Isle of May NNR - Annual Report 2018

The first egg was seen on 13^th May, the first chick was seen in early July, with the first fledged bird seen in late August.  It has been an average breeding season, with 0.49 chicks from each breeding pair.

Shag

 

The plots monitored by CEH showed a low return rate, 68%, the lowest since 2012.  It has been a fairly successful season for shags, with an above average breeding productivity, 1.52 chicks fledging per breeding pair (long-term average 1.15).

The first shag egg was recorded on 29^th April, 38 days later than last year (22^nd March), and the first chick was seen on 3^rd June.  

Kittiwake   

The kittiwakes experienced a high return rate, 87.6%, from the plots monitored, although these did not all breed.  Kittiwakes had a slightly below average productivity, 0.56 chicks from the breeding pairs.  

The first egg was seen on 21^st May, twelve days later than 2017.  The first chick was seen to hatch on 18^th June. 

Guillemot

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
No. of pairs at Cornerstone	198	191	198	201	205	195	193	194	220	229	232	228

 

Using the “k” value (see Table 1.6), the number of pairs has been calculated to 14,902, a 10% decrease on last year’s count.  During the beginning of 2018, the UK experienced several storms and many guillemots were found washed up dead along the coast of Scotland and North East England; this may have had an effect on the Isle of May population. 

The return rate of the marked individuals was 89.1%, an average year for the Isle of May guillemots.  The guillemot breeding season was average, with each breeding pair producing 0.70 chicks.  For the second year running, we have experienced a strong westerly storm during the breeding the season; this year, Storm Hector hit the island on 14^th June and washed away low-lying eggs and chicks.  This would not have been accounted for in the productivity rate as it not part of CEH monitoring plots.

The first egg was seen on 30^th April, twelve days later than last year, and the first chick was seen on 2^nd June.  The first jumpling was noted leaving the cliffs on 25^th June.

Razorbill

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
No. of pairs at Cornerstone	71	64	67	62	69	72	74	72	81	79	82	87

 

Using the ‘k’ value (see Table 1.6), the number of pairs of breeding razorbills had decreased by 4% to 3,738 pairs.

The return rate of colour-ringed individuals is 92.3%, above the long-term average.  Razorbills had a poor breeding season, with monitored pairs producing 0.5 chicks.

The first egg was seen on 5^th May, thirteen days later than last year.  The first chick was seen on 12^th June and the first fledged chick on 1^st July.

Population monitoring of ground nesting seabirds

Puffin

The new method of puffin census was carried out this season.  A survey team set up the plots and order lines in late March, with the NatureScot team placing more permanent markers for each plot in April.  Bex Outram and David Steel surveyed all plots from 10^th-12^th May, completing Rona on 16^th May.  The number of occupied burrows for each plot was recorded along with percentage area of rock (unsuitable puffin habitat).  This data was passed on to Megan Towers, NatureScot statistician.  For a full account of the puffin census, please see the Census of Puffins on Isle of May, Scotland, 2018 report.

CEH undertook a puffin census in 2017, which resulted in a count of 39,200 occupied burrows with a 95% confidence level of between 32,200 – 46,300.

The first puffins carrying fish were seen on 22^nd May; this indicates that the first chicks had hatched.  The last puffin carrying fish was seen in late August; however, the majority of the colony had left earlier in the month.

The return rate of colour-ringed puffins was 95.2%, the highest on record.  The puffins’ breeding success was low, the lowest in six years, with 0.67 chicks per pair.

Herring and lesser black-backed gull

The first incubating herring gull was seen on the 23^rd April and the first chick was noted on 25^th May.  The first lesser black-backed gull egg was seen on 27^th April, six days earlier than the previous year; the chick was recorded on 1^st May. 

Nest count

The gull nest count took place from 25^th May to 31^st May, with some smaller sections being counted at the beginning of June.  The count was carried out by the two reserve managers, long-term volunteers (Sally Reay and James Wilson) and NatureScot staff (Elspeth Christie, Sarah Eaton, Caroline Gallacher, Gavin Johnson, David Shepherd, Jeremy Squire, Neil Mitchell and Anthony Wetherhill).  In sensitive areas in which activity would have caused disturbance to other nesting seabirds, the counts were carried out by CEH staff when they were doing their monitoring.  Other small sections were counted during the AIC as these can only be accessed at low tide and also to minimise disturbance of other species.

The gull count was conducted in two teams, who counted each section of the island including the gull-free zones, recording the nest and its contents (Table 2.1).  Immediately after, the counting efficiency and the species ratio of herring and lesser black-backed gull were completed (see Table 2.2 and Table 2.3 respectively).  This was done by Bex Outram.  Small sections and sensitive areas counted by CEH were not checked for counting efficiency and therefore the average percentage efficiency was applied to these areas.  

Results

The estimated total number of herring gulls is 3,398 pairs, down 11%, and of lesser black-backed gulls is 1,684 pairs, down 13% (Table 2.5). 

No count of herring gull productivity was undertaken this year.

Gull management

The gull-free zones were maintained during 2018.  These areas were North Plateau South to Lochside, East and West Braes, Beacon, St Andrew’s Well, Cross Park and Tennis Courts, along with the 15m boundary around the tern colony at Kirkhaven.  A total of 39 nests (89 eggs) were removed on 25^th May and 12^th June.

