The Strange World of Gull Identification Nick Rossiter October 2001.
-
Upload
pauline-paul -
Category
Documents
-
view
219 -
download
1
Transcript of The Strange World of Gull Identification Nick Rossiter October 2001.
![Page 1: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/1.jpg)
The Strange World of Gull Identification
Nick Rossiter
October 2001
![Page 2: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/2.jpg)
Great Advances
• Moult much better understood
• All ages considered
• Seasonal changes dealt with
• Much more information on Herring Gull/LBB complex world-wide:– accounts of Mediterranean YLG, Caspian Gull,
Baraba Gull, Mongolian Gull, American Herring Gull
![Page 3: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/3.jpg)
Problems
• Later!!
![Page 4: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/4.jpg)
http://www.zestforbirds.co.za/Zest for Birds
Mystery gull no. 5
Can you tell us what this gull is? It wasphotographed in Walvis Bay in Namibia in April2000. We would like to hear your comments onwhat it is and why you say so as well, so pleaseemail us your answer with reasons and we willput them all together and post them to thispage.
![Page 5: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/5.jpg)
![Page 6: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/6.jpg)
![Page 7: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/7.jpg)
For Black-headed Gull:
From Kevin Caley of the U.K.:
This is a black-headed gull, a very common specieshere in Britain.
Note the slender bill, with its dark tip (only found inimm and winter birds) and the two dark patchesabout the eye and at the back of the ear coverts,characteristic for this species in winter plumage.The most telling feature, however, is seen on theopen wing - the triangle of white on the leadingedge, combines with the black tips to the first fourprimaries (counting inwards from the leading ege)are diagnostic for this species, ad cannot beconfused iwth any other species, European orAmerican.
![Page 8: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/8.jpg)
From Verbanck Koen of Belgium:
This is an adult Black-headed Gull (Larusridibundus) in winter plumage. Identification israther straightforward:-typical silhouette-wing-pattern: black on outer web of the first primaryand primary tips inwards as far as 6th-(to 8th).Remainder of the wing pale grey with thin whiteleading and trailing edges.-tail: all white-bare parts: bill red with dark tip; and legs darkreddish coloration-typical (winter plumage) head-pattern: white head,with dusky eye-crescent, prominent blackish ear-spot (often with faint grey extension over rearcrown)
![Page 9: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/9.jpg)
For Grey-headed Gull:
From Nick Rossiter of the U.K.:
Grey-headed Gull -- adult in post-breeding moult.
White is on P5-P7 which is right for Grey-headed Gulland wrong for Black-headed Gull where the white ison P7-P10. Black bar on P4 is also OK for Grey-headed. The extensive black near the tip on the whitefeathers is also right for Grey-headed.
The state of moult in April is right for a southernhemisphere breeder. The characteristic mirrors on P9and P10 of Grey-headed are missing because thesefeathers have been shed and not yet re-grown.
![Page 10: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/10.jpg)
For hybrid Grey-headed x Black-headed Gull:
From Igor Festari of Italy:
Even at first sight, become obvious that's not atypical winter-plumaged Black-headed or Grey-headed Gull; it shows absolutely atypicalcolouration, with some important feature almostintermediate between the two:
- Structure: structure is typical for Grey-headed,with long neck and tail, small headed appearanceand very long legs (especially the tibias); also thebill is too long and has sligthly too broad base anddecurve tip for a Black-headed (more Grey-headed-type). Wings, at the contrary, are moulting primariesbut they still appear too short-handed, broad-armedand pointed for a classic Grey-headed (andtherefore more similar to Black-headed's).
![Page 11: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/11.jpg)
Received more recently from David Allen ofSouth Africa:
This is a Grey-headed Gull. The photo does notreally show the leading edge of the wing well at all.It is probably about one year old. They are winterbreeders so an April date would fit this. Thereforeit's in transition between adult and juv. features, i.e.has dark eye and two-tone bill of juv. but bodyplumage and tail of adult. Hard to tell about theleading edge of the primaries and juv. Grey-headedGulls lack have the mirrors in the primaries ofadults. Essentially there are hundreds of birdslooking just like this in Durban Bay every summer.Head pattern fits a non-breeding Grey-headedperfectly. The hybrid theory is certainly novel butthe breeding grounds of the two species areseparated by the Sahara!
