A Bohemian waxwing, part of a flock of nearly 400 seen feeding on fruit at a park in Ashland, Wis., according to photographer Ryan Brady, conservation biologist with the Wisconsin Department of Natural Resources office in Ashland. (Ryan Brady photo)

A reader, Ed Laarman of Niagara, Wis., said he opened up a northern pike caught while ice fishing late last month to find … a mystery.

Since he was kind enough to allow me to share, I will:

“On Dec. 26, a friend and I caught a 30-inch northern pike in a lake near Eagle River. When I got it home and cleaned it, I was surprised to find an adult leopard frog in its stomach! I thought many leopard frogs hibernated in the mud at the bottom of lakes and ponds in the winter. Perhaps this pike rooted it out of the mud? Or perhaps the frog was just motionless at the bottom when the pike saw it? The frog’s legs were stretched out, away from the pike’s head, so it looked as if it had tried to swim away when the pike swallowed it.

“In any case, I am curious about how the pike caught the frog! A little research has not provided a clear answer. If you have time, can you or any of your sources give me an answer?”

Glad to — it’s always good to be able to learn something new, and I had no better explanation for how a frog could become a mid-winter meal. So I turned to my main source on amphibians, James Harding, an instructor and herpetology specialist with the Department of Integrative Biology at Michigan State University in East Lansing.

He said Laarman’s guesses were on the right track.

“Very often the frogs (and turtles also) will overwinter on the bottom of the water body, either just sitting on the bottom or lightly buried in a thin layer of silt or muck, or obscured in vegetation,” Harding wrote. “The idea that ‘herps’ hibernate by burrowing deeply in the bottom mud is largely erroneous. Deep mud can become quite oxygen deficient, and thus not where a frog would want to be. Also, hibernating frogs and turtles do move around at times during the winter, and can react to stimuli. Their muscle/motion capabilities are a function of temperature. They do spend much of the winter motionless, probably to save energy and cut down on oxygen needs, but move (slowly) when they have to! I do see turtles moving under the ice quite often, and have seen wood turtles attempting courtship in winter — albeit in slow motion!”

So there you are — this frog was unlucky enough to stir from its winter slumber with a hungry pike nearby that probably made an easy catch of the sluggish amphibian. Thanks for the question.

*****

Right now might be a good time to check fruit trees or shrubs that have berries in the region for at least two none-too-common birds known to visit in the winter.

Bohemian waxwings have turned up to the north and south of Dickinson County, raising the possibility this northern counterpart of the more common cedar waxwing could be in our area as well.

These natives of both Eurasia and North America have more gray on the body than the brownish cedar waxwings, and the vent under the tail is rusty orange rather than pale yellow, along with having a blush of orange on the face framing the black eye mask, according to the Cornell Lab of Ornithology. The colors and jaunty crest make them striking birds well worth seeking out.

Their reliance on a fruit diet means they wander to follow food sources, nesting wherever seems favorable rather than returning to the same territory like many other breeding birds. Cornell suggests that’s behind the name Bohemian, because they “wander like bands of vagabonds across the northern United States and Canada.”

In that, they are like the seed-seeking crossbills, which last year could be found in great numbers in northern Wisconsin, but this year have been all but absent, said Ryan Brady, conservation biologist with the Wisconsin Department of Natural Resources office in Ashland.

He calls this winter’s influx of Bohemian waxwings a good, not great, turnout for the species. But the reports are growing, which might signal the birds are on the move after perhaps depleting the food sources in areas they initially went into, Brady said.

If they do show up in a fruit tree or shrub near you, you’ll probably notice — Bohemian waxwings move in large flocks that can have dozens, even hundreds of birds. They don’t sing but do have a high whistle that can tip off their presence.

The other bird turning up with increasing frequency this winter is the pine grosbeak. Again, Brady advised this has been a decent but not great season for this, one of the largest of the northern finches. The majority of the birds Brady has seen have been mostly gray, with a touch of yellow on the females or raspberry on juvenile males, rather than the full, red mantle of the mature males. A week ago, a flock he estimated had 120 pine grosbeaks contained perhaps 10 to 15 males sporting ruby plumage.

As with the Bohemian waxwings, the pine grosbeaks enjoy the energy boost that dried fruit can offer in the winter but also will seek seeds on box elder and conifers. They even will come to platform feeders on occasion for black oil sunflower seeds.

Those fruit trees might offer a robin or two as well; some robins will tough it out each winter rather than migrate if they have access to food and water. Even rarer visitors that favor fruit could be revealed as well, Brady advised, such as a Townsend’s solitaire — native to western and mountain forests, with gray coloring similar to a mockingbird — or a varied thrush, a West Coast bird that has the look of a robin but the orange on its breast extends up the throat, with rust bars on the wings and an orange eyebrow stripe that extends down the nape of its neck. Both come from the same family as the robin, according to Cornell, though the family resemblance is more pronounced with the varied.

They probably offer the best opportunity to see something new and different among birds this winter until the first early movement of species shifting back north comes in late February, Brady said.

*****

With this extreme cold expected to linger through next week, birds will need more fuel to stay warm. Make sure the feeders are stocked with high-energy food, such as black oil sunflower seeds, suet and peanuts. A reliable water source that won’t freeze up helps as well — heated water bowls for dogs often can be found at stores that stock livestock supplies and can make an easy setup for birds to come and drink.

Cornell notes that birds that might not rely on the food at feeders, such as the waxwings, often need more water in winter to offset the concentrated sugar in the dried fruit they consume.

Betsy Bloom can be reached at 906-774-2772, ext. 40, or bbloom@ironmountaindailynews.com.