An Experiment in Chick Sexing Methods

A continuous experiment on old wives' tale methods to determining the sexes of chicks.
By pipdzipdnreadytogo · Jan 17, 2017 · Updated Apr 12, 2017 · ·
  1. pipdzipdnreadytogo
    An Experiment in Chick Sexing Methods

    Chick sexing experiment cover picture.jpg

    We’ve all heard them, those crazy methods for sexing chicks that sound too far-fetched to be true. Often, they are not even backed by good reasoning, and so any logical person would chuckle at the suggestion and brush it off as absurd. But so many swear by these methods that one has to wonder, could they possibly work? Anyone who has discovered the addictive nature of hatching chicks could use a simpler and easier way of sexing the many chicks they hatch, right? And why would these methods gather such a following if they did not work?

    To test these methods, possibly the best route would be to hatch hundreds of chicks, test all of them, and report the results once they have matured enough to determine their actual sex. Unfortunately, I have neither the time, nor the coop space for such a task. Instead, I will be performing these various methods on as many chicks as I can as I hatch or buy them, and then gathering the data from all of these chicks here over time. Only I will be performing these tests to remove any uncertainty in the uniformity of how tests are performed. Both straight run and sexed chicks may be included here, but because knowing the sex of the chicks beforehand may cause some subconscious skewing, results from sexed chicks will always be reported separately from those of unsexed chicks.

    Chick sexing methods were chosen by their commonness, strangeness, or seeming unlikeliness. However, I did have just one ground rule in choosing sexing methods. I decided before I started this experiment that I would NOT do any method that I believe may hurt or cause trauma to any of these chicks. That means I will NOT be lifting them by their beaks, wings, heads, feet, or the backs of their necks, or doing any other method that sounds like it could be harmful to them. To me, enough people have tried these methods unsuccessfully that it is not worth me compromising the health or trust of my chicks just for this experiment. Beyond that, if it seems silly or far-fetched, or it’s very different than any of the other methods I’ve tried, I’m willing to give it a shot! I’m also open to suggestions, so if you have a method that is sufficiently different than the ones already listed on this page, feel free to send it to me in a PM!

    Test Subjects

    Chicks subjected to sexing methods will be of various breeds, all under the age of 4 weeks old when tested. All chicks will be straight run (that is, their sexes were unknown) unless otherwise stated. Subjects are grouped below by hatch date and breed. Subjects from previous broods of chicks will be hidden in 'Spoiler' drop downs to keep the page a bit shorter. Click the blue boxes below to see pictures and more information about previous subjects.

    Bantam Cochin 2017 Chicks.jpg

    Hatch date: January 4 and 5, 2017
    Variety and Breed: Partridge and Red Cochin bantams
    Identification: Identified by markings used to distinguish eggs; Abie, Alpha, Lucky, Onesie, and Omega

    Hatch date for all of these chicks is assumed to be April 3, 2017.

    Dark Dorking 2017 chicks.jpg

    Variety and Breed: Dark Gray Dorkings
    Identification: Identified by breed and marker colors added to their heads; DD-Blue, DD-Green1, DD-Green2, DD-Brown, and DD-Purple

    Red Dorking 2017 Chicks.jpg

    Variety and Breed: Red Dorkings
    Identification: Identified by breed and marker shapes added to their heads; RD-X, RD-O, RD-Dot, RD-Line, and RD-Z. Not pictured is RD-Squirt, who was included in the experiment later. Sadly, RD-Z passed away before its sex could be determined.

    Black Copper Marans 2017 Chicks.jpg

    Variety and Breed: Black Copper Marans
    Identification: Identified by breed and a color spot added to their chests; BCM-Blue, BCM-Green, and BCM-Purple

    Wheaten Marans 2017 Chick.jpg

    Variety and Breed: Wheaten Marans
    Identification: The only one of this breed and variety, so simply identified as WM

    2018 Babies

    Individual pics mashup.jpg

    Hatch date: March 3 and 4, 2018
    Variety and Breed: Black Copper / Birchen Marans
    Identification: Identified with the numbers written on their eggs; distinguished by colored leg bands

    silkied cochins 2018.jpg

    Hatch date: May 12 and 13, 2018
    Variety and Breed: Cochin bantam (variety uncertain as of yet)
    Identification: Distinguished by leg band color, with 'SC' for breed added to eliminate confusion with future chicks