![Page 12: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/12.jpg)
Grey-headed Gull Adults, Gambia, August 1999
![Page 13: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/13.jpg)
Moult in Large Gulls
• Juveniles: (first-generation)– scapulars, back, coverts (post-fledging)
• First-winter: (second-generation)– scapulars, back, coverts (continuous)– primaries (spring, summer)
• (First-summer -- fading, bleaching)
• Second-winter (third-generation)
![Page 14: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/14.jpg)
Timing is Very Variable
• Northern forms (e.g. Scandinavian argentatus, Glaucous Gull) may retain juvenile feathers to late winter or spring
• Southern forms (e.g. Mediterranean Yellow-legged Gull) moult many juvenile feathers in late summer/ early autumn
• Primary moult seems more independent of latitude
![Page 15: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/15.jpg)
Juvenile ‘Yellow-legged Gull’ La Linea August 2001
![Page 16: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/16.jpg)
Juvenile ‘Yellow-legged Gull’ Estepona August 2001
![Page 17: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/17.jpg)
‘Caspian Gull’ Norway, First-winter, February 2001 (Frode
Falkenberg)
![Page 18: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/18.jpg)
‘Caspian Gull’ Norway, First-winter, February 2001 (Frode
Falkenberg)
![Page 19: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/19.jpg)
First-winter ‘Yellow-legged Gull’ San Sebastian, February 2000 (Dick Newell)
![Page 20: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/20.jpg)
Matosinhos, First-winter/1s ‘Yellow-legged Gull’, April 2001
![Page 21: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/21.jpg)
First-winter/1s ‘Yellow-legged Gulls’ (with 2s LBBG), Porto, April 2001
![Page 22: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/22.jpg)
First-winter/1s ‘Yellow-legged Gull’ Fuerteventura, April 1999
![Page 23: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/23.jpg)
Four First-summer ‘Yellow-legged Gulls’ Fuerteventura, April 1999
![Page 24: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/24.jpg)
Two first-summer/2w Yellow-legged Gulls michahellis Royan, August 1991
![Page 25: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/25.jpg)
First-summer ‘Yellow-legged Gull’ Lanzarote, August 1992
![Page 26: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/26.jpg)
First-summer/2w ‘Yellow-legged Gull’ Lanzarote, August 1992
![Page 27: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/27.jpg)
First-summer/2w ‘Yellow-legged Gull’ Lanzarote, August 1992
![Page 28: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/28.jpg)
First-summer ‘Yellow-legged Gull’, Tenerife, July 2000
![Page 29: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/29.jpg)
First-summer/second-winter ‘Yellow-legged Gull’ Estepona August 2001
![Page 30: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/30.jpg)
First-summer/second-winter ‘Yellow-legged Gull’ Estepona August 2001
![Page 31: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/31.jpg)
Second-winter ‘Yellow-legged Gull’ Fuerteventura, September 2000
![Page 32: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/32.jpg)
Second-summer ‘Yellow-legged Gull’ Porto, April 2001
![Page 33: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/33.jpg)
Second-summer ‘Yellow-legged Gull’, Essaouira, April 2000
![Page 34: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/34.jpg)
Second-summer ‘Yellow-legged Gull’, Essaouira, April 2000
![Page 35: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/35.jpg)
Third-winter ‘Yellow-legged Gull’, Gran Canaria, September 2000
![Page 36: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/36.jpg)
Fourth-summer ‘Yellow-legged Gull’, Matosinhos, April 2001
![Page 37: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/37.jpg)
Adult summer ‘Yellow-legged Gull’, Agadir, April 2000
