What research is happening in the area at the moment?
Spurn Bird Observatory is dedicated to enabling and supporting the science and research carried out in the area, using our historic data, collaborating with and facilitating research projects and maintaining the long-term monitoring already taking place. This is in addition to the daily bird log and general bird ringing activities. Here we share some of the work taking place right now. Please feel free to say ‘hello’ if you see researchers at Spurn.
This project has the aim of facilitating the rollout of the UK Motus VHF network, which includes trying to find as much funding as possible, ideally for a nationwide rollout, but also more locally, looking to set up clusters of receivers at particular hotspots. Spurn is part of a growing UK network, having been championed by Spurn committee members after a visit to Long Point Bird Observatory in Canada. During 2019, Spurn was one of the first UK bird observatories to get a receiver, allowing the Observatory to ‘listen’ for passing tagged birds or bats from the continent.
Motus is a collaborative, open-source way of tracking birds and bats. It is based around a network of these passive VHF receivers, that can detect uniquely-coded miniature VHF tags within 5-10km. At less than 1g, the tags are small enough to be deployed onto passerines and bats. The scheme began in Canada and is now used extensively through the Netherlands and Germany, with small localized networks in other European countries.
This network gives us the chance to track some of our understudied migrant species, such as Blackcaps and Yellow-browed Warblers. Species frequently tagged in Europe include both of these species, as well as Robins, Wheatears and Acrocephalus warblers. It is not limited to these species though: bats are also now able to be fitted with Nanotags which means we can acquire more information on their migration as well. Work has begun in the Netherlands by colleagues at Wageningen University to look at Nathusius’s Pipistrelle migration and use of offshore routes - a species our UK Bat Conservation Trust is also very interested in.
Once the network grows, there will be more questions we can answer and more species that will benefit from the system. Anyone will be able to ‘tap into’ the receiver network, meaning that groups can have their tags discovered and discover other researchers’ tags. And, crucially, they will have access to the data which will be open access for registered Motus users. The importance of such a collaborative network is highlighted by direct recommendations made by the 13th Conference of the Parties in February 2020. Better methods are needed to assess threats to migrant species and Motus provides a way of collecting data in an efficient, automated way, leading to fewer biases in those data. It is vital that we understand more about where these small creatures are moving to and from, and which routes they are taking, so that we can protect important stopover sites to aid their refueling, and to take action to maintain populations which provide vital ecosystem services such as pest regulation and nutrient transfer – as well as being biomass themselves for predators!
Ringing groups, conservation bodies, private individuals and companies interested in hosting or sponsoring a motus receiver are welcome to make contact to discuss becoming involved in the network.
“I am passionate about conservation-focused tracking and completed my PhD on Nightjar habitat use using GPS units in 2019, and am always happy to enthuse about migration, nightjars, or both!”
– Dr Lucy Mitchell | Twitter: @lucyjayneryan
BTO/RSPB/JNCC Wetland Bird Survey (WeBS) surveyors monitor the UK's internationally important non-breeding waterbirds. Following a tradition started in 1947, wetland sites are counted once per month, providing data for population and trends in abundance and distribution. At Spurn, counts are organised by the Observatory Warden and have taken place since 1965! During this time, over 100 WeBS species (ducks, geese and swans, waders, rails, divers, grebes, cormorants and herons, gulls and terns) have been recorded!
The network of sites legally protected for their importance to wintering waterbirds depends fundamentally on the WeBS counts, therefore Spurn Bird Observatory sees the huge importance of being part of this long-term monitoring project and would like to thank all the volunteers who help with the monthly counts. For more information on the survey, visit www.bto.org/webs
The rapid decline in the UK breeding population of Curlew is a major conservation priority, with the UK supporting a quarter of the European breeding population. The UK also plays an even bigger role in winter since it supports half of the European population. With an over-wintering population of 2,806 birds (WeBS latest five year average), the Humber Estuary is one of the top seven sites for wintering Curlew in the UK. From bird ringing data, we know that wintering Curlew on the Humber Estuary originate from Fennoscandia and Russia, and individuals start to arrive in early July and leave as late as mid-April to return to their breeding grounds. Individuals breeding locally in the UK also winter on the Humber.
Extensive Curlew research work is led by the British Trust for Ornithology (BTO) across the country to understand the cause of the decline. The research work, undertaken on both breeding and non-breeding grounds, combines a range of desk-based and fieldwork studies. The species’ home range and habitat selection (using GPS tracking data) is one of the ecological aspects investigated. With the miniaturisation of tracking devices, we are now able to track birds for longer periods and at a higher resolution without causing negative adverse long-term effects on bird survival.
