Want to figure out what Minnesota's next state bird could be?

Two unusual sculptures at the Commons Park in downtown Minneapolis offer a guide on the possibilities as rising temperatures alter the state's climate.

How about the little blue heron? It doesn't live here now, but the art installations — a deft combination of data and design — point out that in 80 years it's likely to become a prevalent species.

But the loon — Minnesota's beloved state bird with its haunting cry — will move out of the state as the climate gets warmer and its ecosystems shift to the north.

Named Orbacles — orb for their round shapes and oracle for their predictions — the towers illustrate a tangible outcome of climate change and the way Minnesota's identity could change, said the designers.

"Birds are a lens on climate," said Marc Swackhamer, head of the University of Minnesota School of Architecture and member of the MINN_LAB design collective that conceived and built the project for a contest sponsored by the city of Minneapolis. "We [used] changes in the bird populations to make climate change more understandable."

The idea, he said, was also inspired by the bird controversy at U.S. Bank Stadium, which looms over the sculptures on the east side the park. The Minnesota Sports Facilities Authority and the Vikings are spending $300,000 to determine if the stadium's massive glass walls are fatally invisible to some of the millions of birds that use the nearby Mississippi River as a migratory flyway. It's evident, Swackhamer said, that a lot of people care about birds.

Their fate also fit into the theme of the June 10 Northern Spark festival — "Climate Chaos/People Rising." The Orbacles installation, funded by $50,000 from the city and a $60,000 grant from the University of Minnesota, was first in the chain of artwork set up along the Green Line light-rail stops.

Swackhamer said it worked, at least on the night of the festival. People paused to study the towers and tracked what will happen to their favorite species. And then they talked about it.

"People like to share what they know about birds," he said.

The sculpture works like this: Each tower represents 147 species of birds that are common in the eastern United States and identified in the U.S. Forest Service Climate Change Bird Atlas, which predicts changes in bird populations as a result of changing forests. Dozens of small wooden boxes with small metal hoods encircle each tower like a layer of feathers — each hood signifying one kind of bird, its size equivalent to the size of the bird.

The gray and white tower on the south side represents the species as they are today. The number on each hood reflects how common the species is. Loons, for example, get a score of 27.38 out of 100. European starlings get a score of 90.3.

The northern tower, vivid in orange, yellow and blue, depicts what will happen to each of the 147 species in 80 years if carbon emissions around the globe continue at current rates — the "business as usual" scenario.

Loons drop to 3.04, meaning they will essentially disappear. Northern cardinals jump from 19.44 to 62.85, and the purple finch, that ever so frequent visitor of backyard bird feeders, drops from to 26.4 to 3.4.

There will be some new residents, including the painted bunting and the little blue heron, and some, including the green heron, will increase in number.

A third tower, which has not yet been built due to a lack of funding, would tell the story of bird species if the world succeeds in reducing carbon emissions.

The designers are still working on getting that done before July 31, when the sculptures will be taken down.

Because, like Minnesota's loons, they too will need a new home.

Josephine Marcotty • 612-673-7394