Category Archives: Birding

The definitive guide for distinguishing American crows & common ravens

For two birds that are surprisingly far apart on the family tree, American crows (Corvus brachyrhynchos) and common ravens (Corvus corax) can be awfully hard to distinguish, especially if you rarely see both together.  But with the right tools and a little practice you can most certainly develop the skill.  Fortunately, there are many different types of clues you can use to tell one from the other, so feel free to use the links to skip around to what interests you.

Physical Differences

Although crows and ravens are superficially quite similar, there are variety of features that can be used to tell one from the other. Overall size can be a good place to start.  This especially helpful if you live in an area where they overlap, but even if you don’t, I find that people who are used to seeing crows take notice when they see a raven in person because it feels ~aggressively~ large.  That’s because ravens, by mass, are about twice the size of an American crow.

IMG_3600

A common raven specimen (top) with an American crow specimen (bottom). On average, ravens are about twice as big as crows, but individually there are certainly large crows and diminutive ravens.

This size difference becomes most obvious is when you look at their face.  Raven’s are much more adapted for consuming carrion than crows are (crows cannot break through the skin of a squirrel) and their bills give the distinct impression that they could, in fact, pluck your eyes from your face with little effort. So if your sense of things is that you’re looking at a bill with a bird attached, then you’re probably looking at a raven, not a crow.

IMG_3603

With practice, judging the proportion of crows’ and ravens’ features, like bill size, becomes easier.

Crow vs. raven measuremntsWith practice, judging relative size becomes easier and more reliable, but for a beginner it may not be useful because it’s so subjective.  Instead, it’s easier to look at the field marks (birder speak for distinctive features) which provide more objective clues.

When looking at perched birds, the most helpful attribute is to look at the throat.  Ravens have elongated throat feathers called hackles, which they can articulate for a variety of behavioral displays.  Crows meanwhile have smooth, almost hair like throat feathers typical of other songbirds.

Crow v raven

Even when the feathers are relaxed, the textural differences between the two species throat feathers are apparent. Note that in this photo, the crown feathers of the crow are erect, while the raven’s is not.  The difference in crown shape should not therefor be judged in this comparison.

DSC_0079

When vocalizing or displaying the raven’s hackles become especially obvious.

In addition to the hackles, ravens can also articulate some of their other facial feathers in way crows cannot.  During threat displays for example, ravens will fluff out both the throat hackles and their “ear” tufts.

868AA791-9936-4AD1-BEC7-F7952F0B254F

For birds in flight, however, it’s often difficult—if not impossible—to clearly see the throat feathers.  Fortunately, the tail offers a reliable field mark in this case.  Whereas crows have a more squared or rounded tail (depending on how much they’ve fanned the feathers) a raven’s tail will have a distinct wedge shape. Additionally, although they are a bit more subtle, there are also some differences in the primary wing feathers.  While both birds have 10 primary feathers, in flight, ravens will look like they have four main “finger” feathers while crows will appear to have five. Ravens also have more slender, pointed primaries relative to crows.

crow vs raven

Vocal differences

With a little practice American crows and common ravens can easily be distinguished by their calls.  The call of a raven can be best described as a deep, hollow croak.  Crows on the other hand, caw.  Of course, they can both make at dozens of other sounds including rattles, knocks, coos, clicks, and imitations. With practice even these can be recognized by species, but that level of detail is not necessary for most identification purposes.

Juvenile common raven yell (Recording by Antonio Xeira-Chippewa County, Michigan)
Common raven water sound (Recording by Niels Krabbe-Galley Bay, British Columbia)
American crow call (Recording by David Vander Pluym-King County, Wasington)
American crow juvenile begging call (Recording by Jonathon Jongsma Minneapolis, Minnesota)
American crow rattle (Recording by Thomas Magarian-Portland, Oregon)
American crow wow call (Recording by Loma Pendergraft King County, Washington)
American crow scolding (Recording by Kaeli Swift-King County Washington)

Geographic/habitat differences

While both American crows and common ravens have wide distributions across North America, there are some key differences in where you are likely to find them.  The most notable difference is that ravens are absent throughout most of the midwest and the southeast.  Crows on the other hand, occupy most American states with the exception of the southwestern part of the country.  The below maps from Cornell’s All About Birds website offer more specific breakdowns (hover over the images to see the caption). Note that the reason the American crow’s west coast range appears to dry up from the Puget Sound north is not due to a lack of crows, but rather because the crow species that occupies the upper half of the North American west coast is not the American crow, but the northwestern crow (Corvus caurinus).  The continued distinction between these two “species” is likely coming to a close, however.  For more on our current understanding of the differences (or lack thereof) between those two species check here.

With respect to habitat, both birds are considered generalists, with ravens erring more towards what one might describe as an “extreme generalist”. Ravens can be found along the coast, grasslands, mountains (even high altitude mountains), forests, deserts, Arctic ice floes, and human settlements including agricultural areas, small rural towns, urban cities (particularly in California) and near campgrounds, roads, highways and transfer stations. Crows meanwhile are more firm in their requirement of a combo of open feeding areas, scattered trees, and forest edges.  They generally avoid continuous forest, preferring to remain close to human settlements including rural and agricultural areas, cities, suburbs, transfer stations, and golf courses.  In cases where roads or rivers provide access, however, they can be found at high elevation campgrounds.

Behavioral differences

There are books that could be (and have been) written on this subject alone, so we will limit ourselves to what is likely to be most essential for identification purposes.

Migration
While common ravens are residents wherever they are found, American crows are what’s called a “partially migratory species” because some populations migrate while others do not.  Most notably, the northern populations of crows that occupy central Canada during the summer breeding season, travel south to the interior United States once the snow-pack precludes typical feeding behaviors

Breeding
Although trios of ravens are not uncommon, and there have been observations of young from previous years remaining at the nest, ravens are not considered cooperative breeders. Crows are considered cooperative breeders across their entire range (though specific rates vary across populations and not much is known about migratory populations).  If helpers are present they typically have between 1-3. So if a nest is very busy with more than two birds contributing to nest construction, feeding nestlings, or nest defense, it’s more than likely a crow’s nest, not a raven’s.

