Syrigma sibilatrix
Silhouette: Sheatherius · PhyloPic
In 3 days ~80% in a week >90%
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 |
Likely
About 40% of wildlife watchers report a Whistling Heron sighting in Iberá National Park on a given day, based on 676 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 49th most-seen of the 284 birds we can rate there. Over three days the chance rises to about 80%, and over a week to over 90%, if each day is a fresh chance.
September
In that month about 50% of wildlife watchers report a Whistling Heron in Iberá National Park on a given day, against about 30% in March, the lowest month.
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.
2nd of 16
Of the 16 parks where we can rate Whistling Heron sightings, Iberá National Park ranks 2nd at about 40%. The best odds are in Emas National Park (Brazil, about 50%). All parks ranked.
Same family: Ardeidae
The closest relatives of the Whistling Heron that you can see in Iberá National Park (family Ardeidae, Herons, Egrets, and Bitterns) are Great Egret (about 60%), Cocoi Heron (about 50%) and Snowy Egret (about 50%), 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 Iberá National Park (676 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.