![Page 38: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/38.jpg)
Part 2
Forms of Yellow-legged Gulls
![Page 39: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/39.jpg)
Adult Mediterranean michahellis, Royan, August 1991
![Page 40: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/40.jpg)
Adult Mediterranean michahellis, Royan, August 1991
![Page 41: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/41.jpg)
Adult Mediterranean michahellis, Royan, August 1991
![Page 42: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/42.jpg)
Adult/3s-4w Mediterranean michahellis, Royan, August 1991
![Page 43: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/43.jpg)
Adult/3s-4w Mediterranean michahellis, Royan, August 1991
![Page 44: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/44.jpg)
Two first-summer/2w Mediterranean michahellis Royan, August 1991
![Page 45: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/45.jpg)
Map for Atlantic Forms
![Page 46: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/46.jpg)
![Page 47: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/47.jpg)
Adult ‘Yellow-legged Gull’ atlantis, Tenerife, August 1998
![Page 48: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/48.jpg)
Adult ‘Yellow-legged Gull’ atlantis, Tenerife, December 1996
![Page 49: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/49.jpg)
Adult ‘Yellow-legged Gull’ atlantis, Lanzarote, August 1992
![Page 50: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/50.jpg)
Table 1: Biometrics (in mm) of Herring L .a. argenteus, Yellow-leggedand Lesser-black Backed Gulls L. f. graellsii.
Feature argen-teus
Medi-terraneanYellow-leggedGull
micha-hellis
Atlantic Yellow-legged Gull graell-sii
NWIberia
W Iberia NWAfrica
Macro-nesia
Source Cramp(1983)
Cramp(1983)
Carreraet al(1987)
Cramp(1983)
Urban etal (1986)
Cramp(1983)
Cramp(1983)
wing 404-425
438-460 419 401-431 420-439 423-437 406-427
tail 160-170
169-179 - 158-169 162-170 165-173 152-164
bill 48.9-53.2
51.5-56.6
54.8 49.5-53.6
49.4-55.7
49.1-51.5
47.7-52.1
tarsus 60.5-65.2
64.5-70.6
65.6 60.3-64.4
61.6-65.0
62.7-64.7
60.3-65.2
toe 56.7-61.6
59.2-65.4
- 55.2-59.3
- 58.7-60.3
52.5-56.3
![Page 51: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/51.jpg)
Table 2a: Further Biometrics (in mm) of Atlantic Islands Yellow-leggedGulls.
Feature Atlantic Islands Yellow-legged Gull
Macro-nesia
Azores Azores Canaries(East?)
Canaries-Tenerife
Azores
Source Cramp(1983)
Dwight(1922)
Dwight(1925)
Banner-man(1963)
Volsøe(1951)
Vaurie(1965)
wing 423-437 401-423 402-421
401-418 417-440 418-438
tail 165-173 162-170 162-171
162-170 - -
bill 49.1-51.5 50.3-55.1 50.2-54.3
46.5-54 - -
tarsus 62.7-64.7 61.7-66.6 61.6-66.3
62.5-65.5 - -
toe 58.7-60.3 52.3-56.0 52.2-55.2
- - -
![Page 52: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/52.jpg)
Table 2b: Further Biometrics (in mm) of Mediterranean Yellow-leggedGulls.
Feature Mediterranean Yellow-legged Gull
Medi-terranean
Camargue BalearicIslands
IslasCharafinas
Source Cramp(1983)
Isenmann(1973)
Carrera(1987)
Carrera(1987)
wing 438-460 440-465 447 457
tail 169-179 - - 178
bill 51.5-56.6
56-61 57.4 56.6
tarsus 64.5-70.6
67-72 70.3 68.5
toe 59.2-65.4
- - -
![Page 53: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/53.jpg)
Juvenile ‘Yellow-legged Gull’ atlantis, Tenerife, August 1998
![Page 54: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/54.jpg)
Three Adult Atlantic Yellow-legged Gulls, Agadir, April 2000
![Page 55: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/55.jpg)
Typical Adult Wingtip ‘Yellow-legged Gull’, Agadir, April 2000
![Page 56: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/56.jpg)
Typical Adult Wingtip ‘Yellow-legged Gull’, Fuerteventura, April 2000
![Page 57: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/57.jpg)
Table 4: Percentage of Wingtip Patterns by Location for Adult Atlantic Yellow-legged Gulls.