IMG_5408 2

Common raven eggs left | American crow eggs right

Diet
Although both species consume a host of invertebrates, crows consume a larger proportion of inverts and garbage relative to ravens.  Mammals, especially from carrion, meanwhile make up the largest proportion of a raven’s diet across surveyed populations.  Access to refuse and population location, however, can dramatically shift the dietary preferences of both these omnivores.

Flight
Because ravens consume a lot more carrion, which is unpredictable in its availability and location, they spend a great deal more soaring than crows do.  So if you see a black bird cruising the sky for more than a few seconds, it’s most likely a raven.  Ravens are also unique from crows in that they barrel roll to advertise their territory.  So if you see a  barrel rolling bird, there’s a better chance it’s a raven.

Interactions
In places where they do overlap, interactions between the two are often antagonistic, with crows acting as the primary aggressors in conflicts.  Ravens will depredate crow nests if given the chance.

DSC_0675 (2)

A raven defends itself from a crow by rolling upside down.  Someday I’ll get a better photograph…

Genetic differences

Throughout most of our history, we have used external cues like appearance, voice and behavior, to sort one kind of animal from another.  Now that we have access to a plethora of genetic tools, however, we can ask a new level of the question “what’s the difference between an American crow and a common raven.”

To put it simply, American crows (Corvus brachyrhynchos) and common ravens (Corvus corax) are different species in the same genus, just like lions (Panthera leo) and tigers (Panthera tigris).  Species and genus refer to different levels of the taxonomic tree, where species represents the smallest whole unit we classify organisms.  The issue of species can get complicated quickly, however, so I’ll direct you here if you want to learn what a mess it really is.  Most important thing to appreciate now, is that if you want a quick, back of the envelope way to evaluate if two animals are closely related, look at the first part of their latin binomial (scientific) name.  If they share that part then they’re in the same genus (ex: crows and ravens belong to the genus Corvus).  If they don’t (ex: American crow is Corvus brachyrhynchos and the Steller’s jay is Cyanocitta stelleri) then they are more distantly related. 

Within the Corvus genus, however, there is still a ton of evolutionary space available.  In fact, to find the closest shared relative of common ravens and American crows you’d need to go back approximately 7 millions years.  Although they are more visually distinct and don’t overlap geographically, American crows are more closely related to the collard crows of China, or the carrion crows of Europe, than they are to common ravens.

Crow phylogeny

Image from Jønsson et al. 2012

Laws and protections

US laws
In the United States, both American crows and common ravens are protected under the Migratory Bird Treaty Act.  This means that, like with nearly all native birds species, you cannot kill, possess, sell, purchase, barter, transport, or export these birds, or their parts, eggs, and nests, except under the terms of a valid Federal permit. It is this law that prohibits the average person from keeping these birds as pets, and requires that rescued crows be turned over to a licensed professional.  The MBTA also prohibits the civilian hunting of ravens under any circumstance.  Under 50 CFR 20.133, however states are granted an exception for crows, wherein with some restrictions, states can designate regulated hunting seasons.

In addition, under 50 CFR 21.43 of the Migratory Bird Treaty Act, you can also kill crows without a license and outside of the regulated hunting season if they are in the act of depredating crops, endangered species, or causing a variety of other destructive issues.  You can obtain the specifics of the Depredation Order here.  Such lethal control must be reported to Fish and Wildlife to remain within the law. No such depredation exceptions exist for ravens. 

Canadian laws
In contrast to the US, no corvids receive federal protections in Canada.  Crows and ravens may receive provincial protections, however.

Concluding thoughts

Before we pack it up, I want to leave you with one last useful piece of information.  This whole article was dedicated to the question of how American crows are different from common ravens.  Hopefully, you’re walking a way with a solid understanding that these animals are in fact different morphologically, behaviorally, and genetically. Asking if American crows are different from common ravens is a different question, though, than asking if “crows” are different than “ravens”.  Because while that first answer is a hard, “yes,” there is no one thing that initially classifies a bird as either a type of raven or a type of crow.  Generally ravens are bigger and have those elongated throat feathers, but there are plenty of crow named birds that could have been named raven and vice versa. So proceed cautiously and consider the specific types of birds the question’s author is referring to before offering specific answers.

If you want to continue to hone your skills I invite you to play #CrowOrNo with me every week on twitter, Instragram and facebook, all at the @corvidresearch handle.  While it’s not to quite this level of detail, I promise it will help advance your ID skills and introduce to to more of the world’s fantastic corvids. For a head start, keep this charming and informative guide illustrated by Rosemary Mosco of Bird and Moon comics handy!

raven vs crow

 

Reference literature
Jønsson K.A., Fabre P.H., and Irestedt, M. (2012).  Brains, tools innovations and biogeography in crows and ravens.  BCM Evolutionary Biology 12
https://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-12-72

Freeman B.G. and Miller, E.T. (2018).  Why do crows attack ravens? The roles of predation threat, resource competition, and social behavior.  The Auk 135: 857-867

Verbeek, N. A. and C. Caffrey (2020). American Crow (Corvus brachyrhynchos), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.

Boarman, W. I. and B. Heinrich (2020). Common Raven (Corvus corax), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.

40 Comments

Filed under Birding, Corvid diversity, Crow behavior, Crow curiosities, Raven behavior, Ravens, Taxonomy, Vocalizations, Wildlife

The bird of many names

Camp robber. Whiskeyjack. Canada jay. Gray jay.  I know of no other bird that goes by as many names as the Canada jay.  In fact, it has so many names it’s possible for two people to be swapping stories and not even realize they are discussing the same animal. Why this sweet-faced bird possesses a number of aliases better befitting an agent of espionage is, in part, the result of a rather fascinating bit of birding history replete with controversy, colonialism, chaos, and a contest of national importance.

