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.

Reuse

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!

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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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42 Comments

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

42 responses to “Everything you want to know about crow nests

  1. So interesting! Although I travel around the US in a smallish motor home I’ll be on the lookout. BTW, you write beautifully.

  2. Suzanne Paterson

    Fascinating! Just today, a lovely spring day in the PNW, I was in my backyard observing bird activities…Hawks, blue jays, chickadees, and of course crows, all vocal and active in their own ways. And yes, the crows were busy with their “twigging”, flying from tree to tree with the twigs in their beaks. It really is interesting to watch their activities, and no, I do not see the nest in the picture! ( is that a monkey tree?). Thank you for sharing your observations and insights 🙂

    • I always just say they’re “breaking branches” but “twigging” has a much nicer ring! I may steal that for myself 🙂 As for the Monkey tree nest…It’s just to the left of dead center. Look for the few out of place twigs nestled among the needles of the tree. Can you see it now?

  3. Very interesting. I’ve watched crows on my honeysuckle bush, how they break off parts of twigs for their nests. Such helpful pruners! 🙂

  4. Great post! I wouldn’t have guessed that crows won’t reuse their nests year after year. Seems like a lot of extra work!

  5. Deborah

    We have a pair that has built a nest on a ledge outside our 3rd floor office window. There were 7 eggs – only 3 hatched. Don’t know where the other eggs went. They still have one alive. Don’t know where the 3rd disappeared to. One of the nestlings died in the nest. What do Ravens do when this happens?

    • Most of the time birds will toss dead nestlings out. With some species this may be difficult so the dead nestlings just get smooshed into the bottom of the nest cup. Wouldn’t be an issue for a raven though, they’re more than capable of removing them.

  6. Sue

    Very interesting reading your blog. I draw very detailed birds’ nests in graphite, but have never tackled a nest as large as a crows’ . Living in Australia, I have always wanted to draw a magpie’s nest. Friends give me nests they find which seem to be mainly those belonging to the wren family. I don’t suppose you have any crow’s nests you no longer need. Would be happy to pay the freight.

    • Hi Sue, I’m afraid sending a crows nest would be very much illegal under US law. We even need special permits to possess them. Happy to send lots of photos though!

  7. Robert Hogue

    This morning I observed a crow appear to attempt to give a pancake to a squirrel! The crow approached the crow sideways with the cake in its beak. The squirrel rebuffed the offer(it was busy eating bordered).

  8. Carole Strunk

    Hi,There,

    I was wondering if you know of any corvid researchers in southern California? I live near Peck Park in San Pedro, California, which is simply a giant crow and ravin haven. It is a large nature reserve which is heavily wooded with trees and everywhere you turn it is full of crow society, crows songs, clucking, etc. You can walk along the trails and you will see crows on every trail. I was just thinking that the area is PERFECT crow study habitat.

    Feel free to post this and edit at will.

    Thanks, Carole Strunk

    On Fri, Apr 1, 2016 at 8:35 AM, Corvid Research wrote:

    > corvidresearch posted: “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 materi” >

    • Carol, there’s a number of researchers at UC Davis, but they’re too north of you I imagine. Nothing close I can think of I’m afraid. Looks like you’ll have to conduct some citizen science!

      • Carole Strunk

        Thank you for your reply. I will be happy to do so.P.S. I just realized I made a typo in spelling “raven” incorrectly. Oh dear of all the words to fumble here. : )

  9. JACQUELINE T HATCH

    Do crows ever nest in an attic ??

    • Hi Jacqueline, I’ve never heard of that and I would be surprised if that was the case. In general, the animals you find nesting in your attic are cavity nesters in their natural setting which crows generally aren’t. They’ll definitely nest on the eaves of house though so it kinda of depends on how generous you’re being when you say the nest is actually IN your attic. What makes you think they are?

