Apportioning of the Flamborough and Filey Coast pSPA and ...... · Guillemot Assessment 2.1...
Transcript of Apportioning of the Flamborough and Filey Coast pSPA and ...... · Guillemot Assessment 2.1...
November 2014
Deadline VI - Apportioning of the Flamborough and Filey Coast pSPA and Farne Islands Guillemot and Razorbill Populations - BDMPS Update
DOGGER BANK TEESSIDE A & B
F-EXL-DVI-033 Page 2 © 2014 Forewind
Document Title Dogger Bank Teesside A & B
Deadline VI
Apportioning of the Flamborough and Filey Coast pSPA and Farne Islands SPA Guillemot and Razorbill Population - BDMPS Update
Forewind Document Reference F-EXL-DVI-033
Issue Number 1.1
Date November 2014
Drafted by MacArthur Green
Approved by Michael Stephenson
Date / initials approval MS 14-Nov-2014
Apportioning of guillemots and razorbills
from the
Flamborough Head and Filey Coast pSPA
and
the Farne Islands SPA
among UK North Sea Wind Farms
Prepared by: Mark Trinder
Reviewed by: Bob Furness
Date: 03/11/2014
Tel: 0141 342 5404
Email: [email protected]
Web: www.macarthurgreen.com
Address: 95 South Woodside Road | Glasgow | G20 6NT
Document Quality Record.
Version Status Authorised by Date
1.0 Draft Mark Trinder 31/10/2014
1.0 Minor revisions Bob Furness 03/11/2014
1.1 Final Mark Trinder 03/11/2014
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
MGL/MT/03-11-2014/1.1
CONTENTS
1. Introduction .................................................................................................................................... 1
Guillemot Assessment ............................................................................................................................ 1
2.1 Estimation of North Sea guillemot BDMPS ............................................................................. 1
2.2 Non-breeding season .............................................................................................................. 1
2.3 Breeding season ...................................................................................................................... 3
3. Estimation of the percentage of the FFC pSPA adult guillemot population at risk of effects in
North Sea offshore wind farms ............................................................................................................... 7
4. Estimation of the percentage of the Farne Islands SPA adult guillemot population at risk of
effects in North Sea offshore wind farms ............................................................................................... 9
Razorbill Assessment ............................................................................................................................ 11
5.1 Estimation of UK North Sea & Channel waters razorbill BDMPS and FFC pSPA and Farne
Island SPA proportions ...................................................................................................................... 11
5.2 Winter and migration periods ............................................................................................... 11
5.3 Breeding season .................................................................................................................... 14
6. Estimation of the percentage of the FFC pSPA adult razorbill population at risk of effects in
North Sea offshore wind farms ......................................................................................................... 17
7. Estimation of the percentage of the Farne Islands SPA adult razorbill population at risk of
effects in North Sea offshore wind farms ......................................................................................... 18
References ............................................................................................................................................ 21
Appendix 1 - Review of common guillemot and razorbill foraging ranges from breeding sites .......... 22
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1. Introduction
This report provides estimation of the Biologically Defined Minimum Population Sizes (BDMPS) for
guillemots and razorbills in the UK North Sea during each phase of the year and estimation of the
proportions of these populations which originate from all contributory populations. Using these
values, estimates of the percentage of the total at sea population for each species in each season
which originate from the Flamborough and Filey Coast pSPA (FFC) and the Farne Islands SPA have
been calculated.
Guillemot Assessment
2.1 Estimation of North Sea guillemot BDMPS
Due to variations in the timing of migration among individuals both within and between colonies and
also between different age classes there is considerable overlap in the guillemot seasons for the UK
(MacArthur Green 2014; Table 1).
Table 1. Guillemot seasons in UK waters from MacArthur Green (2014).
Season J F M A M J J A S O N D
Non-breeding (core)
Non-breeding (full)
Pre-breeding migration (UK waters)
UK Breeding season (full)
UK Breeding season (core)
Post-breeding dispersal
For this assessment the following descriptions of the seasons are considered to be appropriate:
UK breeding (March - July)
UK Non-breeding (August - February)
2.2 Non-breeding season
British guillemots are generally regarded as dispersive rather than migratory (Wernham et al. 2002).
During the post-breeding, wintering and pre-breeding periods guillemots from different breeding
colonies mix together to varying extents. Table 2 presents the population size for all British guillemot
SPA colonies plus those non-British populations which are thought to contribute to the North Sea &
Channel populations outside the breeding season within UK territorial waters. The proportions of
each of the breeding populations considered in Table 2 which are predicted to remain in the UK
North Sea & Channel have been derived from MacArthur Green (2014). There is likely to be spatial
variation in abundance within the North Sea; linked for example to the proximity of breeding
colonies. However, evidence to support sub-division of the North Sea into smaller sub-units is
limited (MacArthur Green 2014). Therefore, for the purposes of this assessment the UK North Sea &
Channel is treated as the smallest area for estimating population sizes (as per MacArthur Green
2014).
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Table 2. Guillemot population estimates for major breeding populations (using adult percentage of 57% from MacArthur Green (2014). For each colony the proportion and number of adults and immatures expected to be present in UK North Sea & Channel waters in the non-breeding season is provided.
Breeding colony (year
of count) Pairs
No.
adults All ages
Adults Immatures Total
Prop. No. Prop. No.
