Tachycineta thalassina
Silhouette: Andy Wilson · PhyloPic
In 3 days ~60% in a week ~90%
The violet-green swallow (Tachycineta thalassina) is a small North American passerine bird in the swallow family. These aerial insectivores are distributed along the west coast from Alaska to Mexico, extending as far east as Montana and Texas. With an appearance very similar to the tree swallow, these individuals can be identified by the white rump side-patches that appear to separate their green back and purple tail. Violet-green swallows are secondary cavity nesters, found in a number of habitats including deciduous and coniferous forest. In addition to nesting in tree holes within these habitats, they are also widely observed nesting in the cracks of large cliffs.
The distinct body form of swallows distinguishes them from other passerine birds. Their long pointed wings and slim, streamlined body evolved to catch insects while in flight; the violet-green swallow is no exception. With an average body length of 12–13 cm (4.7–5.1 in), the violet-green swallow is slightly shorter and appears more compact in flight compared to some other members of the genus Tachycineta. The violet-green swallow most closely resembles the tree swallow T. bicolor, but can be distinguished... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Toluca | 🇲🇽 México | |
| 2 | Portland | 🇺🇸 United States | |
| 3 | Seattle | 🇺🇸 United States | |
| 4 | San Francisco | 🇺🇸 United States | |
| 5 | Vancouver | 🇨🇦 Canada | |
| 6 | Anchorage | 🇺🇸 United States | |
| 7 | Denver | 🇺🇸 United States | |
| 8 | Calgary | 🇨🇦 Canada | |
| 9 | Mexico City | 🇲🇽 México | |
| 10 | Mesa | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Violet-green Swallow sighting in Denali National Park on a given day, based on 317 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 20th most-seen of the 113 birds we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
May to July
In those months about 30% of wildlife watchers report a Violet-green Swallow in Denali National Park on a given day, against under 5% in April, the lowest month. November has too few records to rate.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Violet-green 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.
9th of 38
Of the 38 parks where we can rate Violet-green Swallow sightings, Denali National Park ranks 9th at about 20%. The best odds are in Nahanni National Park (Canada, about 60%), Grand Canyon National Park (United States, about 40%) and Rocky Mountain National Park (United States, about 40%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Violet-green Swallow is recorded against all the birds logged in Denali National Park (317 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.
