Rusties

A male rusty blackbird (Euphagus carolensis) perched on a tree limb (2010_02_07_049513)

What happened to all the rusties?  I’m speaking of rusty blackbirds (Euphagus carolensis).  While no one was looking over the past 40 years, the entire population declined 85%-99% throughout North America.  That’s a catastrophic collapse.

I remember more than two decades ago how common they were in autumn and winter.  Oh, never in overly large groups mind you, but always in sufficient numbers to stand out from the crowd in the mixed flocks they inhabited.  And now?  Let’s just say I feel gifted to see three or four over the course of an entire season.

I don’t remember a winter during which I did not see a rusty blackbird, though I can say it once was easy to find them.  Now it takes patience and time.  Where once I could see a dozen or more with ease, today I have to look carefully to find the one or two hiding amongst various other species.

Rusty blackbirds often forage within flocks of starlings, cowbirds, grackles and other blackbirds—most notably around these parts within flocks of red-winged blackbirds (Agelaius phoeniceus) who share the rusties’ affinity for wetlands.  This perhaps explains how they slipped below the radar for so long and how their numbers dropped so abruptly in only four decades.

Well, that and the fact that they literally are black birds.  Like the many species of sparrow that leave most people happy to simply call a bird a sparrow, black birds cover a lot of territory: starlings, grackles, cowbirds, crows and ravens, and blackbirds.  How many would know which kind of bird they were looking at if they were looking at a black bird?  And assuming you could pin it down to a true blackbird, which of the handful of species is it?

Add to those complications two very simple facts: most people do not like or are ambivalent to black birds no matter what species they are, and black birds lack the pretty colors and patterns that most people look for when watching birds.  So they’re boring and they’re ignored, if not reviled, a double-whammy for the rusties.

It wasn’t until 2007 that the IUCN Red List changed rusty blackbirds from “least concern” to “vulnerable.”  The limited research and observation data indicate the population continues to decline; the decline has intensified over the past 10 years; and worst of all, no one has a clue as to the cause of the collapse or how to reverse it.  In other words, rusty blackbirds are teetering on the edge of extinction and got there so quickly and with so little notice that we’re scrambling to get our minds around the event before they’re all gone.

Unfortunately for the birds, it may already be too late.  As their numbers have dropped faster in the last ten years than they did in the 30 years prior to that, the cause and effect seem intent on beating any action we might take.  It would not surprise me to see them listed as endangered within the next year or two.  At the current rate they’re disappearing, that will be akin to closing the barn doors after the horses are gone.

[cross-posted to The Clade]

6 thoughts on “Rusties”

  1. What a catastrophic decline. So sad. I’ve never seen one. Surprising that we don’t know the cause, but I imagine humans have something to do with it.

    1. I think you’re quite right, Jain. The two most popular hypotheses for their decline are habitat loss and mercury poisoning. The unfortunate truth is that we don’t really know. A scientific working group wasn’t formed until 2005; the losses weren’t recognized until a year or two before that; the danger wasn’t officially stated until 2007; and in 2010 the bad news remains so hidden that the birds still don’t have an advocate in the general public. It’s very sad…and I fear the worst for them.

  2. I’m glad to learn of this, Jason. I like the various species of black birds – but then, I’m not like most birders. A lot of black birds (grackles, crows) have an iridescent sheen that I would describe as beautiful. Though non-native, I think that starlings are quite striking. And I often feel like defending cowbirds, since it is not their fault that the ecosystem that helped to shape their habits is now lost. Every species wants to survive, even those species we call “pests,” or worse. I’m due for a trip to the Heard in McKinney – I’ll keep a special eye out for the Rusties.

    1. I’m with you, Amber. I’m mesmerized by the sheen of a grackle’s plumage, I’m in awe of Brewer’s and rusty blackbirds who share that beauty with their own spins on it, and my favorite bird in all the world is so pedestrian that people laugh at me: the red-winged blackbird. (And I’ll add that starlings intrigue me with their singular beauty as well, something that has made me rather unpopular with most. But oh well: I can’t help it when a species does what nature made it do and that we humans are responsible for it being where it shouldn’t be.)