    Mottled Cochin bantams 2018.jpg

    Hatch date: May 21, 2018
    Variety and Breed: Mottled Cochin bantam
    Identification: Distinguished by leg band color, with 'MC' for breed added to eliminate confusion with future chicks

    Sexed Dorking Pullets 2018.jpg

    Hatch date: May 21, 2018
    Variety and Breed: Silver Gray Dorking ** SEXED PULLETS **
    Identification: Identified by leg band color, with 'SGDP' for breed and sex added to eliminate confusion with future chicks


    Below, you will find details of all of the sexing methods used in this experiment. The names of these tests is what will be used in tables and figures in the Results section. Due to time constraints, not all chicks have been tested with every sexing method. It will be apparent when a test has not been performed on every chick by the tables and figures in the Results section.

    To keep the page a bit shorter, please click the blue box below to open the spoiler and read the different methods. If you're simply returning to check on the results, then you can leave the spoiler closed and not have to scroll past all of the descriptions again!

    Wing Sexing

    This is a classic method that is used by big hatcheries, but the thing that people don’t take into account is that it is a trait that must be bred for—not every chick from every source will be accurately sexed using this method! The reason I chose to add this one to the experiment is because so many people spread it as a 100% true sexing method for all chicks. In wing sexing, when the chicks are only a few days old at most, males have a short, even row of pin feathers on their wings, and females have a staggered row of short and long pin feathers on their wings. The picture below (from this thread) shows the difference.

    Wing Sexing example pic (not mine).png

    Tail Feather Method

    I believe this is an extension of the above method, but I figured it was worth mentioning. In this method, females get their tail feathers in sooner than males.

    Tail Tap Method

    By this method, when tapping the chicks on the tail, only males chirp in response and females are silent.

    Tail Pull Method

    In this method, you gently pull on the chicks’ tails. If they are male, they chirp in response, while if they are female, they are silent.

    Needle and Thread Pendulum Method

    This is a method that many, MANY people swear by, both for sexing chicks and unborn human babies, too! In this method, you hang a metal needle from a thread above the chick. If it moves back and forth in a straight line, the chick is male. If it makes a little circle with its swing, the chick is female.

    Lay on Back Method

    In this method, you carefully lay the chick on its back in your hand. If it struggles to right itself, it is male. If it relaxes and just lays there, it is female.

    Leg Stretch Method

    In this method, you carefully lay the chick on its back in your hand. If it stretches its legs out, it is male, while if it keeps its legs tucked in, it is female. I considered all tests in which the chick consistently kept one leg tucked and stretched out the other to be inconclusive.

    Pick Up Method

    By this method, when picking a chick up around its body from above and allowing its feet to dangle, a female will pull its feet up and a male will just let its feet dangle.

    Surprise Method

    In this method, you surprise the chicks in one way or another and gauge how they react. Many people suggest throwing a hat into the brooder, but one can also make a loud noise, BRIEFLY flap a flag or cloth over the brooder, or any other method that might surprise the chicks. If a chick stands up or stays where it’s standing, it is male. If a chick ducks down or runs for cover, it is female. For this experiment, I made a loud noise.

    String Peck Method

    In this method, you dangle a piece of string in the brooder. If a chick pecks it more than twice, it is male. If it pecks the string only once or is disinterested, it is female.

    Pick Up Chirp Method

    By this method, when picking up a chick, only the males chirp indignantly. Females remain silent.

    Tail Fan Method

    For this method, you must wait until the chicks have tail feathers. When holding them, if you tip them forward suddenly, only females fan their tail feathers. Males don’t move their tails.

    Penny Toss Method

    For this method, you rub a penny on the back of the chick in question, and then flip the coin. If it lands on heads, the chick is male, and if it lands on tails, the chick is female.

    Vinegar Water Method

    According to this method, when offered a dish of plain water beside a dish of white vinegar water (at the rate of 1 tablespoon white vinegar per 8 ounces of water), males will prefer plain water and females will prefer vinegar water. To make sure the water was the only thing the chicks were deciding on, I used identical dishes with identical amounts of fluid in them.

    Vent Shape Method

    According to this method, male and female chicks have different vent opening shapes. This is not the same as vent sexing, which requires one to know the difference between the internal part of the vent, but is instead simply looking at the shape of the vent from the outside. Males have small, round vent openings and females have wider, oval-shaped vent openings. Because this can vary a bit, I compared like breeds to like breeds for vent shape.