Whilst tracking of breeding birds will be carried out in the lowland wet grasslands and upland areas, we are fortunate on the Humber to be the estuary for a case study of wintering birds, following a successful pilot study carried out by the BTO and the Humber Wader Ringing Group (HWRG).
Curlew are a very familiar sight to people along the bank of the Humber; the birds are widely distributed on the intertidal areas, from the confluence of the River Trent and Ouse to Spurn Point. They also frequent the agricultural fields and coastal pastures, chiefly on the south bank of the Humber Estuary where they are often seen heading inland in small groups. Little is known about individual strategies and the use of non-tidal habitats (e.g. farmland and coastal pastures) around estuaries. Work done in the early 1980s on the Tees Estuary indicated that male Curlews (shorter-billed birds) were predominantly using inland and coastal pastures to feed whereas female Curlew (longer-billed birds) preferred to forage on the tidal flats – an example of small scale sexual segregation. There is also unpublished evidence suggesting that Curlew switch to inland field feeding in winter when it is no longer profitable to feed on the tidal flats. Clearly, there is still a lot to learn on interactions between farmland habitats and the tidal flats, with some key questions remaining to be answered: are agricultural fields used as supplementary feeding sites when prey are not accessible on the tidal flats? Or are they used as alternative foraging sites to tidal flats?
With the help of 20 GPS/UHF tags fitted to Curlew, we aim to examine individual strategies of Curlew on the Humber Estuary during two field winter seasons. Whilst this seems a low sample of birds, the data recorded by the GPS is of high resolution with the position of the bird recorded every 90 minutes for a period of up to two months. This will give us a good insight of fine-scale habitat use of Curlew, individual strategies and small-scale segregations.
The PhD study is funded through a scholarship from Hull University with direct financial support from the BTO. The catching and fitting of the Curlew is carried with the help of the Humber Wader Ringing Group (HWRG); the group is made up of volunteers ringing waders on the Humber Estuary since 2003. The work is carried out under strict licensing conditions (for ringing and tagging) set out by the BTO.
– Lucas Mander | Twitter: @LucasMander
In autumn 2019, the decision was made to embark on a pilot study using Point Counts as a method to collect standardised data every day through the spring and autumn at given locations for a given amount of time. One of the aims is to see how standardised data with ‘effort’ recording compares to daily log sightings for grounded migrants with regards to the timing of fluctuations through the migratory periods. Additionally, it is hoped species detectability might be teased from these data - how long do you have to stand in a spot before you are likely to hear that Yellow-browed Warbler call? Information on weather and local disturbance has also been recorded and therefore there is scope to take this into account during analysis.
There are six Point Count locations around the Triangle and six along the Peninsula. Between Observatory staff and long-term volunteers, Point Counts were carried out at each site, daily, in all weather resulting in a highly standardised dataset for the spring and autumn seasons. In addition, walks between each point count resulted in sightings contributing to daily bird log and therefore increasing general coverage within the Spurn Bird Observatory recording area. These surveys record a sample of the ‘big picture’, therefore, ad-hoc sightings by local and visiting birders remain crucial to the long-term monitoring of the Observatory continuing more complete recording in the area.
For this project, research focuses on the behaviour of overwintering waders, specifically foraging behaviour and site-use and how this varies between day and night. Understanding what influences when, where, and how waders feed is key for understanding their health and fitness. This is especially important during the harsher winter months when colder temperatures, fluctuating wind speeds and other conditions can greatly increase the amount of energy needed to stay warm. Many waders are able to forage in a number of different ways, either by sight, touch, or both, and looking into the balance of methods used is also valuable for understanding how they respond, and adapt, to different conditions.
Day-to-day fieldwork involves counts of waders at Spurn, and several other study sites around the Humber, both during and following high tide. This is then followed by several hours spent filming the foraging behaviour of a range of species, as well as keeping track of weather variables and disturbance. During the day a normal video camera is used but darkness adds an extra challenge, and at night infrared and thermal cameras come into play.
The Humber Estuary is an ideal study site for this research as it hosts large numbers of waders during the winter months, with the Wetland Bird Survey (WeBS) reporting up to 111,000 in recent years. This number might be less of a surprise to those who have tried to count the waders spread across the vast tidal flats at Spurn. On one visit in Autumn 2020 I saw over 12,000 Knot near the breach, not including the other species present!
However, waders on the Humber don’t all use the relatively natural intertidal areas at Spurn, many forage and overwinter alongside the towns and port complexes on the southern shore. For example, the greatest numbers of Black-tailed Godwit on the Humber can typically be found in these areas - most likely due to the popular roost site at North Killingholme Haven Pits SSSI. It might seem counterintuitive that a wader would choose to spend its winter in areas with such high numbers of people and vehicles but this work so far has found that individuals in these areas are able to forage in relatively safe conditions at low tide.
