Pinnated Bittern

How to find it

Search reed beds in northern lowland wetlands, since the bird hides in dense marsh vegetation. Medio Queso is one of the few places in Costa Rica where birders can reliably see it. Boat tours there are the usual approach, and some visits also bird from the road. Aim for early morning, from dawn to about 8 AM, or for dusk. The road from Los Chiles to Medio Queso is described as productive for hard-to-see birds. Scan marsh areas with short grass for pale spots, then check them through binoculars.

How to recognise it

This is a large heron, about 64 to 76 cm long, with buffy-brown plumage in a camouflage pattern. Males are heavier than females. These marks describe the species across its whole range.

Look for these features:

Throat and middle of the underparts: white.

Foreneck and breast: broad pale brown streaks.

Facial skin: bright yellow.

Bill: horn-colored.

Legs: greenish.

At Medio Queso, birders describe it as the larger, paler, straw-colored bittern. In short-grass marsh areas the birds looked like odd pale spots that turned into straw-colored, striped herons through binoculars. One photo record describes a bird moving stealthily through reeds and being very well camouflaged.

What it sounds like

Recording: Pablo H Capovilla, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

The Pinnated Bittern is mostly nocturnal and solitary. It stays hidden in thick reeds, sometimes with only the raised neck, head and long bill visible. It eats fish, frogs and rodents, and other sources add reptiles and arthropods, all caught after long, patient waiting.

In Costa Rica, one tour report called the birds sneaky, and another noted that two birds sat in view while trying to blend in. Stillness is its main strategy, so patience helps you as much as it helps the bird.

Where it lives

In Costa Rica this is mainly a northern lowland wetland bird. One Costa Rica site says it is seen from sea level up to about 600 meters, but it is mostly a lowland bird and usually stays in dense marshes and reed beds. A photo record places one at Medio Queso, Alajuela, at 44 meters elevation.

Across its range it uses freshwater marshes, lake edges with cattails and tall sedges, and flooded pastures with tall grass. Breeding-range localities listed for Costa Rica include Río Frío, Guanacaste and Turrialba.

When to see it

Costa Rican nesting has been recorded in July, and birds have also been recorded in the non-breeding season, which suggests they live in the country year-round. For Medio Queso, about February to the end of April, depending on water level, is named as a time to look, and it is said to be easier there than at another site.

Similar birds

The American Bittern is a rare visitor to Costa Rica, a casual migrant with very few records, including Medio Queso, a wetland in Paraíso de Cartago and Coto 47. It differs from the Pinnated Bittern by a black stripe on the side of the throat (malar) and an unbarred neck. The Least Bittern is much smaller and shares the same Medio Queso marshes.

Names and lore in Costa Rica

The official Spanish name is Avetoro Neotropical, and the AOCR list also gives the common Costa Rican names Puncus and Mirasol. Other Spanish names used for the species include Mirasol Grande, Mirasol Pinado and Mirasol Neotropical. The second part of the scientific name means feathered or winged in Latin.

Status and conservation

The AOCR list classes the Pinnated Bittern as a resident (R), and the IUCN rates it Least Concern because of its wide range.

Photography tips

Dawn to 8 AM and dusk are the best viewing times. At Medio Queso the bitterns were easy to find in marsh areas with short grass, looking like odd pale spots before turning into straw-colored, striped herons through binoculars. A birding writer says it is tough to find unless you bird at dawn or late afternoon.