    Comb Length Method

    This method states that chicks whose combs end at or past the front edge of their nostrils are male, and chicks whose combs end before there are female. See this thread for more details: Comb Sexing Chicks

    Egg Shape Method

    I am putting this one last because I will not be able to use this method on all chicks. By this method, males hatch out of narrow, pointy eggs, and females hatch out of shorter, rounder eggs from the same hen. These eggs are "eyeballed", not measured, as I believe that's how most backyarders tend to do this test. I will not be selecting eggs based on shape for this method, but I will record the egg shapes of eggs from the same hen where possible and track which chick hatches out of which egg.


    You can view all of the raw data and results on this Google Spreadsheet. There are tabs at the bottom to switch between results by test and results by chick. Please note that I will not add any chick's results to the 'results by test' tab on the spreadsheet OR to the below graphs until their sex is confirmed! I will, however, put them in the 'results by chick' section in the spreadsheet as a means of recording the data until results can be confirmed.

    The spread of male, female, and inconclusive predictions by test for straight run chicks. At minimum, 11 chicks were tested in each method, and at maximum there were 34 chicks tested. On the right is the actual ratio of males and females so far.

    Percent male female 8-25-18.jpg

    Accuracy of each test on straight run chicks is depicted in the below graph showing the percentage of correct predictions by test. Again, some tests were performed on more chicks than others, with a minimum of 11 and a maximum of 34 chicks so far.

    Percent correct all 8-25-18.jpg

    The below graphs show the percentage of correct predictions made by each method, separated by breed. Only straight run chicks are included in these graphs. When separated out by breed, more tests were able to achieve exactly or close to 100% accuracy. However, sample sizes are still small (as few as 5 chicks in some cases), and so these results should not be taken as law.

    Bantam Cochins - As many as 14 and as few as 5 chicks were tested for the percentages in the below graph.

    COCHIN BANTAM percent correct 8-25-18.jpg

    Dorkings - As many as 10 and as few as 9 chicks were tested for the percentages in the below graph.

    DORKING percent correct 8-25-18.jpg

    Marans - As many as 10 and as few as 5 chicks were tested for the percentages in the below graph.

    MARANS percent correct 8-25-18.jpg

    The below graphs show the spread of male, female, and inconclusive predictions for sexed chicks, as well as the percentage of correct predictions on sexed chicks. Only 2 sexed chicks have been tested so far, so these results should not be considered strong evidence of anything at this point. Note also that no sexed chicks so far have been tested for the accuracy of egg shape, and so that test has a 0% accuracy rating only out of lack of any tests performed.

    Percent Predictions Sexed chicks 9-7-18.jpg

    Percent Correct tests sexed chicks 9-7-18.jpg


    • No method was 100% accurate, except for when results were separated by breed. However, when separating by breed, sample sizes become very small (as few as 5 chicks per breed), and so that data is not very strong proof of anything yet.

    • The Needle and Thread, Surprise, and Vent Shape methods are tied as the most accurate tests at 65% accuracy on straight run chicks.

    • So far, the Pick Up method has had consistent reactions of all chicks tested, with a few other methods having nearly consistent reactions with one or two chicks differing from the majority. This would imply that they are all or mostly all the same sex if those methods were true. This also implies that all or most chicks react in the same way to these tests, not based on their sex.

    • Several tests also had unanimous or nearly unanimous reaction in all chicks of the same breed, suggesting that they are related to breed and not sex.

    • Comb Length was the most inconclusive by a tiny margin, with 6 of the 34 chicks (or 17.65%) having inconclusive results. This test has a large gray area where comb length appears past the nostril at one angle, but not at another angle, and so it is difficult to record conclusive results on some chicks. Some practice has improved my ability to conclude male or female on more recent chicks, however.

    • Leg Stretch was the second most inconsistent, with 5 out of the 29 chicks tested (or 17.24%) stretching one leg out while tucking the other in. Some say that even when only one leg is stretched out, this still means the chick is male. In this case, the accuracy of that test would rise from about 31% to about 41.4%.

