Xerospermophilus tereticaudus
Silhouette: Joseph Smit · PhyloPic
In 3 days ~70% in a week ~90%
The round-tailed ground squirrel (Xerospermophilus tereticaudus), known as "Ardillón cola redonda" in Spanish, live in the desert of the Southwestern United States and Northwestern Mexico. They are called "ground squirrels" because they burrow in loose soil, often under mesquite trees and creosote bushes.
Most round-tailed ground squirrels are very small. Weight at birth is approximately 3.9 grams (0.14 oz). Adults weigh around 125 grams (4.4 oz). All have a long round tail and long, hairy hind feet. They have no fur markings, instead having a uniform sandy color, which matches the soil they burrow in. The underside of their body is usually a lighter shade. Round tailed squirrels average 204 to 278 millimetres (8.0 to 10.9 in) in length including the tail which is from 60 to 112 millimetres (2.4 to 4.4 in) long.
The gestation period is 28 days. An average of 5.4 pups are born in each litter. They reach sexual maturity at 325 days. There is little information on the longevity of these animals but one wild born specimen lived to approximately 8.9 years in captivity. They are prey animals for coyotes, badgers, hawks and snakes. Round-tailed ground... Wikipedia →
Recording0:21
United States · 2025
© Daniel Donovan · iNaturalist · CC BY-NC 4.0
Recording0:12
United States · 2026
© nmoorhatch · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Joshua Tree National Park | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Arizona-Sonora Desert Museum | 🇺🇸 United States | |
| 2 | Jardin zoologique de la ville de Lyon | 🇫🇷 France | |
| 3 | Grizzly & Wolf Discovery Center | 🇺🇸 United States |
Possible
About 30% of wildlife watchers report a Round-tailed Ground Squirrel sighting in Phoenix on a given day, based on 468 verified sightings from GBIF citizen-science data. It is the 2nd most-seen of the 14 mammals we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
February to May
In those months about 40% of wildlife watchers report a Round-tailed Ground Squirrel in Phoenix on a given day, against under 5% in October, the lowest month.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Round-tailed Ground Squirrel sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 cities where we can rate Round-tailed Ground Squirrel sightings, Phoenix has the highest daily chance: about 30%. Next come Las Vegas (United States, about 10%) and Mesa (United States, about 10%).
Same family: Sciuridae
The closest relatives of the Round-tailed Ground Squirrel that you can see in Phoenix (family Sciuridae, Squirrels) are Harris' Antelope Squirrel (about 20%) and Rock Squirrel (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Round-tailed Ground Squirrel is recorded against all the mammals logged in Phoenix (468 verified sightings), 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.
