Thamnophilus cryptoleucus
Silhouette: Sheatherius · PhyloPic
In 3 days ~20% in a week ~40%
Castelnau's antshrike (Thamnophilus cryptoleucus) is a species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is found in Brazil, Colombia, Ecuador, and Peru. Castelnau's antshrike was originally described as Myrmelastes cryptoleucus. By the principle of priority, Myrmelastes is junior to Myrmeciza. In 1924 it was transferred to that genus and then in 1927 to its current Thamnophilus. Later some authors treated Castelnau's antshrike as a subspecies of the blackish-grey antshrike (T. nigrocinereus), but that approach was not widely accepted. They are now considered sister species. Castelnau's antshrike is monotypic.
Castelnau's antshrike is 16 to 18 cm (6.3 to 7.1 in) long and weighs 30 to 35 g (1.1 to 1.2 oz). Members of genus Thamnophilus are largish members of the antbird family; all have stout bills with a hook like those of true shrikes. This species exhibits slight sexual dimorphism. Adult males are mostly black. They have a mostly hidden white patch between their scapulars, white tips on the scapulars, white tips and edges on their wing coverts, sometimes very small white tips on their flight... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Amacayacu National Natural Park | 🇨🇴 Colombia | |
| 2 | Yasuní National Park | 🇪🇨 Ecuador | |
| 3 | Cuyabeno Wildlife Reserve | 🇪🇨 Ecuador |
With luck
About 10% of wildlife watchers report a Castelnau's Antshrike sighting in Amacayacu National Natural Park on a given day, based on 52 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 191st most-seen of the 436 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
August
In that month about 30% of wildlife watchers report a Castelnau's Antshrike in Amacayacu National Natural Park on a given day, against under 5% in January–February, April–May and October, the lowest months. That is one of Amacayacu National Natural Park's driest months, with about 160 mm of rain against 390 mm in March.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Castelnau's Antshrike sightings with a recorded time, and about 8 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 Castelnau's Antshrike sightings, Amacayacu National Natural Park has the highest daily chance: about 10%. Next come Yasuní National Park (Ecuador, under 5%) and Cuyabeno Wildlife Reserve (Ecuador, under 5%).
Same genus: Thamnophilus
The closest relatives of the Castelnau's Antshrike that you can see in Amacayacu National Natural Park (genus Thamnophilus, Typical Antshrikes) are Barred Antshrike (about 20%), Mouse-colored Antshrike (about 20%) and Amazonian Antshrike (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Castelnau's Antshrike is recorded against all the birds logged in Amacayacu National Natural Park (52 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.