Another key difference between the more natural sites, such as Spurn, and the industrial complexes of the southern shore of the Humber is the abundance of artificial light on the tidal flats. This work is investigating the influence of this light on the behaviour of waders, with emerging evidence suggesting that it may help them to forage more efficiently at night than birds which stay in the near darkness at Spurn. Ongoing work will continue this and see whether any effects of artificial light at night are detectable on the behaviour of birds during the day.
Overall, I hope that my work will provide some key insights into the challenges faced by overwintering waders and aid in future conservation of overwintering birds, especially in the complex system represented by the Humber Estuary.
Anyone who wants to get in touch to discuss my research is welcome to contact me via the Hull University website, on Twitter, where I often share information and pictures to do with my work.
Spurn Bird Observatory is contributing to the efforts of The Twite Network, a large network of like-minded enthusiasts from across the UK and continental Europe, by colour-ringing Twite on passage through Spurn. This UK Red-listed species of conservation concern colour-ringed by those within the network.
A unique combination of coloured plastic rings and the standard metal ring are fitted to the bird's legs meaning individuals can be identified ‘in the field’. This allows us to follow the lives of individual birds - to see where they breed, who they breed with, where they migrate and spend the winter, all without having to recapture them. This is important as we try to understand more about recruitment between populations and at which point in the annual cycle (and which habitats) they struggle the most.
Please keep an eye out for colour rings everytime you see a group of Twite, and record any combinations you see and report it via www.cr-birding.org and help us learn more about Twite and, in turn, their conservation.
This PhD project aims at addressing potential bias and research gaps in the study of avian influenza (bird flu) transmission and infection in wild birds. The study focuses closely on the role of passerines and non-waterfowl species in avian influenza transmission and the connections and similarities between avian communities at different habitats.
The study begins with a meta-analysis of the literature, collecting data from wild bird sampling for avian influenza worldwide with the aims of looking at what species are sampled the most, why this might be, and what gaps exist. It is hoped that addressing these gaps will help to focus future research into reducing the number of outbreaks amongst poultry in the UK as well as to better understand and compile the varying relationships between virus and host specie(s).
The bulk of the work at Spurn is for a further chapter investigating if migrant birds are carrying avian influenza on migration. By working closely with the ringing team to collect faecal samples during the standard ringing operations at Spurn, and with help from the Animal and Plant Health Agency (APHA), these samples will be tested for avian influenza. The current understanding of avian influenza infection tends to look at waterfowl and their movements, but it is not known at what level passerines and other bird families may carry bird flu during the migration season. Further to this, the study will attempt to connect the species migrating, and being sampled at Spurn, to poultry farms utilising wild bird counts around sites across Yorkshire.
In addition, counts of birds at the various water bodies around the Spurn Peninsula are being carried out to look at the species compositions throughout the winter months and how they interact with the waterbody and each other, in an intra and inter specific way.
Finally, the data collected at Spurn and across Yorkshire will feed into a Bayesian network. This will look to create ‘risk scores’ of the likelihoods of species connecting migration sites, water bodies and poultry farms with the vision that this will be able to highlight the aims for further research, mitigation and sampling in the future.
The Humber Wader Ringing Group was formally established in 2003, with the aim of gaining a better understanding of the movements and survival of waders using the estuary. Almost from the outset colour-ringing has formed part of the group’s strategy, starting on Redshank and increasing to both godwits, Curlew, Knot, Grey and Golden Plovers and Oystercatcher. Colour ringing provides vastly greater quantities of data, compared to standard metal ringing. For example, of 76 Black-tailed Godwits colour-ringed in 2018, 62 have been re-sighted at least once, with a total of 406 individual sightings.
From the Humber Redshank have been seen across the UK, as well as The Netherlands, Belgium, Germany and Iceland. Knot have been seen in the same locations, plua northern Norway which, along with Iceland, is a staging area on their migration route to breeding grounds in Greenland and the high Arctic. We can also look at winter site-fidelity of birds using the estuary. Redshank and Curlew in particular have been shown to return to the same areas of the Humber each winter, and in many cases to the exact same location where they were originally ringed.
Our main catching sites are Welwick, Kilnsea Wetlands and Long Bank Marsh. Overall, there is no doubt that colour-ringing has shed new light on how waders use the estuary during the non-breeding season, and it is hoped work will continue well into the future. Of course, we welcome sightings of any colour-ringed waders, as we should be able to identify the project from which they originate in most cases.