Specialist gulls that predated within the tern breeding colony were identified through tern watches and were removed; a NatureScot marksman came to the island and removed one adult lesser black-backed gull.  More specialist gulls were identified, one herring gull pair at Jetty Rocks, but were not present when the marksman was present on the island. 

Great black-backed gull

The first great black-backed gull egg was seen on 16^th April and the first chicks were seen on Rona on 21^st May.

Productivity

Forty-two nests were monitored on Rona to establish a breeding productivity.  Numbered stakes were placed next to nests and with regular visits the number of eggs, chicks and fledged chicks were noted.  The breeding success was 1.48, an average year.

With the help of the IOMBOT and Mark Oksien we were able to continue with the colour ringing scheme for the fourth year.  This season the colour ring combination changed: yellow ring with five black digits, three digits, colon followed by M (eg. 001:M); these rings are attached to the birds’ left leg whilst a BTO ring was attached to the right leg.  A total of 63 BTO rings were deployed and 39 colour rings.

Great black-backed gull - Rona

-	2018	2017	2016	2015
Nests monitored	42	51	45	28
Breeding attempts	42	51	45	28
Number of eggs	117	140	124	75
Average clutch size	2.79	2.75	2.76	2.68
Hatched eggs	78	117	91	57
Hatching success	0.67	0.84	0.73	0.76
Number fledged	62	88	32	33
Productivity	1.48	1.73	0.71	1.18

Terns

For previous population counts, see Table 1.2 and for how 2018 counts relate to the previous season, see Table 1.5.  Information has been taken from the Isle of May NNR - Annual Tern Report 2018 (S Reay and J Wilson, 2018).

Roseate tern

No roseate terns attempted to breed this year.  There were only a couple of sightings of roseate terns in the roost at Kirkhaven this season, less than in recent years, most likely due to the lack of a tern roost.

Sandwich Tern

No Sandwich terns attempted to breed this year.  Several were seen overhead, circling the Beacon tern colony, but none landed.

Arctic and common tern

The first common tern egg was seen on 25^th May at the Beacon tern terrace.  Common terns had a protracted season with some chicks fledging in July and the last chick fledged mid-August. 

The first Arctic tern egg was laid on 22^nd May, and the first chick hatched 18^th June in front of the Visitor Centre.  The first fledged chick was seen flying at the Beacon on 18^th July and the majority left the island on 1^st August.

Breeding pairs

Each year, three weeks after the first egg laying date, all tern nests on the island are counted to get a measure of total tern nest occupation.  This year, however, with the dramatic rate of predation, many nests had been predated by the time of the island-wide count, so, where appropriate, the peak numbers of nests were taken for each area from the monitoring plots along with a count made on 17^th June.  A total of 261 pairs of Arctic terns bred, a decline of 69%, and 17 common terns, a drop of 41%. 

Productivity

Six plots were chosen to monitor the breeding success of the Arctic terns this season.  Each nest was marked and the number of eggs, chicks and fledged chicks noted.  All chicks in these areas were ringed, helping keep track of the number of chicks that fledged from each plot.  This was then used to calculate a productivity figure.  The table below shows the different areas monitored and their productivity and the overall productivity that can be used to represent the whole colony.  The overall productivity was 0.03 chicks fledging per pair, much lower than previous years. 

Predation

Tern watches were conducted at both the Beacon and Kirkhaven Colony, with a total of 140 hours being conducted this year.  A pair of lesser black-backed gulls was seen predating eggs in the Mouse House and wiped out the whole colony.  One of the pair was removed; however, no terns re-laid in this area.  A pair of herring gulls at Jetty Rocks was seen predating eggs and chicks in the same area and wiped out the rest of the colony, with predation from the resident kestrel also.  Oystercatchers at the Beacon were also noted to have predated eggs on the tern terraces and the kestrel was also seen in this area, although no predation was witnessed.

Eider

The first sitting female was seen on 21^st April, with the first brood of duckling seen on the Loch on 14^th May.

-	Mouse House	Mouse House Terrace	Visitor Centre	Jetty Triangle	South Logan’s	Beacon	Overall A. tern
Nests monitored	24	2	31	11	92	52	212
Breeding attempts	24	2	31	11	92	52	212
Eggs	24	2	48	18	137	83	312
Average clutch size	1	1	1.5	1.6	1.5	1.6	1.5
Number hatched eggs	0	0	2	0	34	16	50
Hatching success	0	0	0.04	0	0.2	0.19	0.16
Fledged	0	0	0	0	0	6	6
Productivity	0	0	0	0	0	0.12	0.03

 

Nest count

The eider population count was conducted in conjunction with the gull count; each sitting female and empty nest was recorded.  To account for any errors, 100 numbered canes were randomly placed next to eider nests one week prior to the count.  All numbered canes were noted when counting the nests; from this a counting efficiency could be produced to convert the raw count to a corrected estimate of breeding female eiders.  This year, the counting efficiency was 90%, which allows the raw count (1,065 nests) to be converted to a final estimate of breeding females as 1,183, an increase of 5%.  This is the third highest population of eiders.

Eider management

No management specific to eiders was undertaken this year.  Visitors were warned during their introductory talk that females would be nesting close to the path network and of the potential risk of coming across a female taking her ducklings to water, and advised to give them a wide berth.  Some ducklings were found paralysed from nettle stings; these were kept in a box for an hour or so until they had recovered and then put with females and ducklings on the Loch, who took them into their crèche. 