DSC_0164

Before we get to the jays though, I want to put in your mind the image of the Ouroboros. If you’ve never seen it before, the Ouroboros is a symbol from Egyptian iconography that depicts a snake or a dragon eating its own tail. The image is meant to imply infinity; the idea that where you end is also where you begin, on and on, forever. Because, as you’ll see, it’s impossible to tell this story without eating our own tails at many different points along the way. So let’s start with the name that’s both the beginning and potentially the end of this story: Canada jay.

ouroboros-snake-eating-its-own-tail-eternity-or-vector-12076546

On May 23rd, 2018 the American Ornithological Society announced that Perisoreus canadensis, the bird formerly known as the gray jay, would be officially recognized as the Canada jay.  Although this change felt disruptive to some, for the folks spearheading the campaign, including foremost Canada jay expert Dan Strickland, this was the righting of a historical wrong more than a half-century in the making.

According to Strickland’s research, which he details in a facinating article called “How the Canada Jay Lost its Name and Why it Matters,” one of the earliest scientific references to this bird was in an 1831 zoology book called Fauna boreali-Americana where they name it as a Canada jay. Even James Audubon used the name Canada jay when he described it in the 1840s. From here the story of the jay’s name gets hairier, with lots of different dates, acronyms, and taxonomic nuance, but I want to try and take you through it because it tells you so much about why things ended up as they did.

During the early 1800’s the process of discovering* and naming birds was something of a wild west operation. It wasn’t until 1883 that an official body, the American Ornithologist’s Union, AOU, (now called the American Ornithology Society, AOS), was formed to take leadership and help legitimize the field of ornithology in North America. Part of this goal was to act as the official body for taxonomic and nomenclature decisions. In keeping with this goal, AOS publishes a checklist of North American birds every decade or so. So who is on that list, and what they call it, means a great deal. For the first two publications (1886 and 1895) our bird was called the Canada jay, but then after 1895 all more or less goes to hell.

At the root of this naming disaster was a failure to provide a clear and rigorous English naming system at both the full and subspecies level. Instead, the system (if you could call it that) was that birds with only one species (monotypic species) were given a binomial Latin name and an English common name, but birds with subspecies (polytypic species) like our bird, may or may not be given an English common name or a Latin binomial name. Instead, their subspecies were given Latin trinomial names and English common names. What this meant is that if you saw a Canada-jay like bird, unless you knew which subspecies it was, the best your guide could tell is that it was merely a Perisoreus jay. This also meant that the name “Canada jay” effectively got downgraded to describing a single subspecies: Perisoreus canadensis canadensis. An effort to name yet another Perisoreus subspecies, Perisoreus obscurus griseus, appears to be when the name “gray jay” first comes into play.

I doubt anyone would question why failing to provide common names to full species would cause confusion, but matters were made worse because there was no system in the nomenclature behind the common names for the subspecies. This lead to problems like not being able to identify from the English name alone if you were talking about a species or a subspecies, and having subspecies from different respective species sharing the same root name. For example “clapper rail” could refer to subspecies of either Rallus obsoletus or Rallus longirostris.

In the late 1930s, people grew increasingly frustrated with this system and started to put pressure on AOS to develop a more logical naming scheme. At the forefront of this effort was a recommendation by Alden Miller to adopt a system where full species would be given English common names and binomial Latin names, and subspecies would only be provided a trinomial latin name. For example, Perisoreus canadensis would be given the English common name of Canada jay, and its Alaskan range subspecies would be known only as Perisoreus canadensis fumifrons.

Although this scheme was well supported, during the 1940 vote, it was inexplicably voted down. Instead, in 1947 the committee welcomed a new system where both the full species and the subspecies were given common names but, in an attempt for clarity, required that the subspecies’ common name was both rooted in the full species’ common name and geographically relevant. It’s this decision that officially killed the “Canada jay” because the committee likely felt it would be too geographically awkward to have subspecies names like the “Alaskan Canada jay” or the “Oregon Canada jay” and so instead, they opted for gray jay as the official full-species name.

By 1954, however, this system grew too taxing and the committee essentially adopted Miller’s 1930’s suggestion: only full species get official common names and subspecies are named and identified by their trinomial Latin name. For some reason, though they did not revert back to the original* name of Canada jay as their rules suggested they should, and instead they curiously retained the name gray jay. This may have been the last of it if not for a ~political~ controversy that would rock the nation of Canada a half-century later.

2016_national_bird

In 2015 the Royal Canadian Geographical Society sought to declare a national bird of Canada, a spot that remained egregiously vacant, by hosting a massive public vote to choose among 40 potential candidates. As the popular vote neared an end, five front runners had emerged: the gray jay, the Canada goose, the common loon, the black-capped chickadee and the snowy owl. Ultimately, the common loon would go on to win the popular vote by a 10% margin. Once voting closed, however, the RCGS convened a panel of experts to debate which bird they thought was most worthy. To the shock and upset of the voters, in 2016 RCGS ultimately chose the gray jay, a bird many voters complained did not have the connotation of national pride that the loon did. In the end, though, none of it-the year and a half long competition, the 50,000 votes, the ensuing controversy-mattered because the actual Canadian government had no interest in naming a national bird.

Still, the public’s perception that the jay was not a strong enough symbol did not sit well with Canadian jay scientists like Strickland and Ryan Norris who knew of the jay’s more patriotic heritage. Determined to understand and ultimately reverse the 1954 ruling, Strickland set out to show AOS that the decision to retain the name “gray jay” was not in keeping with their own rules. And, as you already know, in 2018 he succeeded; the bird formerly known as the gray jay (which was formerly known as the Canada jay) is now officially reknown as the Canada jay. The Ouroboros has finally caught its tail. Well, for many people it has.  I want to enter yet one more heir into this contest, the one that I believe holds the most legitimacy to the throne: the whiskeyjack.

Unlike the name might suggest, whiskeyjack isn’t derived from campfire tales about these gregarious birds robbing campers of their whiskey.  It’s an English name derived from the indigenous Cree (and other Algonquian family languages) name for the bird, Wisakedjak. In Cree culture (and some other First Nations peoples of the subarctic region) Wisakedjak is a sacred figure who is known as a trickster and in some cases for being among the creators of the world.  It’s a befitting name for this clever little corvid and the merits of its legacy are without question.  In fact “whisker-jack” can even be found in the English literature as early as 1740, nearly one hundred years before the name Canada jay would first be used. I’m not alone in my support either, even during the 1947 debate, L.L. Snyder notes that “‘Whiskeyjack’ is used universally in the north (& will continue to be).”

Throughout this article, you may have noticed the occasional * following words like “original” or “discovered” and that’s because those words are only relevant when thinking about natural history in post-colonial terms. But the truth is that most wildlife were already known, already named, already studied by the various peoples that called this continent home before their lands were taken from them, and their traditional knowledge erased in favor of a Western approach. So if our goal is to honor the heritage of this bird, I can think of no name more appropriate than the “whiskeyjack jay.” That is the return to the beginning that this magnificent bird deserves.

***

 

7 Comments

Filed under Birding, Canada jays, Science, Wildlife

A matter of a pinion

Like all subcultures, the world of corvidphilia comes with its own set of corny jokes and puns.  Of these, perhaps none is more well known than the classic: “What do you call two crows?”

“An attempted murder.”

drum

Despite their groan-inducing nature, I consider myself a connoisseur of such jokes.  After all, it’s rather flattering that crows are such a cultural fixture that they get their own jokes and cartoons.

Velcrows

There’s one joke though, that I have no choice but to spoil in the name of scientific accuracy. After all, what kind of scientist would I be if I left semi-obscure memes about crows go unchecked?

Pinion

There are many version of the “matter of a pinion” joke but this one is the most cringe-inducing for me because it has the audacity to present itself as scientific fact.  The truth is, not only do corvids have far fewer than sixteen primaries, but the entire premise of the joke is simply wrong.

All birds have at least nine primary feathers, but most birds, particularly within the passerines, have ten on each wing.  Even outside of passerines, most birds have only ten, though there are exceptions.  Flamingos, for example, have twelve, and ostriches have sixteen.  Crows and ravens, on the other hand, are in no way exceptional, either from the norm or each other.

Crow wing

American crow wing.  Photo c/o the Slater Museum of Natural History.

Revn wing

Common raven wing.  Photo c/o the Slater Museum of Natural History.

So, no, the difference between crows and ravens is not, in fact, a matter of a pinion.  There’s one thing I do want to point out, though, particularly for you #CrowOrNo players.  While it’s true that crows and ravens have the same number of primaries, they do look different enough that in flight you can often identify a bird as either a crow or a raven based on its primaries.  Of the ten primaries, there is a handful that is longer and more distinct than the others, making them look kind of like “fingers”.  Looking at the wing pictures above, you can see that the crow has five evident finger feathers (feathers 5-9) whereas ravens only have four (feathers 6-9).  This difference is a bit easier to detect on birds in flight than on these static wing specimens.

DSC_0503

Common raven in flight showing the typical four “finger” feathers.

DSC_1032

American crow in flight with five evident “finger” feathers.

So with this in mind, it’s possible that with a little handwaving you can actually get away with saying the difference between a crow and a raven is a matter of a pinion, but by now there’s not much of the joke left since you have to leave off the initial context.  A much more scientifically sound version, however, would be to compare crows and song sparrows, which only have nine primaries.  “What’s the difference between a crow and a song sparrow?”

“It’s just a matter of a pinion!” And then, as with any good joke, you would explain to your audience the scientific merit of the punchline by describing the technicalities of wing feathers.

Funny right?

Funny

So what’s your favorite corvid joke? Let me know in the comments!

***

16 Comments

Filed under Birding, Just for fun, Ravens

Denali field notes: Wildlife report

One of my followers on Instagram recently requested a list of all the wildlife I’ve seen in the park.  Since my stay has (for now) come to and end, it’s actually a great opportunity to look back on everything I’ve enjoyed while I’ve been here.  Which animal would you most want to see?  Let me know in the comments!

Mammals
1. Voles.  Unfortunately this is only animal I neither have photos of nor can ID to species.  When you see a vole the sighting usually goes something like this “look there’s a v-” and then it’s gone. Not much time to even wrap your head around it, frankly.  Though I did get one good look once when I got to see one swim across a puddle at my feet.

2. Red squirrel (Tamiasciurus hudsonicus). If you follow me on Twitter you’ll know I was quite enamored with their mighty middens.

DSC_0410

3. Short-tailed weasel (Mustela erminea). Easily one of my favorites of the trip.  They are as hilarious to watch as they are adorable.  It’s like if squirrels rebranded their frenetic stress into something cool.

4. Collared pika (Ochotona collaris). Like hares and rabbits, although pikas may look rodent-like they are actually in the lagomorph family. Pikas can be found on rocky hillsides throughout the park.

5. Arctic ground squirrels (Spermophilus parryii). You can easily find these critters all over the Eielson visitor center, but they’re abundant across most of the park too

6. Muskrat (Ondatra zibethicus). There are at least a half dozen muskrats making their home in Horseshoe Lake alongside the beavers that keep it dammed it up.

7. Snowshoe hare (Lepus americanus).  You can learn more about these animals in this post.

DSC_0532

8. Red fox (Vulpes vulpes). I spotted a fox while en route from Wonder Lake to Eielson, but it was too far off to bother with a photo for.

9. Canada lynx (Lynx canadensis). I was really, really hopeful to see a lynx but until now that’s resulted in nothing more than disappointment.  Finally success!

DSCN1009

The remaining 5 mammals I’ve already dedicated an entire post to.  Check it our here!

10. Grey wolf (Canis lupus)

11. Dall sheep (Ovis dalli)

12. Caribou (Rangifer tarandus)

13. Girzzly bear (Ursus arctos horribilis)

14. Moose (Alces alces)

Birds
15. Boreal chickadee (Poecile hudsonicus). These little winter warriors are everywhere, and are always tricking us into thinking they’re jays and then laughing at us for confusing such a tiny bird with a corvid.

