Passerella megarhyncha
Silhouette: Andy Wilson · PhyloPic
In 3 days ~30% in a week ~60%
The thick-billed fox sparrow (Passerella (iliaca) megarhyncha) group comprises the peculiarly large-billed Sierra Nevadan taxa in the genus Passerella. It is currently classified as a "subspecies group" within the fox sparrow, pending wider-spread acceptance of its species status.
Thick-billed fox sparrows are almost identical in plumage to slate-colored fox sparrows but have a more extensive blue-gray hood and a less rusty tail. The most striking feature of this bird is its enormous beak which can appear to be three times as large as that of the markedly small-billed slate-colored fox sparrows. A thick-billed fox sparrow's beak also differs in color from that of the slate-colored. Although the culmens of both groups are grayish brown, slate-coloreds have yellow lower mandibles instead of the steel blue of the thick-billeds'. (Rising & Beadle 1996) Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Large-billed Fox Sparrow sighting in Sequoia and Kings Canyon National Parks on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 65th most-seen of the 152 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
April and June
In those months about 20% of wildlife watchers report a Large-billed Fox Sparrow in Sequoia and Kings Canyon National Parks on a given day, against under 5% in August to March, the lowest months. Those are among Sequoia and Kings Canyon National Parks's driest months, with about 40 mm of rain a month against 190 mm in January.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Large-billed Fox Sparrow sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Sequoia and Kings Canyon National Parks, in our data
Sequoia and Kings Canyon National Parks is the only park on Wallace's Line with enough records to rate Large-billed Fox Sparrow sightings: about 10% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Large-billed Fox Sparrow is recorded against all the birds logged in Sequoia and Kings Canyon National Parks (13 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.
