Syrigma sibilatrix
Silhouette: Sheatherius · PhyloPic
In 3 days ~30% in a week ~50%
The whistling heron (Syrigma sibilatrix) is a medium-sized, often terrestrial heron of South America. It is the only species placed in the genus Syrigma. A molecular phylogenetic study published in 2023 found that within the heron family the whistling heron is most closely related to the capped heron (Pilherodius pileatus).
The whistling heron measures 53 to 64 cm in length and weighs 521 to 546 g. The southern subspecies is bigger but has a shorter bill in proportion to the body. The overall impression of standing birds is gray, with flying birds showing conspicuous white rear parts (lower back, belly, and tail). In both subspecies, adults' upperparts except the lower back are blue-gray. The feathers of the sides of head, sides of the neck, breast, and scapular area are basically white but are stained gold to buff, perhaps by the powder down typical of herons... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Emas National Park | 🇧🇷 Brazil | |
| 2 | Iberá National Park | 🇦🇷 Argentina | |
| 3 | Sierra de la Macarena National Park | 🇨🇴 Colombia | |
| 4 | El Palmar National Park | 🇦🇷 Argentina | |
| 5 | El Impenetrable National Park | 🇦🇷 Argentina | |
| 6 | Parque Estadual Encontro das Águas | 🇧🇷 Brazil | |
| 7 | Serra da Canastra National Park | 🇧🇷 Brazil | |
| 8 | Henri Pittier National Park | 🇻🇪 Venezuela | |
| 9 | Chingaza National Natural Park | 🇨🇴 Colombia | |
| 10 | Iguaçu National Park | 🇧🇷 Brazil | |
| 11 | Iguazú National Park | 🇦🇷 Argentina | |
| 12 | Serra dos Órgãos National Park | 🇧🇷 Brazil | |
| 13 | Chapada dos Guimarães National Park | 🇧🇷 Brazil | |
| 14 | Itatiaia National Park | 🇧🇷 Brazil | |
| 15 | Tijuca National Park | 🇧🇷 Brazil | |
| 16 | Yasuní National Park | 🇪🇨 Ecuador |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Santa Cruz de la Sierra | 🇧🇴 Bolivia | |
| 2 | Campo Grande | 🇧🇷 Brazil | |
| 3 | Asuncion | 🇵🇾 Paraguay | |
| 4 | Rosario | 🇦🇷 Argentina | |
| 5 | Porto Alegre | 🇧🇷 Brazil | |
| 6 | Caracas | 🇻🇪 Venezuela | |
| 7 | Buenos Aires | 🇦🇷 Argentina | |
| 8 | Curitiba | 🇧🇷 Brazil | |
| 9 | Cordoba | 🇦🇷 Argentina | |
| 10 | Goiânia | 🇧🇷 Brazil |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Parque das Aves | 🇧🇷 Brazil | |
| 2 | Temaikén | 🇦🇷 Argentina | |
| 3 | GüiráOga | 🇦🇷 Argentina |
With luck
About 10% of wildlife watchers report a Whistling Heron sighting in El Impenetrable National Park on a given day, based on 29 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 139th most-seen of the 219 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
November
In that month about 30% of wildlife watchers report a Whistling Heron in El Impenetrable National Park on a given day, against under 5% in February, May and July, the lowest months. That is one of El Impenetrable National Park's wettest months, with about 120 mm of rain against 25 mm in July. December has too few records to rate.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Whistling Heron sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
5th of 16
Of the 16 parks where we can rate Whistling Heron sightings, El Impenetrable National Park ranks 5th at about 10%. The best odds are in Emas National Park (Brazil, about 50%), Iberá National Park (Argentina, about 40%) and Sierra de la Macarena National Park (Colombia, about 30%). All parks ranked.
Same family: Ardeidae
The closest relatives of the Whistling Heron that you can see in El Impenetrable National Park (family Ardeidae, Herons, Egrets, and Bitterns) are Cocoi Heron (about 30%), Rufescent Tiger Heron (about 30%) and Great Egret (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Whistling Heron is recorded against all the birds logged in El Impenetrable National Park (29 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.