Area P10 P9 P6-P10 P5 P4 S Tip
(%)LM(%)
SM(%)
M(%)
S Sol-id(%)
SI(%)
LI(%)
S BB(%)
TB(%)
IM(%)
PN(%)
SanSebastian
6 85 15 0 85 7 0 30 70 6 15 35 50 15
Santander 21 70 30 0 85 21 0 30 70 10 0 80 20 0Porto/Minho
52 15 85 + 35 32 55 40 5 28 50 30 20 15
Setúbal /Lisbon
18 35 65 0 50 18 50 35 15 20 60 10 30 0
Faro 11 20 60 20 10 12 100 0 0 14 85 15 0 15Andalucia 6 50 50 0 15 6 100 0 0 6 100 0 0 100Tanger 19 50 45 5 35 10 60 30 10 17 50 40 10 40Asilah 4 25 75 0 0 4 100 0 0 2 50 50 0 -Agadir/Essaouira
76 55 40 5 25 71 90 10 0 69 35 30 35 10
Fuerte-ventura/Lanzarote
31 30 60 10 30 39 80 15 5 38 55 30 15 15
GranCanaria
56 45 50 5 25 71 80 20 + 63 40 35 25 15
Tenerife/Gomera
84 40 50 10 20 31 95 5 0 49 45 30 25 5
La Palma/El Hierro
17 60 20 20 10 4 100 0 0 14 65 35 0 5
Cantabrican 27 73 27 0 85 28 0 30 70 16 6 63 31 10W Portugal/NW Spaincline
70 19 80 1 39 50 54 37 9 48 54 21 25 10
Dark 279 45 47 8 23 232 87 12 1 249 46 30 24 11Med.intersection
25 51 45 4 31 16 76 18 6 23 61 31 8 57
All forms 401 43 51 6 30 326 74 18 8 336 46 31 23 13
![Page 58: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/58.jpg)
Comparative Wingtip Data
• None available from core area of Mediterranean Yellow-legged Gull in western Mediterranean
• Some data from putative michahellis in northern Europe.
• Are northern European birds typical?
• Birds of known origin are emphasis of current work (e.g. IGM V)
![Page 59: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/59.jpg)
Adult ‘Yellow-legged Gull’, Faro, March 1999
![Page 60: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/60.jpg)
Two Adult ‘Yellow-legged Gull’, Setubal, March 1999
![Page 61: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/61.jpg)
First-winter/1s ‘Yellow-legged Gulls’ (with 2s LBBG), Porto, April 2001
![Page 62: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/62.jpg)
Matosinhos, March 2001, smithsonianus, intermedius, graellsii, ‘YLG’
![Page 63: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/63.jpg)
Matosinhos, March 2001, ‘YLG’ adult, ‘Big Waters Gull’.
