Pantanal Escapes

Cocoi Heron

Known locally as Maguari or Garça-moura, the Cocoi Heron is the largest heron species in Brazil - reaching up to 1.25m tall. It' every easy to recognise thanks to its grey-black on white colouration, and distinctive black cap. When seen in flight it has large grey wings.
it is widely distributed. It is generally solitary, although groups can be observed gathered around shallow pools in the dry season. it feeds on fish, frogs and aquatic insects.

They capture their prey by remaining motionless until stabbing their prey with their sharply pointed beak.



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The cocoi heron (Ardea cocoi) is a species of heron in the family Ardeidae. It is common and widespread throughout most of South America including Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela. It is a non-breeding visitor to Trinidad and Tobago and a vagrant to the Falkland Islands and Tristan da Cunha. Its natural habitats are rivers, swamps, and freshwater lakes.

Description
A large heron, the cocoi can measure 95–127 cm (37–50 in) in length, stand up to 100–130 cm (39–51 in) in height and weigh 1.14–3.2 kg (2.5–7.1 lb).[2][3] Its markings are not dissimilar to a grey heron's, but it is darker with a longer neck and crest. It has a bright orange beak and dull orange legs, and whilst perched holds its neck in an S shape characteristic of all herons. In flight, it is slow and graceful but appears scrawny due to its neck and large wings. The cocoi heron is extremely similar to its North American and European counterparts, the great blue heron and grey heron, with which the cocoi heron forms a superspecies.

Emblematic of the wetlands of South America, where it is the largest heron species (3) (4), the cocoi heron is a distinctive waterbird with an all-black cap, a white neck, white plumes on the breast, a grey back and wings, and white thighs. The lower underparts are black, a few black streaks may run along the midline of the foreneck, and black ‘shoulder’ patches show on the wings when the bird is standing (3) (4) (5) (6) (7). During the breeding season, the cocoi heron has long, black plumes on the cap, tipped with white, a bright yellow beak with a reddish base, and dusky pink legs (3) (6) (7). The eyes are yellow and the facial skin is greenish to blue (3) (5). Outside of the breeding season, the beak is a duller yellow, with a blackish base, and the legs are blackish (3). The male and female cocoi heron are similar in appearance, whereas immature cocoi herons are greyer, and have a duller but still distinctive dark cap, which lacks plumes (2) (3) (5).

The cocoi heron is similar in appearance to the closely related great blue heron (Ardea herodias), but is much whiter, and can also be distinguished by the completely black cap, the white rather than grey neck, and white rather than chestnut thighs and wing edges (2) (3) (5) (6) (7). Southern cocoi herons are reported to be larger than those in the north, and there is also likely to be further geographical variation that has not yet been described (3).

Also known aswhite-necked heron. SizeLength: 95 - 127 cm (2) (3)Weight1.9 - 1.98 kg

Cocoi heron biology

The cocoi heron feeds in the manner typical of large herons, mainly by standing or walking slowly in shallow water as it hunts for prey. Feeding may take place by day or by night, and the diet consists primarily of large fish, although frogs, aquatic insects and even carrion may also be taken (2) (3) (4). Although generally a solitary species, the cocoi heron may sometimes join large, mixed-species groups to feed, particularly during the dry season, and may even steal prey from other species at these times (2) (3).

The breeding season of the cocoi heron varies with location, starting around July in Surinam, October in Uruguay, and August to November in southeast Brazil and Argentina (2) (3). The cocoi heron may nest alone or in colonies, which are sometimes large and may include other species (2) (3) (6). The nest is large and deep, built from twigs and reeds and lined with grass, and is usually located in trees, bushes or reedbeds. Up to four eggs may be laid, which are light blue in colour, with paler speckles. The eggs are incubated for around 24 to 26 days (2) (3).

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Cocoi heron range

The cocoi heron has a widespread distribution, being found over most of South America, excluding the high Andes. It has been recorded from eastern Panama, south to southern Chile and Chubut, Argentina, and is also an occasional visitor to Trinidad, Tobago and the Falkland Islands (2) (3) (4) (5) (8). This species is likely to be resident in most of its range, although birds in the extreme south probably move northwards during winter, and individuals may disperse to other areas after breeding (2) (3) (4).

Cuiabá cityscape, with the Metropolitan Catedral in the foreground. Credit: Shutterstock/Roberto Tetsuo Okamura

Scientific Name

Ardea cocoi

Local Name

Maguari or
Garça-moura

Description
 
 
 

Very striking heron, with distinctive multi-coloured plumage. It has a dark green back, a chestnut brown underside and neck. The neck has a long stripe running down the middle, at the front, bordered by sometimes sickle-like silvery-blue plumes. The Agami Heron stands about 60-76 cm tall, with a very neck (even in comparison with other hero species) when extended.
 


The diversity is also due to the wide range of environments and landscapes occurring within the Pantanal itself. Rather than being a ubiquitous wetland, it also contains large rivers, grasslands, dry forest, and high stony hills and outcrops. Although there is some competition between species, many also survive in parallel by exploiting different foods and different niches.

tv_icon Video: Cocoi Heron in the Pantanal
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Tuiuiu or Jabiri Stork in the Pantanal, Brazil
Amazon kingfisher in the Pantanal, Brazil
Turkey Vulture in flight over the Pantanal, Brazil
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Banner image: Cocoi heron flying over river in Barão de Melgaço (Shutterstock/Roberto Tetsuo Okamura)
Cocoi heron (
Wikimedia Commons/Fernando Flores); Footer images: Tuiuiú, Turkey Vulture(Andrew Mercer); Amazon Kingfisher (Shutterstock/Ecoventurestravel)