Category Archives: Crows and humans

Addressing anti-Indigenous behaviors in corvid fandom

There are few animals that generate the kind of enthusiasm and following that ravens, crows, magpies and other birds in the corvidae family do. Their presence in our lives is so significant, they appear in the creation stories and fables of nearly all peoples. Today, our love for these birds has given rise to what feels like an entire industry of books, jewelry, artwork, and of course literal fan clubs, some of which serve many tens of thousands of followers. This community is not only fun to be a part of, but is doing important things to improve the reputation of corvids among those individuals or communities who might consider them a nuisance.

There are a couple of common ways though that, in our attempt to uplift corvids, our fandom sometimes trivializes the traditional beliefs of Indigenous North Americans, primarily through cultural appropriation and erasure. If it’s a new or esoteric term to you, cultural appropriation is the act of copying or using the customs and traditions of a particular people or culture, by somebody from another and typically, more dominant people or society.1  Here are three small steps the non-Native community (of which I am a part) can take to more respectfully celebrate our love of corvids, and the people for whom they traditionally hold deep cultural meaning. 

#1 Don’t use the term  “totem” or “spirit animal,” choose an alternative

In every place and time that humans and corvids co-occur, people have made culturally important meanings, stories, and symbology about these special birds. As a united group of corvid fans, it may therefore be tempting to sample from these practices as a means of creating community. One common way I see this manifest is in the use of terms like spirit animal to describe someone’s connection to a particular corvid. Like animism (the belief that all material possesses agency and a spirit) the term itself appears to have been an invention of anthropologists, but its intent is to refer to Indigenous religious practices. Co-opting this practice as our own, no matter how well-intentioned, devalues cultural traditions that are not ours to claim. 

A quick Etsy search of the term demonstrates just how far we’ve allowed the abasement and monetization of this practice by non-Indigenous people (i.e wine is my spirit animal t-shirts.) Even in cases where our use of cultural appropriation doesn’t feel objectively derogatory (it might even feel honorific), its adoption by non-Indigenous people is the kind of cultural cherry picking that has long frustrated Indigenous communities

“Dear NonNatives: Nothing is your spirit animal. Not a person, place or thing. Nothing is your spirit animal. You do not get one. Spirit animals derive from Anishinaabe and other tribes deeply held religious beliefs. It is a sacred, beloved process that is incredibly secret.”

Mari Kurisato

To ignore those frustrations and claim that our use of this religious practice is either benign or born out of respect, is to prioritize the needs and feelings of ourselves above those for whom literal and cultural genocide remain contemporary battles.  In other words, it’s an act of racism. Of course, Indigenous peoples are not a monolith, and you may find individuals that feel no harm from non-Natives using this term, or even grant you specific access to it (though beware of plastic shamans.) In these cases, I offer that it’s harmless to decline using it despite any special permissions, while adopting it risks hurting and alienating the broader communities for which this or similar terms are sacred. 

Fortunately, there are many alternative ways to express kinship with corvids that do not rely on cultural theft. Here are a few of my favorites: muse, soulmate, best friend, fursona, daemon, icon, desired doppelgänger, secret twin, and familiar. 

#2 Recognize the diversity of Indigenous nations 

Pretty regularly, I see infographics pass through my social media feeds depicting either a photo or some kind of Indigenous-esque looking art and a sound bite about a “Native American” story about crows or ravens. While the intent here is obviously to celebrate a shared love of corvids, the means of doing so makes  no effort to actually learn the story or, importantly, from whom that story originates. 

There are 574 federally recognized Indigenous nations in the United States. There are even more when you include non-federally recognized tribes (ex: the Duwamish on whose lands much of the Seattle area is built.) While there is certainly shared knowledge and traditions, it’s important to recognize that these are independent nations with their own creation stories and traditions. For example, the story of Rainbow Crow (Mànàka’has), who brought warmth to the world by carrying a burning branch and sacrificing his voice and technicolor feathers in the process, is a Lenape legend.2 Alternatively, the story of Raven stealing the sun to bring light to earth is a Haida, Tsimshian, and Tlingit legend.3

Attributing them as simply “Native American” stories erases their cultural heritage by treating all Indigenous peoples as a monolith with unified cultural traditions. This is especially pernicious when these stories are told in the past tense, as if the people from whom they originate are gone. Putting in the effort to research where specific stories come from, and how and where that community exists now, is an important step to recognizing and respecting different tribal identities.

For the same reason, another important practice is to research on whose land you currently enjoy the corvids you watch or photograph. 

As Larissa Fasthorse explains, “Always know whose land you’re standing on. Who are the original people of that land? You need to find that out. You need to know those people, and,  where are they? Are they still there? If not, why? Where have they gone? Start to learn, start to educate yourself. Whose land are you profiting from and how can you start to pay that back in your own way.”

Larissa Fasthorse, interview on Here and Now 10/12/20

So the next time you see an interesting legend about corvids, do some research to learn about the actual people behind that story. Beware of sharing memes that make no effort to do that work. That’s generally a sign that they were not written by someone of that cultural heritage and are more interested in gaining likes and shares than honoring other people. Know on whose ancestral land your corvid watching takes place, and seek out print or digital resources to learn about those people. 

While the line between cultural appropriation and cultural appreciation can be fine, a willingness to seek out knowledge beyond what caught your initial attention is the best way to ensure you’re not engaging in cultural cherry picking. There are several great resources to starting doing this including Whose Land, which is an Indigenous-led project. You can also find more local resources that may serve you better, including the websites of individual tribes.

#3 Buy books and artwork directly from Indigenous sellers

Be it from Navajo, Tlingit, or Haida origins, Indigenous depictions of corvids are unequivocally beautiful. It’s only natural that corvid lovers might wish to enjoy such artistry in jewelry, paintings, sculptures, or books. As long as it’s not in the pursuit of a costume or other forms of identity theft, purchasing and displaying Indigenous art is encouraged, especially when you can use it to draw more attention to the artist. Sadly though, the number of Indigenous creators are far out-numbered by non-Native people looking to profit off their culture. 

For example, the Alaska Department of Commerce and Development estimates that 75-80% of what is branded as Native art, was not actually made by Alaska Natives, resulting in the redirection of millions of dollars away from Alaska Native communities.4  So before swiping that credit card, make sure that the creator of that piece has the cultural heritage to claim ownership of it. As the Indigenous led Eighth Generation collective puts it, make sure it was created by “inspired Natives” and was not “Native-inspired.” Don’t be afraid to ask shop owners or gallery curators this question directly. That’s not only an easy way to find out, but it signals to that purveyor that sourcing directly from Indigenous creators is something their customers require. Buying directly from Indigenous artists is an even better option. 

