Pileated woodpeckers tend to come and go

Q: For the past several winters I've enjoyed a pair of pileated woodpeckers coming to our suet feeder, but this year I almost never see them. I have other woodpeckers but wonder why the pileateds stopped coming.

A: I wouldn't worry about not seeing those big woodpeckers for some weeks. In my experience pileated woodpeckers are roamers, here one week and gone the next. They probably found other sources of food that satisfies them for a time, but I'll bet they'll be back soon.

Q: I've been using snap traps in the garage and placing mouse carcasses out back. These always disappear but it was a mystery to me about what took them, until today: I watched as a pair of crows flew into a nearby tree, then flew down and each took a mouse. One crow stayed on the ground and ate there, while the other flew off with its catch. I hadn't known crows would do this.

A: I'll bet those crows were very happy to discover the results of your trapping program. Crows will eat just about anything, and freshly killed mice are a step up from frequent roadkill meals. This is a great example of what a good recycler Mother Nature is.

Q: Large numbers of cardinals show up around my feeders on a fairly regular basis — sometimes there'll be as many as 15 birds out back. I hadn't seen this before and wonder if it's common.

A: Yes, it's not unusual for cardinals to gather in numbers at feeders during the winter. Other readers report as many as 24, even 36 cardinals foraging under bird feeders just before dark.

At this time of year the birds feel no need to defend territories, so the sight of a few red birds brings in others. Since cardinals are able to see even at low light levels, they're often the last birds out there as night falls. Watch for this dynamic to change as spring approaches and hormonal changes make cardinals much more aggressive toward one another as they set up breeding territories.

A: Those hearts, aka chips, are what come out of the black oiler shell, so you're offering a very popular treat. And the fact that there are no shells to crack open makes them even more of a prize to birds. The only downside is that the hull-less hearts may become wet in rain or snow, and may need to be replaced after storms.

Q: We fed cracked corn to about 15 mallards all summer in our backyard, and they're continuing to come in the winter. Did we make them miss migration by providing the food?

A: You didn't prevent those mallards from leaving because they probably weren't going to migrate at all. Quite a few mallards remain in the metro area all year long, spending their time wherever they can find open water. So you're probably feeding a resident flock of ducks.

Q: I began hearing robins singing in late December, and this seems awfully early. Is this unusual?

A: Good question, and I've been noticing the same phenomenon, with some robins in my backyard gently "whispering" their springtime song in December and January. The experts say that birds begin to sing their courtship songs based on day length and temperature, hormone levels and interactions with others of their species. But late December does seem early, so I asked Duluth bird expert Laura Erickson for her views, and she replied: "I've received so many questions about this over the years, and I know that robins occasionally break into song, even in the dead of winter. They do what feels right at the moment and no one knows what stimulates spontaneous song in winter. It would be wonderful if someone initiated a citizen science project asking people to record whenever they hear a robin song in winter. Nothing like this has been done before and it could shed light on what's happening."