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  1. pipdzipdnreadytogo
    WM was having some trouble recovering from shipping, and I didn't want to mess with him a whole lot while he was recovering. I simply haven't had time to perform tests on these chicks now that he's up and going.
  2. Minnowey
    What is up with WM?
  3. Jack Speese
    My Delawares and Hamps are now 1 month old. I have 1 Hamp that's a little larger than the others but still has distinctly more down. Don't know whether "she" is just slow feathering or whether "she" is actually a "he". Also got 2 blue cochin pullets yesterday, not that I need more but I couldn't resist. And they were a good deal, the feed store must get some kind of break because they are a lot less expensive than ordering from the hatchery and plus I could get 2 blue ones, whereas if you order them there's no guarantee that they'll actually be blue rather than black, silver, or splash.
  4. Jack Speese
    After having had chickens most of my life and a year's "hiatus" of not having any because of a move, I'll be getting my chicks tomorrow (can't wait!). Delawares, New Hampshire Reds, maybe some Australorps or Comets as well. Hope the sexers did their jobs right, as I really don't want any roosters since we have close neighbors and my new coop is closer to our house. Of course you can't go wrong with sexing Comets, but the other breeds have to be vent sexed. I guess that's still the most reliable way (at least for most breeds), but apparently it does take skill and practice.
  5. pipdzipdnreadytogo
    Phew, lots of comments! Glad many are enjoying all this stuff!

    @Fowl Explorer I agree 100% that if any of these actually worked, the pros would be using these methods. I'm mostly just having some fun with old wives' tales with no expectations beyond that. : )

    @bobhoke, my next batch of chicks are of Dorkings and Marans, not more Cochins. I plan to try this with any future chicks I get as well. I hope that eventually this page will have a variety of breeds listed on it to eliminate any uncertainty based on how tests affect different breeds. : )

    @ChickNanny13, yes, you should be comparing the roundness or pointiness of eggs from the same hen. The five eggs I hatched in January were from the same hen. She lays varying pointy and round eggs, but I just happened to collect the eggs to hatch during a period where she was laying all round eggs. Each egg was so identical in shape that there was no visually distinguishable differences in them. I regret that I didn't take measurements to be sure, but when compared to other eggs laid by the same hen, these eggs were all definitely round. Unfortunately, my next batch of chicks will not be hatched here, so I won't be able to go further with the egg shape method this year, but perhaps I'll hatch more in the future and cover that method more thoroughly!

    Yes, in birds, the female determines the sex of the offspring, the opposite of mammals. Birds have a ZW chromsome sex-determination system, where females have 'mis-matched' ZW chromosomes and males have matching ZZ chromosomes. This is in contrast to mammals, within which males have the 'mis-matched' chromosomes (XY) and females have the matching chromosomes (XX). The 'mis-matched' individual determines the offspring's sex because whichever of those two chromosomes is thrown will decide what the sex of said offspring will be. Obviously, the individual with matching chromosomes can only throw one thing, and so they have no say in that determination! I have heard that some hens tend to throw more males or more females, but that would definitely cause some exponential flock growth to find out, haha!
  6. Jack Speese
    Hi ChickNanny, I believe that you are right, that in birds and reptiles it is the female that determines the sex of the offspring, whereas in mammals (and other animals) it is the other way around, the male determines the sex of the offspring. And there are probably other mechanisms out there as well.
  7. ChickNanny13
    2x WOW! You did put alot of work into this very interesting project and the record keeping very impressive.
    Awaiting your next hatch, curious about the "egg shape" theory....I understood eggs collected should be from one hen to be compared or am I wrong? I also read that the hen determines male vs female chick and that some hens are "prone" to more males/females? This is very interesting but sure too increase a persons flock [​IMG][​IMG] Wish I could join but living conditions won't allow me to [​IMG] Thank you for taking the time to post your experiment and results!
  8. Jack Speese
    The sex-linked black stars, red stars, and rapid featherers, but they are 1st generation crosses rather than breeds and the color/rapid feather growth sexing only works for that generation. Once they actually get their adult plumage, you can sex barred chicks fairly accurately. The cockerels have lighter barring than the pullets. Only this doesn't become evident until the chicks are about a month old. The only breed that I've read about (never raised any) that autosexes as newly hatched chicks is the Legbar. There may be others.
  9. cambriagardener
    I really enjoyed your article. I love these kinds of experiments. I'll try to put a link to it from my "Backyard Hencam" site to show people how difficult it is to sex a chick. Thanks for your work and for sharing.
  10. bobhoke
    I wish a large hatchery would release their techniques for the gazillion other breeds of birds out there. I see this is for Silkie Bantams only, which we all don't raise. It's interesting to know the techniques though - never really got into this yet. Perhaps it's safe to assume some of these techniques are consistent for other breeds, which would be good to know. The article / test should be named silkie bantam sexing test, or something along those lines. Does anyone know a breed(s) that have proven sexing techniques? Thanks!
    - Newby
  11. Jack Speese
    Cool! I've read about the fast feather thing. Apparently the principal is the same as the sex-linked differences in down/plumage color in hybrid layers like red stars and black stars, but since commercial breeds are white, some other trait is obviously needed. With fast feathering it's easy to sort out pullet broiler chicks for Cornish hens, and I think it's also used for commercial white egg layers as well, which being derived from the white Leghorn also have white plumage. The behavior of the cockerel chicks versus the pullet chicks with the surprise method is interesting. I know roosters, at least "good" ones, do exactly that, i.e. watch over their girls and sound the alarm to run for cover if a hawk flies overhead, but wouldn't think such behavior would be expressed in chicks until they become sexually mature. But who knows? There may be something to it. By the way, how do you sex silkies anyway? Both the roosters and the pullets look very similar for a lot longer time than other breeds.
  12. TexasLisa
    WOW! You put in a lot of work on this. Quite interesting! Thank you!!
  13. Fowl Explorer
    Thank you for taking the time to do this debunking for us all! I get so much information, and you wonder sometimes about it. I mean, in this case - why the professionals wouldn't use it if it was so accurate?
  14. ChickNanny13
    Following and very interesting. Great data collection & chart.
  15. TCFarm
    Very interesting! You inspire me to try a couple of these, but I too have found that the best is the comb development. I raise Chanteclers, however; so combs are not 'our thing'. I often have to wait until between three and four weeks to tell. Thanks for a great article!
  16. chicken4prez
    Great idea! I will be following!
  17. pipdzipdnreadytogo
    Enrgizerbunny, yes, vent sexing is the most accurate, but as Roadsidefarm said, even experts make mistakes. The main reason I chose not to do it is because if you don't know what you're doing, you can seriously hurt the chick. Since I have never vent sexed a chick before, I am unwilling to take the chance of hurting one of them.

