Featured eBird checklist

Common Tern

Sterna hirundo

UBIF official use only Quarter Master reach, California

August 23, 2026 · 5:18 PM local time · Reported by Janis Stuurman

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Stylized field-guide illustration of a Common Tern
Flockline species illustration. Not the reported individual.

No photos are attached to this species on the featured checklist.

Notes from this checklist

“Continuing. Red short legs, black bill black carpal bar, dark nape.”

Historical context

0.25% of complete eBird checklists reported Common Tern in San Francisco County, California during August 22-31, 2016–2025.

Based on 4,032 complete checklists. County reporting frequency, not a rarity rating.

Reports documented in 4 of 10 years during August 22-31; 2 years have unknown results.

August (whole month): reports in 6 of 10 years. 2 years have unknown results.

Year-by-year evidence

Each year uses the same county and seasonal period. An exported zero does not prove absence. Unknown means the species row, frequency or checklist sample is unavailable. These records do not estimate your chance of finding the bird or establish rarity.

Annual eBird exports for August 22-31
Year / sourceResultComplete checklists
2016Reported177
2017Unknown216
2018Reported256
2019Reported371
2020Exported zero433
2021Exported zero436
2022Unknown427
2023Exported zero462
2024Exported zero629
2025Reported625
Source and limits

This county-wide sample pools the selected years. It does not establish how regularly the species returned each year, how likely you are to find it at this spot, or whether this flock size is unusual. Percentages can be unstable when few checklists are available. Habitat, observer effort and repeated visits affect reporting. A zero does not establish absence.

eBird and its contributors, Cornell Lab of Ornithology. Downloaded 2026-10-14. eBird source chart · Method · Data terms

Common Tern across Nationwide · Current week

20 report groups

On 26 eBird checklists · 7-day window ending November 11, 2026

Partial coverage. Counts reflect the available eBird notable feed, which may omit other reports. This recent snapshot may be newer than the featured visit.

View all 26 reporting checklists

Checklists with the same location and start time are grouped together. They may be copies from a shared outing, but this feed does not confirm that. These groups are not a count of independent sightings or distinct birds. The featured checklist is outside this feed snapshot.

Checklist details
Survey type
Traveling
Time in the field
32 minutes
Distance covered
0.34 km
Birders on the outing
3 people
Species logged on this checklist
14 different species