      Worst of all: I’m embarrassed to admit I’d never photographed rusty blackbirds before this year. It’s one of those things I’d taken for granted, as though I’d always have an opportunity when circumstances were perfect. Shame on me! The photo in this post is from an interrupted session in the WRL fish hatchery when two red-shouldered hawks blew my close approach to several rusties. Still, I couldn’t let the chance slip away. It’s growing far too difficult to find them, so I had to snap an image while I could. I hope the tide turns for them; I hope I have more chances in the future.

  3. The weirdest thing about the Rusty’s decline is that it seems isolated to that species. And that it is *that* species. I meant, at least in terms of severity and rapidity. They breed in the boreal forest and the subarctic tundra. There almost couldn’t be a safer part of North America from a habitat loss and pollution perspective. There are lots and lots of boreal/tundra species doing just fine. In fact, now that the threat of acid rain has eased, boreal wetlands are recovering and populations are going up, not down, on the Shield (at least here in Ontario). And on the wintering end of the year, they spend their time hanging out with quite a number of other species of blackbird, all of whom are persecuted equally. It seems unlikely that Rusties would be any more sensitive to “management” techniques that kill all equally (an absolutely horrible practice, by the way). On the other hand, perhaps there’s a stratification in foraging among the blackbird flocks, and whatever it is that Rusties prefer and the others ignore, that’s where the problem is? But wouldn’t a hungry Rusty just start eating whatever it could find if its preferred food wasn’t available? It’s a bit of a mystery.

    Interestingly, in the most recent Ontario atlas, while the birds declined significantly in both of the boreal regions of Ontario over the last 20 years, in the subarctic region they actually *increased* significantly in the same time period. Because the second atlas got better coverage than the first in that region due to more available funding for northern data-collection trips, it’s sort of hard to say if some of the increase could be attributed to extra effort or better-skilled atlassers. The author of the species account speculates that perhaps the decline is not as catastrophic as we think it is, and it’s just that the species has been shifting its primary breeding range north, which puts it out of reach of roadside surveys such as the BBS and other similar monitoring programs (though suggests caution, noting the difference in coverage effort). That doesn’t explain observed declines on wintering grounds, though. The author goes on to say, later in the account, that given the relative stability of their breeding habitat, it’s most likely that the cause is one on the wintering grounds.

    1. You really hit one of the big mysteries, Seabrooke. There’s a huge effort here to count rusties while they overwinter. Part of the worry is that something “down here” might be to blame for their precipitous decline. Unfortunately that concern is in serious doubt as the singular cause because of a very obvious reason: the two major cohabitant winter species, Brewer’s blackbirds and the year-round resident red-winged blackbirds, show no indications of negative impact during winters in the same territories occupied by the rusties. That’s especially important since all three species, in addition to European starlings and American robins, occupy and feed in the same places, usually in single mixed flocks. (And the resident red-wings, robins and starlings would certainly have an issue if exposed to a detrimental impact since they never leave the area.)

      Then again, that’s what’s so frustrating: rusty blackbirds spend all that time with and eating the same foods as several other species, none of whom show a correlative decline in winter territories–or in any other way that sheds light on the problem. Hence the biggest concern is the most daunting: it’s a mix of inputs that are so specific to rusty blackbirds that no other cohabitant species is affected. Which means we’re back to where we were: it could be in their winter territory, their breeding territory, or a combination of the two. The only thing we do know is that the cause is specific only to rusty blackbirds–and we don’t know enough about them to come up with a sound answer that fits the facts.

      It’s all so very confusing. I think the consensus is right: it indicates a conspiracy of events throughout their range that is specific to the rusty blackbirds and their habits, tendencies, diet and so on. Considering no other species throughout that range and sharing the same food sources have been devastated like this, our biggest problem is not understanding the rusties as well as we need to. I for one am hoping we resolve that soon enough to make a difference.

Leave a Reply