Here are a few Indigenous creators and collectives and a slideshow of their products: 
Eighth Generation
I-Hos Gallery
B. Yellowtail
Warren Steven Scott
The Shortridge Collection
Seaalaska Heritage Library

As always when buying from artists, expect the price to reflect that the piece supports a livelihood and don’t attempt to barter. The goal shouldn’t be to simply obtain a beautiful object, but to celebrate and support the person who took great care to craft a sharable piece of their identity. 

Reconciling the ongoing pain caused by centuries of brutality, land theft, and cultural erasure will not be an easy process. It’s uncomfortable, for example, to realize that while your intent was simply to love on corvids, something you’ve done or said is being called out as anti-Indigenous. But it’s essential that we are willing to engage with that discomfort because it’s through that process that we learn and initiate positive change. Inviting Indigenous voices into your spaces is the most important way to start or continue that effort. Please look for the following individuals who are but a drop in the list of fantastic people you can find. And if you appreciated this article, please consider making a donation to one of the individuals or organizations listed below.

Twitter
Vincent Schilling (@vinceschilling)
Delores Schilling (@DelSchilling)
Jesse Wente (@jessewente)
Mari Kurisato (@wordglass)
Katherine Crocker (@cricketcrocker)
Chief Lady Bird (@chiefladybird)
Daniel Heath Justice (@justicedanielh)
Jay Odjick (@JayOdjick)
Kat Milligan-Myhre (@Napaaqtuk)
Alethea Arnaquq Baril‏ (@Alethea_Aggiuq)
Ruth Hopkins (@Ruth_HHopkins)
Nick Estes (@nickestes)
Kim Tallbear (@KimTallbear)
Kyle White (@kylepowyswhyte)
Ō’m”kaistaaw”kaa•kii (@mariahgladstone)
Indigenous folks in STEM
Plus everyone on this list

Instagram
Indigenous Rising (@indigenousrising)
Corinne Rice (@misscorinne86)
Ryan Young (@Indigenousvengeance)
Indigenous Women Who Hike (@Indigenouswomenhike)
Calina Lawrence (@calinalawrence)
Adrienne Keen (@nativeapprops)
Winona LaDuke (@winonaladuke)
Indian Country Today (@indiancountrytoday)
Tanaya Winder (@Tanayawinder)
Sarain Fox (@sarainfox)
Decolonize Myself (@decolonizemyself)

Organizations/Resources
Reclaim Indigenous Arts
Native Women in the Arts
Coalition to Stop Violence Against Native Women
Native American Heritage Association
Kituwah Preservation and Education Program
American Indian College Fund
Indigenous Environmental Network
Two-Spirit Resource Directory
Cultural Survival

Many thanks to Liz Landefeld, David Craig, and Vince Schilling for leaving their fingerprints on this article.

Literature cited
1 Cultural Appropriation (2020). In Oxford Online Dictionary https://www.oxfordlearnersdictionaries.com/us/definition/english/cultural-appropriation?q=cultural+appropriation

2 Hitakonanulaxk. Grandfather speak: Native American FolkTales of the Lenape people. Interlink Publishing Group, 4/30/1995

3 Williams, Maria. How Raven Stole the Sun (Tales of the People). Abbeville Press, 11/20/2000

4 Howell-Zimmer J. 12/2000. Intellectual Property Protection For Alaska Native Arts. Cultural Survival Quarterly Magazine. https://www.culturalsurvival.org/publications/cultural-survival-quarterly/intellectual-property-protection-alaska-native-arts

33 Comments

Filed under Anti-racism, Birding, Corvid mythology, Crows and humans, Wildlife

Crows are watching your language, literally

That crows can recognize humans faces (and other physical attributes) has been a staple of our experiences with them for thousands of years.  It’s part of what has allowed them to take such a prominent place within our cultures, and it’s what keeps us refilling our pockets with peanuts or kibble, anxious for the chance to be recognized, to be seen by a wild animal. If, like me, you’ve been committed to such a relationship, you probably found yourself wondering about what it is they’re saying all the time. Although we still have more questions than answers, it’s not for lack of trying; in fact parsing crow “language” is still a hot topic in corvidology.  But for all our efforts to understand what crows are so often going on about, have you ever thought much about what they make of what we’re saying?

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Calling American crow

Ask any crow feeder about their ritual and there’s a good chance that it starts with more than just making themselves visible. To get “their” bird’s attention, about half of crow feeders start with some kind of auditory cue, like a whistle or gentle name calling.¹ Given that American crows (Corvus brachyrhynchos) can be individually distinguished by their calls, and many corvids—including the large-billed crows (Corvus macrorhynchos)—can recognize familiar conspecific* calls, this strategy seems far from superstitious.2,3 In fact, previous work has demonstrated that crows can discriminate human voices.

When presented with playback of their caretakers or unfamiliar speakers saying, “hey,”  hand-reared carrions crows (Corvus corone) showed significantly more responsiveness towards unfamiliar speakers.4 That their response is different is what suggests that they can discriminate, but it’s hard to not do a double take at the fact that the thing they seem more interested in is the person they don’t know.  Shouldn’t they be more interested in the folks that generally come bearing gifts? While we still don’t have a super satisfying answer to this question, it’s possible this comes from the fact that novel humans are less predictable, and therefore more threatening, than a familiar caretaker who can be safely ignored. Likewise, a new study out suggests that it’s not just individual people crows can hear the difference between, but entire languages.