Faeroes (c.2000) 100000 200000 148008 0.1 20000 0.2 29602 49602
Norwegian Sea colonies (c. 2000)
100000 200000 148008 0.05 10000 0.2 29602 39602
Hermaness, Saxavord & Valla (2009)
4620 9240 6838 0.7 6468 0.6 4103 10572
Foula (2007) 16615 33230 24591 0.7 23261 0.6 14755 38017
Noss (2009) 14783 29566 21880 0.7 20696 0.6 13128 33825
Sumburgh Head (2013) 4207 8414 6227 0.7 5890 0.6 3736 9627
Fair Isle (2010) 13066 26132 19339 0.7 18292 0.6 11603 29896
West Westray (2007) 33900 67800 50175 0.7 47460 0.6 30105 77566
Calf of Eday (2006) 6300 12600 9324 0.7 8820 0.6 5595 14416
Rousay (2009) 6200 12400 9176 0.7 8680 0.6 5506 14187
Marwick Head (2012) 11097 22194 16424 0.7 15536 0.6 9855 25392
Hoy (2007) 6300 12600 9324 0.7 8820 0.6 5595 14416
Copinsay (2012) 5607 11214 8299 0.7 7850 0.6 4979 12830
North Caithness Cliffs (2000)
47000 94000 69564 0.7 65800 0.6 41738 107539
East Caithness Cliffs (1999)
106500 241578 178777 0.7 169105 0.6 107266 276372
Troup, Pennan and Lion’s Heads (2007)
10938 21876 16189 0.7 15313 0.6 9713 25027
Buchan Ness to Collieston Coast (2007)
12928 25856 19134 0.8 20685 0.7 13394 34080
Fowlsheugh (2012) 30100 60200 44550 0.8 48160 0.7 31185 79346
Forth Islands (2011) 14674 29348 21719 0.9 26413 0.8 17375 43789
St Abb’s Head to Fast Castle (2013)
22103 44206 32714 0.9 39785 0.8 26171 65957
Farne Islands (2013) 33532 67064 49630 0.9 60358 0.8 39704 100063
Flamborough and Filey Coast (2008)
39641 79282 58672 0.9 71354 0.8 46937 118292
Germany & Denmark (2013)
5000 10000 7400 0.2 2000 0.4 2960 4960
UK North Sea non-SPA (2000)
147000 294000 217571 0.8 235200 0.6 130543 365744
Sule Skerry and Sule Stack (1998)
7633 15266 11297 0.05 763 0.1 1130 1893
North Rona and Sula Sgeir (2012)
5000 6648 4920 0.05 332 0.1 492 824
Cape Wrath (2000) 27359 54718 40493 0.05 2736 0.1 4049 6785
Handa (2011) 37993 75986 56233 0.05 3799 0.1 5623 9422
Shiant Isles (2008) 5148 10296 7619 0.05 515 0.1 762 1277
Flannan Isles (1999) 9807 19614 14515 0.05 981 0.1 1452 2433
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Breeding colony (year
of count) Pairs
No.
adults All ages
Adults Immatures Total
Prop. No. Prop. No.
St Kilda (1999) 15700 31400 23237 0.05 1570 0.1 2324 3894
Canna and Sanday (1999)
3913 7826 5792 0.05 391 0.1 579 970
Rum (2000) 1644 3288 2433 0.05 164 0.1 243 407
Mingulay and Berneray (2009)
13527 27054 20021 0.05 1353 0.1 2002 3355
North Colonsay & Western Cliffs (2000)
13500 27000 19981 0 0 0.05 999 999
Ailsa Craig (2013) 5247 10494 7766 0 0 0.05 388 388
Rathlin Island (2011) 87398 174796 129356 0 0 0.05 6468 6468
Skomer and Skokholm (2013)
16300 32600 24125 0.05 1630 0.1 2413 4043
UK West coast non-SPA (2000)
79000 158000 116926 0.03 4740 0.08 9354 14094
Total 1121280 2242560 1659580 955083 660987 1616070
2.3 Breeding season
The mean maximum foraging range estimate for guillemot is 84km and the maximum range is
estimated to be 135km (Thaxter et al. 2012). Dogger Bank Teesside A and B is located at least 165km
from the FFC pSPA, and this is the closest guillemot breeding colony, while the Farne Islands SPA is
located approximately 235km from Dogger Bank Teesside A & B. These distances suggest that the
potential for connectivity with either colony is extremely small.
Furthermore, breeding success at FFC pSPA is higher than at most North Sea guillemot colonies. This
implies that the food supply near this colony is good and therefore that breeding adults are likely to
have smaller foraging ranges than the maximum (135km) or mean maximum (84km) values reported
in the literature, since the longest foraging ranges tend to occur at colonies where birds are unable
to find food locally. Further discussion on the relationships between auk foraging ranges and food
availability is provided in Appendix 1.
Consequently there are not expected to be any breeding adults from either SPA present on the wind
farms during the breeding season. Birds recorded at this time are therefore assumed to be failed or
non-breeders (including immature birds).
Nonetheless, birds associated with the two SPAs may be present on the wind farms (e.g. failed
breeders and immature birds). Furthermore, at the request of Natural England, maximum
percentages attributable to these colonies have been calculated on the basis of a highly
precautionary assumption that breeding guillemots from the FFC pSPA and the Farne Islands SPA
regularly make foraging trips of up to 200km. Consequently, on this basis the proportions from each
SPA which could be present on wind farms within this distance during the breeding season have
been calculated (but note the extremely low likelihood of this given the discussion in Appendix 1).
These calculations take into account other potential sources of guillemots and account for the
presence of failed breeders and immature birds associated with these colonies. During the breeding
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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season the North Sea has been divided into two regions (north and south) with the dividing line
approximating to the English-Scottish border. This has been used to generate proportions for wind
farms in each half separately and was based on the assumption that during the breeding season
birds are more likely to be found in proximity to their colony (i.e. natal colony in the case of
immature individuals).
The maximum proportion of guillemots seen on wind farm sites in the North Sea located beyond
mean maximum foraging range during the breeding season which could be attributed to the two
colonies has been estimated as follows:
1. The number of breeding adults associated with SPAs in the Southern North Sea region was
summed.
2. The number of associated immature birds was calculated using the stable age ratio of
0.43/0.57 (immatures/adults).
3. The number of FFC pSPA adults (pairs x 2) was divided by the sum of all adults and
immatures calculated above, to estimate the proportion of the total attributable to this
colony.
4. The above was repeated for the Farne Islands, but with the addition of a proportion of the
immatures associated with SPAs as far north as Fowlsheugh.
The calculated values for the two SPAs in relation to the southern North Sea are provided in Table 3
and for the Farne Islands in relation to the northern North Sea in Table 4.
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Table 3. Estimation of FFC pSPA and Farne Islands SPA breeding season maximum potential contribution to OWFs in UK southern North Sea waters (these values are assumed to apply to OWFs located between mean maximum range and 200km from the two SPAs).
Component Bird origin (count type)
No.
