Petrochelidon pyrrhonota
Silhouette: Andy Wilson · PhyloPic
In 3 days ~20% in a week ~50%
The cliff swallow or American cliff swallow (Petrochelidon pyrrhonota) is a member of the passerine bird family Hirundinidae, the swallows and martins. The generic name Petrochelidon is derived from the Ancient Greek petros meaning "stone" and khelidon (χελιδών) "swallow", and the specific name pyrrhonota comes from purrhos meaning "flame-coloured" and -notos "-backed".
Cliff swallows are extremely social songbirds that can be found in large nesting colonies reaching over 2,000 nests. They are frequently seen flying overhead in large flocks during migration, gracefully foraging over fields for flying insects or perching tightly together on a wire preening under the sun.
Cliff swallows build gourd-shaped nests made from mud with small entrance holes. They build their nests tightly together, on top of one another, under bridges or alongside mountain cliffs. Living in large populations, these aerial insectivores use extensive vocalizations to communicate warnings or food availability to the other individuals.
The cliff swallow's average body length is 13 cm (5.1 in), and they have short legs and small bills with relatively long pointed wings. Adult cliff swallows have... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Tijuana | 🇲🇽 México | |
| 2 | Los Angeles | 🇺🇸 United States | |
| 3 | Sacramento | 🇺🇸 United States | |
| 4 | Denver | 🇺🇸 United States | |
| 5 | Salt Lake City | 🇺🇸 United States | |
| 6 | Mesa | 🇺🇸 United States | |
| 7 | San Diego | 🇺🇸 United States | |
| 8 | San Francisco | 🇺🇸 United States | |
| 9 | Ciudad Juárez | 🇲🇽 México | |
| 10 | Dallas | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Cliff Swallow sighting in Redwood National Park on a given day, based on 239 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 82nd most-seen of the 226 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
May and July
In those months about 20% of wildlife watchers report a Cliff Swallow in Redwood National Park on a given day, against under 5% in September to March, the lowest months. Those are among Redwood National Park's driest months, with about 50 mm of rain a month against 360 mm in January.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Cliff Swallow sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
14th of 73
Of the 73 parks where we can rate Cliff Swallow sightings, Redwood National Park ranks 14th at about 10%. The best odds are in Badlands National Park (United States, about 60%), Yellowstone National Park (United States, about 30%) and Isla del Coco National Park (Costa Rica, about 20%). All parks ranked.
Same family: Hirundinidae
The closest relatives of the Cliff Swallow that you can see in Redwood National Park (family Hirundinidae, Swallows and Martins) are Barn Swallow (about 30%), Violet-green Swallow (about 20%) and Tree Swallow (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Cliff Swallow is recorded against all the birds logged in Redwood National Park (239 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