DSC_0659

16. Common redpoll (Acanthis flammea).  I didn’t see any when I was here last March, so this was a lifer for me!

17. Dark-eyed junco (Junco hyemalis). A familiar face from Washington.

18. American tree sparrow (Spizella arborea).  I spotted this one with help from birder extraordinare Noah Strycker, who joined us for a few days to help with data collection.

19. Lincolns sparrow (Melospiza lincolnii).  These birds joined us on one of my favorite hikes of the trip.

20. White-winged crossbill (Loxia leucoptera).  Like all crossbills, these birds use their amazingly adapted bills to fiddle with spruce cones.  They move through areas in fairly large flocks chattering up a storm and raining cones down in their wake.  Then like a flash they are gone.

DSCN2295

21. Pine grosbeak (Periporphyrus erythromelas). The males can be easily mistaken for a crossbill at first glance, but their bulky size and beautiful song distinguishes them.

22. American dipper (Cinclus mexicanus). America’s only aquatic songbird.  We saw a pair of these birds mulling around Horseshoe Lake.

DSCN2078.jpg

23. Varied thursh (Lxoreus naevius). If you’ve never heard it, the varied thrush produces a very whistle-like tone sung in a single pitch for about two seconds. For me, these sounds are familiar forest sounds, but for many visitors these birds and their calls are completely foreign. As a result, evidently it’s not uncommon for visitors to mistake their calls for emergency whistles and report them to park law enforcement!

24.  American robin (Turdus migratorius). A turd I can’t live without.

25. American three-toed woodpecker (Picoides dorsalis).  For all the dead trees around here I am frankly surprised we didn’t see more woodpeckers.  It took about five weeks before I finally saw my first one!  Then it was like we couldn’t shake them.

25. Canada jay (Perisoreus canadensis). It would have been kinda a problem if these birds hadn’t made the list.

26. Boreal owl (Aegolius funereus).  This sleepy bae was very rudely awakened by some cranky Canada jays.  It just gave them a few robotic blinks and went back to sleep.

DSC_0614

27. Merlin (Falco columbarius).  These birds are so fun to watch, but I only ever caught the occasional glimpse while driving through the park.

28. Black-billed magpie (Pica hudsonia). For such a pretty bird they are darn camera shy!

29. Greater scaup (Aythya marila).  I was a little late to see much in the waterfowl department but we did see a few of these in the kettle ponds near Wonderlake

30. Northern hawk owl (Surnia ulula).  This picture is from last spring, but I am claiming the right to never need another hawk owl photo again.

DSC_1005

31. Northern goshawk (Accipiter gentilis). Don’t let their scientific name fool you.  These are serious murder birds and probably the number one killer of hares that we encountered.

DSC_0499-2

A goshawk chases a raven. 

32. Gyrfalcon (Falco rusticolus).  Man I wish I have been able to capture one of these in full glory.  Such beautiful falcons.

33. Willow ptarmigan (Lagopus lagopus).  The state bird of Alaska! Like the hare and the stoat, these birds adopt a new look during the winter.  This one was early in the transition.

DSC_0645

34. Spruce grouse (Falcipennis canadensis).  I wrote about a cool encounter with these birds in an earlier post.

35. Common raven (Corvus corax).  Somebody find me a project so I can study these next!

36. Great-horned owl (Bubo virginianus). It’s within the realm of possibility that this particular GHOW killed one of our jays, but the evidence was circumstantial so I won’t hold them to account just yet.

DSCN0393

37. Sandhill crane (Grus canadensis).  Listening to them fly over the park as they begin their fall migration is a sound so beautiful that it hurts to think how few people will get to hear it in their lifetime. 

38.  Golden eagle (Aquila chrysaetos). Okay, so I didn’t take this picture in Denali, but I couldn’t have ended on a picture-less note! Plus, look at that handsome devil.  My goodness.

DSC_0044

Enter a caption

 

10 Comments

Filed under Birding, Denali Diaries, Field work, Just for fun, Photography, Wildlife

You need to know more about jay spit

Look, I’m a reasonable person.  I know what you’re thinking.

“Literally never has it occurred to me I might know too little about jay spit.”

But here’s the thing: it’s actually super interesting and you really can’t understand Canada jays without knowing about their saliva.  It would be like trying to understand the internet without cat videos-you just can’t do it.  So trust me when I tell you this is the information you didn’t know you needed.

DSC_0164

In the early 1960’s Walter Brock was examining Canada jay corpses when he discovered that they have massive salivary glands on par with the ones found in woodpeckers.1 Such generously sized glands are found in no other songbird.  Furthermore, like the woodpeckers, it’s not just that Canada jays make a lot of saliva, but they make a lot of sticky saliva.  At the time this discovery was made, it was already known that the enlarged glands of woodpeckers served to allow for a foraging tactic called “tongue probing” where, like anteaters, the birds use their long sticky tongues to extract food from narrow crevices.  Although Canada jays don’t have especially long tongues, the ability to tongue probe seemed the most parsimonious explanation for this strange adaptation, and Brock suggested that this strategy may actually be the key to the jays’ winter survival.  A study a few years later examining their foraging behavior revealed that they don’t feed in this manner, however.  They feed more or less the same way the other corvids do.2  It seems instead, that it’s what they do with the food after that’s different.

DSC_0440

Rather than using their copious amounts of weird, sticky spit for acquiring food, it’s used for depositing it.  If you watch a jay closely after it’s got a bit of food you’ll notice it seems to have missed Emily Post’s memo about chewing with your mouth closed. Over the course of a few seconds you’ll see the food peek out from the bill as the bird moves it around inside its mouth.

DSC_0366

This jay picked up this bit of food about 60sec before this photo was taken.  Now it’s working it around with its tongue, coating it in sticky saliva.

Once sufficiently spit coated, the bird will deposit the food blob (called a bolus) onto the foliage or trunk of a tree.  No matter the material or angle, once the spit dries the food is safely secured come hell or high-water.  Because these caches are pretty small there’s little fear that many will be found.  More importantly, by stashing food high in the trees instead of burying them into the ground like many other cache-dependent corvids do, Canada jays can thrive in areas that receive much heavier snowfall, allowing them the title of the most northern residing jay in North America.