Other breeding birds

These are observations of numbers from around the island from NatureScot staff and volunteers, CEH and members of the Isle of May Bird Observatory. 

Manx Shearwater (Puffinus puffinus)

Work by David and Margaret Thorne and Harry Urquhart, IOMBOT, identified nest activity on the island and identified one occupied burrow.  After last year, when only the male was present for the whole season, he has now recruited a new female.  Both have spent time in the burrow but no breeding attempts were made. 

Shelduck (Tadorna tadorna)

Three pairs of shelduck nested on the island this season, on Rona, North Plateau and one at Ardcarran.  One pair was seen with ducklings on the High Road and another (the Ardcarran pair) was seen with five ducklings swimming out of Kirkhaven on 5^th June.  

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	3 - 4	5	6	6	4 – 8	6	4	3-4	3-4	4	3-4	3

 

Mallard (Anas platyrhynchos)

No mallards bred this year; the last breeding pairs were seen in 2014.

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	2	0	0	0	0	0	2	3	0	0	0	0

 

Oystercatcher (Haematopus ostralegus)

This year, a total of 20 nests were identified.  Although no monitoring of the nests was undertaken, several fledged chicks.  One pair at the Beacon caused problems with tern predation, eating many eggs on the terraces.  This could have been due to the dry weather making it hard for the adults to probe the ground.

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	19	19	17	17	14	16	9	20	19	24	13	20

 

Feral pigeon (Columba livia (domest.))

No specific counts were made of feral pigeons on the island.  They nest on the island in burrows and rock crevices.

Swallow (Hirundo rustica)

Four pairs of swallow bred on the island in the following buildings: Bath House, Freezer Room, Wood Store and the Radar Room.  The Bath House pair failed once again this year, with the others all successfully raising two broods.

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	0	0	0	0	0	2	3	3	6	4	4	4

 

Rock pipit (Anthus petrosus)

The numbers of rock pipit territories were up, with 23 pairs breeding on the island.  Some fledglings were caught in the Heligoland traps and ringed. 

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	8-9	9-10	12-14	15	13	23	18	24	24	20	15	23

 

Pied wagtail (Motacilla alba)

Pied wagtail territories were plotted on a map throughout the season and approximately ten pairs bred. 

Year	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018
Pairs	8	9	11	12	13	18	14	13	12	12	9	10

 

Carrion crow (Corvus corone)

One pair was noted for much of the spring, “Patch” and partner (Patch named after white patch on the chest, making this individual easily identifiable), the same individuals as the previous year.  This pair built a nest at the top of the Main Light and to avoid predation of the seabirds, this nest was destroyed and the pair moved on briefly before returning and overwintering on the island.

Peregrine falcon (Falco peregrinus)

Every year a pair of peregrines is seen in early spring displaying but it has been eight years since they successfully raised young on the island (fledged three chicks in 2010).  This year was no different, a pair was seen early in the season, but no breeding attempt was made. 

Wood pigeon (Columba palumbus)

Two pairs have bred this season.  Although elusive at times, they were seen with young on several occasions.  Several nests were found at the Low Light bushes and water tank bushes and it appears that both pairs were successful in raising two broods.

Wader counts

Wader counts were undertaken weekly from the end of July onwards, once the breeding seabirds had departed from breeding sites.  Below is a table of the peak counts per month.

Species	Feb	Mar	Apr	May	June	July	Aug	Sept	Oct	Nov	Dec
Oystercatcher	-	12	27	-	-	-	28	35	61	-	-
Golden plover	-	-	-	1	-	-	4	2	17	-	-
Ringed plover	-	-	-	1	1	1	1	-	2	-	-
Whimbrel	-	-	2	2	1	2	5	2		-	-
Curlew	-	7	68	11	6	29	34	48	111	-	-
Turnstone	-	33	12	6	-	18	64	82	78	-	-
Knot	-	-	-	-	-		2	2		-	-
Dunlin	-	-	-	1	-	1	12	2	3	-	-
Purple sandpiper	-	2	19	21	-	45	87	58	33	-	-
Common sandpiper	-	2	-	1	1	3	2	1		-	-
Common redshank	-	5	30	-	-	3	15	22	32	-	-
Green sandpiper	-	-	-	-	-	1	2	-	-	-	-

 

Mammals

Grey seal

The number of adult seals started to increase throughout September and the first seal pup was born.  However, there was an earlier stillborn pup, again on Rona.  

Cetaceans

It proved to be a very productive season as the warm summer months produced ideal conditions for viewing as light winds and flat seas helped aid detection of cetaceans.  It was also noticeable that good feeding, especially in September, was bringing more cetaceans into the Isle of May waters. 

Harbour porpoise

A very good year possibly linked to the good weather and flat seas making recording easier.  The early part of the season produced four on 12^th March with a single off the north end on 20^th April.  Interestingly, three were seen ‘logging’ off the north end on 21^st April, a behaviour not often recorded from the Isle of May.  Gradually records increased, with singles on 9^th, 21^st and 23^rd May and with 1-3 on 9^th, 10^th and 22^nd June. 

