could arguably be advantageous because this stork breeds during the winter in the part of its range in the southern hemisphere, so that the chicks can be exposed to low environmental temperatures. However, Thomas regards the anti-predator explanation for the dark plumage to be more plausible. Vocalisations Adults utter wheezing, hissing, disyllabic whistles during up-down greeting displays at the nests about every 1–1.5 seconds. These whistles are slower and lower pitched than the corresponding vocalisations of other Ciconia, but sound similar to those of the Abdim's stork and the woolly-necked stork. The quality of these vocalisations is probably linked with the maguari stork's ground nesting habits and may be an adaptation to minimise attraction of predators’ attention. Young make begging calls that have been described as Ehehe-ehehe. Distribution and habitat The maguari stork has a relatively wide distribution over much of South America, and occurs primarily to the east of the Andes. It lives in the Llanos of Venezuela and eastern Colombia; Guyana; eastern Bolivia; Paraguay; Brazil, but rarely in the Amazon and the north-east,); Uruguay and Argentina. The most southerly part of the range lies in the Chubut province. It more rarely occurs to the west of the Andes (e.g. in Chile) and probably does not breed there. It is a rare visitor to the Suriname coast from March until May and also been reported as a vagrant on Trinidad and Tobago. It is especially common and widespread in the Chaco of Argentina, which appears to be a popular destination for flocks of about 30-40 migrant individuals from the southern hemisphere part of the range that come from the south in winter to seek warmer temperatures. The stork is also common in Brazil, especially in the state Rio Grande do Sul, Paraguay and the Pampas of Argentina. It occurs seasonally and is common in the Pantanal of Argentina. Large numbers migrate to the Pantanal in the wet season, probably from the Parana Basin and Rio Grand do Sul. However, overall migration patterns for this species across its range have thus far not been determined exactly. Its habitat largely comprises open lowland and shallow-water wetland such as tropical wet savannah grasslands, marshes, mudflats, and flooded fields. It more occasionally frequents dry fields, but invariably avoids forested regions. Numerous maguari stork assemblages have been observed in their habitat during the dry season, where they forage in low-level bodies of water where