Prop. in
south N Sea
Number
Explanation FFC Farnes
SPAs bordering south N Sea with potential for range overlap with FFC and Farnes
Farne Islands (pairs)
33532 0.6 20,119 SPA population multiplied by proportion predicted to forage within region
FFC (pairs) 39641 1 39,641
Germany / Denmark (pairs)
5000 1 5,000
Total (pairs)
64,760 Sum of above rows
Total adults
129,520 Row above x 2
Individual immatures
97,708 (Row above / 0.57) x (1 - 0.57)
SPAs bordering north N Sea with potential connectivity with south N Sea (pairs and connectivity proportion)
Fowlsheugh (pairs) 30100 0.1 3,010 SPA population multiplied by proportion predicted to forage within south N Sea region
Forth Islands (pairs) 14674 0.2 2,935
St Abb’s Head to Fast Castle (pairs)
22103 0.3 6,631
Total (pairs)
12,576 Sum of above rows
Total adults
25,152 Row above x 2
Individual immatures
18,974 (Row above / 0.57) x (1 - 0.57)
Total birds available in region during breeding season from south N Sea colonies
All age classes, individuals
227,228 Sum of immatures and adult individuals (129520 + 97708)
Total birds available in region during breeding season from south N Sea plus immatures from north N Sea with connectivity
All age classes, individuals
246,202
Sum of immatures and adult individuals plus immatures from south N Sea (129520 + 97708 + 18974)
SPA breeding adults Adults
79,282 67,064 pairs x 2
Proportion of SPA which forages in south N Sea
1 0.6 Proportion predicted to forage within region
Proportion of SPA population on OWFS in south N Sea (southern colonies only)
All age classes
0.349 0.177 (breeding adults x proportion) / total available birds
Proportion of SPA population on OWFs in south N Sea (inc. northern colonies with connectivity)
All age classes
0.322 0.163 (breeding adults x proportion) / total available birds
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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Table 4. Estimation of the Farne Islands SPA breeding season maximum potential contribution to OWFs in the UK northern North Sea region (these values are assumed to apply to OWFs located between mean maximum range and 200km from each colony).
Component Bird origin (count type)
Farnes No.
Prop. in
north N Sea
Farnes No. in region
Explanation
SPAs bordering north N Sea with potential for range overlap with Farnes
Buchan Ness - Collieston Coast (pairs)
12928 1 12,928
SPA population multiplied by proportion predicted to forage within region
Fowlsheugh (pairs) 30100 0.9 27,090
Forth Islands (pairs) 14674 0.8 11,739
St Abb’s Head to Fast Castle (pairs)
22103 0.7 1,5472
Farne Islands (pairs) 33532 0.4 13,413
Total pairs
80,642 Sum of above rows
Total individuals
161,284 Row above x 2
Individual immatures
121,670 (Row above / 0.57) x (1 - 0.57)
SPAs bordering Neighbouring region with potential for cross region connectivity
Farne Islands (pairs) 33532 0.4 13,413
SPA population multiplied by proportion predicted to forage within UK north N Sea waters
Individuals
26,826 Total pairs x 2
Individual immatures
20,237 (total individuals / 0.57) x (1-0.57)
Total birds available in region during breeding season from north N Sea colonies
All age classes, individuals
282,954 Sum of immatures and adult individuals (161284 + 121670)
Total birds available in region during breeding season from north N Sea and immatures from south N Sea with connectivity
All age classes, individuals
303,191
Sum of immatures and adult individuals plus immatures from south N Sea (161284 + 121670 + 20237)
Farnes SPA Adults
67,064 pairs x 2
Proportion of Farnes SPA which forages in north N Sea
0.4
Proportion predicted to forage within region
Proportion of SPA population on OWFs in north N Sea (northern colonies only)
All age classes
0.095 (0.4 x 67064) / 282954
Proportion of SPA population on OWFs in north N Sea (inc. southern colonies with connectivity)
All age classes
0.088 (0.4 x 67064) / 303191
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On the basis of the calculations presented in Table 3, the maximum breeding season proportions on
Teesside A and B (and other offshore wind farms in the southern North Sea region located between
84 and 200km from the colonies) from the FFC pSPA would be between 32% and 35%, and from the
Farne Islands would be between 16% and 18%. Note however that the real values are likely to be
much lower than this, and most likely close to zero.
On the basis of the calculations presented in Table 4, a maximum of 9% of the breeding season totals
on offshore wind farms in the northern North Sea region would be expected to be breeding adults
from the Farne Islands. Note however that the real values are likely to be much lower than this, and
most likely close to zero.
3. Estimation of the percentage of the FFC pSPA adult guillemot population at risk of effects
in North Sea offshore wind farms
On the basis of the estimated movements of guillemots in UK waters, seasonal definitions and
regional definitions (MacArthur Green 2014), the percentage of guillemots within named North Sea
offshore wind farms predicted to be adults originating from the FFC pSPA colony has been calculated
(Table 5). For wind farms located within 84km of the FFC pSPA colony (Teesside, Westermost Rough
and Humber Gateway) it has been assumed that all birds seen on site during the breeding season
originate from this population. For sites located more than 200km from FFC it has been assumed
that none of the adults originate from this SPA. For sites located between 84 and 200km a range (0-
35%) has been provided which brackets the expected values for the breeding season. Within this
range of values it is expected that the true value lies close to zero (Table 3).
During the non-breeding season, the number of SPA birds predicted to be present in the entire UK
North Sea & Channel has been summed using the population estimates and proportions in Table 2.
On the assumption that outside the breeding season, guillemots within the North Sea are evenly
distributed from all colonies, the non-breeding season percentage estimated to originate from the
FFC pSPA population on the wind farms listed in Table 5 was calculated as the colony’s proportion of
the total.
Thus, the FFC proportion in the UK North Sea & Channel waters during the non-breeding season was
calculated as the breeding adult proportion estimated to remain in the North Sea (0.9) divided by
the total number from Table 2:
71354 / 1616070 = 0.044
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Table 5. Percentage of breeding adult guillemots in offshore wind farms during the breeding season and non-breeding seasons which are estimated to originate from the FFC pSPA population.
