Viewing 63 reply threads
    • Bird Academy
      Bird Academy
      Bird_Academy
      What was most interesting or surprising to you about the crow research team’s methods?
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    • Karrin
      Participant
      Chirps: 6
      klukacs
      I am not sure I found anything surprising about their methods. Wait, I take that back - I thought it was surprising that the research teams have already gone through all of the possible letter / number combinations TWICE. What was interesting to me was learning how to identify crows' nests and that baby crows have blue eyes.
    • p
      Participant
      Chirps: 3
      fragaria
      i was surprised to learn that you would actually take the babes out of the nest to the ground to study them.  What are the parent crows doing while you take their babies away?
    • Anne
      Participant
      Chirps: 4
      parrotletlover24
      I was surprised that the baby crows were taken out of the nest and then returned with no adverse effects to the family.
    • Susan
      Participant
      Chirps: 2
      ssl266
      That they use 3 different bands/tags to ID them!
      • Karrin
        Participant
        Chirps: 6
        klukacs
        I thought that was interesting, too - and I kept wondering if the birds are bothered by the one on their wings.
    • Crystal
      Participant
      Chirps: 3
      Cris720
      I had heard previously about some of how crows are researched but I did not know that they sex them via blood samples.
      • Karrin
        Participant
        Chirps: 6
        klukacs
        Yes! That was a fascinating tidbit!
    • Claire
      Participant
      Chirps: 2
      CCavanah
      I'm surprised that the big plastic tags don't get in the crows' way. And the radio trackers, those seem cumbersome. I'm surprised that the processing that the researchers do doesn't disrupt the family life of the crow.
    • Elaine
      Participant
      Chirps: 6
      Elaine0421
      Going up into the nests to capture the baby crows to take blood and band them.  I hope they are gentle with them :)
    • Linda
      Participant
      Chirps: 1
      LindaMillar
      in the hand
    • Sandra
      Participant
      Chirps: 1
      Sandra224
      That they take the babies so young to mark and study.  Also that the markings stay on for such a long time. That crows live to be 19 years old
    • Paul
      Participant
      Chirps: 5
      FairmontFarm
      Getting up to those tall nests!  AND blue-eyed young.  I learned that in ornithology, but had forgotten.
    • Morgana
      Participant
      Chirps: 1
      ravensdotter
      I knew most of it as I have been corvid crazy since the cradle and have followed Dr. MacGowan's work for a very long time.  I guess the fact that the team could so closely follow individuals and identify their relationship with other other birds within the different flocks/families.
    • Diane
      Participant
      Chirps: 6
      djohnson6141
      That they can climb up into those high trees to tag babies in the nests and that it doesn't disturb the mother's interest in her nest. Also the multiple banding method and that sexing the crows comes by taking blood.
    • Fiep
      Participant
      Chirps: 1
      fdebie
      I didn't know that sex was determined by taking blood and DNA testing. If crows live up to 19 years in the wild, how long would they live if they are in captivity/in a park/non-releasable facility?
    • Kimberly
      Participant
      Chirps: 1
      Brunodog01
      The way they identify them with three different ids.
    • Julie
      Participant
      Chirps: 13
      juliehoskins
      The multiple banding  method and the ability to track crows for 18 years. I did not know they lived this long. This is the kind of meticulous work that reminds me of Jane Goodall tracking primates. Fascinating to know there are such personalities in crows. Admirable work. Great to finally understand why they hang out in cemeteries.
    • Donna
      Participant
      Chirps: 2
      woodley555
      1)length of life 2) no down on babies 3) at least in NY, maintain same nests
    • Donna
      Participant
      Chirps: 2
      woodley555
      1) that mom and babies tolerate banding, blood samples so well.
    • Erica
      Participant
      Chirps: 1
      ericaann
      The longevity of a crow is mind blowing!
    • Vicki g
      Participant
      Chirps: 21
      vickigoldsmith
      `my reaction is a repeat of most all comments below. I love that they become individually known over time. I tend to be amazed that they tolerate all that "stuff" on them - bands, and tags, and radio thingies, and that those things do not alter their behavior in some way. Wee comment, if photographers are willing to give up their credits occasionally, it was hard for me not to peek at the credit ... which was often a dead giveaway as to which the crow was). HOWEVER, I still paid attention to the difference and learned something so it was fascinating - though I would count myself fortunate indeed to see a (non-stranded) baby in the field!
    • ReikiDave
      Participant
      Chirps: 2
      ReikiDave
      I'd agree with Ben.  I'm amazed at the nest to grave study !!  And on a highly individualized level !  Bird by bird, year after year.  I'm also amazed to learn of their longevity.  I'd have thought crows lived somewhere around five to six years.  Eighteen or nineteen !!!  Wow !!
    • Shea
      Participant
      Chirps: 19
      runnerboy13
      I thought that crows would have lived way longer than 13 years.
    • J
      Participant
      Chirps: 2
      jdogstevens
      I was surprised by their longevity.
    • Ben
      Participant
      Chirps: 1
      benito59
      most interesting was the nest to grave approach. the amount of data that studying individuals that way must generate is kind of mind blowing! also, kudos to you brave souls for scaling such heights to collect data.
    • Randall
      Participant
      Chirps: 1
      rmikkelsen
      I liked that they studied the birds as individuals and tracked how they were related to other crows.
    • suzanne
      Participant
      Chirps: 1
      smellard
      I was surprised not only by the fact that they took babies but by the blood sampling.
    • Audrey
      Participant
      Chirps: 5
      AQHall
      I was surprised that researchers took baby crows from their nests.
      • Anne
        Participant
        Chirps: 4
        parrotletlover24
        Me too! And that it didn’t disrupt their family life when they put them back again!
    • Debra
      Participant
      Chirps: 9
      naturgal
      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
      kweymouth
      I found the details about tagging and how long some of them live very interesting.
    • betty
      Participant
      Chirps: 1
      bettyn
      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
      dearosalie
      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.
    • Dawn
      Participant
      Chirps: 1
      Dawn Hall
      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
      brightside99
      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.    
      • Lee Ann van Leer
        Bird Academy
        LilacRoller

