The yellow-legged gull (Larus michahellis) is a widespread species along the Atlantic coasts of France and the Iberian Peninsula, the Azores Islands, Madeira, the countries of the Mediterranean basin and the Black Sea. It was formerly considered as a subspecies of Herring Gull ( L. argentatus), with which it coexists in some reproductive areas. Only recently L. michahellis has been recognized as a distinct species. Following detailed comparison of the two species, researchers found that the L michahellis's restricted but dense head-streaking and advanced primary mol in late summer, are not compatible with L. argentatus. Larus michahellis has a proportionately longer, heavier bill and bulkier head and body than L. urgentutus. In addition, L. michahellis's yellow bill has a red gonydeal spot, both colors typically brighter than in L. urgentutus outside breeding season. They also have an orange-red to vermilion orbital ring and yellow legs. DNAresearch, however, suggests that the yellow-legged gull L. michahellis is actually closest to the great blackbacked gull L. marinus and the Armenian gull L. armenicus comparing with L. urgentutus. Therefore, researchers concluded that these similar-looking yellow-legged gull should be recognized as a separate species. Based only on the evidence described above, suggest 1. species concepts that are consistent with the view that the yellow- legged gull L michahellis represent a separate species; and (note: researchers use multiple lines of evidence to support a conclusion.) 2. a species concept that does NOT support that view (i.e., that supports the historical one-species classification). For each species concept, explain your reasoning in 1 or 2 sentences. Figures of the two bird species are posted in a sperate file on eClass..

1. The yellow-legged gull (Larus michahellis) is a widespread species along the Atlantic coasts of
France and the Iberian Peninsula, the Azores Islands, Madeira, the countries of the
Mediterranean basin and the Black Sea. It was formerly considered as a subspecies of Herring
Gull ( L. argentatus), with which it coexists in some reproductive areas. Only recently L.
michahellis has been recognized as a distinct species. Following detailed comparison of the two
species, researchers found that the L michahellis's restricted but dense head-streaking and
advanced primary mol in late summer, are not compatible with L. argentatus. Larus michahellis
has a proportionately longer, heavier bill and bulkier head and body than L. urgentutus. In
addition, L. michahellis's yellow bill has a red gonydeal spot, both colors typically brighter than
in L. urgentutus outside breeding season. They also have an orange-red to vermilion orbital ring
and yellow legs. DNAresearch, however, suggests that the yellow-legged gull L. michahellis is
actually closest to the great blackbacked gull L. marinus and the Armenian gull L. armenicus
comparing with L. urgentutus. Therefore, researchers concluded that these similar-looking
yellow-legged gull should be recognized as a separate species. Based only on the evidence
described above, suggest 1. species concepts that are consistent with the view that the yellow-
legged gull L michahellis represent a separate species; and (note: researchers use multiple lines
of evidence to support a conclusion.) 2. a species concept that does NOT support that view (i.e.,
that supports the historical one-species classification). For each species concept, explain your
reasoning in 1 or 2 sentences. Figures of the two bird species are posted in a sperate file on
eClass.