RED-WINGED BLACKBIRD (Agelaius phoeniceus) – (See images below)
DESCRIPTION: The Red-winged Blackbird breeding adult male is entirely black except for a red patch on the shoulder, edged in yellow. The bill, eyes and legs also are black. In non-breeding plumage the patches is faint and the black plumage is lightly mottled. The female is brown with a beige bar above the eye, a beige face and neck. It has brown streaks on beige under parts. The bill is brown and the legs are grey. Juveniles are similar to the female. The male is around 23 cm (9 inches) long, and the female is slightly smaller. There are many subspecies.
VOICE: – and its typical spring call is a familiar sound
NAME: The Red-winged blackbird is thus called because of its red (and yellow) ‘epaulets’ on the wing shoulder. The Latin genus name ‘Agelaius’ is from Greek and means ‘flocking’. The Latin species name ‘phoeniceus’ means ‘red’.
HABITAT: Either saltwater or freshwater wetlands, rice paddies in the summer; in addition, agricultural fields, meadows and other open areas near water in the winter.
DIET: Omnivorous – mainly insects in the summer, mainly seeds and grain in the winter.
NESTING:  The nest is built near or on the water, amid dense vegetation. Around three light green eggs are laid, which are incubated by the female. Both parents feed the chicks. This bird is very protective of its nest. It will attack potential predators, including humans, who come too close to it.
DISTRIBUTION: The breeding range of the red-winged blackbird covers most of Canada up to the tree line, and the USA region around the Great Lakes. It is a year-round resident in most of the USA and parts of Mexico. There is a wintering group in the western part of Mexico.
Distribution map:
ON PEI: The red-winged blackbird is very common on Prince Edward Island on all seasons except winter, when it is uncommon.
CONSERVATION: The population of this species has declined over the last few decades, but it is still around 130 million. It is not considered at risk.
NOTES: In the fall it associates with other black birds such as Common Grackles and Brown-headed Cowbirds, and turn into an agricultural pest as those flocks can have millions of birds.
SIMILAR SPECIES: Rusty Blackbird, European Starling, Common Grackle, Brown-headed Cowbird
REFERENCES: (Maritimes Breeding Bird Atlas)

Red-winged blackbird at Elizabeth Park, Hartford, CT. It is a juvenile because the shoulder has no red plumage yet, only yellow and orange - by Denise Motard
Red-winged blackbird male juvenile, CT

This video shows the same male juvenile: