The Mysterious Gray-headed Chickadee

(Image copyright Julio Mulero used under Creative Commons License. More images: https://www.flickr.com/photos/juliom/)

(Image copyright Julio Mulero used under Creative Commons License. More images: https://www.flickr.com/photos/juliom/)

Gray-headed Chickadee. Ever heard of one? If not, you aren’t alone. In fact, very few people, even among passionate birders and researchers, have ever seen one. It may be the rarest regularly breeding bird in North America, and it is almost certainly the least known. There has never been a dedicated study of the species, some years go by when there are NO recorded sightings, and the most recent specimen from North America, to my knowledge, was collected in 1984.

So yeah, we know basically zilch about the Gray-headed Chickadee (Poecile cincta). And in my opinion, that makes the species awesome, enticing, and ever-so frustrating.

In mid-June I led a birding trip down a river in the Arctic National Wildlife Refuge where Gray-headeds have been recorded, most years, over the past decade or so. I won’t hold you in suspense: despite hiking miles and spending hours with binoculars plastered to our faces, we didn’t find one. But we’ve got plans, big dreamy plans, to try again another year.

The Gray-headed Chickadee is a weird little thing. Take a read through the Birds of North America (BNA) account for the species, and just how little we know, and how conflicting the information is, becomes glaringly obvious.

The species can be found across most of northern Europe and Asia at the northern extent of the boreal forest. The only place the Gray-headed Chickadee makes it into North America is northern Alaska (and a few records from the Yukon Territory). Information in the BNA is largely from the better known populations in Scandinavia and Siberia, and much of what we think we know about Alaska’s Gray-headed Chickadees, we draw from that information. But things are different here. Most notably, in Alaska, Gray-headed Chickadees don’t seem to hang out in the same types of habitats that they do in the old world, at least not recently, or at least we don’t think they do.

AK-CanningMarshFork-1066-49

Woke up to this on summer solstice. The day before, as all that snow fell, we pondered the ecology of Gray-headed Chickadees.

And here is where parts of this article are going to become wild supposition, unfounded hypotheses, and brainstorming. On my recent trip, the clients were basically a dream-team of adventurous birders and biologists. Of our group of five clients and two guides, there were four science PhDs (two ornithologists), and two that weren’t Docs had masters degrees (including myself). It was a smart group to say the least. During a couple of days of bad weather, we occupied the (snowy) hours pondering this weird little bird. A lot of what I’m going to mention here, comes from those discussions.

The BNA describes the species as occurring at the northern extent of the tree line, primarily in conifer forest. But in Alaska, Gray-headed Chickadees haven’t been regularly found in conifer forest for at least a few decades. The only place they seem to be seen regularly now, is in patches of Balsam Poplar that grow in a few drainages in the Brooks Range, and there, not consistently.

AK-NoatakRiver-13-22Aug2011-128

A stand of Balsam Poplars along a tributary to the Noatak River in the western Brooks Range in August.

Here are few things we know:

Gray-headed Chickadees are cavity nesters.
This much is fact. Chickadees and tits across the world are cavity nesters. All recorded Gray-headed Chickadee nests have occurred in cavities of one kind or another. The species is cavity-limited. And for the most part (with a few notable exceptions) that means they need trees to nest. (The exceptions are reports of Gray-headeds nesting in Cliff Swallow nests and crevices in cliffs.) But yeah, – trees are important.

2. Gray-headed Chickadees do not occur in high densities.
From what we know of the species in the old world, they are low density, and possibly patchy across their range. In Alaska, we know this is the case from the simple fact that they are so rarely observed, even in areas where they are known to occur. Where they are found, there tend to be a pair or two but rarely more.

3. Gray-headed Chickadees are not migratory.
In northern Asia and Europe, the species spends the winter in the same habitat in which they breed. In Alaska? Well, who knows, but I’ll do some pondering on that here in a bit.

4. Populations seem to be low and may be in decline.
In northern Europe, declines have been documented due to deforestation in their preferred habitat. Here in Alaska, however, there has been very, very little habitat loss, but there is circumstantial evidence for a decline in population, or a change in distribution since mid-century. More on that shortly.

There are few other bits and pieces, but I think I’ve covered the big topics.

