FOULA  HERITAGE

Foula - The Edge of the World

Home

Information

Books, DVD and Video

Foula Bibliography

Guided Walk

Guided Walk No 2

Guided Walk No 3

Guided Walk No 4

Ranger News

Ranger Service History

Ranger Service 2004 Report

Funder Publications

Foula's Designations

Archaeology

Archaeology 2006

Foula's Archaeological Sites

Erosion

Foula Airstrip

Foula Pier

Lighthouse

Foula Froak (Ganzy)

Foula & St Kilda

Foula 1590

Foula 1774  Norn

Foula 1821 Captain Vetch

Foula 1828

Foula 1830 Storm Petrel

Foula 1834

Foula 1865

Foula 1872

Foula 1880

Foula 1883

Foula 1884

Foula 1892

Foula 1894

Foula 1900-01

Foula 1914   RMS Oceanic

Foula 1924-37  Telegraph Installation

Foula 1930-31

Foula 1933 Bonxie

Foula 1934

Foula 1936  The Edge of the World

Foula & Fair Isle 1938

Shipwrecks around Foula

Foula Field Mouse

Foula's Birds Check List

Bird Studies Bibliography

Seabird Monitoring 2006

The Puffin

The Fulmar or Maalie

The Great Skua or Bonxie

Red-throated Diver or Rain Goose

Butterflies and Moths

Foula Fungi

Foula Lichens

Weather Sayings

Life Sayings

Bairns Rhymes

Travel

Links

Seabird monitoring in Foula 2006

Sheila C. Gear

EIDERS

Eiders had a late breeding season, with females still on eggs well into July. No females with chicks were observed on the west side of the island. Adult numbers were badly down on previous years. Chick numbers halved over the two counts, suggesting possible high predation.

Throughout the winter, although scattered numbers were seen along the coast, the normal big raft of 200 – 500 birds was not observed.

                                  Table 1. Eider counts in Foula 2006

Both counts were done in good conditions. On 22nd July, the wind was variable light with sun. On 24th August, the wind was north east light and it was cloudy bright.

RED-THROATED DIVERS

The breeding season was late and there were only nine observed breeding attempts (or possibly ten; two adults being observed on Loch F throughout the season but no scrape found). All three pools at lochs L, M and N were occupied for the first time for several years. Seven pairs produced chicks, indicating that the first part of the breeding season was quite successful. However only three chicks survived to be large enough to possibly fledge successfully. The rest disappeared, mainly during the second half of July. At this stage, adults frequently no longer stay with their chicks throughout the day when feed is scarce, leaving them vulnerable to possible predation.

 Table 2. Red-throated divers in Foula in 2006

FULMARS

Although breeding was later than usual, with many chicks still downy on 19th Aug, they went on to fledge successfully. No dead chicks were seen. Mean productivity of plots was 0.63. Five sites that were not classified as Apparently Occupied Sites (AOSs) also produced fledglings. AOSs were considered to be those occupied on each of the four observations at the end of May and beginning of June. 

 Table 3. Counts and productivity of Fulmars in study plots in Foula in 2006

MANX SHEARWATERS

A bird was heard calling on the night of 9th Sept.

STORM PETRELS AND LEACH’S PETRELS

Petrels were not much in evidence this year. A survey of accessible areas frequented by petrels was carried out using tape-playback, from 26th June to 26th July. No AOSs were found. However many large areas suitable for breeding are not accessible. Only one burrow in the small Leaches colony near the top of the Noup had visible signs of possible occupation but no response was heard.  

SHAGS
 

Shags were generally more in evidence through out the summer, with counts along the east coast on 22nd July and 24th Aug totalling 1614 birds and 1846 birds (adults plus fledglings). Numbers breeding on the west coast, although still well below normal, were also up on last year.

Although the number of breeding attempts was very low, those birds that did produce chicks were relatively successful in rearing them to fledging. One pair produced three fledglings. Thirteen pairs started building nests in April, however eight of these breeding attempts failed. A raven was observed on 30th April taking an egg from the Heddlikliv area. There were also several late breeding attempts that failed.

Table 4. Productivity of Shags in Foula in 2006

Table 5. Mean productivity of Shags in Foula 2001-2006

ARCTIC SKUAS

Arctic Skuas had another very bad breeding season. Although better than 2005, conditions were still not good enough for the production of fledglings.

Birds were slow to return. The first was seen on 26th April but numbers seen during the first three weeks of May were very low, nine and 12 being the maximum. On 24th May, after a fine, warm day, there was an influx of birds and by evening about half the normal number of breeding birds were back on territory.