Here’s where it all really comes together though.  If you’ve seen me write about Canada jays before you’ll have noticed that it’s almost inevitable that I’ll use the phrase “Cute little faces” at some point to describe them.  But have you ever wondered why? Why do they have such cute little faces?  While jays do feed more or less in the same way as other corvids the one exception is that they don’t hammer at objects.  If you’re ever given a crow or a Steller’s an unshelled peanut you’ll know exactly the motion I mean. Without the need the hammer objects, or dig holes for burying food, Canada jays don’t need the heavy bills their cousins do.2  Instead they have the blunt little bill that helps give them their characteristic baby-faced look.  So not only is their spit responsible for their ability to tough it out in some of the harshest winter environments this continent offers, but it also means they get to look super cute while doing it.

So like I said, you don’t really know Canada jays until you know a thing or two about their spit.

DSC_1042

Literature cited

  1.  Brock WJ. (1961). Salivary glands in the gray jay (Perisoreus). The Auk 78: 355-365
  2. Dow DD. (1965). The role of saliva i food storage by the gray jay.  The Auk 82: 139-154

16 Comments

Filed under Birding, Canada jays, Corvid trivia, Diet, Field work, Jay behavior, Science

Meet Ferdinand

Around this time last year I was both delighted and intrigued when a reader emailed me about a very usual crow showing up in her yard.  Unlike its flock mates this crow was not black, but white and brown, like the kind of milked-down coffee that inspires the comment “would you like some coffee with your cream?”.  Understanding what would cause such a unique coloration in her crow sent me down a most unexpected rabbit hole where the science of what I call ‘caramel crows’ turned out to be somewhat subject to mystery.

Within months of publishing that article, I couldn’t believe my luck to encounter a caramel crow of my own named Blondie.  Whereas the science of their pigmentation may be up for debate, their beauty most certainty is not and I considered myself exceptionally lucky to lay eyes on one in person.

Photos of Blondie from 2017

Now, it seems my perception of their rarity may not have been quite justified as I have since discovered yet a second caramel crow, who I call Ferdinand, in a completely different part of the city.  Unlike Blondie, who lives exclusively in a residential area, Ferdinand’s haunts include a public park.  I won’t give his or her precise location, but if you’re a Seattle native I encourage you to use the clues provided in the text and photos of this post to see if you can find Ferdinand.  If you do use the hashtag #FoundFerdinand to update us on its activities but remember not to give away its precisely location.  This is both to encourage people to get outside and explore on their own, and to protect Ferdinand’s safety.  If seeming him in person is not possible I hope these photos will suffice.  As a last bit of fun feel free to let me know in the comments who you think wore it better, Ferdinand or Blondie.

DSC_1106

DSC_1175

DSC_1032

DSC_1156

DSC_1063

DSC_1235

DSC_1236

33 Comments

Filed under Birding, Crow curiosities, Just for fun

15,000 crows

I had imagined it like a beckoning flood.  A small sputter of water followed with increasing force until a great river finally makes its way.  Rather than water though, the flood I was trying to envision was the ascent of 12-15,000 crows to their nightly roost in Bothell, Washington.

DSC_5117.jpg

Witnessing it in person, I found that my water analogy was not entirely accurate.  Rather than being a steady stream with a predictable course, their arrival ebbed and flowed, sometimes leaving the sky lonely with only its fading grey light while other times exploding into seemingly endless black clouds.  They arrived from all cardinal directions, colliding into a mass that could be deafening at close range.  Although the movement of the flock as a whole was more restrained, individually they showed off with spontaneous dives and barrel-rolls.  Soon the light receded completely, and all I could sense was the cacophony of so many crows settling into the willow trees they would call their beds for the evening.

Time lapse of Bothell crow roost I took with my GoPro in December of 2016.  Music by Andy McKeen.

Since that first experience, I have visited the Bothell roost many times, each as awe inspiring as the time before.  This behavior isn’t unique to my region, however.  Cities and rural areas all over the world call themselves home to the upwards of thousands, even hundreds of thousands of crows that may seek their refuge when darkness falls.  Even in the greater Seattle area, Bothell is only one of two roughly equally sized roosts.  This kind of mass sleepover, known as communal roosting, isn’t unique to crows, but it certainly captures our attention in ways most other birds don’t.  So what exactly are the characteristics and functions of roosts?

For all species of corvid, roosts are places where anywhere from a small handful to hundreds of thousands of individuals may converge to spend the night together.  Though roosting occurs year round, it peaks in winter, when territorial pairs are free from the eggs or nestlings that demand all-night attention.  They may occur in wildlands, but more typically occur in cities, where sequestration of heat is higher than in surrounding areas.  Here in Bothell, the roost converges in a wetland outside of the University of Washington’s Bothell campus, but in other areas they may take over the rafters of abandoned buildings or trees dotted within a business district.

Historically Danville, IL hosted North America’s largest roost, a whopping 325,000 birds but I do not know if they remain the contemporary record holder.  The midwest is particularly primed to host such large numbers because many thousands of crows head there during winter from their too cold territories in Canada and because appropriate roosting locations are few and far between.

DSC_5079

Prior, or just after roosting crows attend “staging” or “pre/post-roost” areas where they gather in the trees or on the ground by the hundreds or thousands.  Since these staging areas often occur on asphalt or turf where there’s little food or water, their function continues to elude scientists though social or anti-predator implications seem likely.1 A new UW research study is attempting to parse why crows are so vocal during the staging period and what they might be trying to communicate.  Perhaps their findings will shed some much needed light on these events. 

Corvids get different things out of roost itself depending on the species or possibly even the region they live.  For example, for ravens roosts act, in part, as mobile information centers.2  A raven knowledgeable of a food bonanza such as a moose carcass will display to other ravens at first light, and recruit others to the food.  Rather than being a sign of food altruism, this kind of recruitment is often the only way a lone raven can gain access to a large carcass.  Finding and gaining access to an animal carcass is challenging both because its arrival is unpredictable but also because it’s intensely guarded by the pair whose territory happened to claim the animal’s life.  Overpowering a pair takes a small army, so by recruiting other birds, rather than giving up food in the name of helping others, the lone raven actually gains access to a resource it would have otherwise been boxed out of.