AK-CanningMarshFork-1066-113

A large stand of willows along the river. I made the image from a hillside stand of Balsam Poplars, sadly too small to contain cavities. Some of these willows however, were large enough to contain cavities, though we didn’t find any.

To sum up, we’ve got a cavity-limited, low-density, low-population, possibly declining, non-migratory bird that lives in the far north.

It’s habitat that I ponder most often when it comes to this strange little chickadee. In Europe, they occur primarily in conifer forest at the northern extent of the boreal forest. In Alaska, such habitat contains chickadees, but from personal experience, and what little information there is from that area, those birds are almost all Boreal Chickadees. Recent Alaska records come almost entirely from north of the spruce line in the aforementioned stands of Balsam Poplar. But that hasn’t always been the case. There are historic records from Denali National Park, including a record of an adult with four young in late July of 1926 along the Savage River. A summer record of juveniles in Denali implies possible breeding in that area. Other descriptions of habitat selection in Alaska vary from patches of spruces on hillsides north of the contiguous forest line, to willow-spruce mix along river valleys of the southern Brooks Range at spruce-tundra interface.

There is a caveat, a big one. Very few people go birding or conduct surveys at the north end of the spruce line. When the population of Gray-headed Chickadees was found consistently in isolated patches of poplars on a river in the Brooks Range, that’s where the few birders and biologists went to look for them. The rest of their known habitat? Mostly ignored.

So, are Gray-headeds really absent from that northern tree line? I don’t know, but I’d sure like to find out.

Winter records too seem to have changed. The BNA notes wintering birds in Denali National Park during the 1920s, and there are mid-century records from elsewhere in the Alaska Range and the interior, including Fairbanks, though nothing recently. There are reports from the past few years of Gray-headed Chickadees visiting bird feeders during winter in Wiseman, Alaska near the northern end of tree line.

As for the poplar stands where they are known to breed? No one really goes into those areas during the long dark winter, so we have no idea if they winter there or not. Personally, I kind of doubt it (and this that wild supposition I noted earlier). I doubt it because those patches of habitat are very small, and I doubt that space could sustain a population, or even a family group over the winter. At the peak of winter, visible daylight that far north is measured in minutes, and the sun doesn’t actually break the horizon for months at a time. Temperatures are brutal, and few bird species, let alone small-bodied passerines, manage to live there. If Gray-headed Chickadees do persist in those areas during the winter, then they are uniquely tolerant of such conditions.

I think the north-slope breeders must move south to the tree line on the south side of the mountains. Chickadees in general don’t migrate. Equipped with short, rounded wings, they just aren’t built for long flights. But it isn’t far from the poplar stands to the contiguous forest on the south slope of the Brooks Range (just 30 miles or so by my reckoning). I think that kind of distance is within their capability, particularly if they move south as soon as breeding is done, following the stringers of willows up the creeks, towards the continental divide. Once over the passes, more willows will lead them right down to the spruces. Following such a route, long, sustained flights would not be necessary

One more thing I wanted to add: what we know of these birds in Alaska comes from either historic records, or recent breeding records from a small and isolated population in the north-eastern Brooks Range. That population in the Arctic Refuge, a handful of pairs at best, cannot possibly be large enough to be sustainable in the long term. So there must be more birds, probably a lot more, elsewhere in northern Alaska. The poplar stands are small, isolated from one another, and very widely distributed. Even if every suitable patch is occupied (which doesn’t seem to be the case) that still doesn’t seem like enough space. If I’m right about that, then there must be Gray-headed Chickadees breeding somewhere else and presumably that “somewhere else” is the northern extent of the tree line, but where exactly? Damn, I’d like to find out.

My curiosity has been piqued, which brings me back to the grand plans I noted early on in this post. My clients and I did a lot of talking about future trips, and we started hatching an idea to return to first find, and then figure out what’s going on with Gray-headed Chickadees. We even did some brainstorming on how we could actually survey for them in a real, and quantitative way.

If that ever happens, you can count on me to be a part of the effort.

Here is the citation for the BNA if you want to learn more:
Hailman, Jack P. and Svein Haftorn. 1995. Gray-headed Chickadee (Poecile cinctus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/196