        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
      Harold & Shirlee
      I didn't realize that baby crows did not have black down....great to know and much easier to distinguish.
      • Eveline
        Participant
        Chirps: 17
        WonTolla
        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: 1
      happy2cu
      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
      DeeBlack
      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?
      • Lee Ann van Leer
        Bird Academy
        LilacRoller
        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
      KatCrow
      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
      ingrid.blanton
      I didn’t know crows lived so long.
    • Evvie
      Participant
      Chirps: 2
      inkybirbs37
      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: 7
      Angela.Snow
      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
        cpennisi
        This is a good question and I am disappointed that no expert responded to it
    • Tracy
      Participant
      Chirps: 1
      TracyHench
      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
      dlahaise
      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
        cpennisi
        I'm also disappointed that no expert responded to any unusual behavior that tagging the crows cause.
    • charlene
      Participant
      Chirps: 3
      charlene cyr
      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
      Bookista
      I had no clue they could live 18+ years!
    • Susan
      Participant
      Chirps: 30
      susangreta
      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?
      • Lee Ann van Leer
        Bird Academy
        LilacRoller
        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
      OBbirder
      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
      faith m sullivan
      All of the different types of banding
    • Kendra
      Participant
      Chirps: 1
      kendrahunding
      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. ;)
      • Lee Ann van Leer
        Bird Academy
        LilacRoller
        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
        WonTolla

        @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?)