In a newly released study conducted by Schalz and Izawa (2020), eight wild large-billed crows were captured in major cities around Japan and subsequently housed in aviaries at Keio University where they were cared for by fluent Japanese speakers.5  Given both their life histories and their time in the aviary, it’s safe to assume these birds had listened to a tremendous amount of Japanese throughout their lives. So, it stands to reason they might be able to actually recognize this language as familiar, but to date no one had looked at crows’ ability to discriminate between languages.  To test this question the researchers used playback to present recordings from multiple unfamiliar Dutch or Japanese speakers.  As with the carrion crow study, when these crows were presented with playback of a more familiar acoustic style—in this case a Japanese speaker—they didn’t show a strong reaction. Play them what was likely a completely unfamiliar language—Dutch—and the crows were rapt. Or at least they acted more vigilant and positioned themselves closer to the speaker. In other words, large-billed crows were able to discriminate between human languages without any prior training!

junlge crow

Large-billed crow (Corvus macrorhynchos) Photo: Anne Kurasawa

The next most obvious question is, well, why? What purpose would it serve to discriminate between different languages among unfamiliar speakers? One possibility is that it’s just an artifact of the auditory perceptual skills they need to successfully be a crow.  As I mentioned earlier, there’s a lot of information encoded in their calls, including individual identity, so being attentive to rhythmic classes may be important.  Another reason that’s worth pursuing, though, is that it may help tip them off to tourists, who may be more inclined to share or easier to take advantage of, than locals.  Fortunately the lead author on this study, Sabrina Schalz, will be starting her PhD on this topic in the coming fall. You can find her on twitter at @Sabrinaschalz, where she’s promised to keep us abreast of her future discoveries.

So the next time you’re hanging out in Japan, don’t forget to literally watch your language around the local crows. And to be safe, I wouldn’t divulge any secrets to them either.  They’re not called large-billed crows for nothing.

*conspecific=member of the same species

Literature cited
1. Marzluff JM, & Miller M. (2014). Crows and crow feeders: Observations on interspecific semiotics.  In: Witzany, G. ed., Biocommunication of Animals.  New York: Springer Science+Business Media Dordrecht. pp 191-211.

2. Mates EA, Tarter RR, Ha JC, Clark AB & McGowan KJ. (2015). Acoustic profiling in a complexly social species, the American crow: caws encode information on caller sex, identity and behavioural context, Bioacoustics, 24:1, 63-80, DOI: 10.1080/09524622.2014.933446

3. Kondo N, Izawa EI, & Watanabe S. (2010). Perceptual mechanism for vocal individual recognition in jungle crows (Corvus macrorhynchos): contact call signature and discrimination. Behaviour 147: 1051–1072.

4. Washer CAF, Szipka G, Boeckle M, and Wilkinson A. 2012. You sounds familiar: carrion crows differentiate between the calls of known and unknown heterospecifics. Anim Cogn 15: 1015-1019.

5. Schalz S. & Izawa E. (2020). Language Discrimination by Large-Billed Crows. In Ravignani, A., Barbieri, C., Martins, M., Flaherty, M., Jadoul, Y., Lattenkamp, E., Little, H., Mudd, K. & Verhoef, T. (Eds.): The Evolution of Language: Proceedings of the 13th International Conference (EvoLang13). doi:10.17617/2.3190925.

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Filed under Crow behavior, Crows and humans, New Research, Science

Dumpster diving is giving crows higher cholesterol—but does it matter?

Whether it’s from actively watching crows, or simply just existing in a city, we’ve all seen it: the overflowing garbage bin with fat-stained wrappers littered at its base, and the crows snapping up each bit of leftover junk like spilled money.  Cheetos, cheeseburgers, fries, nuggets, chips, or pizza, they will devour basically anything fatty and salty with absolute glee.  This behavior is so canonically crow that it’s stapled into our contemporary imagery of these birds.  Take this 12ft statue called “Crow with Fries” by artist Peter Reiquam.

cikSOsc

Photo c/o salishsea

I’d wager that most people don’t think about this behavior beyond simply finding it amusing or annoying, but I suspect that if you describe yourself as crow lover, naturalist, or bird watcher, you’ve been struck with the same thought as me: “This stuff is called junk food for a reason—it’s bad for you.  What’s it doing to these birds?”

Given that anthropogenic foods can account for as much as 65% of an urban crow’s diet, it seems essential to understand what a diet derived from regularly feasting at McDonalds might do to an animal with 0.7% the body mass of a typical human.1  Unfortunately, we could do little more than shrug and speculate as to its effects.  The data for a more informed understanding just didn’t exist.  That is, until today.

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A new study published in The Condor by Dr. Andrea Townsend et al. examines the relationship between urbanization, junk food, and the body conditions of crows.2  To conduct this study, her team blood sampled 140 wild crow nestlings along an urban to rural gradient.  They found that plasma blood cholesterol levels increased in correlation with the amount of impervious surface, which is a typical way we measure urbanization.  This finding suggests that crows in the city have more access to high cholesterol foods and they make haste in gobbling it up.

Correlation is not causation, however, so to confirm this, they ran an additional supplementation study where they provided 10 rural crow parents with 3 McDonalds cheeseburgers 5-6 days a week, and then looked at how their nestling’s blood cholesterol levels compared with unsupplemented nestlings from the same area. They found that eating cheeseburgers most days of the week had a demonstrable effect on the subject’s cholesterol levels.  While this finding may not be raising any eyebrows, the actual logistics of carrying out a study that required buying hundreds of cheeseburgers each week, and sometimes in one order, certainly did.  In one of their more memorable attempts, Hannah Staab called to place an order for 125 pickle-less cheeseburgers, a request to which McD’s staff replied, “Sure, we’ll get right on that.”  When she arrived several hours later to pick them up, however, they hadn’t made any, having been convinced that the call was a prank.  The peculiarities of urban fieldwork never falter.

prank

So far, these findings tell us little more than what most people could have probably intuited, but they were crucial to laying the foundation for the real clogged heart of this study: Whether any of this is actually a bad thing.  In the final piece, they examined the body condition, and 2-3 year survival of the 140 nestlings sampled along the urban to rural gradient.  They found that cholesterol levels had no detectable effect on survival and were actually correlated with higher indices of body condition (meaning mass adjusted for size), a feature that is sometimes tied to higher reproductive success and survival. In other words, there might actually be a scenario where regularly pigging out on McDonalds doesn’t kill you and is maybe kinda helpful?

Needless to say, this caught everyone off guard, including Dr. Townsend, who told me, “I was surprised that we didn’t detect any negative health effects. I was thinking—based on the human literature—that high-cholesterol birds would have lower survival rates, but we didn’t see any effect of cholesterol on survival.”

So what gives? Is the universe really just this unfair?  While we can’t rule out that the answer is simply, “Yes,” the authors speculated that it’s possible a longer study would bear out health consequences that take more than a few years to accrue. There’s also something to be said for the fact that body condition has complex and not always agreed upon relationship with fitness and survival.3 While some studies show pudgy birds have more resources to produce more offspring and keep on ticking, others find inconsistent support. Alternatively, crows may just not live long enough to see their lifestyle catch up to them.  Future long-term studies will be necessary to fully understand whether crows have truly found a loophole in the junk-food problem. For now however, I’m happy to wish my favorite dumpster divers well, though I’ll hold off placing my own orders.