The Little Tern is Britain's smallest, and one of the rarest, breeding seabirds with around 1,450 pairs (BTO Bird Facts). It is a migratory species (Hoyo et al., 1996) coming to Europe from West Africa for the breeding season (May-August) and the breeding or nesting habitat is preferably located in the coast with salines or sandy beaches (Catry et al., 2004; Paiva et al., 2006; Medeiros et al., 2007).
The colony at Beacon Lagoons is the only one in Yorkshire and has been with us since the 1800s, with the species formerly nesting at the Point of the Spurn peninsula.
Little Tern populations have been in decline across the UK since 1980 and are considered as a conservation priority (Eaton et al., 2009), and the species is legally protected through its inclusion in Wildlife and Countryside Act 1981 (Schedule 1). Nevertheless, the Little Tern population in the UK has declined by around 25% between 1969 and 2002 (Ratcliffe, 2003; Mitchell et al., 2004). Some of the causes responsible for this decline have been and continue to be: predation, food shortage, habitat destruction, disturbance e.g. human presence, and extreme weather conditions such as sea level rise or strong storms (Ratcliffe, 2003; Catry et al., 2004; Medeiros et al., 2007). Predation has been identified as one of the most relevant causes of the reduction in breeding success, with the main culprits being foxes (Vulpes vulpes) and kestrels (Falco tinnunculus) (Sears and Avery, 1993; Holloway, 1993; Ratcliffe, 2003; Ratcliffe et al., 2008). Another important factor towards the decline of the Little Tern population is human presence, which can have both direct and indirect impact: an increment in human presence and man made surfaces close to the colonies can create a situation which will result in the abandonment of nests or the direct destruction of them by humans. Moreover, the presence of people around the colonies can increase indirectly the number of potential predators by introducing new species (dogs) or calling the attention of predators about the presence of eggs and chicks (Scarton et al., 1994; Hong et al., 1998; Medeiros et al., 2007; Aitken and Amery, 2014).
Here at Spurn, the Observatory has been running a protection scheme for the Little Tern colony since the 1990s after taking over from The South Holderness Countryside Society, who still help out wherever they can. The Little Tern project annually employs two wardens to watch over the colony 24/7, and erects and manages electric fences around the colony to prevent predator incursions.
As a declining species within the UK, a Little Tern recovery project was set up in 2014, managed by the RSPB, co-ordinating all the Little Tern colonies around the country. Funding was sought through the European Union and a five year project was set up across the country to try to halt the species’ decline.
This partnership included the Beacon Lagoon colony which had also suffered some decline in recent years. Incorporated into this project was a new colour ringing scheme using darvic rings. These are plastic rings with numbers and letters on them, allowing for easier identification and reporting of individual birds in the field. There are different colours and letter/number combinations for different colonies. The ones here at Spurn are fitted with yellow darvic rings with black letters/numbers U01-99. These are fitted to the left tarsus of the chicks and right tarsus of the adults.
Previously, a colour ringing scheme was set up with a few colonies, with very limited success: birds were fitted with just a single colour ring, (mauve rings for Spurn birds, which faded to dull white or silver with age) and very few re-sightings were received.
The new darvics are much better for re-sightings and are much more easily read.
The idea behind the colour ringing projects was to explore how much site fidelity the terns exhibited, and to detect any movement between colonies.
Colour-ringing is not without its challenges. Our main issue with the Little Terns is their leg length: it can still be a struggle to see or read the ring in its entirety.. We can also only colour-ring the chicks when they are just over half-grown, this happens to be when they are at their hardest to find, so only a limited number get ringed with these darvics every year.
Within some colonies across the UK, adults have been targeted for colour-ringing. We are looking into the possibility of this here at Spurn.
We have already received some interesting ringing recoveries from ‘our’ Little Tern colony (all involving birds which were ringed here as chicks):
The national longevity record for Little Terns was held for a short while after a chick which was ringed here on 16th June 1993 was found dead at Holme-Next-The-Sea Norfolk on 15th August 2016 at the ripe old age of 23.
A chick ringed here in June 1999 was later trapped as a breeding adult inin Zeebrugge Belgium in 2004 and then in Heist Belgium in 2007.
One of the first darvic-ringed chicks (U04) ringed on 16th July 2014 was seen roosting on a beach at Crimdon Dene in Cleveland on 21st July 2016.
A chick ringed at Beacon Lagoons in 2013 was trapped breeding at Gronnant in Wales and another which was ringed in 2015 was trapped as a breeding adult Foulney, Cumbria and later seen at Gronnant, Wales (both in 2018) showing that there is definitely some movement between colonies. These were both fitted with darvics for that area when trapped.
