Hypopachus variolosus
Silhouette: Jose Carlos Arenas-Monroy · PhyloPic
In 3 days ~60% in a week ~90%
The northern sheep frog (Hypopachus variolosus) is native to Central America, Mexico, and extreme south Texas, United States. It occurs in the lowlands from Sonora, Mexico, to northern Costa Rica on the Pacific coast, and south Texas to Honduras on the Gulf of Mexico and Caribbean coasts. The sheep frog inhabits semiarid thornscrub, savannas, pasturelands, and open woodlands, as well as more humid, moist forest in the canyons, basins, foothills, and lower elevations of mountains slopes. It is a fossorial, burrowing frog that is seldom seen on the surface except at night after heavy rains when they emerge to breed. The sheep frog gets its name from its distinctive call that resembles a sheep's bleat. It is a diet specialist primarily feeding on termites and ants.
The sheep frog is a small, stout frog with short legs, ranging about 2.5-3.8 cm, with females growing larger than the males. The dorsal color ranges from tan, to reddish-tan, to various shades of brown with irregular black flecks or spots, which may be extensive on some individuals, or absent on others. An orange, red, or yellowish mid-dorsal stripe, running from the snout to the vent is present on some specimens, but may by absent, vague, or fragmented on others. It is a common species in some areas of its range, but it is uncommon in the US and listed as a threatened species in the state of Texas. Wikipedia →
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| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Santa Rosa National Park | 🇨🇷 Costa Rica | |
| 2 | Palo Verde National Park | 🇨🇷 Costa Rica | |
| 3 | Calakmul Biosphere Reserve | 🇲🇽 Mexico | |
| 4 | Tikal National Park | 🇬🇹 Guatemala |
Possible
About 30% of wildlife watchers report a Sheep Frog sighting in Calakmul Biosphere Reserve on a given day, based on 40 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 3rd most-seen of the 13 amphibians 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.
June and September
In those months about 40% of wildlife watchers report a Sheep Frog in Calakmul Biosphere Reserve on a given day, against under 5% in May and November, the lowest months. Those are among Calakmul Biosphere Reserve's wettest months, with about 130 mm of rain a month against 15 mm in February.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Sheep Frog sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
3rd of 4
Of the 4 parks where we can rate Sheep Frog sightings, Calakmul Biosphere Reserve ranks 3rd at about 30%. The best odds are in Santa Rosa National Park (Costa Rica, about 70%) and Palo Verde National Park (Costa Rica, about 30%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Sheep Frog is recorded against all the amphibians logged in Calakmul Biosphere Reserve (40 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.