The summer months proved very productive, with 1-4 seen on twelve dates from 3^rd-24^th July, with a peak of seven recorded on 10^th July.  The month of August was quiet, with 1-3 on four dates, and peaking with four on 1^st and 30^th August.  Although sightings in September were less frequent, the number of animals was more noticeable, with three on 4^th, 7^th and 29^th September, with a peak of eight on 6^th September, and with 1-2 noted on four dates.  The good numbers continued into early October, with six off the south end together on 6^th October and four on 24^th October.  

Minke whale

The first of the year involved a single noted surfacing three times off the north end on 7^th June whilst another was seen off the east side of the island on 11^th July.  The most noticeable sighting of the year involved a single breaching at least five times off the east side on 26^th July, close to the island in a strong north-west wind.  This unusual behaviour is not noted very often from the island. 

The month of August was quiet, with a single off the south end on 25^th-26^th August, but from early September a small number of animals became resident around the island.  Between 5^th September-8^th October, at least 1-2 were seen feeding and deep diving off both the east and west side of the island on fourteen dates.  This included one large adult and both animals put on an impressive feeding display off the south end for most of the afternoon of 6^th October.  These sightings were combined with some large seabird concentrations (especially gannets), which indicated good feeding in the area.   

Bottle-nosed dolphins

The majority of bottle-nosed dolphin records involve animals seen hugging the Fife coast (often recorded from the visitor boats) and therefore just outside the Isle of May recording area.  Records around the island are much scarcer and included three south on 29^th March and eight off the east side on 16^th April.

Mice

Lepidoptera

Butterfly

Records of butterflies were made by informal observations from members of Fluke Street and the IOMBOT residents throughout the season.  Ten species were recorded throughout the year, with the first being sighted as residents moved on to the island on 26^th March, single painted lady and small tortoiseshell.  Small tortoiseshell was seen throughout the year, noted every month, whilst red admiral was the most numerous species.  A single wall brown was recorded on 25^th August and is the first record for the island.  See Table 3 for full details of the records.

Moth

Moth trapping at Fluke Street was undertaken on most nights, when possible, by NatureScot staff, volunteers and CEH staff.  The MV light trap was set up in the garden outside the principal keeper’s cottage; the trap could be moved into the outdoor shelter during adverse weather and when puffins were leaving their burrows (to prevent them from being drawn towards the light).  A second trap was available to those at the IOMBO, who had the trap running by the Low Light bushes.  Trapping commenced on 5^th April and continued throughout the season until 29^th October. 

Trapping was conducted on a total of 114 nights, with a total of 117 different macro species being recorded along with 36 micros; this is the most ever recorded in any one year.  See Table 4.1 and 4.2 for the overall review of 2018 trapping data.

A total of six new species were recorded on the island this season: double-striped pug, fanfoot, juniper pug, pale November moth, streak and white-speck moth. A further seven species were recorded for the second time on the island: cloaked minor, common footman, shaded broad-bar, small dusty wave, straw dot, triple-spotted clay and turnip moth.  A notable absence this season was cinnabar.  Other highlights included a convolvulus hawkmoth found on the netting of the Bain trap on 19^th August.

The most numerous moth caught was dark arches, with a total of 181 individuals being trapped on 19^th July and on 51 different nights.  However, silver Y is probably the most numerous species present on the island but they are more often seen flying during the day rather than being attracted by the light of the moth traps.  These were recorded on 79 days throughout the season, with over 100 seen during the days in July and September.

VISITOR REVIEW

 

Annual visitor numbers, Isle of May 2008-2017

2018	2017	2016	2015	2014	2013	2012	2011	2010	2009	2008
13,754	12,895	12,064	10,929	10,676	10,809	7,070	9.220	8,728	7,208	6,566

 

Weather

Weather plays a key role in the Isle of May season and the superb summer resulted in plenty of calm seas and a good number of sailings.  The period between May-August proved specifically productive, with the loss of only five days due to weather compared with eleven during the same months in 2017.     

Number of days open/closed, Isle of May 2015-2018

-	Days sailed	Officially closed	Bad weather closure	Percentage bad weather closures May-August
2018	145	21	17	29%
2017	142	21	20	55%
2016	149	23	19	42%
2015	132	22	29	66%

 

Boats

As usual, boats departing from Anstruther brought the majority of visitors, with the May Princess bringing 11,112 (10,385 in 2017) whilst the fast RIB Osprey carried a further 1,373 (1,349 in 2017).  During the season, boats travelled from the Lothian side of the Firth of Forth with the Seabird Centre RIB bringing 1,029 (798 in 2017).  Overall, this resulted in all three boats breaking their own visitor records with the Seabird centre RIB being noteworthy.  Forthwild brought a very modest 19 visitors (112 in 2017) from 1^st August-30^th September.  Small private leisure craft and kayaks carried a further 221 (251 in 2017) visitors during the summer.             

Visitor numbers on individual boats 2018        

-	May Princess	Osprey RIB	Seabird RIB	Others	Total
April	920	140	94	10	1,164
May	2,245	276	214	22	2,757
June	2,243	260	250	44	2,797
July	2,852	341	299	75	3,567
August	2,281	277	154	53	2,765
Sept	571	79	19	36	704
Total	11,112	1,373	1,029	240	13,754

 

VOLUNTEER REVIEW

During the season, both short and long-term volunteers made a valuable contribution to the day-to-day running of the Isle of May.  Three long-term volunteers helped throughout the seabird breeding season, with Sally Reay helping from 18^th April-22^nd September, James Wilson from 23^rd May-28^th August and Daryl McLeod from 29^th May-27^th July.  Their hard work and support ensured some excellent work was achieved on the island and overall, they contributed an impressive 282 working days.