The Beacon Lagoons Nature Reserve is the location of Yorkshire’s last and only little tern colony. The site is rich with a mosaic of coastal habitat including protected sand dunes vegetated by marram grass and saline lagoons. The nesting area selected by little terns is nestled between these lagoons and the North Sea. Conservation efforts, directed by the Spurn Bird Observatory, continue to monitor, and manage the site in order to boost productivity.
As the dunes migrate southwards and the vegetation expands through natural succession, this location may soon become unsuitable habitat for little terns. Therefore, mapping the dunes and vegetation while evidencing the spatial requirements of little terns were paramount to this study.
Little terns were found to select nests close to the water’s edge of the saline lagoons and remain at a distance from sand dunes and vegetation where early detection of predators was still possible. Anti-predator measures have been installed to reduce human disturbance and terrestrial predation. However, aerial predators still pose a large threat to the survivability of little tern chicks. Variables affecting predator visitation and peak times of predator presence were analysed to aid in the management of personnel at the site, warden/volunteer shift rotations and advise on anti-predator precautions. Carrion crows were observed to make up the majority of predators causing disturbance at the colony and culls at the site may increase chick survival. Predator presence was less during evening and night warden shifts. Shifts with south easterly winds were also found to have a negative effect on predator presence.
Understanding how these aspects attract breeding pairs or effect tern breeding success is key to creating, managing, and preserving colony sites and maximising productivity therein.
Populations of many shorebird species are declining worldwide, with migratory species most at risk. Reductions in breeding success can be attributed to disturbance, habitat loss and degradation, and increasingly, climate change. Vegetation and dune encroachment could prevent shorebirds from nesting or resting within an area. The management of dune vegetation can be controversial due to its own designations, therefore evidence for the success of management is important. A study of Little Terns (Sternula albifrons) and Ringed Plovers (Charadrius hiaticula) was conducted within a shorebird colony at Beacon Ponds, a saline lagoon on the Yorkshire coast. The boundary of the dominant vegetation, Marram Grass, and the location of the shorebirds’ scrapes were mapped to determine the distance at which birds nest from areas of dense vegetation. Photographs were used to determine the presence of scrapes within Marram Grass and in proximity to microvegetation. The distance and orientation of the shorebirds at rest was observed to determine the influence of vigilance or of other factors (wind direction and thermoregulation). Little Terns preferred nesting and resting with distance between themselves and the Marram Grass. Ringed Plovers showed a preference for nesting within open spaces but no avoidance of Marram Grass when at rest. Wind was the primary influence for their orientation at rest. The removal of encroaching Marram Grass to improve existing breeding sites and create new habitat has the potential to increase breeding success of Little Terns and Ringed Plovers by reducing the risk of predation to eggs and young and allowing shorebirds to nest further from the high tide line, reducing nest loss to high tides, extreme weather, and sea-level rise. Creation of vegetation-free areas will improve roosting habitat for Little Terns, as they can rest further away from vegetation, allowing for faster responses to predators.
The Little Tern (Sternula albifrons) is one of the UK's rarest breeding seabirds, having experienced a 37% population decline over the past 30 years. This decrease is attributed to various factors, including predation, human disturbance, and habitat destruction, all of which contribute to reduced breeding success. This study examines feeding frequency and fish size provided to chicks during the breeding season, as these are also factors influencing breeding success. The research identifies and investigates the effects of several factors on feeding frequency and fish length.
Observations were conducted over five weeks at a Little Tern colony in Yorkshire, analyzing the impact of disturbances, wind, time of day, weather conditions, chick age, wave height, and tidal cycles on feeding frequency, fish length, energy per fish, and total energy per hour. The feeding frequency rate and the absence of chick mortality in the colony suggest that the Little Terns had adequate food resources to sustain their chicks. Results also showed that chick age significantly influenced fish length, average energy, and total energy, aligning with findings from previous research. Additionally, wave height had a significant effect on fish length, average energy, and total energy—a novel finding that suggests stronger waves may pull larger fish to the sea surface. Human disturbance and wind direction also affected energy per fish and fish length, respectively. However, a small sample size and lack of significance in other factors call the validity of these specific results into question.
Overall, these findings support the effectiveness of current conservation measures to protect fishing grounds. They also provide insights for future feeding studies, identifying potential factors that may impact results and thereby enhancing the accuracy of future research and conservation efforts focused on Little Terns.
There are a range of project ideas which could be available. A few examples of what may be possible are as follows:
This list is not exhaustive and project ideas could be explored with Observatory personnel who may also be able to assist with obtaining any necessary permissions.
