed. A small number of Lowestoft colour-ringed Kittiwakes have joined a colony at Boulogne-Sur-Mere harbour in Northern France, where re-sightings are submitted annually to KRG by local enthusiasts. A table of re-sightings during 2023 are shown in Appendix 1.
The Kittiwake’s site fidelity means that they are ideal for geolocation technology. They return to the same nesting localities each year and adults are relatively easy to catch as they sit tightly on their nests. However, recapturing is quite challenging as birds previously caught quickly realise the intentions of the trappers. Captured birds are fitted with small geo-locators, which are tracking devices that weigh no more than eight grammes. The data retrieved provides an annual movement cycle for each bird. During Kittiwake ringing activities between 2012 and 2019, KRG carried out a small study by fitting geo-locators to breeding adults to investigate winter dispersal from the Lowestoft colonies. This resulted in a paper published by group member, the late Mike Swindells, in the Seabird Journal. A total of 27 birds were fitted with geo-locaters, some for multiple years. Fifteen individuals were recaptured with usable data, some with tracks for up to four successive years. Three of these birds stayed in the North Sea, one visited Portugal and the others wintered in the North Atlantic (Swindells, 2019). Although this is a very small sample, the recoveries conform to the international trend.
Kittiwakes in Lowestoft 2023
Sites and Methodology
There are three key areas in Lowestoft that contain colonies of breeding Kittiwakes: Waveney Dock, Claremont Pier and the town centre. Within the town centre there are several sub-colonies that can be independently identified (see Map 1). The largest sub-colony centres on Our Lady Star of the Sea Roman Catholic Church in Gordon Road. A large sub-colony is centred around the BT building on Surrey Street. A mini-colony exists at the Marina Theatre. There are many small nest sites spread out around the buildings east of the lower section of London Road North which have been grouped together. There is also an important colony directly around the landward side of the bascule bridge and a small site around the port channel and trawl basin. All nests are within 700 metres of the true coastline or 400m from the docks.
It is clear from this map that Kittiwakes prefer to nest together, taking every opportunity to remain within sight, or even earshot, of other nesting birds. Most nest sites have been constructed opportunistically on buildings within the town. Over the last two years there have been purpose-provided ledges constructed at two of the key sites; the BT building and the Marina Theatre. The Kittiwakes have taken instantly to these ledges, primarily as they have been displaced from pre-existing nest sites, but this uptake has also involved many first time breeders.
Surveys of the main breeding sites were carried out during the period 18th March until 23rd August, usually at two-week intervals. First visits were made to count adults in attendance and to observe breeding activity. From May onwards counts were made specifically looking at apparently occupied nests (AONs) as well as noting any trace nests. From mid-June until mid-August visits counted how many chicks were present. All counts were carried out using a Swarovski ATM85 spotting telescope and 10×42 binoculars. There are considerable difficulties in monitoring most of the colonies within the town due to the height of the nests from the ground and the available angle of observation. At no point was it possible to make any accurate counts of eggs at any of the nest sites in Lowestoft. Colour rings were read at every possible opportunity and 179 sightings were submitted to the BTO via Kessingland Ringing Group.
Map 1: The Lowestoft sub-colonies, with total number of AON
Key Sites
Waveney Dock
The Kittiwakes here nest on tyre fenders and dock stanchions just above the water line (see photo). There are a few nests on buildings beside the docks but these were not monitored for breeding observations. Six arranged visits were made at Hamilton Dock to survey activity across the water towards Waveney Dock. This was only possible with a spotting telescope which could only be practically used when the weather was appropriately calm. Two surveying visits were made into Waveney Dock by small dingy, kindly captained by Dick Houghton, on 4th and 18th July. This gave very accurate counts of AON’s and chicks at peak breeding season, using only binoculars from the boat.
Our Lady Star of the Sea Roman Catholic Church
The church has nests on all four sides of the tower, on the top parapets and just a few other nests on other parts of the building. Due to the height and angle of observation, it is quite difficult to see into the nests. Most of the chicks could only be counted once they had reached a medium size and could be seen from ground level.