      • Jonathan Rovick

        I actually found this blog today looking for similar information. I have a crows nest in the overhang of my roof on my one-story house in New Orleans. I’m certain they have attic access as I believe I understand the construction of my house, but it appears that they either found or created a hole in the overhang and the nest is on the edge. I first noticed it this past weekend while mowing the front yard. I haven’t seen the adults entering or exiting, but they have been on the roof and foraging on the ground near a lot more lately and less likely to fly off when I’m near. Now I know why, they are protecting the babes. I saw at least one small crow coming in and out of the attic. I don’t what stage of life it would be called. It’s considerably smaller than the adult, but looks like the adult in every other way.

        I am actually wondering what to do. I’d like to fix the hole in my house, but obviously would like to let the baby crow get out on his own before I do so.

        Suggestions? Any idea how long I’ll be waiting?

      • Hi Jonathan, that’s quite the problem. Generally, when crows get up out of the nest they don’t come back. This is called fledging. If you’re seeing the baby up and about it’s only a matter of days before it’s on the ground. Once the rest of its siblings (3-4 nestlings is typical) are out too, the nest is permanently vacated. You shouldn’t have to wait too much longer. It’s been 4 days since you posted this, I wouldn’t be surprised if they were already out!

  10. Here in southeastern Illinois I’ve been getting acquainted with a mates pair of crows and finally today the male landed on my side mirror and flew a short distance away to caw at me. I haven’t fed them any unsalted peanuts in over a month and they let me know they were hungry. They are amazing and incredibly smart animals.

  11. SamLeannaforever

    Hi! I’m attending college at Alfred State in upstate New York. The campus is home to at least a thousand crows. I’m going to make a hobby of mapping where the crow nests are on the campus, and this was some very helpful information! Crows are so beautiful! I may choose to befriend some of them. A few weeks ago there were a few pecking at a closed food container in the parking lot so I emptied the container on the ground for them then threw the container away.

  12. John Dowding

    Hi I live in the UK. I have an albino Carrion Crow who has just started what appears to be attempting to mate but he always does it after it has gone dark outside. Do crows normally mate late in the day

  13. Fred Huston

    Live in Mukilteo, but currently in Florida enjoying the “eastern” crows and their different vocalizations. Lots of nest building activity here!

  14. kris0723

    Hi Kaeli! Love your blog! Our neighborhood crows are doing just what you wrote, not reusing an old nest but building one above it higher in the tree. They seem to be reusing some of the twigs from the old nest. So excited to go to Japan this Spring. Hope to see lots of Jungle crows!

  15. Hi I live in London (England) and work as a tower crane operator, a pair of crows have just finished constructing their nest on the jib (the long arm) of my crane, they seem to have laid their eggs now as one of the crows is constantly sitting on the nest. This is a busy building site and the crane is constantly moving but it doesn’t seem to deter the crows! I have been trying to do some research on dealing with crows nests as the crane will be dismantled soon. I’m hoping that by then the eggs will have hatched and fledged but I’m not sure what to do if they haven’t? I can’t seem to find much information over here.

    • Although they’ll be really aggressive your best bet might be to move the entire nest to a new location. A wedge in a nearby tree would be your best bet, or in a protected location on a building. This is often what is done if a nest is knocked down by a storm, so I don’t know why it wouldn’t work in this case. Let me know what you end up doing!

  16. Kathryn Celidonio

    Ok so today I found 4 baby crows dead in my front yard and one more making it 5 across lying in the neighbors yard there insides where hanging out looked like there intestines all of them where found with there insides hanging out the backsides and some of the intestines where scattered around the yard the babies were killed but not eaten what could have happened we also found the best in our yard just sitting on the groun though still pretty intact I took pictures please email me back so I can send them to u

    • Hi Kathryn, has there been inclement weather? We’re the babies nestlings (mostly naked) or fledglings? If the former then it’s possible they died by whatever force was strong enough to knock their nest out of the tree. After that is sounds like scavengers got to them. If it was simply a predator then the nest would be intact. My best guess!