In total, a further eight short-term volunteers helped at different times of the year, contributing a further 58 working days (346 days combined) to the island.  These included (in order of the number of days contributed) Gus Routledge (16), Viv Hastie (12), Andy Denton (8), Ciaran Hatsell (8), Sacha Riley-Smith (5), Simon Ritchie (3), Beckie Lakin (3) and Sam Oakes (3).     

Number of days worked for short and long term volunteers, 2018

-	March	April	May	June	July	Aug	Sept	Oct	Total
Sally Reay	-	13	20	25	24	26	22	6	136
James Wilson	-	-	9	26	30	26	-	-	91
Daryl McLeod	5	-	3	27	26	-	-	-	61
Gus Routledge	5	-	-	-	9	2	-	-	16
Viv Hastie	4	7	-	-	-	1	-	-	12
Andy Denton	6	2	-	-	-	-	-	-	8
Ciaran Hatsell	6	2	-	-	-	-	-	-	8
Sacha Riley-Smith	-	-	-	-	-	5	-	-	5
Simon Ritchie	3	-	-	-	-	-	-	-	3
Beckie Lakin	3	-	-	-	-	-	-	-	3
Sam Oakes	3	-	-	-	-	-	-	-	3

 

Setting Up

In late March, a team of eight spent over one week preparing the island for visitors, from Monday 26^th March to Monday 2^nd April.  The team helped open the island, including preparations for visitors and getting various aspects of the island ready for the new season as well as constructing a new boardwalk along Holyman’s Road.  The total contribution was equal to 46 working days.  

Events

The Isle of May provides a series of events during the summer months including Family Weekend (24^th-25^th July), Open Doors (1^st-2^nd September) and Seal Weekend (29^th-30^th September).  There were also smaller events including an archaeological event with Peter Yeoman on 18^th-19^th August, and ‘Meet the Artist’ in the lighthouse on 25^th-26^th August.  As well as events, we also had the biannual gull/eider counts, which were supported by staff.  The preparation and support on these days is offered by several NatureScot staff including Caroline Gallacher, Sarah Eaton, Dave and Wendy Shepherd and a total of 43 working days are contributed by the various people (not included in the above totals)

Volunteering

Volunteering is valuable to the Isle of May and without the contributions of the volunteers the island could not function as it does.  Overall, 26 different people helped contribute a total of 389 working days during the 2018 season (409 in 2017).     

Table 1.1: Population estimates of cliff-nesting seabirds, 1980-2018

Year	Fulmar (AOS)	Shag    (AON)	Kittiwake  (AON)	Guillemot (Individual)	Guillemot  (Estimated pairs)	Razorbill (Individual)	Razorbill (Estimated pairs)
1980	143	1,041	n/c	n/c	-	n/c	-
1981	n/c	1,163	n/c	16,300	-	2,086	-
1982	n/c	1,425	n/c	n/c	-	n/c	-
1983	101	1,567	6,115	22,550	-	2,220	-
1984	175	1,639	6,012	19,005	-	2,051	-
1985	156	1,524	5,510	18,390	-	1,825	-
1986	150	1,310	4,801	19,151	-	1,864	-
1987	n/c	1,916	6,765	17,546	-	1,887	-
1988	n/c	1,290	7,638	16,791	-	2,128	-
1989	212	1,703	7,564	18,328	-	2,613	-
1990	198	1,386	8,129	16,778	12,632	2,368	1,508
1991	250	1,487	6,535	16,834	11,440	1,633	1,425
1992	266	1,634	6,916	17,512	11,511	2,581	1,909
1993	266	715	7,009	17,919	12,418	3,022	2,052
1994	279	403	3,751	19,186	13,843	3,034	2,227
1995	296	503	7,603	25,754	15,326	4,248	3,108
1996	308	512	6,269	24,468	14,500	3,405	2,989
1997	382	502	6,518	26,711	17,340	3,478	2,719
1998	365	621	4,306	26,963	17,384	3,859	3,126
1999	312	259	4,196	21,694	16,933	3,786	3,429
2000	367	541	4,618	27,045	17,979	3,958	3,105
2001	369	734	3,639	28,103	18,442	4,114	3,346
2002	338	676	3,666	24,369*	20,185*	3,050*	2,844*
2003	248	968	3,335	26,722*	19,519*	3,105*	2,233*
2004	236	687	3,876	22,970*	20,332*	3,313*	2,677*
2005	276	281	3,790	22,667*	18,858*	4,109*	4,713*
2006	298	485	3,167	21,444*	15,578*	3,811*	2,975*
2007	281	399	3,424	16,770*	15,536*	3,635*	2,735*
2008	293	427	3,354	17,157*	15,036*	3,464*	2,591*
2009	358	465	2,316	16,888*	14,143*	3,008*	2,400*
2010	381	492	3,422	18,096	15,029	3,234	2,557
2011	306	540	2,685	15,691	14,955	3,012	2,705
2012	290	648	2,465	16,991	14,100	3,305	3,068
2013	218	322	1,712	14,764	13,349	3,155	2,879
2014	325	338	2,464	16,602	14,248	3,796	2,987
2015	309	401	3,433	21,598	15,945	4,590	3,202
2016	309	387	2,922	23,038	16,132	5,117	3,570
2017	341	474	3,507	20,531	16,468	5149	3,899
2018**	283	404	2,516	18,705	14,902	4,867	3,738