Literature cited

  1. Marzluff JM, McGowen KJ, Roarke D. and Knight RL. 2001. Causes and consequences of expanding American crow populations in Avian ecology and conservation in an urbanizing world (J.M. Marzluff, R. Bowmanm and R Donelly, eds).  Kluwer academic Press, norwell, Ma.
  2. Townsend AK, Staab HA, and Barker CM. 2019. Urbanization and elevated cholesterol in American Crows. The Condor page 1-20
  3. Milenkaya O, Catlin DH, Legge S, and Walters JR. 2015. Body Condition Indices Predict Reproductive Success but Not Survival in a Sedentary, Tropical Bird. Plos One https://doi.org/10.1371/journal.pone.0136582

16 Comments

Filed under Corvid health, Crow behavior, crow diet, Crows and humans, New Research

Crow Vocalizations Part I: New Science

If there’s one general area of questioning that overshadows all others that I receive, it’s questions about vocalizations. One caw, five caws, quiet wows, and loud clicks. We can’t help but to ask what it all means, and wonder how we might better understand and connect with crows if only we knew. To the chagrin of virtually everyone that has asked me a vocalization question, however, the answer is almost always a very disappointing shrug of ignorance. So to help you better understand what we do know about crow vocalizations and why it pales in comparison to what we don’t know, I am dedicating two posts to this topic. The first one–this one–will cover a recent study authored by my colleague and former labmate, Loma Pendergraft. Part II will take the form of a vocalization Q&A. So sit back, grab a snack, and get ready to know more, or maybe less, about crow vocalizations than you ever thought you could.

***

Why are you yelling at the dinner table?

If you’ve ever fed a crow  you may have noticed that shortly after whatever tasty morsel you’ve offered hits the ground, the receiving crow will give a couple caws. If you’re anything like Loma Pendergraft, your next thought will be, “Why?” Are they inviting family members to the feast? Are they trying to scare off competitors? Do the number of caws mean anything?

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Unlike most crow feeders that have to settle for a disappointingly fruitless Google search for an answer, when Loma first asked this as a graduate student he was in a unique position to test it. After three years of labor, his findings have been published in a new paper entitled: Fussing over food: factors affecting the vocalizations American crows utter around food.1 As I can already feel your anticipation in finally finding out what all those food calls are about let me start with a spoiler; you are probably not going to learn what you had hoped to from this study. But you will learn something invaluable about crow communication and how we study it. So with that out of the way let’s start at the beginning.

Generally speaking, if an animal vocalizes at a food source, it must incur some benefit from that vocalization that outweighs the potential costs. Costs include things like getting your food stolen by a competitor or drawing the attention of predators. Conversely, the benefits may consist of things like being able to share resources with your mate or kin, claiming ownership, or attracting other individuals to help you secure a food source away from another bird.

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To try and determine what, if any, of these might motivate the calls that crows produce, Loma conducted three experiments. In the first, he attempted to look for patterns in their vocal behavior by categorizing and quantifying the calls given around food of varying amounts. For example, perhaps for an amount of food small enough as to be consumable by one crow they keep quiet, but for a significant amount they have a specific three-note “I found food” call to alert their mate. In Experiment 2, he ground-tested his ideas about how he was interpreting the calls from Experient 1 by doing playback. Essentially, he wanted to show that if he thought a three-note call was used to attract a mate, then by playing it back the mate should come in. Finally, in Experiment 3 he tested whether the different calls he had recorded had any effect on the listener’s ability to find the food.

To conduct these tests, Loma used wild crow pairs that he located all around Seattle. To prevent the birds from learning his face, he used a variety of sometimes hilarious disguises.  He fed each pair three different amounts of food over the course of three trials: 1 peanut, 5 peanuts or a bountiful 25 peanuts. To try and suss out both if there were any patterns in calls given around food and if calls varied with the amount of food, he recorded their behavior before and after feeding them, and then used vocal analysis software to detect patterns in call structure.

What he found was that, unlike the grand reveal we were all hoping for, few clear patterns emerged from the call data. When crows are around food, they give shorter calls than they did before, and their calls around only a single peanut are longer than when they are around a more substantial amount of food. But in all the other areas where you might expect some pattern to emerge; call rate, peak frequency, the number of syllables, etc., none did.

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Still, the fact that they give short calls around food is suggestive of something, so Loma attempted to determine in Experiment 2 if these short calls are used to either attract birds in or repel them away by playing back those short calls and watching for how the birds responded. The resulting response was more of a whimper than a bang. Or maybe I should say more of a short call than a bang. Because outside of matching the short calls with their own short calls, the crows hardly changed their behavior. Even in Experiment 3 where he looked for whether specific calls aided in the listener’s ability to locate the food, he came away still puzzled. Crows were only able to locate food in 38% of cases and were no better than when played the control chickadee calls.

A cynic may walk away from these findings feeling as if nothing has been gained; that we know little more about what crows are saying around food than we did before. While it’s true we may not have learned much about what they are saying, this study did reveal something important about what they are not saying. Because while Loma found few patterns once the food was down, he did discover that crows give longer calls in the absence of food and that those medium calls prompted territorial behavior when played back. The implication is that crows do not give territorial calls around food, perhaps to avoid risking its discovery by adversaries.

In addition, while it makes for a less compelling headlines, failing to support our hypotheses offers fundamental insights and lays the groundwork for future studies to keep pressing forward. In this case, Loma and his coauthor John Marzluff question whether the difficulty of detecting clear patterns in “x” vocalization leading to “y” behavior is because crows encode so much context-specific information in their calls. In fact, a previous study on American crows found that acoustic variation can indicate the caller’s sex and identity.2 Perhaps the reason we have so much difficulty in mapping out the world of crow communication is that, unlike a crow, we fail to detect all of the information they can ascertain and use to determine how to respond.

So, yes, in some ways we are no closer to Dr. Doolittling the crows than we were before. Instead, we are left with the more compelling reality that our inky friends likely posses an incredibly rich and complex vocal system. For me, this continued mystery only serves to endear them further. After all, do any of us love these birds because we find them straightforward and predictable? I doubt it.

***

Want to learn more about Loma’s research or this study in particular? Don’t forget to head over to his blog.  There you can drop him a line with more crow questions or to request his new paper in full.  He did so much more than I summarized here, it’s really worth a full read!