Project UK Round Status
Period
Breeding Non-
breeding
Beatrice Scottish Consent Authorised 0
4.4
Blyth Demonstration Site - Consent Authorised 0-35
Dogger Bank Creyke Beck A & B 3 Consent Application Submitted
0-35
Dogger Bank Teesside A & B 3 Consent Application Submitted
0-35
Dogger Bank Teesside C & D 3 Concept / Early Planning 0-35
Dudgeon 2 Consent Authorised 0-35
East Anglia ONE 3 Consent Authorised 0
European Offshore Wind Development Centre
Consent Authorised 0
Firth of Forth Alpha and Bravo (Seagreen)
Scottish Consent Authorised 0
Galloper 2 - extension Consent Authorised 0
Greater Gabbard 2 Fully Commissioned 0
Hornsea Project One 3 Consent Application Submitted
0-35
Humber Gateway 2 Consent Authorised 100
Inch Cape Scottish Consent Authorised 0
Lincs 2 Partial Generation / Construction
0-35
London Array 2 Fully Commissioned 0
Moray Scottish Consent Authorised 0
Neart na Gaoithe Scottish Consent Authorised 0
Race Bank 2 Consent Authorised 0-35
Sheringham Shoal 2 Fully Commissioned 0-35
Teesside 1 Fully Commissioned 100
Thanet 2 Fully Commissioned 0
Triton Knoll 2 Consent Authorised 0-35
Westermost Rough 2 Partial Generation / Construction
100
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4. Estimation of the percentage of the Farne Islands SPA adult guillemot population at risk of
effects in North Sea offshore wind farms
On the basis of the estimated movements of guillemots in UK waters, seasonal definitions and
regional definitions (MacArthur Green 2014), the percentage of guillemots within named North Sea
offshore wind farms predicted to be adults originating from the Farne Islands SPA colony has been
calculated (Table 6). Two wind farms are located within 84km of the Farne Islands colony (Blyth and
Neart na Gaoithe). For Blyth it has been assumed that all birds seen during the breeding season
originate from this population (i.e. 100%). For Neart na Gaoithe, owing to the proximity of this wind
farm to other guillemot colonies (e.g. Isle of May) and the long distance from the Farnes (73km), this
site has been included in the 84-200km category. For wind farms located in the North Sea between
84 and 200km from the Farnes, a range (0-9%) has been provided which brackets the expected
values for the breeding season. Within these ranges of values it is expected that the true values lies
close to zero.
During the non-breeding season, the number of SPA birds predicted to be present in the entire
North Sea has been summed using the population estimates and proportions in Table 2. On the
assumption that outside the breeding season, guillemots within the North Sea are evenly distributed
from all colonies, the non-breeding season percentage estimated to originate from the Farne Islands
SPA population on the wind farms listed in Table 6 was calculated as the colony’s proportion of the
total.
Thus, the Farne Islands’ proportion present in the North Sea during the non-breeding season was
calculated as the breeding adult proportion estimated to remain in the North Sea (0.9) divided by
the total number from Table 2:
60358 / 1616070 = 0.037
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Table 6. Percentage of breeding adult guillemots in offshore wind farms during the breeding season and non-breeding seasons which are estimated to originate from the Farne Islands SPA population.
Project UK Round Status
Period
Breeding Non-
breeding
Beatrice Scottish Consent Authorised 0
3.7
Blyth Demonstration Site - Consent Authorised 100
Dogger Bank Creyke Beck A & B 3 Consent Application Submitted
0
Dogger Bank Teesside A & B 3 Consent Application Submitted
0
Dogger Bank Teesside C & D 3 Concept / Early Planning 0
Dudgeon 2 Consent Authorised 0
East Anglia ONE 3 Consent Authorised 0
European Offshore Wind Development Centre
Consent Authorised 0-9
Firth of Forth Alpha and Bravo (Seagreen)
Scottish Consent Authorised 0-9
Galloper 2 - extension Consent Authorised 0
Greater Gabbard 2 Fully Commissioned 0
Hornsea Project One 3 Consent Application Submitted
0
Humber Gateway 2 Consent Authorised 0
Inch Cape Scottish Consent Authorised 0-9
Lincs 2 Partial Generation / Construction
0
London Array 2 Fully Commissioned 0
Moray Scottish Consent Authorised 0
Neart na Gaoithe Scottish Consent Authorised 0-9
Race Bank 2 Consent Authorised 0
Sheringham Shoal 2 Fully Commissioned 0
Teesside 1 Fully Commissioned 0-9
Thanet 2 Fully Commissioned 0
Triton Knoll 2 Consent Authorised 0
Westermost Rough 2 Partial Generation / Construction
0
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Razorbill Assessment
5.1 Estimation of UK North Sea & Channel waters razorbill BDMPS and FFC pSPA and Farne
Island SPA proportions
Due to variations in the timing of migration among individuals both within and between colonies and
also between different age classes there is considerable overlap in the razorbill seasons for UK
waters (MacArthur Green 2014; Table 7).
Table 7. Razorbill seasons in UK waters from MacArthur Green (2014).
Season J F M A M J J A S O N D
Non-breeding (core) (winter)
Non-breeding (full)
Pre-breeding migration (UK waters)
UK Breeding season (full)
UK Breeding season (core)
Post-breeding dispersal
For this assessment the following descriptions of the seasons are considered to be appropriate:
UK breeding (April - July)
Post-breeding dispersal migration (August - October)
Winter (November & December)
Spring migration (January - March)
5.2 Winter and migration periods
During the early post-breeding period in late summer razorbills do not move far from their colonies
(the young are completing growth and adults are moulting; Wernham et al. 2002). Subsequently
birds move predominantly southwards and individuals from different breeding colonies mix together
to varying extents. Table 8 presents the population size for all British razorbill SPA colonies plus
those non-British populations which are thought to contribute to the UK North Sea & Channel
populations outside the breeding season. The proportions of each of the breeding populations
considered in Table 8 which are predicted to remain in the UK North Sea & Channel have been
derived from MacArthur Green (2014). There is likely to be spatial variation in abundance within the
North Sea; linked for example to the proximity of breeding colonies. However, evidence to support
sub-division of the North Sea into smaller sub-units is limited (MacArthur Green 2014). Therefore,
for the purposes of this assessment the UK North Sea & Channel is treated as the smallest area for
estimating population sizes (as per MacArthur Green 2014).
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Table 8. Razorbill population estimates for major breeding populations using adult percentage of 57% from MacArthur Green (2014). For each colony the proportion and number of adults and immatures expected to be present in UK North Sea & Channel waters in the migration and winter seasons is provided.
