• Debra
      Participant
      Chirps: 16
      I like how the team can track individuals and find out how long they live and who they hang out with. To get to know the crows as individuals would be so rewarding, like having an old friend. It is so miraculous to see how the little ones look so helpless and how they change over time. It was so interesting how they are born with blue eyes! Neat to see the bird's eye view from their nests. It makes me wonder how you would tell a squirrel nest from a crow nest.
    • Kelly
      Participant
      Chirps: 5
      I found the details about tagging and how long some of them live very interesting.
    • betty
      Participant
      Chirps: 1
      I learned so many interesting things but most surprising was how long they lived. Also interesting was the blood sample to tell sex of the crow.
    • Rosalie
      Participant
      Chirps: 3
      That the nestlings are tagged three different ways. I have not heard of tagging the wings before. It was neat to learn that the birds can be followed for much of their lives, up to 18/19 years. I was really happy to learn that they are studied as individuals.
      • Ellen
        Participant
        Chirps: 10
        Putting tags on wings is not uncommon, especially for bigger birds. Wing tags have been used to identify California Condors in the wild for years, especially for those who were captive-bred and then released into the wild. It is much easier to see a large wing tag than any leg bands on a bird that spends much of its time soaring/flying.
    • Dawn
      Participant
      Chirps: 1
      By tagging the birds you were able to find out how their community is structured and how it changes over time.
    • erin
      Participant
      Chirps: 2
      So interesting how you have these study methods . . Two questions: I imagine you have to use the gear that tree trimmers do to get to the tallest part of the tallest tree where the nest and babies are, and handle the babies and put tags and bands that are strange to them.    Why does that not spook the parents and make them leave the nest?  You always hear that birds and animals will abandon young ones if you scare them or make too much of a ruckus near their nests. If humans need to use a blood test to tell the gender of the birds, how do the birds know who is male and female?    I have often wondered this because I have parakeets at home, one type (budgie) I have a male and female you can sort of tell by the color of their nose but the other (parrotlet) you are supposed to give them a dna test to tell.   Two of them squabble and the other one so I assume it's the boys arguing over the girl.    
      • Erin asked: <

        I imagine you have to use the gear that tree trimmers do to get to the tallest part of the tallest tree where the nest and babies are, and handle the babies and put tags and bands that are strange to them.    Why does that not spook the parents and make them leave the nest?  You always hear that birds and animals will abandon young ones if you scare them or make too much of a ruckus near their nests.>>

