DU Podcast Transcript: Ep. 39 – Myth of the Northern Mallard

Hosts Chris Jennings and Dr. Mike Brasher debunk the myth of the northern, or “red leg” mallard

© Michael Furtman

Clay Baird: Welcome to the Ducks Unlimited Podcast, the only podcast about all things waterfowl. From hunting insights to science based discussions about ducks, geese and issues affecting waterfowl and wetlands conservation in North America. We bring the resource to you, the DU podcast with your hosts, Chris Jennings and Dr. Mike Brasher.

Chris Jennings: So today's show is a very interesting show. We are going to discuss the Northern Mallards or what some people have referred to as the red-legged Mallard, and I've got Doctor Mike Brasher here and he's going to bring some of the more scientific aspects of this; where I kind of bring the layman's version of man, there are people online, there are people everywhere, convinced, there's duck hunters convinced that these are different birds. This is a different species of bird, a larger duck, with these big bright orange legs. All right, lay it down for us Mike, what's the deal?

Mike Brasher: The answer to this question is actually pretty straightforward, but we're not going to get into that right now. We're going to delay here a little bit. We're going to build a story. We're going to have a little bit of mystery, a little bit of intrigue. Whenever Chris first brought this idea to us. I think you've tried to get me to do this episode twice now.

Chris Jennings: I have.

Mike Brasher: And both times I said, "Yeah, no, let's wait and I need to bring something else to the story, there needs to be something else to it." And I found it the other day walking through the halls of headquarters here. And it's one of the interesting things about being here as someone who loves waterfowl conservation, waterfowl science, there's so much history.

Mike Brasher: There's so much history from the perspective of the organization as well as just from the science behind waterfowl management all over the halls and our library. And I was walking down the hall the other day and I noticed this, an old print, I think it was from 1934 or 1937, it's a print where it has all the species of ducks on one... dabbling. It actually called them surface feeding ducks at that time. Those are all the dabblers and puddlers, and they had another one where it showed all the species of sea ducks and mergansers. Diving ducks, sea ducks, mergansers. And it was from... And as I walking past it, I glanced at some of the names that it had for the ducks. And I saw red-legged black duck, and I saw right beneath it was the common black duck, and so I stopped and said, "Wait a minute, what is that?"

Mike Brasher: So I looked into that a little bit and we could... I could talk for about five minutes alone on the unique elements of that print. I believe it was 2000 of them were produced. The copies that we have here at headquarters are numbers 576 out of a series of 2000. And it has some of the old taxonomic names for those duck species. This goes back to an earlier where we talked about bluing ducks now have the the genus spatula. spatula. That was the genus that was used for some of those names for some of those birds back when that print was produced. So there's a whole number of connections there on that print related to taxonomy, names of ducks, which is pretty cool. But I saw that red-legged black duck and I said, "I need to look into that and see what that's about."

Mike Brasher: And it's about this phenomenon of red-legged ducks, red-legged Mallards, red-legged black duck. So-

Chris Jennings: Now we're bringing it full circle.

Mike Brasher: Now we're bringing it full circle. Really what's going on it... These are not... The appearance of bright red legs later in the season is not an indication of a different suite of birds, a different collection of birds. Really what's driving the red legs is the same thing that's driving the appearance of the bright bill on a Mallard. And those are hormonal changes, which carry out through time as those birds begin to prepare for the pairing season. The males want to be showy. They have a fair degree of ornamentation, whether it be on their plumage, but then they also... Remember the plumage is put on in the breeding, at the end of the breeding season. Once they put on feathers, the colors on those feathers don't change, but they can change the colors of the fleshy ornamentation, the bill, the legs, through time.

Mike Brasher: They can go from duLl to bright, and that's actually what's happening. They're not different groups of birds. It's just an artifact of the hormones changing, primarily testosterone that's driving these changes as those birds begin to prepare for the pairing season. So not different birds or not different groups of birds. They're not necessarily representing a northern group of mallards that are coming down. It's just it may just be that what you're seeing is an artifact of time. Later in the season, yeah, maybe you are getting some birds that were farther north, but yeah.

Chris Jennings: And these birds... Yeah. But these mallards are doing this at different times. Not every Mallard in Minnesota is putting on this hormonal shift and these bright red legs at the same time. So I think that's where hunters can get confused is you shoot two or three mallards and you're putting them side by side and you've got one that's got these bright red legs, and that's where... I see it on social media a lot. I see emails coming in to the website, things like that that, that I see a lot of questions about these, or I see people comment on things like, "Oh the Northern mallards are here, the red legs are here."I think that's where people get a little bit confused.

Mike Brasher: And it could be an age effect as well. Definitely the adults are going to be farther along in their molt, and their development of their feathers than are the young birds. And they're going to be farther along in those hormonal changes as well. However, there, there can be other environmental factors that impair a bird's ability to develop those bright red legs. So if you see a bird that has dull legs, does not all showy on bill or on the legs, it could be something else going on with it. There was some research out of Spain, I believe it was, which was, which correlated blood lead levels with coloration on the bill and feet. And those individuals that had higher blood lead levels had duller coloration on their feet and bills.

