American Herring Gull (smithsonianus)
(last update: October 30, 2015)
American Herring Gull (smithsonianus) adult.
P8 (figure 7, table 4-6)
The grey tongue is usually very long, covering more than 3/4 of the visible part of the inner web, and leaving only a rather thin black subterminal band. The tongue on p8 is of approximately the same length as the tongue on P7. On the underside of the wing, the long tongues on P5-P8(P9) leave only a thin and rather straight black trailing edge (cf figure 1b and 2b). In argenteus and many birds of other European forms, the pale tongue is slightly shorter than the one on P7, so the amount of black on the inner web is also larger.
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| % NF smithsonianus | 55.4 |
19.2 |
16.1 |
9.1 |
| % argenteus | 0.0 |
1.3 |
0.0 |
0.7 |
| % argentatus | 10.8 |
10.8 |
18.9 |
8.1 |
| % E-Baltic Herring Gull | 3.0 |
10.4 |
6.0 |
6.0 |
FIGURE 7 Variation in pattern of P8 in herring gulls (Peter Adriaens). Percentages refer to the combination of characters illustrated. Here, for instance, it is stated that 55.4% in our sample of NF smithsonianus combined a 'bayonet-pattern' on the outer web with a very long pale tongue (3/4 or more of the inner web) and a white tongue-tip (at least a thin crescent), as illustrated in figure 7a. |
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The tongue-tip is often white; some birds have an obviously broad, rounded white spot at the tongue-tip (cf figure 1a and 3), which, together with the white tongue-tip of (P5)P6-P7 may create a ’string of pearls' effect, We did not find an adult argenteus in our sample with such a broad white tongue-tip on P8; in fact, the majority have no white at all here. Among the European forms, the ’string of pearls’ seems to be mostly shown by argentatus, and a few intergrades. Keep in mind, however, that even slightly over-exposed photographs may exaggerate the whiteness of the tongue-tips, and may create the false impression of a broad white spot on the tongue-tip of P8 when there is none. The other extreme is also possible: a more over-exposed photograph can obliterate the white ’string of pearls’.
| TABLE 4 Length of grey tongue on inner web of P8 | |
| P8 | % of birds with pale tongue
as long as on P7 |
| NF smithsonianus | 83 |
| argenteus | 3 |
| argentatus | 49 |
| Eastern Baltic Herring Gull | 30 |
TABLE 5 Extent of white on tongue-tip of P8 |
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| P8 | % of birds with thin white tongue-tip (crescent-shaped) |
% of birds with broad white tongue-tip (large, rounded spot) |
Total (%) |
| NF smithsonianus | 57 |
39 |
96 |
| argenteus | 33 |
0 |
33 |
| argentatus | 24 |
41 |
65 |
| Eastern Baltic Herring Gull | 70 |
3 |
73 |
TABLE 6 Shape of black colour on outer web of P7 and/or P8 |
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| P7/P8 | % of birds with "bayonet" on P7 and/or P8 |
| NF smithsonianus | 73 |
| argenteus | 3 |
| argentatus | 19 |
| Eastern Baltic Herring Gull | 20 |
The shape of the black pattern on the outer web is another important character. Here, and/or on the outer web of P7, many NF smithsonianus have a rather peculiar shape, which we would like to call the ’bayonet pattern' (see figure 7a and 8a). Basically, the pattern consists of a straight or slightly oblique upper border, which then projects towards the primary coverts in a thin, very pointed black wedge (almost ’needle-shaped’) along the outer edge. The shape recalls a French ’bayonet', hence the name. It is important to note the difference with the pattern in figure 7c and 8c: these also show a pointed black wedge towards the primary coverts but it is broader at the base, starting from the shaft and lacking a distinct step. The combination of the three characters mentioned above (’bayonet’, tongue-tip, length of tongue) is significant, as can be seen in figure 7a and the percentages below it.