American crows on the other hand do not have this need because urban waste and invertebrate filled yards are so easy to come by.  For crows, roosts act in large part as predator protection.  The odds of successfully fleeing an incoming owl are much better when there are thousands of you, rather than just you and your mate.  They may serve other purposes as well though including socialization, mate finding, and thermoregulation.  Lastly, while there isn’t strong evidence of information sharing among crows it would be arrogant to claim we know it doesn’t occur.

How roosts are organized remains largely mysterious.  For example some evidence shows that ravens that come from the same food bonanzas also sleep near each other in a roost,2 whereas other work done on crows suggested that group cohesion is low at roosts.3  Still, other research suggests that while group cohesion from the territory is low,  it’s high leaving the staging area.  So perhaps there is deep rhyme and reason for who they sleep with, it just hasn’t been captured by the questions we’ve so far asked.  One thing is for certain though; the one place you don’t want to be is low in the trees with others above you.  There would be no escaping the white shower raining down throughout the night.

Even the people who share the UW’s campus are sensitive to this reality.  In perfect synchrony with the incoming cloud of birds, the umbrellas bloom like moonflowers.  Here in Seattle, people seem willing to take such measures to coexist with the birds (though I’m sure there are many who only do so only by rule of law).  In other areas though the cultural attitude or resulting damage makes such cohabitation difficult, even deadly.  In the most extreme case, 328,000 crows were killed in 1940 when the city of Rockford, IL elected to dispose of a local roost with dynamite.4  Today, crows are protected under the migratory bird treaty act and cities are usually required to take more creative, non-lethal approaches including noise and light deterrents.

City living doesn’t always lend itself to witnessing the kind of mass animal movements we fawn over when they appear in Planet Earth footage, but that doesn’t mean they are devoid of such spectacles.  The mass micro-migration of thousands of crows is an awe inspiring event,  grand in both scale and the mysteries it contains.  Any corvid or birdwatcher would be remiss to ignore such an opportunity and I encourage everyone to get outside, head to your roost, and watch the magic unfold.

Literature cited

  1. Moore JE, and Switzer PV. (1998).  Preroost aggregations in the American crow, corvus brachyrhyncos.  Canadian Journal or Zoology.  76: 508-512.
  2. Wright J, Stone RE, and Brown N. (2003).  Communal roosts as structured information centers in the raven, Corvus corax. Animal Ecology 72: 1003-1014.  DOI: 10.1046/j.1365-2656.2003.00771.x
  3. Donald F. Caccamise, Lisa M. Reed, Jerzy Romanowski and Philip C. Stouffer
    (1997). Roosting Behavior and Group Territoriality in American Crows. The Auk 114: 628-637
  4. Marzluff, J.M. and Angel, T. 2005. In the company of crows and ravens.  Yale University Press

10 Comments

Filed under Birding, Crow behavior, crow conflicts, Crow curiosities, Crow life history, Crows and humans

My first caramel crow 

A few months ago I was both bewildered and delighted when someone emailed me some photographs of a brown crow that regularly visited them.  I had never seen such a bird myself, and was eager to arrive at an explanation for the crow’s strange caramel-colored appearance.  If you follow the blog, you know that I came to realize there was little to offer by way of explanation.  Instead, this color abnormality presents a rather fascinating mystery of conflicting opinions and an overall dearth of science.

So, after penning my answer I tucked this bird away in the back of my mind and moved forward with the science more relevant to my PhD.  Namely, testing how different crows across the Seattle area respond to dead crows.

To this aim, I spend my days wandering the neighborhoods of Seattle looking for crow families to use for my experiments.  Since I need lots of data points it means I encounter lots (think hundreds) of individual crows.  And wouldn’t you know it.  Sometimes the twain shall meet.

Its mate first caught my eye because, of course, I was looking for black things, not blond things.  Even after I registered the bird, I instinctively thought pigeon.  But then it called, and I realized what was happening.

DSC_0758

At 60m away with my naked eye, I first mistook Blondie for a friendly pigeon.

I FOUND A CARAMEL CROW!  And not just a caramel crow, but a caramel crow with a mate and three fledglings.  A black mate and three black fledglings.  Which suggests that whatever is going on is either recessive or not genetic.  It also shows that, for at least this one caramel bird, the color abnormality did not prohibit it from successfully reaching sexual maturity or finding a mate.  After speaking with the neighbors, it appears “Blondie,” as they call it, has been in the neighborhood for several years and it’s possible she’s not the only caramel crow, though I never confirmed any others.  Outside of that, I can’t say much more from a scientist’s standpoint that I haven’t said before.  So I’ll simply finish the post with a photo story of Blondie.  Enjoy!

DSC_0887 (1)

Meet Blondie

DSC_0743

 

DSC_0930

Blondie and its mate.  Since I discovered this bird after its nestlings had already fledged, I have no way of determining its sex.

DSC_0708

So beautiful in this juniper tree!

DSC_0751

Blondie’s fledglings were typical looking crow kiddos.

The next batch of images are probably one of the most hilarious bits of fledgling dramatics I’ve ever seen.  It is a scene familiar to many parents I’m sure.  Forgive me for taking my scientist hat off, but I couldn’t help but add some anthropomorphic captions.

DSC_0916 (1)

Hello parent I am hungry.

DSC_0924 (2)

DID YOU HEAR ME, I SAID I’M HUNGRY.

DSC_0918 (1)

(whispering) help, parent, I need sustenance for my growing body.

 

DSC_0919 (1)

(muffled whispering) please, have mercy, it’s been over 15 minutes since I was last fed.

DSC_0925 (1)

MAYBE I’VE ALREADY DIED AND NOW I’M A GHOST IS THAT WHY YOU AREN’T LISTING TO ME???

DSC_0928

I’m sorry.  I’m just hangry.  I love you.

DSC_0753

DSC_0911

DSC_0893

Cheers to yet another beautiful crow.  Goodbye for now!