Mike Brasher: Those are the things that can change is that fleshy ornamentation. So it could be other things going on with an individual bird if it does not have those red legs. But to get to this element of mystery and intrigue, if you will, I think this is something that our listeners would probably be interested in. I found it... Of course, I'm a scientist, this kind of stuff is, I don't know, I kind of get geeky on, and it's just of interest to me. But so I, after seeing that print, I dug into this issue of the red-legged black duck a little bit more, and the story dates back to the early 1900s. And this actually might make some people feel more comfortable about having believed in this myth of the Northern Mallard for so long. Because if you go back far enough in the literature, you'll actually find some ornithologists that believed it as well.

Mike Brasher: Believed it to the point that they recommended it as a separate species or at least a subspecies of what at that time and was recognized in the Northeastern U.S. as the common black duck or typical black duck. So-

Chris Jennings: I'll note that Mike gave me notes for this.

Mike Brasher: Yes, not that Chris did not know this, can't be shown up by Chris on this.

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Mike Brasher: So the original name for the black duck was the anas obscura. And then Brewster comes along, he's this ornithologist that was believing in the red-legged black duck, and he actually proposed it as a sub species anas obscura rubripes. And that's where the radish leg comes into play. Folks that are familiar with waterfowl taxonomy will know that rubripes is the current scientific name, a specific epithet for black ducks, which rubripes is Latin, it means ruddy lagged or reddish. Ruddy is reddish. Well, then what they realized around 1905 is that anas obscura was already in use for some other duck species in Europe, so they had to change it. Well, they adopted anas rubripes for the overall, for the common or for the black duck.

Mike Brasher: And so this guy that had proposed the red-legged black duck kind of found it amusing that the taxonomic community had used his name, the one that he had proposed for the red-legged black duck to be used as the name for just the black duck in general. For those that still weren't believing in his claim of there is this separate red legged-black duck. And so this debate went on for quite some time. He actually, in response to this, to this thing, failure to continue to recognize the red-legged black duck, he proposed a new scientific name for the red-legged black duck: anas obscura tristis, if I said that right. Tristis. Tristis, which means sad, as a reflection of his disappointment on how the ornithological community was treating his suggestion.

Mike Brasher: And so this debate went on for some time. Eventually, what they discovered through some new research or some new observations of the molt of waterfowl is that really what they were seeing is nothing more than seasonal changes in the coloration pattern on the legs of these birds. So the story goes that eventually around 1943, or was it 1946? Sometimes in the '40s, things were finally put to bed with this. But this persisted for about four decades where people were debating whether there was in fact a separate subspecies that would have consisted of this red-legged black duck.

Chris Jennings: I feel like the general population, hunting population, out there is still not necessarily arguing the specific of the red-legged black duck, but they're still convinced that there's a separate red-legged Mallard. And now with this podcast, we've basically provided the myth-buster mentality. There is no such thing as the Northern Red-legged Mallard.

Mike Brasher: That's right. That's right.

Chris Jennings: And even in instances that I just... I described to Mike earlier that I had a friend growing up on the Wabash River in Indiana, a friend of mine was hunting one day and he came home and he had shot a Mallard that was three times the size of the rest of the mallards and we laid them side by side, I still have the pictures somewhere. What did he shoot, Mike?

Mike Brasher: He probably shot a farm Mallard.

Chris Jennings: Hmm. farm Mallard. I'll have to tell him that 25 years-

Mike Brasher: Domesticated Mallard.

Chris Jennings: ... I will ruin his hopes and dreams of his Northern Mallard.

Mike Brasher: I wonder how it tasted though.

Chris Jennings: Probably pretty good.

Mike Brasher: You'll have to ask him about that.

Chris Jennings: All right, Mike, I think we've narrowed it down. We've eliminated the red-legged Mallard, along with mike brought up on an awesome historical note on taxonomy and how how birds are labeled, and through science even there can be some miscommunication and a little bit of misdirection there, but it sounds like they got it straightened out, so appreciate you bringing up the red-legged black duck story. That's awesome. And once again, I apologize to everyone out there who's convinced that they're seeing the Northern Mallard or Northern Red-legged Mallard, because Dr. Mike Brasher Has just shattered your dreams. Thanks, Mike.

Mike Brasher: But you don't have to feel too bad because even the best ornithologist of their time were also fooled. So you can take some consolation from that.

Chris Jennings: All right. Thanks a lot, Mike.

Mike Brasher: You're welcome, Chris.

Chris Jennings: All right. I would like to thank Dr. Mike Brasher, my co-host here, and our awesome producer, Clay Baird, because without him, we would not be doing any of this and bringing this great information to all of you listeners. And most of all, I would just like to thank all of you for listening and supporting wetlands conservation.

Clay Baird: Thank you for listening to this episode of the DU podcast. Be sure to rate, review and subscribe to the show and visit www.ducks.org/DUpodcast for resources based on today's topics, as well as access to more episodes. Opinions expressed by guests do not necessarily reflect those of Ducks Unlimited. Until next time, stay tuned to the ducks.