Breeding colony (year of count) Pairs No.
adults
No.
Immatures
Migration (Aug-Oct / Jan-Mar) Winter (Nov-Dec)
Adults Immatures Adults Immatures
Prop. No. Prop. No. Prop. No. Prop. No.
Russia (1990s) 3500 7000 5174 0.05 350 0.1 517 0.01 70 0.02 103
Iceland (2008) 315400 630800 466243 0.3 189240 0.4 186497 0.1 63080 0.2 93249
Norway (1990s) 30300 60600 44791 0.2 12120 0.5 22396 0.05 3030 0.1 4479
Denmark, Finland, Sweden (1990s) 16000 32000 23652 0.1 3200 0.3 7096 0.02 640 0.05 1183
Faeroes (2012) 4500 9000 6652 0.5 4500 0.5 3326 0.3 2700 0.3 1996
Foula (2007) 375 750 554 0.95 713 0.9 499 0.3 225 0.1 55
Fair Isle (2010) 915 1830 1353 0.95 1739 0.9 1218 0.3 549 0.1 135
West Westray (2007) 550 1100 813 0.95 1045 0.9 732 0.3 330 0.1 81
North Caithness Cliffs (2000) 1700 3400 2513 0.95 3230 0.9 2262 0.3 1020 0.1 251
East Caithness Cliffs (1999) 12500 25000 18478 1 25000 0.9 16630 0.3 7500 0.1 1848
Troup, Pennan and Lion’s Heads (2007) 1743 3486 2577 1 3486 0.9 2319 0.3 1046 0.1 258
Fowlsheugh (2012) 3524 7048 5209 1 7048 0.9 4688 0.3 2114 0.1 521
Forth Islands (2012) 2625 5250 3880 1 5250 0.9 3492 0.3 1575 0.1 388
St Abb’s Head to Fast Castle (2013) 1219 2438 1802 1 2438 0.9 1622 0.3 731 0.1 180
Farne Islands (2011) (NB assmbl sp.) 390 780 577 1 780 0.9 519 0.3 234 0.1 58
Flamborough and Filey Coast (2008) 10001 20002 14784 1 20002 0.9 13306 0.3 6001 0.1 1478
UK N Sea non-SPA colonies (2000) 9610 19220 14206 1 19220 0.9 12785 0.3 5766 0.1 1421
North Rona and Sula Sgeir (1998) 1089 2178 1610 0.02 44 0.05 81 0.1 218 0.05 81
Cape Wrath (2000) 2090 4180 3090 0.02 84 0.05 155 0.1 418 0.05 155
Handa (2010) 5165 10330 7635 0.02 207 0.05 382 0.1 1033 0.05 382
St Kilda (1999) 1700 3400 2513 0.02 68 0.05 126 0.1 340 0.05 126
Shiant Isles (2008) 4248 8496 6280 0.02 170 0.05 314 0.1 850 0.05 314
Flannan Isles (2013) 1051 2102 1554 0.02 42 0.05 78 0.1 210 0.05 78
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Breeding colony (year of count) Pairs No.
adults
No.
Immatures
Migration (Aug-Oct / Jan-Mar) Winter (Nov-Dec)
Adults Immatures Adults Immatures
Prop. No. Prop. No. Prop. No. Prop. No.
Mingulay and Berneray (2009) 10111 20222 14947 0.02 404 0.05 747 0.1 2022 0.05 747
Rathlin Island (2011) 15393 30786 22755 0.02 616 0.05 1138 0.05 1539 0 0
Skomer and Skokholm (2013) 6001 12002 8871 0.02 240 0.05 444 0.05 600 0 0
UK western non-SPA colonies (2010) 10000 32000 23652 0.02 640 0.05 1183 0.1 3200 0.05 1183
Ireland (2000) 17000 34000 25130 0.02 680 0.05 1257 0.01 340 0.02 503
France (2000) 25 50 37 0.01 1 0.02 1 0.05 3 0.05 2
Total 488725 977450 722463 302317 285366 106184 110811
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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5.3 Breeding season
The mean maximum foraging range estimate for razorbill is 48km and the maximum range is
estimated to be 95km (Thaxter et al. 2012). Dogger Bank Teesside A and B is located at least 165km
from the FFC pSPA, and this is the closest razorbill breeding colony, while the Farne Islands SPA is
located approximately 235km from Dogger Bank Teesside A and B. Thus, the wind farms are located
beyond the maximum range of this species from FFC and thus no breeding adults from this colony
would be expected to be present on the wind farms during the breeding season.
Cumulative foraging range data for razorbills (seabird.wikispaces.com) indicates that 95% of trips
occur within 25km of the colony. On this basis no more than 5% of foraging trips would be predicted
to extend beyond this distance, with this percentage decreasing still further as the distance
increases. Furthermore, seabird breeding success at FFC pSPA is higher than at most North Sea
colonies. This implies that the food supply near this colony is good and that breeding adults are
therefore likely to have smaller foraging ranges than the maximum or mean maximum values
reported in the literature. Further discussion on the relationships between auk foraging ranges and
food availability is provided in Appendix 1.
Consequently there are not expected to be any breeding adults from either SPA present on the wind
farms during the breeding season. Birds recorded at this time are therefore assumed to be failed or
non-breeders (including immature birds).
Nonetheless, birds associated with the two SPAs may be present on the wind farms (e.g. failed
breeders and immature birds). Furthermore, at the request of Natural England, maximum
percentages attributable to these colonies have been calculated on the basis of a highly
precautionary assumption that breeding razorbills from the FFC pSPA and the Farne Islands SPA
regularly make foraging trips of over 130km and 195km (respectively). Consequently, on this basis
the proportions from each SPA which could be present on wind farms within this distance during the
breeding season have been calculated (but note the extremely low likelihood of this given the
discussion in Appendix 1). These calculations take into account other potential sources of razorbills
and account for the presence of failed breeders and immature birds associated with these colonies.
During the breeding season the North Sea has been divided into two regions (north and south) with
the dividing line approximating to the English-Scottish border. This has been used to generate
proportions for wind farms in each half of the North Sea separately and was based on the
assumption that during the breeding season birds are more likely to be found in proximity to their
colony (i.e. natal colony in the case of immature individuals).
