Here's a good site I found that tracks the oriole migration. If you look at the 'first oriole sighting' map for previous years you'll see they arrive in the Iowa to Detroit corridor either in the last week of April or first week of May. I was going to put out orange halves in mid-April, but that looks pointless given these migration maps. Here is a link that might be useful: Oriole migration tracker

Susan, you may be right that the adult is a male, not a female. Stereotypes die hard, and I'd read that the female can look very similar to the male, so I assumed this bird was the mother. I just checked the Cornell All About Birds Guide, and I looked at some of the other photos I took at the same time. According to the Cornell Lab of Ornithology, the female can look similar to the male, but with two white wingbars. "Female Description Variable in appearance. May be similar to male, but head more dark brownish olive than black, and body paler orange. Usually face, throat, and underparts orange. Tail brownish olive, without black. White in shoulder gives it two white wingbars." In these two photos, the second wingbar (shoulder) looks orange, not white, and the tail seems to have black in it. I wonder if the female is also around. Claire

Folks if you like orioles, enjoy gardening and have the space I have a truly cool tip: plant a grape arbor. I live in Boston near downtown and have always enjoyed gardening. Living in the city, seeing orioles was a rare treat... but not any more. Three years ago I planted a concord grape and trained it up to cover our 2nd story deck. The number of birds attracted has risen exponentially of these three years. Seeing ten orioles at a time is now pretty common. Also attracted are cardinals, jays, and catbirds. There are so many birds out there right now that there probably won't be enough grapes to make jam once they fully ripen. Do I mind, not at all

orioles usually return to the area they were born in. they winter in old mexico and central america and some in florida and the islands. just guessing that they would be returning again in mid to late April to your area either to nest or to fill up before they migrate further north. they are probably eating at your place to fill up before they head further south. the ones i get here eat the jelly and necter best but some really get after oranges or orange juice and a couple like watermelon or diced fruit pieces.