Literature cited

  1. Pendergraft LJ T and Marzluff JM. (2019). Fussing over food: factors affecting the vocalizations American crows utter around food. Animal Behaviour 150: 39-57
  2. Mates EA, Tarter RR, Ha JC, Clark AB, and McGowen KJ. (2014). Acoustic profiling in a complexly social species, the American crow: caws encode information on caller sex, identity and behavioural context. Bioacoustics 24 

16 Comments

Filed under Crow behavior, crow diet, Crows and humans, New Research, Science, Vocalizations

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.

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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.

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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

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

Gifts for crow lovers

With the holiday season upon us, many people find themselves tasked with finding thoughtful gifts for their loved ones.  Although birds are seemingly so universally adored that finding bird themed gifts is no trouble, if it’s specific species you’re after, the challenge can be more immense.  Fortunately for crow lovers, there are lots of options to choose from if you know where to look.  Since you’re looking here, rest easy that half the battle is now over.  So sit back, enjoy, and feel free to add your own suggestions in the comments.

    1. Jewelry and apparel
    2. Art
    3. Books and education
    4. Kids
    5. Conservation


    Jewelry and apparel

     

    Sometimes you want to wear your passions on your sleeve, literally.  Fortunately online marketplaces like Etsy makes this more than possible.  A quick search of “crow t-shirt” reveals hundreds of options for any aesthetic.  Personally, I like to stick with shirts featuring original art.  Here are some of my top Etsy picks:

    Coyotees Maine

    Elusive Catfishery
    Maison Hydre
    Kathy Morton Stanion

    Outside of Etsy the apparel options can be harder to find but they are out there.  Charlie Harper for example, has an awesome screen printed tee that any crow lover will adore.

    For jewelry you can turn, once again, to Etsy but there are other options too.  June Hunter, who I also recommend elsewhere on this list, has a great collection of corvid themed jewelry.  The bonus here is that I can personally attest to the care and passion June has for these birds, so finding something in her shop will not only deem you an awesome gift-finder among your crow friends, but you’ll be supporting the work of someone who is themselves an ardent lover of crows.  Your local art galleries can also be great places to find amazing crow themed jewelry.  A favorite among my own collection was sourced from the Mary Lou Zeek gallery in Salem, Oregon.

    For something more personalized, consider getting a custom embroidered necklace or full size loop from the talented Sarah Buckley.  I had her make a custom necklace from one of my favorite jay photos to commemorate my PostDoc research.  I couldn’t be happier with the result!


        Art

 

I can’t stress enough here that your city’s art galleries and boutiques can be great places to find local, handmade, and even one of a kind items.  Many people (including artists) love crows, which is good news for your brick and mortar shopping prospects.  Please, spend your money locally as much as possible.  That said, here are some online shopping options that support talented artists:

From prints, to wall art, to totes and calendars, June Hunter has you covered.  Her Vancouver based studio celebrates the beauty of urban wildlife, with a special emphasis on crows.

If ever I find myself with a great deal of disposable money, purchasing one of Jason Tennant’s astounding wood carvings will be among my top priorities.  Seriously, they’re unbelievable.  And wouldn’t luck have it, ravens are a fairly regular subject of his work.

If it’s illustrations and painting you’re after, Etsy is once again a great resource. From acrylic to watercolor, there’s something for everyone.  Heck, even if you want something more out of the box like stained glass, you’re bound to find something.

Don’t limit your search to etsy, however as there are lots of great artists that sell via their own websites.  Julia Eva Bacon produces stunning oil paintings and has several pieces dedicated to corvids.  Although her originals would be worth every penny, you can also buy prints.  A luck would have it one of my favorite pieces is actually on sale right now!

  1. CorvusCorax_borderPerhaps the person you are shopping for already has walls covered in corvid paraphernalia and you need to get a little more creative with housewares.  Laura Zindel will help you outfit their shelves and table tops with gorgeous ceramics.  I own a set of plates and can attest to their beauty and durability.


    Books and Education

    There are so many excellent books on the topic of corvids that covering them really requires its own post. Fortunately, that post already exists, so I’ll simply direct you to it here.

  2. Books aren’t the only way, however, to give the gift of knowledge. Back in 2010, PBS first aired their NATURE documentary, A Murder of Crowswhich showcases a number of great studies and anecdotes, including the facial recognition work conducted by John Marzluff. Although you can stream the video for free, $18 is a small price to pay for being able to watch it whenever you please, and showing PBS some love.
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    For the ultimate crow education however, you should consider registering your loved one for the North Cascades Institute’s corvid class that’s offered over the summer.  In previous years the class has been co-taught by myself and John Marzluff, but for the 2019 edition I will be the sole instructor.  As usual, it’s a two day class complete with lovely and TAG approved accommodations, great food, beautiful scenery, and more information about corvids than you can possibly retain.  We often see nearly every species of corvid found in Washington, including ravens, crows, magpies, Clark’s nutcrackers, Steller’s jays and grey jays.  Registration for this year won’t open until January or February, but who doesn’t like an IOU for a gift?  It is worth noting the class fills up quickly once registration is open so make sure to stay on the ball.

  3. Kids

     

    I firmly believe that the indoctrination of crow love into kids should begin early; immediately if possible.  Fortunately, Etsy has your back with onesies, night lights, and probably whatever else your imagination can cook up.  For stuffies, local children’s stores or nature stores often carry raven or crow themed plush toys including this awesome raven puppet.

    There’s no shortage of corvid books aimed at kids either.
    10 roudy ravens by Susan Ewing is a counting book great for early readers.
    Lila and the crow by Gabrielle Grimard tells the story of a little girl who learns the beauty of being different from her neighborhood crow.
    Clever crow by Cynthia De felice uses rhyme to tell the story of a young girl trying to outwit a mischievous crow that is stealing trinkets from her mother.  Obviously the biology isn’t a highlight here, but the reviews are otherwise great.
    If accurate biology is what you’re after, Crow smarts by Pamela Turner promises to introduce children (and adults!) to the astounding minds of crows.
    For a children’s book that is more for adults than kids, consider Aldous Huxley’s The Crows of Pealblossom.  Considering that crows and snakes are both often on the receiving end of misguided public vitriol, I’m not a fan that the crows’ triumph comes at the  expense of the snake’s grisly end.  While the snake’s fate may not be appropriate for sensitive children, any adults that share a love of crows and Huxley’s other works will surely be delighted.