        Erin, American Crows can be initially agitated when the tree climber is near the nest or young. However, the American Crows typically have too much invested in their 'kids' to abandon them or ignore their begging calls after they are returned to the nest.
        Erin asked < < If humans need to use a blood test to tell the gender of the birds, how do the birds know who is male and female?  >>
        There are some differences between male and female that a crow would be better able to access than a human or researcher. We are not aware of any studies that have been done to determine how the crows themselves know male vs. female.  The male does have a slightly lower voice than the female and while that is difficult for humans to easily use for "sexing" a bird the crows themselves might be better at using voice to tell male from female. There are probably other differences they pick up on such as slight differences in bill size or shape. Even trained researchers have a difficult time with any visual differences and that is why to be 100% sure researchers go by DNA tests. There are probably behavioral cues they could pick up on but without a proper study it is all speculation. Thanks for asking.
    • Harold & Shirlee
      Participant
      Chirps: 1
      I didn't realize that baby crows did not have black down....great to know and much easier to distinguish.
      • Eveline
        Participant
        Chirps: 17
        Agreed. I noticed they are never really all that cute ;) They kind of go from breath-takingly ugly to almost full feathered like an adult. THe blue eyes when they are young is also helpful.
    • Linda
      Participant
      Chirps: 2
      I think the most interesting was the banding of the banding of the birds. What I was surprised by is by telling the sex bt taking a blood sample.
    • Dorothy
      Participant
      Chirps: 2
      I have a question? At 3:36 in the video there are three still images showing the handling of the babies for research. The image where the researcher is examining the inside of the crows mouth, there is a colour chart in the frame. Can information regarding the baby’s health be detected by the colour of their tongue?
      • Can information regarding the baby’s health be detected by the colour of their tongue?
        Dorothy, The color chart you noticed was used that year by a graduate student that was looking to see if inside mouth color variation was indicator of anything such as health, quality, or temperature. That student has not published study results so no updates or conclusions for us to post about.
    • KATHRYN
      Participant
      Chirps: 6
      Probably how scientists went from colored bands to metal bands then to wing tags and transmitters. It also must be a challenge to locate the new nests each year.
    • Ingrid
      Participant
      Chirps: 1
      I didn’t know crows lived so long.
    • Evvie
      Participant
      Chirps: 2
      I had no idea they could live that long, and be tracked individually for so long. That's wonderful! I didn't realize their feathers would start to turn white with age either, though it makes sense if they're living past ten.
    • Angela
      Participant
      Chirps: 8
      I was surprised that the researchers would put large, visible wing tags on the birds.  I would be concerned that this would make the crows more visible to predators as well as to researchers!  The crows seem to be doing okay with the tags since some of the individual birds live up to 19 years.  Still, crows evolved to be all black, not black with rainbow wing patches, so I am still concerned that there is a fitness cost to this tagging method.
      • Chris
        Participant
        Chirps: 13
        This is a good question and I am disappointed that no expert responded to it
    • Tracy
      Participant
      Chirps: 1
      I didn't know the white feathers were a sign of aging.  Can crows of any age have naturally occurring white feathers?
    • Diane
      Participant
      Chirps: 4
      I didn't know that their eyes changed colors like that! That's really interesting. Also, I am surprised at how well they tolerate those big, gaudy wing tags. Do untagged crows ever attack the tagged ones, thinking there is something wrong with them or that it is a stranger? Or is it that they are smart enough to realize "Ok, that's still my sister, even thought she has that pink thing on her"? Curious...
      • Chris
        Participant
        Chirps: 13
        I'm also disappointed that no expert responded to any unusual behavior that tagging the crows cause.
    • charlene
      Participant
      Chirps: 3
      I had no idea that crows were being studied and banded.  Great way to collect data and identify them. I have trouble keeping track of who’s who. That was very good news to hear they live to 17.
    • Katie
      Participant
      Chirps: 3
      I had no clue they could live 18+ years!
    • Susan
      Participant
      Chirps: 30
      That you have been following them for so many years!  And the three tags - I thought that leg bands lasted forever. Aren't the wing tags - and I noticed some kind of antennae on their backs in one shot - obtrusive or invasive in the crows' movements?
      • The local researchers haven't noticed anything to indicate that the tags impede movement. The tags usually stay on for several years, but not as long as the leg bands. Crow "AP" the longest lived of the research crows still had remnants of his wing tag at age 17. When they first get the wing tags they fuss with them, investigating the new adornments. However after a day or so they seem oblivious to their presence. The antennas  haven't been put on very many crows thus far and don't stay on for very long. They usually fall off in less than 1 year.
    • Student Birder
      Participant
      Chirps: 1
      I was surprised that team members had to be hoisted up to the nests at the top of those tall trees.
    • Faith
      Participant
      Chirps: 6
      All of the different types of banding
    • Kendra
      Participant
      Chirps: 1
      I wonder why males and females look alike when so many other species of birds have such sexual dimorphism. Do male crows not need to impress females visually? Maybe it's his sense of humor or some other sign of intelligence that makes him attractive. ;)
      • When the males and females look the same they are called sexually monomorphic. The males are slightly larger than the females but not enough for humans to easily notice the difference without taking measurements and that is why DNA testing is the best way for humans to tell the sexes apart. Crows do have some courtship displays. However there is more that could be researched about the American Crow courtship process. The local researchers don't witness the meeting of a crow with a mate or potential mates and the courtship period is thought to happen quickly perhaps. They don't know if the males need to impress the females visually. It is difficult to make an assessment since the local researchers don't witness much if any of the courtship process.
      • Eveline
        Participant
        Chirps: 17

        @Lee Ann van Leer Great question Kendra. Very interesting that so little is known about the courtship ritual. This is usually such a big part of what you read about whenever trying to learn about different birds from your standard guidebooks. Now I'm really curious why crows are so different (i.e., if it is in fact a short courtship period, then why? Does it make them vulnerable somehow?)

