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Species · accepted · checked 2026-08-05

Larus heermanni

Heermann's Gull

WoRMS 343913ITIS 176841key itis:176841
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2026-08-05: worms_id 343913 via WoRMS TSN crosswalk (status accepted)

Silhouette · Sharon Wegner-Larsen · CC0 1.0 · PhyloPic, drawn from Larus argentatus
Heermann's Gull53 cm
bongo net ring71 cm

max · sealifebase

Photograph of Larus heermanni
Photo · David Batchelor · CC BY 4.0 · inat

Heermann's gull is a gull resident in the United States, Mexico and extreme southwestern British Columbia, nearly all nesting on Isla Rasa in the Gulf of California. They are usually found near shores or well out to sea, very rarely inland.W CalCOFI holds 475 observations of it in 1 dataset between 1989 and 2022.R

475
observations
475
records
475
sampling events
1989–2022
years
1
datasets

Observed in
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One row per dataset, one cell per year, darker with more observations — the same strip the front door draws per dataset. Each row ends with the name that dataset uses (dataset_taxon); the accepted name is written once, in the title above. A quiet pill marks a name the authority does not accept.

How big is it
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Every mark is a measured length with its own source — hover one to read it. The reference objects are _data/size_reference.csv: two of them, the 505 µm bongo mesh and the net's ring, are CalCOFI's own sampling gear.

Groups

calcofi:seabirds

Ways in
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Read from taxa.json of release v2026.09.11, written at release by calcofi4db::build_taxa_catalog(). The catalog's index is /species/.

Explorerdb-query
ERDDAPCalCOFI's own server, the Seabirds & Marine Mammals table constrained to this taxon
https://erddap.calcofi.io/erddap/tabledap/farallon_bird-mammal.html?&taxon_key=%22itis:176841%22