    Conservation

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    Perhaps your family tradition is that gifts should give back, or you recognize that your recipient would be happier knowing money was spent towards helping crows.  The Alalā, or Hawaiian crow, is one of the most endangered animals on the planet. Since 2002, they have been considered extinct in the wild.  Thanks to captive breeding efforts by the Alalā project, which is a partnership between San Diego Zoo Global and the Hawaiʻi Division of Forestry and Wildlife, and the US Fish and Wildlife Service, eleven individuals were just released into the forests of the Big Island.  These kinds of captive breeding and reintroduction programs are the only hope for these birds, but they are expensive.  By donating not only can you directly help their cause, but you can demonstrate public interest in keeping this species alive.  Currently, there is no way to donate money online but you can do so the old fashion way.  Make checks payable to San Diego Zoo Global and put in the memo line that the money is to be directed to the the Hawaiian crow project.  I called San Diego Zoo Global to confirm that money can be allocated to the Alalā project specifically.  Mail checks to: P.O. Box 120271 San Diego, CA 92112.

    With these suggestions in mind, I wish you the best in your search for the perfect gift for the crow lover in your life. Happy hunting and please feel free to mention your own gift suggestions in the comments section.

 

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Filed under Crows and humans, Just for fun

Saving the rarest crow

It can be hard to imagine crows as anything but ubiquitous.  During winter across the country, dusk marks the time where some cities see their skies turn black with thousands, even hundreds of thousands of American crows converging to roost.  These crows have taken nearly all that people have thrown at them: deforestation, mass waste, and the urban sprawl that simplifies previously complex ecosystems, and uses it to their advantage.  Not all species of crow have thrived in the Anthropocene, however.

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Thousands of gather accumulate in the skies above UW’s Bothell campus in the winter

Far from being icons of the ultimate adapters some species of crow represent some of the most endangered animals in the world.  Among those, the ‘Alalā or Hawaiian crow, is arguably one of the rarest birds on earth. Once locally abundant in the forests and woodlands of Hawaii’s Big Island, their decline began in the 1890’s following persecution by coffee and fruit farmers1.  Back in September, 2015 there remained only 114, all living  exclusively in captivity giving them the unenviable title of ‘extinct in the wild’.  How can one species thrive with such zeal while another holds on by a thread?

Island species are generally more specialized and therefore more sensitive to human induced changes.  In fact proportionally, islands host a higher number of endangered or extinct species than continental areas2.  In Hawaii alone, 77 different species of endemic birds have gone extinct since the arrival of the Polynesians 2,000 years ago4, all largely for similar reasons: habitat destruction and invasive species.

Unlike their generalist, continental counterparts, the ‘Alalā is more specialized to feed on understory fruits and nuts and in fact were key seed distributors for many of Hawaii’s native plants.  Island living also fostered a similar behavior seen in only one other species of crow: tool use.  Like the New Caledonian crow, the ‘Alalā is a dexterous tool user, though the two species are only distantly related.  Scientists believe this example of convergent evolution is fostered by aspects typical of islands, namely low predation and low competition for embedded food5.

Unfortunately, limited distributions and higher specialization also meant their population was more fragile than that of continental crows.  Logging, agricultural development, loss of native pollinators, and alterations by non-native ungulates challenged both food acquisition and breeding habitat.  Introduced diseases such as avian pox, malaria and the Toxoplasma gondii parasite carried by cats further weakened an already ailing population6,7. Invasive predators including rats, mongoose and cats consumed eggs, nestlings and fledglings.  Finally, humans continued their tradition of persecution, particularly feral pig hunters who would shoot the birds before they could alarm call and scare off their prey2.

Together, these threats set into motion a decline in population we failed to recover despite some increases in research and management starting in the 1970’s.  The last known wild egg was laid in 1996, and the last wild pair was seen in 20022,3.  Some people did recognize the urgency of their decline prior to 2002, however, and a captive breeding population was started successfully rearing over 90 birds8.  Although such a small number of breeders may raise red flags with respect to inbreeding and genetic depression, this is rarely as big of an issue as is commonly perceived.  Unfortunately, light management and depredation by the also endangered Hawaiian hawk (‘io), decimated the released population and reintroduction efforts were halted in 1999 until a larger captive population and better management strategy could be devised.

Since that time, the ‘Alalā Restoration Project (collaboration between the State of Hawaii, the U.S. Fish and Wildlife Service, and San Diego Zoo Global) has spearheaded captive breeding programs on Maui and the Big Island culminating in a population of over 100 birds.  An important part of these captive breeding programs is the use of puppets, which help prevent habituation to humans9.  In addition, intensive management operations have taken place to ready their prospective home at the Pu‘u Maka‘ala Natural Area Reserve including the removal of invasive/feral animals, erecting exclosure fencing, and constructing a sort of half-way house to help ease the birds into life in the wild.  These efforts have not been without setbacks, however.  Back in June, 2015 two miles of protective fencing was cut down by vandals, though their motivations remain unknown.

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A human dressed as an ‘Alala feeds captive reared nestlings. Photo c/o San Diego Zoo Global

Finally, after so much work, the end of 2016 marked the first time researchers and managers agreed the elements were in place for a reintroduction effort.  On December 14th, five male birds were released onto the reserve, marking the first time the ‘Alalā set claw into the wild since 2002.  Sadly, within weeks all but two had died. Two were killed by the native Hawaiian hawk or ‘lo, and the third was killed by “natural circumstances” which, I’m guessing, is related to a heavy storm that occurred shortly after their release.  As a protective measure, the remaining two were recaptured until the results from the necropsies are obtained.

While clearly disheartening, early hiccups in a release effort like this are not unusual and conservationists and biologists are not losing hope that success is still possible.  Part of ensuring such success, however, is undoubtedly public support particularly with respect to maintaining the strength of the Endangered Species Act and support of the ‘Alalā Restoration Project.  The perception that all crows are alike or that generous populations of American crows means protections for other corvus species is unwarranted or redundant will be a disaster for these rare birds.  So make your voice heard when funding for conversations efforts come under fire, and share your passion for endangered corvus species with friends and family.  The fate of the world’s rarest crow quite literally depends on it.