    I mostly just wanted to use the methods that people cite to sex chicks without the use of vent sexing, especially the funny sounding old wives' tales. It's just a fun little experiment and not really meant to be accurate--although if any of these methods prove to be accurate it would be a bonus!
  18. Roadsidefarm
    Yes, enrgizerbunny, the vent sexing is the most accurate way to sex day old chicks, but even trained professionals sometimes get it wrong (as evidenced by my Australorp rooster). Most average chicken owners can't vent sex because it is very hard to learn how to do.
  19. enrgizerbunny
    The needle and thread method is only possible by a person holding the string. You don't notice, but the hand causes the movement. If you attach the string to something inanimate, it won't move at all. I thought you could sex chick by their vent? The chicken industry must have an accurate method...
  20. Roadsidefarm
    Very interesting scientific post. I look forward to hearing your future results.
  21. pipdzipdnreadytogo
    Thanks for the comments, everyone!

    IdyllwildAcres, very interesting! I think it's too late to look at these five chicks for that now (I'm about 90% sure of their sexes at this point; the three boys have very prominent combs now), but I'm going to see if I can determine where their combs stop from pictures and add that one to the list. If nothing else, I can do it on the next batch.
  22. IdyllwildAcres
  23. ChickFanatic8
    I will be interested to see how this turns out!
  24. dekel18042
    Last spring I hatched 18 rounded eggs. Should have been all girls by that method, right? Got 11 boys and 7 girls. I think the wing feather method works on certain breeds only? The tail method is correct to a certain extent. Pretty good but not 100%. This year I will try the comb method and see if that is any better.
  25. Nardo
    Following with great interest
  26. ChickNanny13
    Great job! When I have a reasonable amount of chicks to raise (I raise for a breeder; hatch to about 6 - 8 wks), I keep records of my "guesses". I've done the Flip on the Back, Leg Dangle but the best is wait for the comb & wattle development which depends on the breed. Just raised 37 Serama/Silkies, I guessed 13 Cockerels @ 4wks, they left at 6wks and my count hadn't changed. Will check with the breeder in 2wks to see if the count changed!

    Thank you for your "experiment" , will be following you with you final results and up coming hatch.
  27. mymilliefleur
    Very interesting. This is a great experiment
  28. Chicken Girl1
    Love this idea! Can't wait to see the final results!
  29. orrpeople
    What a fun idea! Would be a great elementary science fair project too!
  30. mustangrooster
    Very intresting! Would love to see the outcome
  31. penny1960
    curious agreed would like to know how it all comes out

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