Tuesday 19th January comments: Over the last few days we’ve continued our series of looking at the breeding seabirds of the Isle of May NNR. Our recent focus has been on the European Shag as we looked at the breeding biology, identification and the trends in their populations over the last thirty years. Today we are asking for your help in tracking these birds down if you find them dead or alive.
Research on the Isle of May is hugely important and our friends at UKCEH have been studying the islands Shag population for a considerable amount of time. During this period a colour ringing scheme between the University of Aberdeen and UKCEH has been looking at the dispersal of the breeding Shags from the Isle of May and other east coast breeding sites. During the summer breeding adults and chicks are fitted with a unique colour ring with three digits; which makes it easy to read at distance with binoculars or telescopes.
What we now need is those sightings! Anyone can take part, so if you are out and about along the coast (especially the east coast) with a pair binoculars, telescope or camera, check out the roosting Shags and spot the coloured rings. If you find any or discover them as tideline corpses over the winter please report all sightings to: firstname.lastname@example.org
It’s all part of the science and you’ll be making a valuable contribution to increasing our knowledge of this very special seabird. Now go find some colour rings…
As a snap-shot the findings revealed that field resightings of colour-ringed adult European shags known to have bred on the Isle of May were followed to quantify individual variation and repeatability in winter location within and among three consecutive winters. In total, 3,797 resightings of 882 individuals were recorded over 622 km of coastline. The distances from the Isle of May at which individuals were resighted during winter varied substantially, up to 486 km and 136 km north and south respectively.
Repeatability did not differ significantly between males and females or among different age classes, either within or among winters. This data demonstrates that the focal shag population is partially migratory and moreover that individuals show highly repeatable variation in winter location and hence migration strategy across consecutive winters. Such high among-individual variation and within-individual repeatability, both within and among winters, could lead to substantial life history variation, and therefore influence population dynamics and future conservation management strategies (Grist H, Daunt F, Wanless S, Nelson EJ, Harris MP, et al. (2014) Site Fidelity and Individual Variation in Winter Location in Partially Migratory European Shags).
Sunday 17th January comments: Yesterday we introduced the European Shag as p[art of the series on the seabirds of the Isle of May. Today we bring you the news of what has been happening to the Shag population on the Isle of May and the national picture. The seabirds we have featured so far in the series (Guillemot, Razorbill and Fulmar) have shown increases or with a stable population. However the populations of Shags on the island and nationally have been shown concerning declines over the last few decades.
Last year the full island census revealed some positive news as 495 pairs were counted nesting, an increase of 27% compared to 2019. However if you look at the longer term figures, this still remains a real concern as it wasn’t that long ago (the early 1990’s) when the island supported populations of over 1,600 pairs. There have been a number of reasons for these drops, such as the algae toxin blooms in 1992 which dropped the Isle of May Shag population from 1,634 pairs to a dramatic 715 pairs the following year. This dramatic drop (which the population has never really recovered from) was also noted in other North Sea seabird colonies. Overall the national picture has revealed a decline of 37% in populations of European Shags between 1986-2018 to an estimate of 17,500 pairs. This perilous number shows that there is so much more to be done for our seabirds as climate change and over-fishing are just some of the serious threats our seabirds face.
Tomorrow we’ll continue the series with news in how you can help report Shag movements, as we bring you some important citizen science.
Saturday 16th January comments: Today we introduce the fourth species of our seabird series which is taking a closer look at the seabirds of the Isle of May. We have featured the cliff nesters of Guillemot, Razorbills and Fulmars. Today we introduce the European Shag.
Shags are a medium sized bird approximately 68-78cm in height (27-31 inches) long and with a 95-110cm (37-43 inch) wingspan. Generally, the species is a dark metallic green/black with a yellow throat patch and during the breeding season displays a very elegant crest on its head (and hence how the species got it’s name). The species is smaller than its close relative the Cormorant which we’ll feature next on the blog. The species can be found all around the British Isles, the Faroe islands, Iceland, along the Norwegian coast and into Siberia, around the Iberian peninsula, north Africa, the Mediterranean and the Black Sea. They are generally long living (over 20 years) and are some of the deepest divers amongst the Cormorant family as they are benthic feeders (find their prey on the seabed) and have been recorded as diving as deep as 60-70 metre depths in search of prey. Unlike Cormorants, Shags are exclusively coastal birds with very few venturing into fresh waters
Shags will start breeding from 3-4 years of age and are the first seabirds to start nesting in a season. If the spring is mild, birds can be established on territories on the cliffledges by late February and nest building can commence soon after. Nests are usually constructed on rocky ledges or small caves and they build untidy nests of seaweed, twigs and anything else they can drag into their nest structure (including dead birds!) The first eggs are usually laid by late March and clutches vary from 1-6 eggs but usually average 3-4 and the incubation period is 30-31 days.