 In poor breeding seasons, such as this, the number of Apparently Occupied territories (AOTs) is difficult to ascertain with complete accuracy as territories may be very poorly attended, with some birds only being seen once. Seventy-four pairs were seen on territory and a further five colour ringed birds were seen once on territory with no apparent permanent partner, giving a possible 79 AOTs. Three other apparent pairs were seen moving around various different territories.

Only four pairs were seen to lay in May, with the first egg observed 26th May. Mean clutch size observed was 1.68. A total of 61 pairs was seen to lay. There were two relays.

 Twenty-five pairs hatched out chicks. Mean hatching date was c.1st July (normal expected hatching date c.20th June). Most chicks did not appear to be fed by the parent birds and died or disappeared during the first few days after hatching. Fourteen chicks survived long enough to be ringed. Regurgitates were of larval whitefish. Two chicks survived to fledge on 25th July and 10th August. Productivity per possible AOT was 0.03.

 Table 6. Productivity of Arctic Skuas in Foula 2001-2006

 No immature non-breeding birds were seen.

 Ninety-two identifiable colour ringed birds were seen and a further nine birds that were difficult to identify with certainty because of missing rings were also seen, giving a total of 101. Several had been missing for a number of years. Twenty two birds seen last year were missing, giving a possible mortality rate of 27%, although it is likely to be lower than this due to lost colour rings and to some birds missing a year because of the continuing poor conditions for breeding.

 Table 7. When colour ringed Arctic Skuas, identified in 2006, were last
seen in Foula

GREAT SKUAS

Bonxies had a rather poor, late season. The first sighting was two on 2nd April. On 12th May, there were a few scrapes but none had laid. The first egg was seen on 15th May. Some territories were poorly defended or not defended at all. Many chicks disappeared through the season and cannibalism was high during the last half of August.

 Table 8. Productivity of Bonxies in Foula 2004-2006

COMMON GULLS

Three pairs laid at the small new colony at the Groups quarry. Ravens were observed twice taking all the eggs. Two chicks fledged successfully from the third re-lays, on 15th August.

LESSER BLACK-BACKED GULLS

One pair nested at the Swaa, alongside Herring Gulls.

KITTIWAKES

Numbers showed an increase of 18.60% from 2005 and were comparable to 2003. Resting and bathing birds were evident in numbers, in places where they have been few or absent for a number of years, including 316 at the Freshwater Geo on 3rd August.

 Two counts were done of well built nests. Swell prevented an accurate count of some sites on 7th June, particularly the section of the colony with the most nests, from Mirkie to Waster Hoevda, so a second count was done on 3rd July, which although late, was deemed to be more accurate.

 Table 9. Counts of Kittiwakes in Foula in 2006

Productivity

Another very bad breeding season for kittiwakes in Foula, despite the encouraging increase in numbers.

 Kittiwakes returned in good time this year with birds on their nest sites from 2nd April. In this area, many of the old nests from last year were still intact despite the very wet year and severe storms in November and March. The breeding season was several weeks later than normal with chicks not fledging until mid to late August.

 Productivity per well-built nest was 0.22. However, possession of an old nest did not appear to affect productivity, which was 0.21 per well-built old nest. Predation of chicks after fledging, but before leaving the breeding sites, was high, with remains scattered along the cliff tops both in this area and along the east coast. Large chicks observed on 6th August or 20th August were considered likely to fledge.

 No broods were observed with more than one chick. Thirty five percent of pairs observed with chicks did not produce a chick that survived long enough to be considered likely to fledge.

 Table 10. Productivity of Kittiwakes in Foula in 2006

Table 11. Productivity of Kittiwakes in Foula 2001-2006

ARCTIC TERNS

Arctic terns were first seen ashore on 17th May. On 22nd May, small numbers of terns were observed fishing off the west side of the island where they are not normally seen. Numbers slowly built up through the summer to a maximum of 112 observed at the south end of the island on 6th July, but there were only eight at the small colony on Stremness. No breeding attempts were seen. By mid July only a few terns were left.

 Table 12. Productivity of Arctic Terns in Foula 2001-2006

GUILLEMOTS

Guillemots had a poor breeding season, although somewhat better than 2005. On 27th May at the Lang Hoevdi, there were 49 adults including 13 on eggs, and on 29th May at the colony below the Rubbish Tip, there were 59 adults including nine on eggs. Two weeks later, on 10th June, there were still only 25 on eggs at the Lang Hoevdi and 11 at the Rubbish Tip. On 6th July 18 chicks were observed at the Lang Hoevdi with 52 adults and 14 chicks at the Rubbish Tip with 55 adults.