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Two newly released ‘Alalas peer around their new surrounding in the Pu’u Maka’ala Natural Area Reserve.  Photo c/o the San Diego Zoo Global 

Literature cited

  1. https://www.fws.gov/pacificislands/fauna/alala.html
  2. Faike, E. 2006. Wild voices in captivity: the date of the ‘Alala. Birding 38: 64-67.
  3. Banko, P. C.; Burgett, J.; Conry, P. J.; David, R.; Derrickson, S.; Fitzpatrick, J.;
  4. National Research Council (US) Committee on Scientific Issues in the Endangered Species Act. Science and the Endangered Species Act. Washington (DC): National Academies Press (US); 1995. 2, Species Extinctions. Available from: https://www.ncbi.nlm.nih.gov/books/NBK232371/
  5. Rutz C, Klump BC, Komarczyk L, Leighton R, Kramer J, Wischnewski S, Sugasawa S, Morrissey MB, James R, St Clair JJH, Switzer RA, and Masuda BM. (2016).

    Discovery of species-wide tool use in the Hawaiian crow.  Nature 537: 403-407 doi:10.1038/nature19103

  6. Maxfield, B. 1998. Wild ‘Alala population suffers major setback. ‘Elepaio 58: 51.
  7. Liebermann, A.; Nelson, J. T.; Simmons, P.; Unger, K.; Vitousek, P. M. 2003. Draft revised recovery plan for the Alala (Corvus Hawaiiensis. US Fish and Wildlife Service, Portland, OR, USA.
  8. Lieberman, A. C., Kuehler, C. M. 2009. Captive propagation. In: Pratt, T. K.; Atkinson, C. T.; Banko, P. C.; Jacobi, J. D.; Woodworth, B. L. (ed.), Conservation Biology of Hawaiian Forest Birds: Implications for Island Avifauna, pp. 448-469. Yale University Press, New Haven.
  9. Valutis LL, and Marzluff JM. (1999).  The appropriateness of puppet-rearing birds for reintroduction.  Conservation Biology 13: 584-591

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Filed under Conservation, Corvid diversity, Corvid health, crow conflicts, Crows and humans, Ecosystem

5 reasons to leave baby crows alone 

Those blue eyes, that awkward gate, their seemingly constant precariousness, they’re all calling to you to intervene. Here are 5 reasons second guessing that instinct might be in the bird’s best interest.

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1) The vast majority don’t need your help. It’s totally normal for baby crows to be on the ground and flightless as long as they’re covered with feathers and appear otherwise alert and mobile. Even nestling crows are usually on the ground on purpose. Not because they are ready, but because their parents have intentionally rejected them for one reason or another. They will die and that’s ok. Part of coexisting with wildlife is giving them the agency to be wild. The story is different of course for species where the survival of individuals may mean the difference between population survival and extinction, especially because these situation are almost always driven by human activity.

2) It’s hard to tell when they’re stressed.  Recently, I saw a video on Facebook of a Steller’s jay fledgling in the care of a very well intentioned person.  She was giving it gentle strokes with her fingertips, each touch resulting in the young bird turning its head towards its back and opening its mouth.  The comment thread filled with ooo’s and awww’s and general comments of encouragement or gratitude for her actions.  For me it was like watching an alien attempt to care for a human child, the child recoiling and screaming while its caretakers congratulated themselves on how kind they were being.  Having handled baby corvids before, I know what that kind of posturing means, it means “I’m scared and stressed.”  To an untrained eye though, it may not look much different than the kind of gaping that means ‘feed me.’  Being stressed to death is a reality for young, or even adult animals, so any handling best be done by experts whenever possible.

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3) It’s illegal to rehab crows without a license. You can provide temporary care until you can get them to a licensed facility, but do not attempt to rehab them on your own.  Mistakes like the one I just described are a prime example of why the law seeks to protect animals by ensuring they are only raised or rehabilitated by experts.  For more information on how to handle them until you can get them to a facility visit my previous post.

4) Imprinted crows do not survive well in the wild.  Even if baby crows are receptive to being treated like a pet, doing so is both a legal violation and I would argue a violation of their right to be a wild animal with a healthy fear of people.  Of all my daydreams, at the top of the list is having a wild but imprinted crow that follows me around.  I even have a name picked out.  This fantasy of mine will forever remain just that, however, because it’s too dangerous to allow a crow to become that comfortable with people.  All it would take is one cranky neighbor with a pellet gun and it would be over.  Not to mention being imprinted on people, instead of crows, denies them access to skills and relationships with other crows that will help them survive into adulthood. 

5) It may do more harm than good.  The conventional wisdom suggests “well, worse case scenario is I try and rehab this baby crow and it dies, which it would have done anyway so really, nothing’s been lost.”  The more we study death in social animals the more we are beginning to realize there may be a cost to prematurely removing ailing or dead animals from their groupmates.  Being able to interact with their dead may serve an important role for social animals, and denying them this opportunity may have serious implications in their ability to process that death.  So be thoughtful about how slim the chance of survival is.  It might be that the kindest, most responsible action is no action at all.

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Filed under Corvid health, Crow behavior, Crow curiosities, Crow life history, Crows and humans, Uncategorized

Everything you want to know about crow nests

Spring marks one of my favorite times of year.  Cherry blossoms abound, the rain smell sweet and the birds get busy putting their carpentry skills to good use. Starting early March, the silhouettes of crows with bill loads of timber or wads of soft material dot the skies as they shuttle back and forth to their nest tree. Like a townhouse development, these construction projects are over in the blink of an eye and soon, their bill loads of twigs will be replaced by food for their mate and, eventually, their insatiable young. Spotting these nests is both a great way to observe and engage with your local crow family and avoid unpleasant conflicts with protective crow parents.  With a little knowledge and a bit of practice, tracking down your resident crow nest will become one of your favorite spring traditions in no time.

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Nest construction and site selection

Nest construction begins in early March and will continue (as nests fail) through about June. It takes 1-2 weeks to finish a nest after which the female will lay a clutch of 2-6 eggs. Unlike similarly sized squirrel nests (aka: dreys) which are made of leaves, crow nests are made mostly of pencil-width twigs. A new nest is usually about 1.5 ft across and 8-10 in deep.  After the bulk of construction is complete, they’ll line the cup of the nest with soft materials like grass, tree bark, moss, flowers, paper or fur. Once we saw a crow ripping out the hair of an outdoor manakin, no doubt to use as lining material.

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A crow gathers moss off the branches of a big leaf maple to use as lining material.  

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This bird toyed with this branch for a few minutes before rejecting it and letting it fall to the ground.  

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A sidewalk littered with twigs is good evidence that the nearby deciduous tree is a favorite among the local crows to pull branches from.  I’ve only once seen a crow try and retrieve a branch it dropped, so these are all rejects.  