48 Comments

Filed under Birding, Crow curiosities, Just for fun

RAVENous for crow eggs 

Given their similarities, it might surprise folks to see crows occasionally harassing and chasing ravens. After all, birds of a feather right? Not in this case.  Rather than being in cahoots, the relationship between crows and ravens is most often competitive, though it can also be predatory.

DSC_0675 (2)

A raven barrel rolls to scold an attacking crow.

Such is the case in a recent video shared with me by a reader, Ty Lieberman.  To the dismay of him and his colleagues, a crow nest they had been observing outside their Los Angeles office window was partially dismantled, and at least one egg taken by what they believed was a pair of crows.   Concerned for the survival of the nest, Ty reached out for my interpretation.  Based on his initial description, I wondered if maybe he had witnessed egg transport, something I knew had been observed in black-billed magpies and pinon jays.1  Previous accounts of these species included descriptions of eggs being taken, and then returned to the nest, as well as eggs being deposited into the nests of neighbors, both of which are utterly fascinating behaviors and probably warrant their own post.

To date, however, there are no accounts of crows engaging in this behavior, though there is one documented observation of a nestling being deposited into a nest from which it did not originate.2  Again, utterly fascinating, but not helpful here.

Later, a more detailed account from Ty made mention of the size of the intruding birds, which quickly led me to the story’s true explanation.  Shortly after my ‘ah ha’ moment, to the dismay of he and his colleagues the nest raiders returned, and this time were caught on video by one of Ty’s colleagues (who you can follow on twitter, @namnam).  Rather than being crows, these literal homewreckers were common ravens.

Instead of being something out of the ordinary, Ty had witnessed a typical breeding season interaction between crows and ravens.  It’s no wonder then, that crows can be so hostilie when ravens enter their territory. 

DSC_0676

Crows (top) mobbing a raven (bottom) in Kent, WA

Eggs of all kinds are one of the most power-packed meals in the animal kingdom, so it’s no surprise ravens would take advantage of crow nests when they find them.  Around this same time back in 2015, a black bear made a similarly memorable meal out of a raven nest, reminding us that for corvids of all kinds, it’s a constant fight between being predator or prey.

Literature cited

  1.  Trost CH and CL Webb. 1986. Egg moving by two species of corvid. Animal Behaviour 34: 294-295.
  2. Schaefer JM and Dinsmore JJ.  1992.  Movement of a nestling between American crow nests.  The Wilson Bulletin 104: 185-187

12 Comments

Filed under Birding, Breeding, Crow behavior, Raven behavior

What’s in a (corvid) name?

Most people know various corvid species by their common names but have you ever wondered what etymologies inform their scientific names? Turns out it’s a pretty fun little exercise to find out!

img_56531.jpg

Before we get to breaking down individual corvids though, a quick word on scientific names more generally.  Scientific names always have the format: Genus species. Meaning, the first word in the name tells you what genus the plant/animal belongs to and the second tells you the species name specific to that organism. So for example crows, rooks, jackdaws and ravens are all in the same genus so their scientific names will all start with the same word: Corvus. The second word, however, will be unique to each species. This system of binomial nomenclature was first developed by Carl Linnaeus in the 1700’s.  By looking up the roots of an animal’s scientific name we can learn a thing or two about what he, (or whoever named it) was trying to highlight. Then again, sometimes they’re just fans of Beyoncé or Jonny Cash.

One more note: although scientific names are often referred to, informally, as Latin names, their roots may actually pull from many languages.  Though by far the most common languages are Latin and Greek.

As it happens, I have an old book of  root words I inherited from my late grandfather, Richard Swift. Something about having that book in my hands begged for this exploration in a way that having the breadth of the Internet at my fingertips never did. What can I say, a childhood spent in the library of my grandfather’s office has made me a sucker for old, smelly books. So let’s get started!

Common raven: Corvus corax
Common ravens are the biggest of the corvids (and in fact, the biggest of all the songbirds) so it makes sense their name might be the yardstick by which other corvids are measured. Cora literally translates to “crow, raven” so the common raven’s scientific name essentially just means raven.

DSC_2853

GO, the American crow

American crow: Corvus brachyrhynchos
Turning to American crows, we can see that yardstick I mentioned coming into play. Brachy means “short” and rhynch means “a beak or snout.” So the American crow’s full scientific name basically translates to the “short-beaked crow.”

junlge crow

Jungle crow, photo c/o Anne Kurasawa

Jungle crow: Corvus macrorhynchos
At this point, the meaning of the jungle crow’s name probably needs no explanation. The bird looks essentially like an American crow but with a more pronounced bill. Macr rhynch = large beak.

corvus_albus_-etosha_national_park_namibia-8

Pied crow, photo c/o Frank Vassen

Pied crow: Corvus albus
Alb means “white.” No mystery here.

house-crow444

House crow, photo c/o Benjamint444

House crow: Corvus splendens
Splen means “a badge or patch.” With grey sweater they sport, it’s likely the person who named them was trying to highlight this physical distinction.

thick billed raven

Thick billed raven, photo: Ignacio Yufera

Thick-billed raven: Corvus crassirostris
Sometimes, scientific names are precisely their common names. Such is the case here. Crass means “thick” and rostr means “beak.” This is a good example of where we see different languages influencing the names.  In this case, thick-billed ravens got the Latin root, whereas American and jungle crows got the Greek root for beak.

16757988474_95447ac3f6_z

Rook, photo c/o Pam P.

Rook: Corvus frugilegus
This one is less clear to me. Frugi means “useful, fit” and legus means “lie down; choose; or collect” depending on what language you pull from. My guess is it’s supposed to be ‘collect’ and the name refers to the more specialized bill they have for collecting insects.

Finally,

grey-crow

The grey or bare-faced crow, photo c/o B.J Coates

The grey crow: Corvus tristis
Trist means “mournful; sad.” I have a feeling I know the backstory for this one but I’ll leave it to my readers to see if they can figure it out. Leave me your best explanation (made up or researched) in the comments!

12 Comments

Filed under Birding, Corvid trivia, Crow curiosities, Uncategorized