 The first chicks off at sea were observed on 19th July, 2-3 weeks later than normal. On 21st July, there were still seven chicks at the Lang Hoevdi and six at the Rubbish Tip. Productivity was variable around the island, with some areas faring worse. On 11th June in the small colony south of In Under da Stee, only two adults were on eggs where in a normal year there would be c35. By 25th July the breeding ledges right round the island were almost empty.

RAZORBILLS

Razorbills also had a late season. The first egg seen was on 20th May. By 11th June about two thirds of the normal number had laid in the plots that used to be monitored. On 3rd July, the chicks were calling continuously and a few dead ones were seen. On 23rd July, all birds had left this colony.

TYSTIES

Numbers were the lowest recorded. Few birds were observed coming in with feed for chicks and no fledglings were seen.

The first count took place from 7.30 –9.45 am on 20th April, with light to moderate south east wind, sun, 5/10 cloud cover and not much swell but choppy, ebbing with low tide about 9.00 am. The second count took place from 6.40 – 9.35 am on 29th April, with a light variable wind, sun, 9/10 cloud cover, light swell, flowing with low tide about 5.30 am.

PUFFINS

On 11th June a transect search down the slope on the route to In Under da Stee, found 82 occupied burrows and 7 unoccupied, a high occupancy rate of 92%.

 On 3rd July, a number of dead small chicks were found outside their burrows in the Sneck area. By 17th August about two thirds of the adults appeared to have left the island. On 20th August 8 predated chicks were found outside their burrows on the transect slope, most still with some down. Throughout the season, no birds were seen carrying sandeels.

FISH STOMACH CONTENTS

Fish were scarce around Foula throughout the summer and fishing effort, as a result, was somewhat erratic. A total of 97 fish (young saithe) were sampled. Only six contained sandeels in each case just one single sandeel. A small patch of larval G. semisquamatus appeared off Ham Voe mid July but disappeared after a few days.

 Most fish sampled were feeding on larval whitefish that appeared to be quite abundant. These larval fish grew well through the summer, enabling both saithe and seabirds to survive. Very few saithe were feeding on crustacea. Other stomach contents were limpets, winkles, tube worms, jellyfish and seaweed.

Seabird numbers and breeding success in 2005

 Arctic Skua.  Only 18 of the pairs on 68 AOT actually nested, compared with 48 in 2003.  Just two chicks hatched from 18 nests and only one survived to fledging.

 Arctic Tern.  107 pairs of Arctic terns nested; an increase from the complete lack of breeding in 2004 but still low for Foula.  Birds were seen feeding mainly on herring fry.

 Great Skua.  Seven young fledged from a sample of 22 AOT.

 Kittiwake.  Little change occurred since 2004, when 942 AON were recorded in early July; 898 AON were counted during the same period in 2005.  Breeding success was still far lower than other Shetland sites.

 Razorbill.  Birds on Foula fledged 0.45 chicks per pair but success has generally been low although few years are available for comparison.

 Red-throated Diver.  Eleven pairs fledged 0.64 chicks per pair compared to a 0.47 mean over a 19 year period.

 Shag.  Once the largest colony in the north-east Atlantic, numbers remained low after the decline reported in 2004; a count of the Mucklabrek sub-colony in mid-June recorded just 18 nests in an area which held 1,009 nests in 2000.  The number of Shags (of all ages) estimated around the island in mid-July, on land or close inshore, was just a small proportion of what would usually have been present, indicating further decline from 2004; 244 birds were found, only one of which was a chick (468 birds from a comparable count in 2004).  At this time of year the colony would normally hold over 2,000 breeding pairs plus associated non-breeders and immatures.

SEABIRD MONITORING SUMMARY 2004

 Another disastrous breeding season for Foula birds…

Bonxies:  Only a handful of chicks survived from the normal 2,500 breeding pairs

Arctic Skuas (allens):  Total breeding failure – 13 pairs out of the normal 100+ laid eggs, a few chicks hatched, none survived

Puffins (nories):  Total breeding failure as far as can be ascertained – adults only managing to feed themselves

Guillemots and Razorbills:  Total breeding failure as far as visual check can ascertain

Kittiwakes:  6 Kittiwake chicks in the cave at Hodden in August, normally 100 nests, all other colonies failed

Arctic Terns (tirricks):  Usual large numbers arrived in June but disappeared 2 weeks later due to lack of food

Fulmars (maallies):  Maallies bred reasonably well but other species predated many chicks and eggs

Shags (scarfs):  Worst failure, did not breed, and abandoned the island

Others …  Three, possibly four, raingoose chicks fledged from 13 possible sites.  Fewer eider duck and wader chicks due to predation.

Go to Link