Kittiwakes nesting at Waveney Dock – Photograph: Julie Martin
The BT Building
Over the last decade this building has been a heavily occupied nesting site, with birds using window ledges around the building. Netting was put in place in 2021 leading to trapped and distressed birds and a national campaign took place in the media to remove the netting. This led to the construction of 13 levels of purpose-provided plank ledges on a blank, west facing wall. Part of the ledging is obscured by a large tree which makes viewing difficult (see photo). The Kittiwakes tend to occupy from the top-most ledge downwards, so viewing activity from ground level is not easy. In 2023 the Kittiwakes managed to make nests on the window ledges on the Surrey Street side of the building despite measures put in place to dissuade them. These nests were constructed several weeks later than the main colonies, leading to later broods. These nests were much easier to observe from ground level. It was discovered late on in the breeding season, that there are more nests at the rear of the building where there is no public access or viewing. This means that there were approximately 10-20 nests that did not have any breeding observations.
Kittiwakes nesting on the purpose-provided planking at the BT Building – Photograph: Robert Wincup
The Town Centre
For surveying purposes, this area covers everywhere not separately detailed in this section. There are many mini-colonies within the town centre. They tend to be built on commercial buildings where viewing is made difficult by the angle of observation from ground level. Notable mini-colonies exist at the Marina Theatre, Lowestoft Music Centre in Grove Road, Mattressman on Bon Marche/Beach Mews, a residential house on Battery Green Road, residential homes in Commercial Road and on buildings at Pier Terrace and Papa Johns on Station Square.
Claremont Pier
A full breeding survey was carried out on the nests that are visible from land using the methods prescribed in the Seabird Monitoring Handbook for Britain and Ireland 1995, and was submitted to the BTO’s Seabird Monitoring Programme. This is the only site where visibility for observations is good for 61 AONs. Here the Kittiwakes nest on the posts and braces that previously supported the pier planked-flooring. Despite the current pier owners removing much of the planking for renewal outside the breeding season, Kittiwakes continue to nest at this important site. A visit to the seaward end of the pier by dingy on 18th July found that there are another 40+ nests that cannot be seen from land and did not have any breeding observations.
Colour ringed Kittiwakes nesting at the Claremont Pier – Photograph: Robert Wincup
Breeding Results
The results have been broken down into observed AONs (Actively Occupied Nests), number of chicks counted at the site and overall productivity.
- Waveney Dock had 166 AONs producing 174 chicks with a productivity of 1.05 per nest. There was a significant failure of nests at this site sometime in late-June which was almost certainly caused by human activity. A total of 42 nests were observed to have failed on 4th July, with 33 alone in one of the four nesting sections.
- Our Lady Star of the Sea Roman Catholic Church had 195 AONs producing 225 chicks with an average productivity of 1.15 per nest.
| Nest Site | AONs | Chicks | Productivity |
| Tower North Side | 44 | 57 | 1.29 |
| Tower East Side | 50 | 60 | 1.2 |
| Tower South Side | 59 | 61 | 1.03 |
| Tower West Side | 30 | 30 | 1.0 |
| Other Areas | 12 | 17 | 1.4 |
Table 1: Breakdown of AONs and productivity by area at Our Lady Star of the Sea Roman Catholic Church
- The BT Building had 94 AONs producing 104 chicks with a productivity of 1.10 per nest.
- The Town Centre had 367 AONs producing at least 430 chicks with a productivity of 1.17 per nest.
- Claremont Pier (landward) had 61 AONs producing 71 chicks with a productivity of 1.16 per nest. There were 13 failed nests observed during the breeding bird survey at this site.
Overall there were 883 monitored AONs throughout Lowestoft.
A total of 1004 chicks were counted at these nests giving an overall productivity of 1.13 chicks per nest.
