In the Jardins do Palácio de Cristal, Oporto, Portugal.
Brief description of what you observed
The Muscovy Duck (Cairina moschata) is a large duck native to Mexico, Central, and South America. Small wild and feral breeding populations have established themselves in the United States, particularly in the lower Rio Grande Valley of Texas, as well as in many other parts of North America, including southern Canada. Feral Muscovy Ducks are found in New Zealand and have also been reported in parts of Europe.