The first chicks will hatch by late April without and down (completely naked) and rely on tehit parents for warmth. Both parents with feed and care for their young, bringing in a variety of fish species depending on the season and locality but sandeels are highly prevalent in their diet. Chicks are fed by partial regurgitation with the young putting their bill inside the parents mouth. From hatching it can take 50-53 days to fledge and family parties will stick together for a few weeks after this period. By late July large numbers of young can crèche together around the island. The species can move some distances (more on that in the forthcoming days) but a good percentage of birds remain on the island all year, over-wintering on the island. Tomorrow we’ll bring you news of how Shags are doing on the Isle of May and the national picture as we continue our series on seabirds.
Thursday 14th January comments: As part of the seabird series we are running on the blog, today we follow on with looking closely at the Fulmar as we reveal how the population levels are doing and what the national picture is all about.
During the 2020 full island census, the Isle of May supported 324 nesting pairs, a 16% increase on the previous season’s total. However it was still below the 2017 breeding figure of 341 pairs and way short of the all-time record of 369 pairs on 2001. In general, Fulmars have been doing well on the island although the population is fairly stable and is around the 300 pairs mark per year.
In contrast, the national picture is a bit more glum as Fulmars are not doing that well with almost a third of the population has declined between 1986-2018. During this period numbers in the U.K declined by 38% to a current estimate of 350,000 pairs with the majority of them nesting on the northern and western islands. A number of reasons are attributed with this decline including climate change, prey availability, change in fish discards, long-line fishing techniques amongst others. It’s not all good news for seabirds as we continue to look at the seabirds of the Isle of May…. More coming soon.
Tuesday 12th January comments: Today we continue our series on the breeding seabirds of the Isle of May and we take a close look at a real specialist; the Fulmar.
Fulmars are part of the Shearwater and Petrel group, which also includes albatrosses. The group can sometimes be referred to as ‘tube noses’ because they have a tubular nostril on top of the bill. The word Fulmar comes from the old English word meaning ‘foul gull’.
Fulmars are a common nesting seabird in northern Europe with large populations in the Northern Atlantic from Canada to Russia which includes two varieties; the darker variety is the majority breeder in the high arctic, while the lighter variety is the predominant breeder further south. The species also breeds in the Northern Pacific. Fulmars started colonising the east coast of the UK in the 19th century and the first written account of the species on the Isle of May was in May 1914 with the first breeding pair noted in 1930.
Fulmars are very specialist seabirds as they have a salt gland above the nasal passage which helps them excrete salt due to the high amount of ocean water that they take in. They also have a very good defensive mechanise even from a young age which allows chicks to be left unattended without coming to any harm. If anything or anyone gets too close to Fulmars, they excrete a stomach oil which is sprayed out of their mouths which will mat the plumage of avian predators , which can lead to the predators death.
Fulmars remain around the island for the majority of the year, only ever being really absent for a longer period between the end of the breeding season (late August) to mid-November when birds move far out into the North Sea. During the winter months they’ll occupy the cliff ledges and by early spring, the new breeding season will have started.
Fulmars don’t start breeding until they are 6-7 years of age (which is old for any bird species) and will lay a single white egg on bare rock ledges or shallow depressions lined with plant material (usually the first eggs are found in mid-May on the island). However just before egg laying, the entire population disappear (this has been referred to as the honeymoon period) for 4-5 days and it is thought that birds do this to build up fat reserves. Once the egg is laid, they’ll then incubate for 49-53 days after which the young will hatch, usually in early July. The growing cycle is slow as can take 50+ days to fledgling with the first youngsters leaving the Isle of May in mid-August.
The diet of the Fulmar ranges from fish offal, whale meat, crustaceans and even jelly fish (hence why plastic bags can be a problem for Fulmars). They are also long living birds with records of individuals well beyond the age of 50.
Tomorrow we’ll bring you the latest on the populations of Fulmars on the Isle of May as will they follow the trend of the Guillemot and Razorbill and show signs of increasing? Tune in tomorrow for the answers….
Monday 11th January comments: Our mini-series continues this week as we follow on from looking at both the Guillemot and Razorbill in a little bit more detail. Today we bring you the news of last seasons population counts of razorbills and what it means nationwide.
Razorbills have been one of the success stories of the Isle of May (and several other North Sea seabird colonies) as the population has been increasing year-on-year for a few decades. The availability of nest sites, good breeding seasons and reasonable prey availability has helped the species increase in number with last year’s census counts revealing a new record population for the Isle of May. The full island census revealed a total of 6,292 individual’s counted with an estimated 4,124 pairs nesting. This has increased over the years with only 1,508 pairs counted in 1990, so some very welcome increases along the way (and long may it continue!)
Very recently a report on the ‘State of the UK’s birds 2020’ was published by the RSPB with support from several organisations including NatureScot giving long-term trends of many of our bird species. Although seabirds have been struggling nationally, both the Razorbill and Guillemot have been bucking this trend with latest figures suggesting they are doing well.
The report highlighted that Guillemot is our most numerous seabird species with an estimate of 950,000 pairs nationwide which is an increase of 32% over the 1986-2018 period. The Razorbill have had similar success with 88% increases between 1986-2018 with an estimated population of 165,000 pairs.
However it’s not all good news and we’ll continue bringing you more seabird species in this series this week, so stay tuned for more facts!