The maximum proportion of razorbills seen on wind farm sites in the North Sea located beyond
mean maximum foraging range during the breeding season which could be attributed to the two
colonies was estimated as follows:
1. The number of breeding adults associated with SPAs in the Southern North Sea region was
summed.
2. The number of associated immature birds was calculated using the stable age ratio of
0.43/0.57 (immatures/adults).
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3. The number of FFC pSPA adults (pairs x 2) was divided by the sum of all adults and
immatures calculated above, to estimate the proportion of the total attributable to this
colony.
4. The above was repeated to generate estimates for the Farne Islands.
The calculated values for the both SPAs in relation to the southern North Sea are provided in Table 9
and for the Farne Islands in relation to the northern North Sea are provided in Table 10.
Table 9. Estimation of FFC pSPA and Farne Islands SPA breeding season maximum potential contribution to OWFs in the southern UK North Sea region (these values are assumed to apply to OWFs located beyond mean maximum range but less than 150 km from each colony).
Component Bird origin (count type)
Number Explanation
FFC Farnes
FFC and Farnes adults and immatures
FFC (pairs) 10001 SPA population
multiplied by proportion predicted to forage within region
Farne Islands (pairs)
390
Prop. in SW region 1.0 0.6
Total (pairs) 10235
Total adults 20470
Individual immatures 15442 (Row above / 0.57) x (1 - 0.57)
Immatures from colonies with potential range overlap with FFC and Farnes
NE Fife to N. Yorkshire (pairs)
4262 From Seabird 2000
Sweden/Finland/ Denmark (pairs)
16000
Total (pairs) 20262
Total adults 40524
Individual immatures 30571 (Row above / 0.57) x (1 - 0.57)
Total birds available in region during breeding season from southern N Sea colonies plus immatures from northern N Sea regions with connectivity
All age classes, individuals
66483
Sum of immatures and adult individuals (20470 + 15442 + 30571)
Breeding adults Adults 20002 780 pairs x 2
Proportion of SPA which forages in southern N Sea
1 0.6 Proportion predicted to forage within region
Proportion of SPA population on OWFs in southern N Sea
All age classes 0.301 0.007 (breeding adults x proportion) / total available birds
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Table 10. Estimation of the Farne Islands SPA breeding season maximum potential contribution to OWFs in the northern UK North Sea region (these values are assumed to apply to OWFs located beyond mean maximum range but less than 150 km from each colony).
Component Bird origin (count type)
No.
Prop. in
north N Sea
Farnes No. in region
Explanation
Colonies bordering northern N Sea with potential for range overlap with Farnes
Aberdeenshire - Berwickshire
9666 1 9666 Population multiplied by proportion predicted to forage within region (Seabird 2000)
Colonies bordering southern N Sea with potential foraging in northern N Sea
Northumberland - N. Yorkshire
500 0.4 200
Total adults
19,732 sum of above rows x 2
Individual immatures
14,886 (Row above / 0.57) x (1 - 0.57)
Immatures from colonies with potential range overlap with FFC and Farnes
Sweden/Finland/Denmark (pairs)
16000
16000
Sweden/Finland/Denmark (adults)
32000 Row above x 2
Sweden/Finland/Denmark (Immatures)
24,140
(Row above / 0.57) x (1 - 0.57)
Total birds available in region during breeding season from north N Sea colonies
All age classes, individuals
93376
Sum of immatures and adult individuals (19732 + 14886 + 24140)
Farnes SPA Adults
780 pairs x 2
Proportion of Farnes SPA which forages in north N Sea
0.4
Proportion predicted to forage within region
Proportion of SPA population on OWFs in north N Sea (birds from northern colonies only)
All age classes
0.003 (0.4 x 780) / 93376
On the basis of the calculations presented in Tables 9 and 10, the maximum proportion of FFC and
Farne Islands birds on wind farms between 48km and 150km from each colony would be 30% and
1% respectively. Note however that the real values are likely to be much lower than this and most
likely close to zero.
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6. Estimation of the percentage of the FFC pSPA adult razorbill population at risk of effects in
North Sea offshore wind farms
On the basis of the estimated movements of razorbills in UK waters and seasonal definitions
(MacArthur Green 2014), the percentage of razorbills within named UK North Sea waters offshore
wind farms predicted to be adults originating from the FFC pSPA colony has been calculated (Table
11). The only wind farm located within 48km of the FFC pSPA colony is Westermost Rough. It has
been assumed that all birds seen on this site during the breeding season originate from FFC. For
wind farms between 48km and 150km in the southern North Sea, the breeding season percentage
was assumed to be the value calculated in Table 9 (30%). For wind farms beyond 150km no breeding
adults from FFC are expected to be present.
During the migration (post-breeding and pre-breeding) and midwinter periods, the number of FFC
pSPA birds predicted to be present in the southern North Sea has been summed using the
population estimates and proportions in Table 8. On the assumption that outside the breeding
season, razorbills within the North Sea are evenly distributed from all colonies, the non-breeding
season percentages estimated to originate from the FFC pSPA population on the wind farms listed in
Table 11 were calculated as the colony’s proportion of the totals.
Thus, the FFC proportion in the North Sea during the migration seasons was calculated as the
breeding adult number estimated to be present in UK North Sea & Channel waters at this time
divided by the total numbers from Table 8:
20002 / 587683 = 0.034
Thus, the FFC proportion in the North Sea during the winter period was calculated as the breeding
adult number estimated to be present in UK North Sea & Channel waters at this time divided by the
total numbers from Table 8:
6001 / 216995 = 0.028
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Table 11. Percentage of breeding adult razorbills in offshore wind farms during the breeding, post-breeding and pre-breeding migrations, and winter seasons which are estimated to originate from the FFC pSPA population.
Project UK Round Status
Period
Breeding (min. – max.)
