The sexing of Java's is at times a very difficult to do, even with the aid of all the different recognised methods laid out before us. Apart from the song of the cock bird and a hen actually laying an egg their is no 100% way to do it, although some people might tell you otherwise. Let's go through the ways I am aware of to aid your final decision on the sex of your Java's. Please do remember that none of these methods are foolproof!
A movie of a cock Java sparrow singing and displaying ~ plus more movies.
This is sometimes possible with the Fawn and the Silver colour mutations, the cock has a darker "brown feathering" than the hen on his head and tail feathers in the Fawns and the same is for the Silvers. This can, and does, vary from bird to bird but in my experience can prove fairly reliable. The Normal and White varieties do not have any visual differences in the sexes, to us anyway! I have not kept any other Java mutation so I am unable to comment on these.
Above a true pair of Fawns, cock on the left
with darker skull cap.
I have noticed that a cock bird in breeding condition appears to have a more pronounced eye ring, a thicker, redder ring than the hen bird, but remember that this too can vary from bird to bird.
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Normal cock bird | |
Normal hen bird |
Beak size and shape
This again, is something that can vary from bird to bird but in
general a cock bird in breeding condition will have an all round
"more swollen beak", the upper mandible (top half of the
beak) will appear more "domed" when viewed from the side.
The lower mandible will also look thicker where it joins the birds
head, also the base of the lower mandible will have a small flat
at the bottom of the beak, this is due to the thicker area at the
head, giving the cocks beak a more robust look altogether. The hen
Java's beak is a more slender affair, and seems to be more triangular
in shape when viewed from the side. The upper mandible is flatter,
not having the "domed" appearance and also does not have
the thickness at the head and lower mandible area. Beak colour is
said to be a sign, a cock's beak will be a brighter red.
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Note
on the cock how the top of its beak appears to be going further
back over the top of its head compared to the hen on the right. |
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The underside of
the beaks is a big clue as Tony Gladwin says and with practice,
I am still practicing! it is possible to spot the difference,
use you known sex birds to practice on, the cocks have a bigger
radius on the lower mandible and the lower mandible is wider
across the 2 points near the cheek patches. |
The sketch above I have produced above is taken from the method Tony Gladwin (UK Java specialist) uses relating to the beak, this is from the underside and side view of an adult birds beak, please also go to the Java sexing gallery below to see what Tony's method actually looks like in photo form.
Please take a look at the photos below to see the sexing methods described earlier.
Tony Gladwin, UK Java specialist, wrote in Cage and Aviary newspaper about one of his sexing methods, using the underside of the birds beak, when I went to Tony's to buy some birds and compile the article for this site I got him to show me what his theory was. Below you will see a couple of photographic examples of his method. Tony says that the cock birds beak underside is a more robust fuller shape. Where the beak forks out towards the neck it is thicker and spreads out wider than the hen. The hens beak underside is a more pointy affair and is visibly thinner at the widest point, where the beak forks out. Tony says he is over 90% successfully with this way of sexing his Java's but the birds are far easier to sex this way as other methods when they are in breeding condition.
All the photos below are of known sex Java's (remember that birds may vary!)
Above a true, proven pair of Normal Java's, cock on the left
The way most people say they sex their Java's is by the beak shape and the photos on this page illustrate this well. For cocks look at the prominent dome on the top mandible and how thick the lower mandible is where it joins the head, also I think the eye ring is a guide too because when in breeding condition the cock birds eye ring is a deeper red and is a lot thicker than the hens eye ring in my opinion.
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Please remember that the beaks on the birds and the depth of colour on your Fawns and Silvers may very well vary from what you see here, you will have to take time to study your own stock to start to pick out the differences between the sexes.
Alternative methods
I have over the years heard of several different and in some
cases, unusual methods to sex the Java sparrow. I will list them all
below, please do remember these are not guaranteed ways more birdkeepers
personal ideas and thoughts, you make
you own mind up on the best way to sex your Javas and also if these
methods actually work for you.
Sexing using a sex indicator?
- I have had published an article on the magnetic sex indicators
available in the UK, please click here
to go to the articles page and download the article and read, digest
and make up your own mind.
Skull cap width? - I
have seen on a couple of USA based websites that they feel the width
of the skull cap on the Java is wider in males than in hens. I am
not saying this is not the case in the birds the Java keepers have
made this observation from but I am a little wary due to the fact
you can get a small cock bird to a larger hen and I would assume that
the bigger bird would have a larger head and therefore a bigger, wider
skull cap!
Primary flight feathers?
- I have spoken to a person who knows a Java keeper who swears by
using a sexing method apparently used by those who keep European Goldfinches.
They say the outermost primary flight wing feathers on cocks are longer
than those of hens. The keeper uses this method on Javas and reports
a very high success rate for himself.
Bird in the hand? -
I have also heard that if you catch up a bird and then while it is
still in you hand move it onto its back and then slowly release your
grip on the bird hens will stay in the same position and take a few
seconds until they turn and try to fly away. The reverse is said of
cocks they will try to get away immediately you start to release your
grip. I tried this and had a Silver Java I had for nearly 12 months
and I felt was a hen, I tried the bird in the hand method and this
Silver hen? stayed put in the palm of my hand for what seemed like
ages, in fact it stayed still long enough for my to take several photos
of it in the resting position in my hand! click
here to see a pic Around 3 / 4 weeks after this was done it was
witnessed singing like a good one!!! So another so called good way
to sex birds blown away? You tell me!
Why not let me know how
you sex your Javas? E-mail me today!