Saturday 9th January comments: We started a new mini-series looking at the Isle of May seabirds and today we focus on the second family member of the Auk family;
meet the Razorbill…
The species is a member of the Auk family and has a very similar breeding biology to its close relative the Guillemot. It is black and white (unlike the cholate brown and white of a Guillemot) with a distinctive white stripe across its face and a broad laterally compressed bill which gives the species its English name. Both sexes are identical in plumage although males can be slightly larger. Like most seabirds, they are designed for a pelagic lifestyle, only ever coming ashore for the breeding season.
Birds return to the cliff ledges in late winter before eventually settling in mid-April. Like Guillemots, birds don’t build a nest structure but lay a single egg and incubate on their feet. Parents can pair bond for life and the oldest Razorbill has reached the ripe old age of 51 years.
Incubation is carried out by both parents for between 34-39 days and following the chick hatching, the youngster will jump of the cliffs after three weeks and follow the parent out to sea. Razorbills are good swimmers and feed on fish but are known (seen annually on the Isle of May) to Kleptoparasitise; a method of stealing prey from other birds especially Puffins. The breeding season is usual compete by late July and birds will head out into the north Sea for the autumn and winter before returning the following spring.
Tomorrow we will reveal how well the Razorbill population is doing on the Isle of May with the results and the trends. So keep checking the blog for more info!
Friday 8th January comments: This week we’ve started a mini-series to bring you all the latest on our different seabirds which nest on the Isle of May National Nature Reserve (to lighten the mood at this difficult time). In our first featured bird; the Guillemot, we brought you the breeding biology, identification and the good news that the islands population has been increasing over the last decade. In the final chapter on Guillemots today we feature the species whereabouts at this moment in time, in mid-winter.
Guillemots breed on the Isle of May cliffs from April-July and as the summer progresses, the cliffs become bare and the Guillemots and young head out into the open north Sea. However after a two month absence, there is a noticeable return to Isle of May waters in October and soon after the birds start appearing on the cliffs from early November.
Various ongoing studies by Professors Mike Harris and Sarah Wanless of UKCEH indicate that birds return daily throughout the winter months to the cliffs usually from dawn for a few hours (and can be up to four hours) before heading back out to sea. This unusual behaviour involves birds in varying winter plumage and they return to cliff ledges occupied during the summer as the urge to establish and defend a good cliff ledge is far too strong, even in winter. It is also considered that this behaviour is also used to maintain their pair bond.
As the New Year and the new spring season approaches, birds will moult into their fine summer plumage and once again, the cliff ledges will be occupied by breeding Guillemots from early April to start the cycle all over again.
Thursday 7th January comments: Yesterday we started the New Year with a new mini-series about the seabirds of the Isle of May. The start of the new series featured the Guillemot and we looked at their breeding biology and main features.
Today we can reveal that Guillemots had a good breeding season last year as the population increased by 8% over the entire island on the 2019 total. This welcome increase has to be taken into consideration as seabird populations can fluctuate on an annual basis (for example birds can take a year off breeding etc) but overall the news is positive, as over the last decade, the islands population has been slowly increasing (as the trend line indicates in the graph above). In 2020 the full island census revealed a total of 23,306 individuals giving an estimate of 16,865 nesting pairs (this is calculated from study plots). This was an increase from the previous year from 21,493 individuals, an increase of 8% and the highest population count since 2003.
This is positive news for Guillemots as breeding numbers are slowly increasing and it will be interesting to see what the new year will bring; more increases we hope. However we are still some way off the start of the new seabird season and just where are our Guillemots at this moment in time, in deepest darkest winter? Well tomorrow we bring you the answers…
Wednesday 6th January comments: Its time we started a new mini-series where we look at the various nesting seabirds of the Isle of May and recap on their biology, the connections with the island and where they are at this very moment in time (in deepest darkest January).
Today we meet the Guillemot.
Guillemots are a member of the Auk family (which includes Puffins and Razorbills) and is a common species of seabird in the U.K. Guillemots are chocolate brown and white (Razorbills are black and white) and have a very upright posture due to the position of their legs (the legs are at the back of their bodies as these birds are designed for swimming rather than being on land). During the winter, the birds will moult and show more white on their faces which varies with individuals. Interestingly between 4-5% of the islands birds have a white spectacles around their eyes, known as ‘bridled’ Guillemots.
The first Guillemots start arriving on the cliffs of the Isle of May in late March as they prepare for a new breeding season. The species does not breed until it is at least four years old and they do not build a nest structure, as they lay a single large egg and incubate on their feet. Both sexes will help incubate and as colonial nesters, neighbours will help defend against predators. Following incubation, the young chicks are tendered for by both parents until they reach 20-21 days old and youngsters are encouraged to jump and scramble off the cliff ledges to meet their father below (starts in late June on the Isle of May with most gone by July). It is then solely the dad’s job to take the chick out to the open sea (in some case 60 miles out) and raise the chick until it’s ready to fledge. Thereafter small numbers return to Isle of May waters in late August and early autumn.
And tomorrow we reveal how the population is coping, what happened in 2020 and what the birds are doing during the winter months. Stay tuned…