Many of us think of May 1 as oriole day, as it's quite often the first day the birds are seen in southern Minnesota. Baltimore orioles winter in Costa Rica and other parts of Central America, are night migrants and arrive in numbers the first two weeks of May. They have a strong homing instinct and often return year after year to nest in the same yard and even the same tree. The female will build a sock-like nest at the outermost branch of a tall tree. Other common back-yard birds returning around May 1 are the house wren, the ruby-throated hummingbird and the rose-breasted grosbeak.

A fantastic songster, the Baltimore oriole has a cheerful series of whistles and chattering that is often heard before it's seen. The orioles are easily attracted to feeders offering grape jelly, orange halves or sugar water. Mix the jelly half and half with water using an eggbeater, then pour it into glass jars in the feeders. These orioles are summer residents throughout the state. They feed on insects but also eat wild fruits and may probe flowers for nectar.

Flame-orange below and largely black above, the male is very conspicuous as it searches for food. These colors caught the attention of early European settlers in Maryland, who named the bird in honor of George Calvert, Lord Baltimore, an early colonizer there; orange and black were his family colors. Females are a paler orange-yellow and gray-brown.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.