There were over 100 additional AONs that were found in Lowestoft but could not be observed due to access: 21 on the buildings at Waveney Dock, 45 on the seaward end of Claremont Pier, 22 in the port channel/trawl dock and c20 at the rear of the BT building. This brings the total of AONs to 991, with a total of 1982 individual breeding birds. There were also non-breeding birds present across the town during the breeding season, which leads to an estimate of c.3000 individual Kittiwakes present in Lowestoft.
Avian Influenza
Highly Pathogenic Avian Influenza (HPAI) has been affecting UK seabird populations in large numbers since 2021 (BTO, 2023). It is a virus that spreads quickly through dense colony nest sites. Sadly, 21 of the UK’s 25 breeding seabird species have tested positive for the virus since 2021 (RSPB, 2024). HPAI was noted as moving down the east coast during the seabird breeding season in 2023, notably affecting the seabirds at RSPB’s Bempton Cliff during mid-July (BBC, 2023). HPAI was also reported along the entire Norwegian coast in 2023 and Kittiwake colonies in the High-Arctic have been decimated by the disease. There are reports of a staggering 11,000 dead Kittiwakes being removed from colonies around Vadsø Municipality, Finmark, which may account to more than half of the local population (Bird Guides).
The Lowestoft population of Kittiwakes was closely monitored during the breeding surveys for signs of HPAI. A fledged juvenile was found at Ness Point on 2nd August with suspected HPAI and was removed by the RSPCA. This led to an inspection of the main colonies on 3rd August where a chick was seen displaying vivid and typical visual symptoms of HPAI at the Claremont Pier. There was also concern that eight adults across the town may have been displaying visual signs of early HPAI infection. The few birds that showed symptoms of HPAI became apparent at the tail end of the breeding season when colonies further north were dispersing. It is impossible to ascertain the extent of the disease locally or whether the casualties generally involved passage birds. All sightings of sick or dead seabirds have been submitted to the BTO by Birdtrack. However, it is suspected that sick or dead birds found by others have not been reported.
The Future
The future of the Lowestoft Kittiwakes had been looking quite uncertain with displacements throughout the town being unavoidable. Recently, there has been construction of some Artificial Nesting Structures (ANS), purposely provided by two energy companies at Lowestoft, in mitigation for offshore windfarm disturbance; one land-based site and two offshore platforms. A third platform has been stationed off Minsmere. It is expected that in time, Kittiwakes will take up residence on both the onshore and offshore structures. Ringing returns show that Kittiwakes have site fidelity and birds that have been successfully nesting on buildings in the town for years will take time to relocate to these new structures, even with displacement. Any birds that do relocate will also attract ‘new recruits’ – young birds reaching breeding age for the first time.
The ban on industrial sandeel fishing in the North Sea ought to bring about positive increase in Kittiwake productivity and abundance along the East coast over the coming decade, notwithstanding the as-yet unknown full impact of HPAI. However, if a significant outbreak of HPAI occurs within Lowestoft’s town centre it would be devastating for the Kittiwake colonies. Not only due to mortality but it may prompt a public outcry that would result in a massive cull on health grounds. It is likely that there would be concerns of the disease spreading to the human population.
Conclusion
Lowestoft’s urban Kittiwake population has continually grown since the first birds nested here in the 1950’s culminating in almost 1000 nesting pairs in 2023. The overall breeding productivity of 1.13 chicks per nest in 2023 is well within the mean tolerance of 0.8-1.5 fledged young per year for maintaining Kittiwake population (Coulson, 2017). With the addition of the newly constructed ANSs and the sandeel fishing ban, it is hopeful that the breeding population in Lowestoft will continue to increase.
Acknowledgments
We would like to acknowledge the help and assistance of Andrew Easton (Waveney Dock monitoring), Robert Wincup (photographs), Dick Houghton (for use of his dingy,) John Casey and Martin Sanford (advice and assistance).
Markers will be added to this interactive map over the coming days which
help users note where the colonies and Artificial structures are located.