      • @Eveline Hello Eveline, Corvids in general don't show a lot of display for courtship. With the American Crows they typically form a long term pair bond so they aren't having to do a lot of courtship displays and rituals every year for breeding season like some other types of birds might do. Once the bond is formed it can last for many years or until one dies so the odds of a researcher observing that first time period that a new couple is pairing up for the first time is slim. That coupled with the difficulty in humans differentiating individual crows which can't be reliably told apart from another crow without them being tagged and or color-banded.  If you are observing unmarked crows you don't necessarily know if you are observing a male or a female, parent, partner, child etc reliably. In the course there is an offer for course takers to get a discount on Birds of North America (BNA) subscriptions. BNA is  our more in depth online encyclopedia of North American Birds. Here is an excerpt from Birds of North America, American Crow : Pair Bond Courtship Displays and Mate-Guarding. Courtship display, if it exists, is rare, judging by the paucity of reports on the subject (Good 1952). Allopreening, often actively solicited by either mate, occurs regularly, but largely ceases during incubation (Kilham 1989). Billing, seen infrequently, involves a mated pair gently fencing with their bill tips, and bill-grasping (Kilham 1989, CC). Members of a breeding pair stay in close contact during egg-laying stage (Caffrey 1992). Breeding male guards mate during time of sexual receptiveness. At start of egg-laying in Florida, males stood generally on 1 of 2 or 3 favorite perches, on the ground below the nest, on a fence post, or in a tree as far as 150 m away, watching for periods of 30 min. Males hardly fed their incubating mates during mate-guarding period; helpers fed the females (Kilham 1989). In California and Oklahoma, guarding males sit for hours at a time, with only short breaks, in obvious high perches near incubating females (CC). Copulation; Pre- And Postcopulatory Displays Based on Black 1941 , Kilham 1989 . During precopulatory display, both sexes crouch, bodies horizontal, wings out and drooping, and tails vibrating up and down; females use same display posture during courtship begging (accompanied by nasal “ waahs ”; CC). Sometimes this same display occurs in other context; juveniles give it to older siblings and some-times to each other (CC). Begging nestlings and fledglings assume the same posture and produce nasal “ waahs ” as well (CC). Males sometimes pick up objects as part of copulatory behavior. During copulation, male settles on female, waving his outstretched wings; female stands and vibrates her tail up and down while the male works his tail under hers. Loud, hoarse calls by female, audible 250 m away, heard during 13 of 30 copulations seen. Copulations occur on the ground, in trees, and on nests; last from 4 to 12 s. Reverse mounting occurs (Kilham 1989 ).

      • Chris
        Participant
        Chirps: 13

        @Eveline Sounds like an idea for a research project, albeit, it would be a difficult one to observe in the wild, since it seems difficult even under more controlled conditions like the researchers have.

    • Valerie
      Participant
      Chirps: 1
      It's nice to know that crows can live for so long in the wild.  I didn't know about the need to be redundant with tagging - that's interesting!
    • Andrea
      Participant
      Chirps: 1
      Three tags
    • Eye color changing in birds fascinates me. WHY do their eyes change color? WHEN do their eyes change color? is there some purpose for eyes being difference colors?
      • For crows the eye color is a cue for the recognition of juvenile status. The blue eyes show that they are babies.  The blue eyes change to their adult color within a month or two after they fledge (leave the nest). The pink inside out the mouth is another visual cue for crows to recognize that the crow is a young crow. The pink inside of the mouth can last up to two years.
      • Chris
        Participant
        Chirps: 13
        Sounds like another good advanced degree research project!
    • What it takes to be an ornithologist.  I just can't imagine myself climbing such tall trees and bringing down chicks and then climbing back up to put them back.  I like watching crows and wish the ones around me were banded so I could tell if I see the same one repeatedly.  I've seen crows do so many interesting things.