      • Lee Ann van Leer
        Bird Academy
        LilacRoller

        @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
        cpennisi

        @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
      vryanbuzz
      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
      amdrogers
      Three tags
    • Kristin
      Participant
      Chirps: 1
      kristin0515
      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?
      • Lee Ann van Leer
        Bird Academy
        LilacRoller
        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
        cpennisi
        Sounds like another good advanced degree research project!
    • Student Birder
      Participant
      Chirps: 7
      elydick
      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.
    • Jo Anne
      Participant
      Chirps: 1
      jothar
      I'm still mulling over the fact that the only truly reliable way of determining the sex of a crow is blood analysis.  I have been attempting to guess males( by what seemed to me to be useful) that in a pair one seems to have a slightly larger head due to more or ruffled feathers.  Is this at all reliable?
      • Lee Ann van Leer
        Bird Academy
        LilacRoller
        The size difference between male and female is so slight that even the crow experts don't always guess the sex correctly just by visual characteristics. Size can be deceptive and feathers can be fluffed up or smoothed down variably by a bird. So the only reliable way to sex crows is by DNA. Thanks for asking about this.
    • Kathryn
      Participant
      Chirps: 1
      kathygeorge
      Definitely the wing tags for distance ID!  And I was interested to know how long the crows live.
    • Michele
      Participant
      Chirps: 5
      MGarlick
      Most interesting --  the wing tags for distance identification!  So curious as to how these were developed, made, coded, attached.  Would love to learn more.
    • Peggy
      Participant
      Chirps: 10
      MPage815
      What was most interesting to me is the focus on individuals, and the ability to stay with an individual bird through its life. To me, this brings understanding of the species to a whole new level - beyond the abstraction of “crow” to a specific, concrete, real life. To our untrained eyes, individual birds of a species look identical. We can’t sort out sibling relationships or even mates outside the breeding season. How much richer to know this crow is 17 years old, the brother of this bird and the mate of that one! How much more connected we become to a fellow creature when we are able to see it as a unique individual.
      • Chris
        Participant
        Chirps: 13
        cpennisi
        I agree; well said!
      • Anne
        Participant
        Chirps: 4
        parrotletlover24

        @Chris Yes, so true!

      • Anne
        Participant
        Chirps: 4
        parrotletlover24
        We see our pet birds and other pets as individuals, so why not view crows and other wild animals the same way?
    • Desiree
      Participant
      Chirps: 16
      Weeziehupy
      I was very happy (and surprised) to hear about the crows that had been tagged and observed for so long. I think it’s wonderful that the people working on the crow research are able to track family relationships. I really wish I could do this with the crows I feed, but unless one crow has some unusual feature or personality tic, I have a hard time telling the ones in my yard apart. I also was surprised and very charmed by the elderly crow’s white face feathers. In the picture he looks dignified and wise. I hope the younger crows are taking his advice.
    • Susan
      Participant
      Chirps: 3
      Avianna
      Interesting the number of tags used.  Did not realiza this.
    • Amanda
      Participant
      Chirps: 3
      adguzman
      I was a little surprised at how tolerant the crows seemed to be with the researchers. In my own personal study, I'd read accounts of crows remembering for years the faces of researchers and reacting adversely to their presence. Perhaps I was just misinterpreting what I saw in the lesson in that regard. And I was pleasantly surprised at how long the crows lived. I'm definitely in the love crows category, and I hope this work helps to improve the lives of crows everywhere.
    • Sherry
      Participant
      Chirps: 6
      sherrybay
      I was surprised that they were able to take track of individual crows for up to two decades, that they understood the family ties between crows and that they could find family members still flocking together (such as sisters two years apart).
    • janine
      Participant
      Chirps: 1
      jbonura
      I am very surprised at how long they live and at their changing eye color.
    • Mary
      Participant
      Chirps: 10
      James949
      I was also surprised at how long they can live and that you can still recognize them when they have lost all their Id tags. I also wonder if the wing tags are annoying. I was also wondering when researchers would start using some kind of broadcasting tag since miniaturization has gotten so good. And I was wondering what kind of camera the researchers have that can now catch birds on the fly.
      • Chris
        Participant
        Chirps: 13
        cpennisi
        The idea of using a smaller digital device on the crows seems like a better idea than the unwieldly big tags; then the crows could be identified from longer distances, and perhaps more accurately.
    • Sean
      Participant
      Chirps: 1
      SeanMcGuire
      I was surprised to learn how long crows can live.
    • DLadetto
      Participant
      Chirps: 6
      DLadetto
      I was surprised that some can live so long that their leg bands fall or wear off.
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