  17. Lisa

    This was a missing plank on the outside of my apartment. I noticed that black birds flew back and forth. I quickly realized there was a nest there. It didn’t bother me until I heard scratching in my vent. Thats when I called maintanence. They filled the hole with some type of filler that hardened and spilled over. I was angry that they didnt check before filling. When the birds returned at the end of they day, they went wild. I feel so bad, knowing now that that was a nestling plave. I have small children here who play closeby. The area is actually above my patio. How long should I be concerned about possible retaliation? #sorrymamacrow.

    Ps. The information you provided was very informative. I guess I have to paint eyes on my pit cover and umbrella!

    • Hi Lisa, you don’t need to worry about retaliation at all since you weren’t involved (from the crow’s perspective) in the threat to their young. They’ll give up soon and try to renest elsewhere. That is awful though, thinking they may have had nestlings that will now slowly starve to death. A good lesson that we can do better when dealing with wildlife conflicts.

  18. Tyler Lieberman

    We have been watching a crows nest from our office window for the past 3-4 weeks. We cannot actually look down into the nest, but by the birds behavior and the info we found online, we assumed the eggs were on the verge of hatching any day now. Today, we watched the two birds start to shake the twigs from the nest and fly away with two eggs carried away between their beaks. Is this a common occurrence, or has something gone wrong with the incubation?

    • Hi Tyler. Um no, this is not a thing known to crow science. Would you be willing to email me a more detailed account of what you witnessed? Or at least email me and I’ll tell you the details I would like (should you accept this challenge 🙂 kaelis@uw.edu. Thanks!!!

      • Tyler

        Later that night, two smaller crows were settled into the nest. We believe these were the original nesting crows, and there were two larger birds (we still think crows) that raided the nests and flew away with two eggs. This morning, the nest appears to be even more torn apart over the last 12 hours, and no crows have been seen at all. Do you think we witnessed a kidnapping? A murder? Or something else?

  19. Dana Bennett

    Under the eves of my garage, on top of last years blue jay nest on the large light was built another nest. Today I saw 2 med to small crows standing & sitting guard. There was a blue jay below on a bush crying loudly. Whose nest is it?

    • Hi Dana, you’ll need to watch it for a few more days and see who sticks around. If it’s in active now, it’s likely the crows were there in their capacity as predators. If they’re still around, then it’s their nest. Fun opportunity for some natural history!

  20. I am in North Carolina. I noticed a very large pine straw nest in a corner of my eaves under my front porch overhand and I saw 3 large crows hovering around it yesterday. I want to clean it out but don’t know what’s in it because it’s in a dark corner area. When do they usually have their babies and leave the nest in this area?

    • Hi Bob, it’s variable enough that I can’t wager a guess as to your specific nest. For example, while many crows around here are fledging young, some are just building their nests. Just watch the nest for a few days. If there’s an adult bird consistently sitting in the nest, they have eggs, if the male and female are making frequent trips, they have nestlings, if you can hear lots of loud begging they’re older nestling and fledging will be in the near future. Hope that helps!

  21. Bert

    I have a crows nest in a dead tree in my yard. The young have hatched and gone. I want to remove this tree as long as they are done. Will they renest in it?.

    • They might, but not this year. That said, dead trees are invaluable habitat for lots of birds. From primary cavity nesters like woodpeckers to secondary cavity nesters like swallows, chickadees and flying squirrels, if there’s anyway for you to keep the tree I urge you to do so. The right arborist can help figure out how to cut the tree such that its presence is minimally dangerous, but still leave enough to make good habitat. If it’s possible please leave it! Thanks for your question

  22. JeroyKok

    I would like to know how to make a crow leave/move their nest. It’s troublesome to have them build a nest in a cleavage at my rooftop.

    • There’s no way to legally remove a nest without going through fish and wildlife first. Once the breeding season is over, you can use netting or spikes to prevent future nesting attempts.

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