Q: Would it be unusual for swans to have nested right here in Roseville? I thought I saw a swan family on the small lake along Larpenteur Avenue between Rice and Dale streets in early August.

A: I was surprised to learn that swans appear to be nesting in such an urbanized spot, so I contacted several local swan experts for their views. According to David Wolfson, a University of Minnesota doctoral researcher with the Interior Population Trumpeter Swan project, many trumpeter swans nested in the metro area this year.

"While swans seem to avoid lakes and wetlands that have a lot of boating and fishing disturbance, they seem much less picky about people being in the general area," Wolfson noted. Young swans don't gain flight ability until September, so we know the Roseville swan family was on or near its nesting lake.

And Carrol Henderson, who until he retired headed up the DNR's Nongame Wildlife Program, noted that the statewide swan population now numbers around 25,000 to 30,000 trumpeter swans. The fact that swans are raising their cygnets in a suburb "says a lot about the value of preserving wetlands in the metro area," he added.

And it says a lot about the restoration efforts headed up by Henderson at Nongame and staffers at Three Rivers Park District, among others, because about 50 years ago there were no wild trumpeter swans in the state at all.

Is stadium safer?

Q: I contacted you in 2016 about U.S. Bank Stadium and bird casualties from running into the building's glass. Now that we're five years into the stadium's life and about to start the 10th migration season, I'm wondering how things are going with bird mortality.

A: Good, timely question. I contacted Jerry Bahls, with the Audubon Chapter of Minneapolis, which has been pressing for change at the stadium for some years, and he indicated that the ball is in the Minnesota Sports Facilities Authority's court.

A consultant hired by the authority and the Minnesota Vikings studied the issue of bird deaths at the stadium and reported back in November 2019, with three key findings that could benefit birds: reduce night lighting for night-migrating birds, avoid vegetation near glass walls and then the big one — reduce the expanse of untreated glass.

The minutes for the authority's board meeting last Nov. 15 indicate that the authority had already taken some steps to reduce night lighting and was working with landscaping experts to scale back the trees and shrubs. When asked about plans to reduce the area of untreated glass, an authority spokesperson sent a statement drafted for November 2019: "As it relates to glass treatment, we need to better understand the effectiveness of the various applications and the impact such treatment would have on the stadium's architectural integrity and aesthetics."

My conclusion: Birds migrating through downtown Minneapolis this fall will benefit from the COVID-19 restrictions on crowded events, which should mean less confusing night lighting, but will still have to rely on some luck to avoid the stadium's lethal walls of glass.

Crane sounds

Q: Is there an internet site where you can name a bird and then hear its call? I've looked at the Cornell Lab site but am not finding recordings of the sounds of sandhill cranes.

A: There surely is such a site and the Cornell Lab of Ornithology maintains it, but it's maybe not the one you found. Try their All About Birds site (allaboutbirds.org), type in the name of the bird you're interested in, then click on the icon for "Sounds."

A gang of herons

Q: At our cabin in north central Minnesota in early August we noticed a group of at least 16 great blue herons flying around and perching in trees near each other. Since we're more accustomed to seeing them solo along the lakeshore this was surprising. Since then we haven't seen any herons and wonder: Do they group together for migration?

A: After their breeding season, which would have concluded some weeks before you saw the great blues, herons and egrets often gather in large numbers as they feed and prepare for migration. I often see their smaller cousin, the green heron, in groups of five to 10 birds in early to mid-August, and another reader recently sent photos of 50 or more great egrets searching a Mississippi River backwater for frogs and fish.

The other nuthatch

Q: I was excited to see a red-breasted nuthatch at my seed feeder today, because I so seldom see them and never in late summer. Was it migrating or are they more common than I think?

A: Red-breasted nuthatches are always fun to spot, and the fact that one visited your feeders in early August just might be a sign that we'll see many of these small birds this fall and winter. They're northern birds that rely on cone seeds and move south some years when food is scarce. The last time this happened in great numbers was in 2018, so keep your fingers crossed.

Warblers in the birdbath

Q: Two birds I hadn't seen before were using our backyard pond and stream for bathing this spring and summer. I looked them up in our bird book and was amazed to learn that they were American redstarts. Are they common in Minnesota?

A: How wonderful to see this handsome warbler — some call it the "little oriole," for its handsome orange and black feathers — in your backyard. Like many other warbler species, redstarts flood into Minnesota in the spring, spreading throughout the state to set up nesting territories. These aren't rare birds, but they're more often found at the edges of woodlands, near water, than in backyards.

Note to readers: Recent items about hummingbird behavior inspired several readers to send in their experiences with these tough little birds. One has seen hummingbirds attempting to drive off migrating bald eagles at Hawk Ridge in Duluth in the fall and has photos of a hummingbird attacking a perched merlin. Another reader has seen a hummingbird buzzing a pygmy owl and a hawk, both in Mexico. Two other readers have observed hummingbirds bathing in shallow pools or streams, indicating that they sometimes do bathe as other birds do.

St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.