Serpophaga griseicapilla
Silhouette: Emily Willoughby · PhyloPic
In 3 days <5% in a week ~10%
Straneck's tyrannulet (Serpophaga griseicapilla), also known as the monte tyrannulet and grey-crowned tyrannulet, is a small species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.
Straneck's tyrannulet has a confusing taxonomic history. It had been known since the 1990s by the binomial Serpophaga griseiceps, which had previously been assigned to specimens that were later recognized as immatures of what was then the white-bellied tyrannulet (Serpophaga munda) and so was invalid. Roberto Straneck formally described the species and assigned its current binomial in 2007. It was later given its English name in his honor.
Straneck's tyrannulet is monotypic. Straneck's tyrannulet is 9 to 11 cm (3.5 to 4.3 in) long and weighs 4.4 to 7.5 g (0.16 to 0.26 oz). The sexes have the same plumage. Adults have a gray crown and nape with a hidden bit of white on some black central crown feathers. They have a thin white supercilium, a white crescent under the eye, and a dark gray line through the eye on an otherwise grayish white face. Their upperparts are olivaceous brown. Their... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | El Impenetrable National Park | 🇦🇷 Argentina | |
| 2 | El Palmar National Park | 🇦🇷 Argentina | |
| 3 | Península Valdés | 🇦🇷 Argentina | |
| 4 | Amboró National Park | 🇧🇴 Bolivia | |
| 5 | Iberá National Park | 🇦🇷 Argentina |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Rosario | 🇦🇷 Argentina | |
| 2 | Cordoba | 🇦🇷 Argentina | |
| 3 | Buenos Aires | 🇦🇷 Argentina | |
| 4 | Santa Cruz de la Sierra | 🇧🇴 Bolivia | |
| 5 | Asuncion | 🇵🇾 Paraguay | |
| 6 | Montevideo | 🇺🇾 Uruguay |
Rare
Under 5% of wildlife watchers report a Straneck's Tyrannulet sighting in Península Valdés on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 92nd most-seen of the 96 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
January
In that month about 10% of wildlife watchers report a Straneck's Tyrannulet in Península Valdés on a given day, against under 5% in February–May and August–December, the lowest months. June and July have too few records to rate.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Straneck's Tyrannulet sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 5
Of the 5 parks where we can rate Straneck's Tyrannulet sightings, Península Valdés ranks 3rd at under 5%. The best odds are in El Impenetrable National Park (Argentina, about 30%) and El Palmar National Park (Argentina, under 5%).
Same family: Tyrannidae
The closest relatives of the Straneck's Tyrannulet that you can see in Península Valdés (family Tyrannidae, Tyrant Flycatchers) are Gray-bellied Shrike-Tyrant (about 20%), Lesser Shrike-Tyrant (about 10%) and Tufted Tit-Tyrant (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Straneck's Tyrannulet is recorded against all the birds logged in Península Valdés (5 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.