![Page 64: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/64.jpg)
Part 3
Northern Forms, Med/Atlantic Intersection and Summary
![Page 65: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/65.jpg)
Porto, March 2001, Pair ‘YLG’ adults
![Page 66: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/66.jpg)
Minho, April 2001, ‘YLG’ adult
![Page 67: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/67.jpg)
Noja (Santander), August 1990, 3s ‘YLG’
![Page 68: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/68.jpg)
San Sebastian, February 2000, ‘YLG’ adult (Dick Newell)
![Page 69: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/69.jpg)
San Sebastian, February 2000, ‘YLG’ adult (Dick Newell)
![Page 70: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/70.jpg)
Table 3: Comparability of Long and Mew Calls of Adult Atlantic Yellow-legged Gulls to LesserBlack-backed Gull L. f. graellsii, Herring Gull L. a. argenteus and Mediterranean Yellow-legged
Gull L. michahellis
Area Long calls % like Mew calls % likegraellsii Shrill
graellsiiDeepargenteus
Mediterraneanmichahellis
graellsii argenteus Mediterraneanmichahellis
Santander 0 0 100 0 0 100 0Porto/Minho + 45 55 0 75 25 0Setúbal /Lisbon 0 90 10 0 95 5 0Faro 20 70 10 0 100 0 0Tanger 0 92 8 0 100 0 0Agadir/Essaouira
0 90 10 0 100 0 0
Fuerteventura/Lanzarote
0 20 80 0 35 65 0
Gran Canaria 0 20 80 0 45 55 0Tenerife/Gomera
0 80 20 0 100 0 0
La Palma/ ElHierro
40 60 0 0 100 0 0
Cantabrican 0 0 100 0 0 100 0W Portugal cline + 68 32 0 85 15 0Dark 10 57 33 0 80 20 0Med. intersection 0 92 8 0 100 0 0All forms 6 57 37 0 75 25 0
![Page 71: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/71.jpg)
Map showing Areas for Forms
![Page 72: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/72.jpg)
‘YLG’: Mauritania, Azores; Kelp Gull (Birding World)
![Page 73: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/73.jpg)
Separating dark form from michahellis
C. michahellis by their:
1. smaller size by 5-10%;2. less attenuated appearance at rest;3. shorter legs, typically 70% of height of body above legs compared to about 100%;4. rounded heads, lacking angular appearance;5. blunt wingtip giving bunched primary tips on the folded wing;6. smaller white primary tips on the folded wing;7. slightly darker mantle shade with a marked blue-grey sheen;8. shriller long calls lacking a guttural component, less deep mew calls,9. long calls given at 60 rather than 90 ;10. ochre tint to the yellow legs;11. less white in wingtip with only 25% carrying a mirror on P9.
![Page 74: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/74.jpg)
Intersection Area -- Atlantic / Mediterranean
• Do they mix?
• Do the breeding areas overlap?
• Are there intermediate forms?
![Page 75: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/75.jpg)
![Page 76: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/76.jpg)
Tanger, August 2001, Adult ‘YLG’
![Page 77: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/77.jpg)
Tarifa, August 2001, Adult ‘YLG’
![Page 78: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/78.jpg)
Tarifa, August 2001, Two Adult Mediterranean YLG
![Page 79: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/79.jpg)
Comparison Med/Atlantic YLG adults, Conil, August 2001
![Page 80: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/80.jpg)
Conil, west Andalucia
![Page 81: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/81.jpg)
Gibraltar from La Linea
![Page 82: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/82.jpg)
Gibraltar, June 1994, Adult + chick ‘YLG’ (Tom Cadwallender)
![Page 83: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/83.jpg)
Estepona, east Andalucia
![Page 84: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/84.jpg)
Estepona, August 2001, Adult ‘YLG’
![Page 85: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/85.jpg)
Estepona, August 2001, 2s/3w ‘YLG’
![Page 86: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/86.jpg)
Estepona, August 2001, ad + imm ‘YLG’
![Page 87: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/87.jpg)
Strange World?
• Because too many id criteria rely on studies of migrants to northern Europe, rather than of populations in their native areas.– Such migrants are putative– Main forms described but variation cannot be
determined reliably– Even marked/ringed individuals may not be
typical of the ones that stay at home
![Page 88: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/88.jpg)
Current situation
• Difficult
• Forthcoming BB paper based on studies of populations to the east rumoured to question id of Caspian Gull
• Work to the west (as here) shows definition and id of Western Yellow-legged Gull to be far from settled
![Page 89: The Strange World of Gull Identification Nick Rossiter October 2001.](https://reader036.fdocuments.us/reader036/viewer/2022062408/56649eba5503460f94bc1c5d/html5/thumbnails/89.jpg)
The End
of the Seagull Story