** including boat counts. 

Table 1.2: Population estimates of ground nesting seabirds, 1980-2018

Year	Gulls LBB gull	Gulls Herring gull	Gulls GBB gull	Common tern	Arctic tern	Terns ‘Commic’ tern	Terns Sandwich tern	Terns Roseate tern	Eider
1982	550	2300	1	14	0	14	0	0	241
1983	1385	2578	0	29	0	29	0	0	545
1984	1488	2230	0	36	19	55	0	0	413
1985	1053	2165	1	80	87	167	0	0	520- 550
1986	682	1943	3	22	128	150	0	0	557
1987	534	2117	3	76	126	202	0	0	735
1988	563	1711	3	50	200	250	0	0	600- 700
1989	643	1629	3	NC	NC	312	0	0	680
1990	618	1551	3	190	285	475	1	0	841
1991	788	1447	4	195	435	628	0	0	592
1992	751	1462	8	94	491	585	0	0	810
1993	1259	2059	7	143	538	681	0	0	651
1994	1270	2122	6	144	544	688	0	0	998
1995	1635	2554	7	181	608	789	0	1	1169
1996	1641	2969	7	248	532	780	0	1	1075
1997	1540	2856	9	338	630	968	0	0	1191
1998	1533	2607	14	127	451	578	2	0	866
1999	1519	3115	19	415	737	1152	110	0	1200
2000	1442	3067	23	303	908	1211	176	0	892
2001	1203	2845	27	132	916	1048	305	0	947
2002	1198	2367	20	2	228	230	0	0	783
2003	1128	2451	23	60	577	637	58	0	1156
2004	1221	2428	23	62	666	728	151	0	1101
2005	1320	2094	33	65	609	674	0	0	1070
2006	1732	2851	25	99	515	614	0	0	823
2007	1665	2854	30	83	525	608	0	0	1009
2008	1944	2962	37	102	511	613	2	0	1088
2009	NC	NC	38	89	316	405	0	0	NC
2010	2348	3215	36	17	34	51	0	0	1099
2011	NC	NC	40	26	224	250	0	0	NC
2012	2352	3281	40	20	265	285	0	0	902
2013	NC	NC	36	-	-	419	0	0	NC
2014	2047	4200	51	13	402	415	0	0	975
2015	NC	NC	53	13	484	497	0	0	NC
2016	1924	3799	72	19	527	546	21	0	1128
2017	NC	NC	87	29	832	861	4	0	NC
2018	1,684	3,398	79	17	261	278	0	0	1183

 

Table 1.3: All-island count sections of cliff-nesting seabirds, 2018

Section	Fulmar AOSs	Shag AONs	Kittiwake AONs	Guillemot Ind	Guillemot Pairs	Razorbill  Ind	Razorbill Pairs
A Rona (West)	11	35	100	615	517	165	99
B Altarstanes to Peregrine's Nest	33	28	296	1705	1207	802	502
C Greengates	33	4	488	2773	2451	679	597
D South Plateau	31	10	637	6155	4712	1291	922
E Cornerstone to Pilgrim's Haven	16	6	292	4375	3550	989	925
F Pilgrim's Haven to Lady's Cave	22	19	145	1096	903	218	164
G The Maidens	11	46	14	135	117	69	56
H South Ness to Lady’s Bed	0	13	113	293	255	90	69
I South Ness to Colm's Hole	21	69	62	0	0	38	27
J Colm's Hole to Low Light	28	86	131	451	347	198	141
K Low Light to Tarbet	29	71	135	992	750	288	202
L Rona (North and East)	7	16	-	-	-	-	-
M Lochside (South)	31	-	-	-	-	-	-
N Lochside (North)	10	-	52	-	-	28	25
O West Cliffs from Boat	0	1	51	115	93	12	9
Total	283	404	2516	18,705	14,809	4,867	3,738

 

Table 1.4: Population change of cliff-nesting seabirds, 2017-2018

-	Fulmar (AOS)	Shag (AON)	Kittiwake (AON)	Guillemot Ind.	Guillemot Pairs	Razorbill Ind.	Razorbill Pairs
2018 total (AIC)*	283	403	2465	18590	14809	4855	3729
2017 total       (AIC)	341	474	3507	20531	16468	5149	3899
Change 20172018	-58	-71	-1042	-1941	-1659	-294	-170
%age change    2017-2018	-17	-15	-30	-9	-10	-6	-4

 

*not including boat counts, so a comparison can be made with 2017.

Table 1.5: Population change of terns, 2017-2018

-	Common tern	Arctic tern	Sandwich tern
2018 total	17	260	0
2017 total	29	832	4
Change 20172018	-12	-572	-4
%age change 2017-2018	-41	-69	-100

 

 

 

APPENDIX 1

Isle of May research reports for 2018 season

Foraging behaviour of shags

Y Yonehara¹, K Sato¹,M Newell², S Burthe² & F Daunt²

¹Department of Marine Biological Sciences, Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho, Hakodate, 041-8611 Japan.  ²CEH Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB.

