Cebuella pygmaea
Silhouette: T. Michael Keesey · PhyloPic
In 3 days ~70% in a week ~90%
The western pygmy marmoset (Cebuella pygmaea) is a marmoset species, a very small New World monkey found in the northwestern Amazon rainforest in Brazil, Colombia, Ecuador, and Peru. It was formerly regarded as conspecific with the similar eastern pygmy marmoset, which has whitish underparts. Although the western pygmy marmoset occurs further west than the eastern pygmy marmoset, the primary separators of their ranges are the Amazon River (Solimões River) and Marañón River, with the western occurring to the north of them and the eastern to the south.
The western pygmy marmoset is the world's smallest monkey. Pygmy marmosets have only a slight degree of sexual dimorphism; in the wild the average male weighs 110 g (3.9 oz), which is slightly smaller than the average female at 122 g (4.3 oz). Fully grown western pygmy marmosets have an average body length of 13 cm (5.1 in), and a tail marked with black rings that is on average longer than their bodies at 20 cm (7.9 in). They have fluffy "brownish-gold fur with black ticking on their shoulders, backs, and heads, while their ventral fur is light yellow to white". There are very little visible physical differences... Wikipedia →
Call0:20
Colombia · 1987
© Frank Lambert · XC1031607 · CC BY-NC-ND 4.0
Territorial call0:11
Brazil · 2008
© Dante Buzzetti · XC959862 · CC BY-NC-SA 4.0
Recording0:07
Colombia · 2024
© Moses J. Michelsohn · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Yasuní National Park | 🇪🇨 Ecuador | |
| 2 | Amacayacu National Natural Park | 🇨🇴 Colombia | |
| 3 | Cuyabeno Wildlife Reserve | 🇪🇨 Ecuador |
Possible
About 30% of wildlife watchers report a Western Pygmy Marmoset sighting in Yasuní National Park on a given day, based on 81 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 9th most-seen of the 33 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.
November
In that month about 50% of wildlife watchers report a Western Pygmy Marmoset in Yasuní National Park on a given day, against about 10% in May, the lowest month.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Western Pygmy Marmoset 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 parks where we can rate Western Pygmy Marmoset sightings, Yasuní National Park has the highest daily chance: about 30%. Next come Amacayacu National Natural Park (Colombia, about 30%) and Cuyabeno Wildlife Reserve (Ecuador, about 10%).
Same family: Callitrichidae
The closest relatives of the Western Pygmy Marmoset that you can see in Yasuní National Park (family Callitrichidae, Marmosets and Tamarins) are Golden-mantled Tamarin (about 30%) and Black-mantled Tamarin (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Pygmy Marmoset is recorded against all the mammals logged in Yasuní National Park (81 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.