Migration Winter
Beatrice Scottish Consent Authorised 0
3.4 2.8
Blyth Demonstration Site - Consent Authorised 0-30
Dogger Bank Creyke Beck A & B
3 Consent Application Submitted
0-30
Dogger Bank Teesside A & B
3 Concept / Early Planning
0
Dogger Bank Teesside C & D
3 Concept / Early Planning
0
Dudgeon 2 Consent Authorised 0-30
East Anglia ONE 3 Consent Application Submitted
0
European Offshore Wind Development Centre
Consent Authorised 0
Firth of Forth Alpha and Bravo (Seagreen)
Scottish Consent Authorised 0
Galloper 2 -
extension Consent Authorised 0
Greater Gabbard 2 Fully Commissioned 0
Hornsea Project One 3 Consent Application Submitted
0-30
Humber Gateway 2 Consent Authorised 0-30
Inch Cape Scottish Consent Authorised 0
Lincs 2 Partial Generation / Construction
0-30
London Array 2 Fully Commissioned 0
Moray Scottish Consent Authorised 0
Neart na Gaoithe Scottish Consent Authorised 0
Race Bank 2 Consent Authorised 0-30
Sheringham Shoal 2 Fully Commissioned 0-30
Teesside 1 Fully Commissioned 0-30
Thanet 2 Fully Commissioned 0
Triton Knoll 2 Consent Authorised 0-30
Westermost Rough 2 Partial Generation / Construction
100
7. Estimation of the percentage of the Farne Islands SPA adult razorbill population at risk of
effects in North Sea offshore wind farms
On the basis of the estimated movements of razorbills in UK waters and seasonal definitions
(MacArthur Green 2014), the percentage of razorbills within named North Sea offshore wind farms
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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predicted to be adults originating from the Farne Islands SPA colony has been calculated (Table 12).
No wind farms are located within 48km of the Farne Islands therefore there are no wind farm sites
at which all the birds present would be attributed to this colony. For wind farms between 48km and
150km the breeding season percentage was assumed to lie between zero and the values calculated
in Tables 9 and 10 (0.3-0.7%). For wind farms beyond 150km no breeding adults from the Farne
Islands are expected to be present.
During the migration (post-breeding and pre-breeding) and winter periods, the number of Farne
Island SPA birds predicted to be present in the southern North Sea has been summed using the
population estimates and proportions in Table 8. On the assumption that outside the breeding
season, razorbills within the North Sea are evenly distributed from all colonies, the non-breeding
season percentages estimated to originate from the Farne Island SPA population on the wind farms
listed in Table 12 were calculated as the colony’s proportion of the totals.
The Farne Island proportion in the North Sea during the migration seasons was calculated as the
breeding adult number estimated to be present in UK North Sea & Channel waters at this time
divided by the total numbers from Table 8:
780 / 587683 = 0.001
The Farne Island proportion in the North Sea during the winter period was calculated as the
breeding adult number estimated to be present in UK North Sea & Channel waters at this time
divided by the total numbers from Table 8:
234 / 216995 = 0.001
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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Table 12. Percentage of breeding adult razorbills in offshore wind farms during the breeding, post-breeding and pre-breeding migration, and winter seasons which are estimated to originate from the Farne Islands SPA population.
Project UK Round Status
Period
Breeding (min. – max.)
Migration Mid-
winter
Beatrice Scottish Consent Authorised 0
0.1 0.1
Blyth Demonstration Site - Consent Authorised 0 - 0.7
Dogger Bank Creyke Beck A & B
3 Consent Application Submitted
0 - 0.7
Dogger Bank Teesside A & B
3 Consent Application Submitted
0
Dogger Bank Teesside C & D
3 Concept / Early Planning
0
Dudgeon 2 Consent Authorised 0
East Anglia ONE 3 Consent Application Submitted
0
European Offshore Wind Development Centre
Consent Authorised 0
Firth of Forth Alpha and Bravo (Seagreen)
Scottish Consent Authorised 0 - 0.3
Galloper 2 -
extension Consent Authorised 0
Greater Gabbard 2 Fully Commissioned 0
Hornsea Project One 3 Consent Application Submitted
0
Humber Gateway 2 Consent Authorised 0
Inch Cape Scottish Consent Authorised 0 - 0.3
Lincs 2 Partial Generation / Construction
0
London Array 2 Fully Commissioned 0
Moray Scottish Consent Authorised 0
Neart na Gaoithe Scottish Consent Authorised 0 - 0.3
Race Bank 2 Consent Authorised 0
Sheringham Shoal 2 Fully Commissioned 0
Teesside 1 Fully Commissioned 0
Thanet 2 Fully Commissioned 0
Triton Knoll 2 Consent Authorised 0
Westermost Rough 2 Partial Generation / Construction
0
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References
Brown, A. and Grice, P. (2005). Birds in England. T & AD Poyser, London.
Burke, C.M. and Montevecchi, W.A. (2009). The foraging decisions of a central place foraging seabird
in response to fluctuations in local prey conditions. Journal of Zoology 278: 354-361.
Hughes, R. (2013). Annual research report summary: RSPB FAME seabird tracking project. Fair Isle
Bird Observatory Report 64: 120-121.
Langton, R., Davies, I.M. and Scott, B.E. (2014). A simulation model coupling the behaviour and
energetics of a breeding central place forager to assess the impact of environmental changes.
Ecological Modelling 273: 31-43.
MacArthur Green (2014) Biologically appropriate, species-specific, geographic non-breeding season population estimates for seabirds. Report for Natural England and Marine Scotland.
Pennycuick, C.J. (1997). Actual and ‘optimum’ flight speeds: field data reassessed. Journal of
Experimental Biology 200: 2355-2361.
Shetland Bird Club (2013). Shetland Bird Report (2012). Shetland Bird Club, Lerwick.
Thaxter, C.B., Wanless, S., Daunt, F., Harris, M.P., Benvenuti, S., Watanuki, Y., Gremillet, D. and
Hamer, K.C. (2010). Influence of wing loading on the trade-off between pursuit-diving and flight in
common guillemots and razorbills. Journal of Experimental Biology 213: 1018-1025.
Thaxter, C.B., Lascelles, B., Sugar, K., Cook, A.S.C.P., Roos, S., Bolton, M., Langston, R.H.W. and
Burton, N.H.K. (2012). Seabird foraging ranges as a preliminary tool for identifying candidate Marine
Protected Areas. Biological Conservation 156: 53-61.
Uttley, J.D., Walton, P., Monaghan, P. and Austin, G. (1994).The effects of food abundance on
breeding performance and adult time budgets of guillemots Uria aalge. Ibis 136: 205–213.
Webb, A., Tasker, M.L. and Greenstreet, S.P.R. (1985). The distribution of guillemots (Uria aalge),
razorbills (Alca torda) and puffins (Fratercula arctica) at sea around Flamborough Head, June 1984.