The fine scale foraging behaviour of shags is poorly understood, especially in terms of effort to reach feeding sites.  By attaching accelerometers to adult shags we are able to calculate energy expenditure and how this varies with wind speeds and direction.  This project aims to obtain fine scale data on the interaction between shags and the environment.  Two types of loggers will be used, providing a wealth of novel behavioural data.    

We achieved 32 successful deployments of GPS loggers simultaneously with accelerometers.  Flight recorders were deployed on 8 shags.  The detailed analyses of these data will take place over the winter.  The aim of the work is to fine tune our method of estimating the amount of food captured from wing beat frequency by accounting for the effect of wind, which also affects wing beat frequent Long term studies of breeding seabirds on the Isle of May M Newell, M Harris, S Burthe, C Gunn, S Wanless & F Daunt  CEH Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0Q

After a fairly cold but benign winter, early spring blasted in with strong onshore winds when the ‘Beast from the East’ hit in early March, to be followed over the next month by its subsequent diminishing relatives.  This resulted in over 2,500 dead seabirds washing up along the Scottish east coast, although most were immature birds.  The result of a month of rough sea conditions was a late breeding season for most species and a drop in the numbers making a breeding attempt.

The 2018 season proved a mixed year amongst the main study species.  With CEH present on the island continually for three and a half months, the cliff-nesting seabirds are monitored on a daily basis, identifying just when any failures occur and establishing the effects of any extreme weather.  The Isle of May was hit by a westerly gale in early June but it had minimal effect on the breeding success of any of the study species; otherwise, it was an extraordinarily calm season.  

With the exception of European shag, the average or above-average return rate for the other study species indicated that the seabird mortality during March and April largely affected immature birds rather than the breeding population which were either still offshore or able to seek foraging in less turbid sea areas.  However, it clearly affected condition as all species except fulmar commenced laying much later than average and significant numbers of individuals did not attempt to breed even though they returned to the colony.  The numbers of pairs nesting in the plots showed a decrease from 2017 for all species and this was reflected in a decrease in the all-island counts carried out by NatureScot.

Breeding success

• Common guillemot breeding success at 0.70 chicks per pair laying was average.
• Razorbill breeding success at 0.50 chicks per pair laying was one of the poorest on record.
• Atlantic puffin breeding success at 0.67 chicks per pair laying was the lowest for 6 years
• Black-legged kittiwake breeding success at 0.56 chicks per completed nest was slightly below average.
• European shag breeding success at 1.52 chicks per incubating nest was well above the long-term average (1.15) for the 11^th consecutive year.
• Northern fulmar breeding success at 0.49 chicks per incubating nest was above average.

Return rates

• Common guillemot return rate at 89.1% was average. 
• Razorbill return rate at 92.3% was above average.
• Atlantic puffin return rate at 95.2% was the highest on record.
• Black-legged kittiwake return rate at 87.6% was above average with only five higher years.
• European shag return rate at 68.0% was below average and the lowest since 2012.

Sandeels (Ammodytes sp.) remained the main food of young puffins, shags and kittiwakes.  The diet of razorbills and guillemots was dominated by clupeids. 

We are grateful to Caroline Gallacher, David Steel and Bex Outram of Scottish Natural Heritage for logistical and occasional fieldwork support on the Isle of May.  Jude Barbour, Maria Bogdanova, Lila Buckingham, Alice Carravieri, Ruth Dunn, Jon Green, Olivia Hicks, Rich Howells, John Harrison, Sam Langlois-Lopez,

Heather Lowther, Daryl McLeod, Polly Philpott, Sally Reay, Sheila and Debbie Russell, James Wilson and

Yoshinari Yonehara all helped with fieldwork.  We are grateful to Alex Gardner and the crew of the May

Princess and Roy Giles with RIB Osprey for providing transport to and from the Isle of May throughout the season.

Over-wintering foraging ecology of seabirds

M. Newell, M Harris, S Burthe, S Wanless & F Daunt 

CEH Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB

This project aims to obtain fine scale data on movements and foraging behaviour of seabirds in winter, by attaching specially designed loggers to European shags, Atlantic puffins, black-legged kittiwakes, razorbills and common guillemots.  The loggers record daily location and foraging effort.  Detailed data on location-specific foraging effort of seabirds will enable patterns of distribution and behaviour in relation to season and breeding status to be analysed.

The work on shags is a continuation of work commenced in 2002.  A total of 24 geolocator loggers were retrieved from shags with a further 23 deployed which we plan to retrieve in 2019.  

In 2018, 14 retrievals of geolocator loggers were made from guillemots with a further 30 deployments.   In 2018, 12 geolocator loggers were retrieved from razorbills with a further 30 deployments.  In 2018, 27 loggers were deployed on puffins with 22 retrieved from previous deployments.  Of these, one was retrieved from a dead puffin which had been predated by great black-backed gulls in an area of over one hundred predated puffins.  These deployments will be targeted for retrieval in 2019.

A total of 14 loggers were retrieved from kittiwakes in 2018 which had been deployed in previous years.  A further 23 new deployments were made.

Quantifying the Impact of Parasites on Seabirds 

Sarah Burthe¹, Mark Newell¹, Carrie Gunn¹, Emma Cunningham², Francis Daunt¹, Jon Green³, Mike Harris¹ & Sarah Wanless¹

¹Centre for Ecology & Hydrology, Penicuik, Midlothian, ²Institute of Evolutionary Biology, University of

Edinburgh, ³ Oceans and Ecosystems Department, University of Liverpool

The role parasites play in driving seabird population dynamics has been largely ignored, despite the fact that seabirds are hosts to a wide variety of endo- and ectoparasites that reach high densities in most colonies and can act as disease vectors.  The ultimate aim of this project is to evaluate how parasites impact their seabird hosts, particularly focussing on the European shag (Phalacrocorax aristotelis). 

