#deju systematics

YOU’VE ACTIVATED MY TRAP CARD!!!

YOU’LL REGRET THIS!!!!!!!

Okay so dark-eyed juncos (Junco hyemalis) are one of the most fascinating and overlooked species of songbird in the US because they are, generally, fairly plain looking and common. They’ve been called Snowbirds throughout the Eastern US and they’re often disparaged because spotting a junco means it’s about to snow. However, this is often not true because many places have resident populations (meaning they live there year round) and they are subject to a sort of confirmation bias—you’ve heard they’re a winter-only bird so you’ll only notice them during winter, similar to American robins that are known as a “first sign of spring” bird even though their seasonal movements are very complex and they often have resident populations.

Onto why they are FASCINATING, or at least why I think so (and I am correct always obviously) there are many, many different subspecies of dark-eyed juncos. And we have NO IDEA how many there actually are! It is highly debated and depending on who you ask there’s anywhere from 14-15 recognized subspecies, with 2-3 different large groups and 3-4 smaller ones. I’ve even heard people say as little as 9 and as many as 17. I have watched seasoned professionals with tenure get up in arms about this. It’s incredible.

Here’s an example of some!

Read Top to Bottom/Left to Right: Rocky Mountain (Cassiar) Junco (cismontanus), Pink-sided Junco (mearnsi), White-winged Junco (aikeni), Slate-colored Junco (hyemalis), Gray-headed Junco(caniceps), Red-backed Junco(dorsalis), Oregon Junco(oreganus)

If you live in the east of the us, the little guy in the middle (slate-colored junco) is going to be the one you see the most, and if you live in the west it’s the bottom right (Oregon junco). Usually. Very broad, and there are many subspecies within the Oregon group that often get (incorrectly, but understandably) labeled oreganus when they are likely something else.

It’s extremely difficult to identify junco subspecies in field and without particularly great photos most people are left shrugging and putting them in slate-colored or Oregon groups.

This range map is incredibly simplified

And THIS range map is. Well. Yeah. Don’t get me started on intergrades.

There’s several subspecies within the Oregon group and a large, unresolved debate about whether or not the Oregon group is actually its own species separate from slate-colored, with several subspecies.

Their systematics is a MESS (loving) and we’ve just recently moved the Guadalupe Junco to be it’s own species!

MY research has centered around this

You see this little guy right here?

This absolute little stinker that took me forever to photograph because they were being scared by hawks?

Yeah, that’s a Cassiar Junco.

Probably my greatest, rarest observation to date. And most people would write it off!

(Not sharing downloaded image bc location stuff lol. When I say rare I mean RARE.)

The Rocky Mountain Junco, also known as the Cassiar Junco, (Junco hyemalis cismontanus) is a presumed subspecies within the slate-colored group.

Depending on who you ask! Some believe it to be a subspecies, some believe it to be an intergrade between the slate-colored junco and Oregon junco, and others believe slate-colored and Oregon juncos to be distinct species making the Cassiar junco a hybrid. I will not give my opinion here yet since this is, technically, research I am currently doing but…let’s say I am observing breeding behaviors for a reason :)

They are incredibly rare, with most sightings taking place in the Northwest. Though they are spotted across much of the lower 48 a lot of these sightings are thought to be mistaken identity.

Looking at eBird range maps they fall within 0-2% sighting frequency, and all but disappear during summer months.

Is this because they are mistaken for slate-colored and written off? Or are they truly this rare? And if so, why?

There’s so many unsolved mysteries about this group of forgotten birds and especially the Cassiar junco.

Recently I’ve been looking into the research in gonadal growth delay in migrant populations vs resident populations and oh my god I could infodump a whole post on that but I’ll spare you. For now. If you express further interest there will be no saving you. It’s so cool man (said like siren song)

I am incredibly excited to focus my field research on them this winter (especially now that I have…connections) and I am very fortunate to live in a place that seems to get them more often than others.