Nature Conservancy Council CSD Report No. 590.
Wernham, C.V., Toms, M.P., Marchant, J.H., Clark, J.A., Siriwardena, G.M. and Baillie, S.R. (2002). The Migration Atlas: movements of the birds of Britain and Ireland. T. & A.D. Poyser, London.
FFC pSPA & Farne Islands SPA Guillemot and Razorbill Apportioning Among UK North Sea Wind Farms
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Appendix 1 - Review of common guillemot and razorbill foraging ranges from breeding sites
Foraging ranges of breeding auks have mainly been studied during the chick-rearing period. It is
possible that breeding adults make longer foraging trips during the early breeding season before
chicks hatch, but data are not available to assess that possibility.
Few common guillemots, razorbills or puffins from the Flamborough and Filey Coast pSPA bring fish
back to their chicks from a distance of more than 30km from that colony (Webb et al. 1985, Brown
and Grice 2005). Thaxter et al. (2012) reported the foraging range of breeding common guillemots to
be a mean of 38km, mean maximum across five studies of 84km, and largest recorded maximum
distance of 135km. Due to the large number of studies and large quantity of data on which these
estimates were based the authors assigned high confidence to these estimates. They reported
foraging range of razorbill to be a mean of 24km, mean maximum across four studies of 48km, and
largest recorded maximum distance of 95km. They assigned moderate confidence to these
estimates.
Subsequent studies (such as the RSPB FAME project) have recorded some greater maximum
distances, suggesting that even longer foraging trips are possible. However, the longest trips appear
to have been made by individuals attempting to breed at colonies where the food supply had
collapsed and birds were unable to find food locally. For example, a tracked guillemot breeding at
Fair Isle travelled 340km from the colony in 2011 (and its chick died) during a year when the sandeel
stock at Shetland was known to be greatly reduced, and the breeding success of most seabirds in
Shetland, including common guillemots and razorbills, was close to zero (Hughes 2013, Shetland Bird
Club 2013). To make clear how exceptional this distance was, a common guillemot flies at about
19m/sec (Pennycuick 1997) so would take almost 10 hours to complete this round trip even if it
spent no time on the water or diving for food. This is incompatible with bringing enough food back
to keep a chick alive. The species is a single prey loader so carries only one fish at a time and
common guillemot chicks need about 5 feeds per day. Yet chicks are normally attended and
protected by one adult at the nest site while the partner is foraging (Uttley et al. 1994), so there are
simply not enough hours in the day to allow successfully breeding guillemots to make such long trips
to provision a chick.
Hughes (2013) reported that guillemots and razorbills tracked as part of the FAME project on Fair
Isle in 2012 did not travel ‘anywhere near as far’ in 2012 as in 2011, and related this to slightly better
(though still extremely poor) feeding conditions near Fair Isle in 2012, resulting in breeding success
of 0.14 chicks per pair in 2012 compared to 0.00 chicks per pair in 2011. The conclusion that birds
fed closer to the colony when food supply was better is supported by detailed research studies that
have shown that seabirds of many different species tend to travel further from colonies to search for
food when food supply is reduced.
Specifically considering common guillemots, Uttley et al. (1994) compared common guillemot
breeding in Shetland in 1990 and 1991. Sandeel abundance was considerably lower in 1990 than in
1991. In 1990, chick provisioning trips averaged 178 minutes away from the nest, while in 1991 trips
averaged 76 minutes. The authors inferred that adults were travelling further to forage in 1990, the
year of lower food abundance. Guillemots fly at about 19m/sec (Pennycuick 1997) so a continuous
flight of 76 minutes would permit a guillemot to cover 87km, equating to a foraging range of 43.5km
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if the bird spent no time in catching prey. However Thaxter et al. (2010) reported that guillemots
tracked from the Isle of May spent only 10% of their foraging trips in flight to and from the feeding
site. If the birds in Shetland did the same, their 76 minute foraging trip would allow them to forage
only 4.4km from the colony in 1991, but 10km from the colony in 1990. Uttley et al. (1994) found
that guillemot chicks were in better body condition in 1991, and chick survival in 1991 was 98%
whereas in 1990 it was significantly lower at 78%. Thaxter et al. (2010) found that razorbills spent
about 20% of their foraging trip in flight compared to only 10% by common guillemots. However,
because flight speed of razorbills is less than that of common guillemots (16m/sec compared to
19m/sec; Pennycuick 1997), their foraging range is not much different from that of common
guillemot. At the Isle of May, common guillemots foraged up to a mean maximum of 14.4km from
the colony while razorbills foraged up to a mean maximum of 18.4km from the colony (Thaxter et al.
2010).
Burke and Montevecchi (2009) also compared common guillemot breeding in two consecutive years
differing in food availability, but they not only measured fish abundance precisely, but also tracked
adult guillemots rather than inferring foraging distance from time spent away from the nest. Around
their study colony forage fish density was six times higher in 2004 than in 2005. In 2004, adults had a
mean maximum foraging range of 60km, while in 2005 this increased to 81km. Chick body condition
was also significantly lower in the year of longer foraging trips and low fish abundance. Interactions
between guillemot chick condition, foraging distance and food abundance have been further
explored in models by Langton et al. (2014). Burke and Montevecchi (2009) suggested that in 2005
when birds foraged up to 81km from the colony, the birds were close to an energetic limit, such that
they would have been unable to increase foraging effort further, suggesting that a maximum
foraging range of about 81km may be at the limit of what common guillemots can do and still have a
moderate chance to keep their chick alive.
The relatively high breeding success of common guillemots (0.74 chicks per pair) and razorbills (0.69
chicks per pair) at colonies in east England (14% and 8% higher on average than at colonies in east
Scotland), suggests a better food supply near the English colonies, and contrasts with the near-zero
productivity of these species in Shetland in many years since 2001 (Shetland Bird Club 2013). This
predicts that foraging ranges of common guillemots and razorbills at colonies in east England will be
considerably smaller than found at some colonies in Scotland where food supply is depleted. This
prediction is consistent with the observation that few common guillemots, razorbills or puffins from
the Flamborough colony bring fish back to their chicks from a distance of more than 30km from that
colony (Webb et al. 1985, Brown and Grice 2005).