 

Crows will nest in an astounding array of places, from the eaves of skyscrapers to the crooks of well concealed tree limbs. They can tower in the sky or be almost within reach. Most commonly, I see them built close to the trunk in the top third of Doug fir trees, but this is, of course, specific to the PNW.  Both partners participate in nest construction. Helpers will aid to some degree but most of the work is left to the parents.

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Differences among corvids

Crow, jay and raven nests are similar in shape and material but differ in overall size in accordance with the size of the bird. The main standout are magpies,  which build incredible domed-shaped nests the size of a large beach ball.  The nests require so much material, they can take as much as 40 days to build.  Japanese jungle crows are another species of note, as they have a (relatively) new and problematic habit of building nests out of wire hangers and causing massive blackouts.

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A Jungle crow nest in urban Japan. Photo: Götz

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The magpie’s nest is the big clump in the middle of the tree.

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The life of a typical nest is only about 9 weeks (1-2 weeks of building, 6 days of laying, 20 days of incubating and 4 weeks of nestlings) though they are hardy structures and can remain intact in a tree for years.  After the young fledge, the crows will not return to the nest.  Crows will only use a nest once, and generally only fledge one brood a year. They will, however, build on top of an old nest particularly in areas where nest trees are especially sparse like downtown Seattle. This also appears to be more common in the Midwest.

Avoiding conflicts

Most breeding related dive bombs occur as the result of a person being too close to a fledgling, but some crows get feisty around their nest too. Crows in areas where they are less persecuted (like cities) tend to be more aggressive than their rural counterparts. If you know where a nest is and can avoid it, do so and save everyone the aggravation. Otherwise carry an umbrella or paint eyes on the back of a hat. Crows rarely attack from the front so having eyes on the back of your head can be an effective deterrent!

***

Putting all this together to actually find nests, is one of the most rewarding moments an urban naturalist or crow enthusiast can have.  Be warned though: crows are wary of potential predators (including people) spying on them and they have a few tricks for throwing you off, so don’t be surprised if a nest location you were certain of turns out to have been a ruse!

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Can you spot the nest? 

Have more questions? Let me know in the comments!

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Filed under Birding, Breeding, Crow behavior, Crow life history, Crows and humans

Crow curiosities: Do crows collect shiny objects?

The notion that corvids, especially magpies, have a special affinity for shiny object has been around for more than a century.  In fact to refer to someone as a magpie is to describe them as someone who ‘compulsively collects or hoards small objects’.   This idea is so old hat that it can feel a bit frivolous to even wonder if it’s true.  The trouble with this bit of corvid whimsy, however, is that when we do investigate it, and scientists have, we find there’s no empirical evidence to support it.

'Crow Collects' by Cori Lee Marvin.

‘Crow Collects’ by Cori Lee Marvin.

For instance, one study presented both captive and free-living magpies piles of blue or shiny silver screws, rings, and pieces of tin foil near piles of food to which they had been previously habituated.1  They found that, rather than thieving and subsequently caching the gleaming objects, the birds were actually more nervous to take food than they had been previously.  In the 64 conducted tests, only two instances of contact between a bird and an object were recorded.

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Experimental set-up for magpie study.

Cornell crow expert Kevin McGowen, elaborates on this general conclusion, suggesting that perhaps the origin of this folklore is pet crows who are attracted to the objects of obvious value to their owner like coins, keys or jewelry.  Speaking personally as someone who has spent countless hours observing hundreds of individual crows in the field, I can also attest to the fact I have never witnessed anything resembling this behavior.  So there you have it, corvids do not, according to the best empirical evidence, show an attraction to, or are otherwise known to collect shiny objects.

And yet…

And yet I still hear anecdotes about this behavior that peak my curiosity.  For instance, once or twice a year I’ll see a headline about crows thieving shiny stones at the expense of bereft family members.  In Jewish culture, it’s tradition to leave a small stone atop a gravestone, as a way to honor the deceased and indicate that they’ve been visited.  For whatever reason, particularly across Ireland, these stones occasionally go for joy rides in the mouths of crows.  In Omagh, Patsy Kerlin who mounts headstones in his town’s graveyard recently told a local reporter that “It seems to be only the black shiny ones they take and a lot of them go missing.”  Even in my own neck of the woods at the University of Washington one of the gardeners at the Urban Horticulture Center regaled John Marzluff and I with his story of how the crows regularly steal the shiny metal placards that identify the center’s plants.

In science, we often like to say “the plural of anecdote is not data”.  This is unequivocally true.  But just because they’re not data doesn’t mean they’re meaningless either.  I’m inclined to believe there’s more to these stories than random chance and I think they are worth exploring.  Perhaps these stories emerge out of confirmation bias, meaning people tend to report theft with respect to shiny things more often because they’re looking to confirm a suspicion they already had.  If so, it would be yet another fascinating example of the extent to which corvids have infiltrated our culture.  Or perhaps this is the work of curious juveniles as has been suggested by my crow colleague Dr. Jennifer Cambell-Smith.  If so, teasing out any evidence of discrimination or bias juveniles are using when selecting objects to explore could give us insight into how they learn about the world, or how our garbage is modifying that behavior.  Or perhaps crows do like to carry off with glossy objects, but for textural, rather than visual reasons.  At least some corvid species swallow small stones to aid in digestion and these stones are most often partially smoothed.2  These ‘grit stones’, however, are considerably smaller (on average only 2.9 mm) than I imagine grave stones are, so perhaps this behavior is evidence of poor grit stone selection among naive birds.

Or maybe it’s none of the above, we simply cannot say.  Which, for me, is exactly why I find these anecdotes so interesting.  While we can rule out that this behavior isn’t a manifestation of corvids’ love for bling, we can’t exactly explain this behavior either.   It’s yet another item on the shelf along with thieving golf balls and wiper blades where we can’t do much more than offer an educated guess.  So while I’m quick to clarify that crows are not attracted to shiny objects, I’m not dismissive of these anecdotes either.  My friend and colleague David Craig likes to say that every bird has a story, and citizen science is part of sharing that story.  In my book, the story of corvids and their light fingered behavior seems an ideal project for the crow minded bird nerd.

  1.  Shepard, T. V, Lea, S. E. G., and Hempel de Ibarra, N.  2014.  Thieving magpie’?  No evidence for attraction to shiny objects.  Animal Cognition 18: 393-397.
  2. Gionfriddo, J.P., and Best, L. B. 1996.  Grit-use patterns in North American birds: The influence of diet, body size and gender.  The Wilson Bulletin 108: 685-696

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