Nematode infections in shags

This research builds on previous work from 2010-2017 which significantly advanced our understanding of the role parasites play in this host.  Endoscopy was developed as a novel and extremely useful way of measuring natural parasite loads in shags and also evaluating drug efficacy.  We found that there was significant variation in parasite loads between individual birds and, importantly, that parasites are having significant impacts on shags.  We have found that shag chicks experimentally treated with ivermectin show different responses to treatment in terms of behaviour and growth depending on their position in the brood hierarchy (shags hatch asynchronously), with the youngest chick in a brood responding the most to altered parasite load (now published in Ecology and Evolution: Granroth-Wilding, H.M.V., Burthe, S.J., Lewis, S., Reed, T.E., Herborn, K.A., Newell, M.A., Takahashi, E.A., Daunt, F. & Cunningham, E.J.A. (2014)  Parasitism in early life: environmental conditions shape within-brood variation in responses to infection. Ecology and Evolution, doi: 10.1002/ece3.1192).  There are also interesting effects of parasites on adults - parents of shag chicks treated to remove parasites were found to spend less time foraging during the winter (a period when shag mortality is high) and to subsequently come back and breed earlier on the colony (journal manuscript currently in the final stages of writing). 

One of the aims now is to establish, by monitoring over a number of years of variable environmental conditions, whether parasites tend to be more prevalent in some years (which may be indicative of environmental differences between years, e.g. diet, etc.).  We also want to know whether individual shags’ worm burdens vary between years or whether individuals can be consistently classed as having low or high burdens, and to establish whether individuals with higher burdens have reduced breeding success or increased probability of mortality.  In order to do this, we are planning to measure parasite burdens in a number of individual shags each year, particularly targeting birds that have previously been assessed.  We have now successfully built up 8 years of data from 2011-2018, where we have measured burdens across naturally parasitized shags and obtained repeated measures from individuals.  We sampled a total of 44 adults successfully in 2018.

Bacterial gut communities and parasites

In conjunction with this long-term work on parasite loads and implications for the host, we aimed to build on this work and to try and investigate how parasite burdens may be linked to gut microbiomes (bacterial communities within the gut).  Recent literature suggests that the microbiome of individuals can be linked to differences in diet, and also potentially to variation in parasite loads.  Since 2013 we have successfully measured parasite loads and obtained swab samples of gut bacteria from the endoscope and from faecal samples to investigate this, with 44 adult shags sampled in 2018.  Samples will processed and sequenced by colleagues at CEH Wallingford.  

In conclusion, 2018 was a highly successful field season, in which we achieved all of our aims.  Sampling of adults to investigate microbiomes went smoothly and it is hoped that this will lead to interesting results and build on results obtained in previous years.  We built on our successful development of endoscopy as a method for quantifying endoparasites in live, wild seabirds and obtained vital data for exploring variation in natural parasite burdens.  This will prove crucially important for achieving our ultimate aim of quantifying the impact of parasites on seabird hosts and we hope to develop this work further in 2019. 

Effects of contaminants on seabirds – an energetics approach A. Carravieri, S. Burthe, F. Daunt, J. Green

Increasing quantities of contaminants are found in marine food webs, exposing seabirds to high doses of them through food ingestion.  Contaminants have direct and indirect negative effects in vertebrates, but the energetic consequences of exposure are largely unknown, in particular in combination with other stressors such as disease.  Our aim is to quantify the effects of natural (mercury, Hg) and man-made (perfluorinated compounds, PFCs) contaminants on the energy expenditure and reproductive output of the European shag, which frequently suffers from severe infections of gastro-intestinal parasites. 

A total of 44 individual shags (18 females, 26 males) were captured at their nests during early chick-rearing in July 2018.  They were endoscoped to quantify their parasite loads, and blood sampled (approximately 2ml). Of these birds, 36 were also fitted with data loggers: 32 with Technosmart Axytrek accelerometers, and 4 with a combination of IgotU GPS recorders and Little Leonardo accelerometers.

We centrifuged blood in the field, in order to perform the following, and ongoing, laboratory analyses:

1. bulk stable isotopes of carbon and nitrogen, and amino acid specific stable isotopes of nitrogen

(proxies of feeding habitat and trophic position) – in red blood cells

2. mercury – in red blood cells
3. perfluorinated compounds – in plasma

Ongoing analyses on data retrieved from loggers will enable us to calculate: 

1. foraging habitat and diving behaviours 
2. energy-related parameters, such as activity-specific costs and daily energy expenditure 

Together, these measures will make it possible to: 

1. understand the trophic drivers of contaminant and parasite exposure
2. quantify the relationship between contaminant and parasite loads
3. calculate the interactive effects of contaminant and parasite loads on energy expenditure.

Preliminary bulk stable isotopes results indicate a strong sexual difference in diet, which will likely result in significant differences in contaminant exposure.  Preliminary results on perfluorinated compounds in plasma indicate that these contaminants are present in the population, some of them at high concentrations (Perfluorooctanesulfonic acid, PFOS).