Monday, April 25, 2011

Red-breasted Merganser

A female red-breasted merganser was one of the highlights of a quick early-evening trip to the ponds near Superior Drive today. According to Janssen's Birds in Minnesota, the only Minnesota breeding grounds of these diving ducks are along the north shore of Lake Superior -- which (at Grand Marais) is the only place I've seen one before. In the Cowling Arboretum bird list, it has been recorded rarely, and only in spring, and it does not appear at all on the River Bend Nature Center's bird list.

The red-breasted merganser winters further south (along the coasts and close to the Gulf of Mexico) than the other mergansers we see in this area, which helps explain why they would be passing through our area now. The common mergansers (which winter as close as Wisconsin and southern Iowa) started showing up here in late winter, and we started seeing  hooded mergansers (which winter throughout the Gulf states and southeast) more than a month ago.

This bird is distinctive for the white wing-patches and (like other mergansers) its very long, thin bill.

We also saw a spotted sandpiper and a lesser yellowlegs today, and a couple of greater yellowlegs northwest of Northfield on Saturday, so shorebird season is under way. To round out the evening's sightings: a great blue heron flew majestically by; we saw a couple of yellow-rumped warblers; red-winged blackbirds and robins seemed to be everywhere; and blue-winged teals and coots were easy to see on the ponds, as was a beaver muskrat an aquatic mammal of some kind [see comments regarding this change in identification].


Mary S. said...

Your beaver photo may settle a debate we've been having about whether a beaver family is in the ponds this year. I've heard there is one, but all that I've spotted are some VERY large muskrats. The tail on this photo looks more like a beaver. Was the critter pretty large? Beavers can be the size of medium-sized dog, while muskrats are like big rats.

Penelope said...

Mary -- I didn't think this was a beaver until I saw the tail because it wasn't very big -- but your comment has prompted me to look at photos of muskrat tails, and now I think this was a muskrat, and will correct the post to say so. It looks more vertically oriented than a beaver tail, which I remember thinking seemed odd at the time, but that's exactly the description I've found of a muskrat tail. So I think you're right to call me out on this one. However, a few weeks ago we did see something in the same pond that I was certain was a beaver based on its size. It climbed up a heap that looked something like a beaver house in the pond that's between Jefferson and Superior; I no longer see that house in our most recent visits.

Penelope said...

It's hard to tell at a distance, but I would guess this animal was more like cat-size. I have seen some swimming in the water that are much smaller than that, which I have assumed to be muskrats. The Minnesota DNR says muskrats are about 20 inches long, including their 9-inch tails. I think that's consistent with the animal in this photo. But I have seen other things swimming that I'd say were seemed to be no more than about a foot long, total, that would barely be visible if they were out in the middle of the pond instead of at the edge. Possibly these are mink, which the DNR says are present in practically every body of water in the state and are 14-20 inches long including a 5- to 9-inch tail

Billie Jo said...

Another type of merganser! I'm learning so much from your posts. :)

I tend to weigh in on the beaver side of the beaver vs. muskrat debate. We've had problems with pesky muskrats on our shoreline doing some damage to our boat, and their tails, when wet, look very much "rat-like." This tail looks thicker and more beaver-like. Maybe it's a juvenile beaver and that's why it looks smaller?

Penelope said...

Billie Jo - I'm so pleased whenever I hear that others are learning from my blog, or being inspired to notice things they haven't noticed before.

It's very much a learn-as-I-go process for me, since I'm by no means an expert on any of the subjects I write about.

Regarding the muskrat, here is the language from the source I linked to in an earlier comment that convinced me this was a muskrat: "It's the tail that is probably the most noticeable of the 'skrats' evolutionary design. This appendage is sort of a sideways beaver tail - laterally compressed, or thin and tall." That's exactly what I saw here -- the tail was not flat on the water, but stuck up like a rudder, exactly like one of the photos in the piece I linked to. I just assumed anything with a flat tail must be a beaver, but the modest size of this creature and the orientation of its tail have now convinced me it was not a beaver.

Penelope said...

Okay, maybe it was a beaver. The size range for beavers is very large. Per the Minnesota DNR:

Length: May attain a length of five feet; 35 to 40 inches is typical.

Weight: Weighs as much as 90 pounds; 40 to 50 pounds is average.

In comparison, the DNR describes the muskrat like this:

Length: The muskrat is about 20 inches long, including its 9-inch tail.

Weight: Adults weigh from 2 to 5 pounds. (That really does seem too small for what we saw.)

I don't remember anymore how big this animal, seen at a distance, really seemed to be. It might have been a smaller beaver, or it might have been a large muskrat. I know we thought it was a beaver at the time, so perhaps that's the most likely identification. I'll just leave it at that!