# Lighting affecting gender



## Rhasputin

Does anyone have links to the studies done on this? I know I've seen them somewhere, but I'm a failure at searching for them. :lol:


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## moustress

Someone either posted a link to that or an excerpt and a link....within the last week or so.


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## Rhasputin

I know, I'm looking for it but I can't seem to find it. I think it was on JAX? :?


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## bethmccallister

Here is a link to the thread where the topic is discussed.

viewtopic.php?f=22&t=4003&start=20


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## moustress

Thanks, beth. ooh, it's alive!


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## Wight Isle Stud

This is vital information. If a stud is producing lots of does, it will be very efficient as opposed to one that is not, with ten times the amount of mice. Conversley, if you want to produce an excellent-buck !!!! I am looking at it very closely.


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## Roland

Please do not believe everything that is written in the www. The link given about light and plants and genders is anecdotal only.
The distribution of genders differs between 100:110 in both directions and the influence of outer factors is small.
Spermcells have an x or an y, that is all and gives a ratio of 50:50. Since thousands of years people think about ways to influence the gender and separating spermcells by centrifugation and artificial insemination of the selected fraction seems to be the only way which really works.

Anyway, it is father's occupation, what determines the gender! It must be true, because it is written in the www!








http://www.sexratio.com/facts.htm

Best regards, Roland


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## The secret garden

With reptiles heat determines or at least helps influence the gender of its embryos.

With the lighting thing, i myself have seen the changes in what lighting does to the number of bucks i have been producing. I do believe in what has been said i have been having more bucks since moving into the garage and using a synthetic light strip.


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## Jack Garcia

Roland is correct.

This sounds almost too-obvious to state, but mice are not reptiles.


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## SarahY

Well, it worked for me.

Sarah xxx


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## Roland

The secret garden said:


> With reptiles heat determines or at least helps influence the gender of its embryos.
> 
> With the lighting thing, i myself have seen the changes in what lighting does to the number of bucks i have been producing. I do believe in what has been said i have been having more bucks since moving into the garage and using a synthetic light strip.


There are different physiologies in reptiles and mammals. You and others have seen differences, sure, but that does not mean very much. It is typical for statistical numbers, that small numbers can differ very much from the statistical mean. yes, there are families who have girls only, others have boys only. 
Many Roulette players had to make this experience. While there is a chance of 50:50 to get the ball on red or black, it does not help to bid on red ever and ever again. In deed it will happen that from 10 rounds you get ten black and get bankrupt, and you will tell us that it is not true that the chance is 50:50.


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## SarahY

Strangely coincidental though that my litters went from producing at most three does in a litter and an average of seven bucks and then suddenly switched from that to an average of three bucks and seven does after I changed from incandescent to fluorescent lights in my stud. And this has been _every single litter_. Lighting affects hormone levels, we see that in people with seasonal affective disorder. I have no 'proof' except to say that for me it has worked so I'm happy.

Sarah xxx


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## Rhasputin

This is why I'm looking for scientific studies. :lol: 
I'm not sure what to believe!


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## Roland

and Blacklight gives hermaphrodites.


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## The secret garden

I will be changing my incandescent to fluorescent lights because for me it works too


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## WillowDragon

Rhasputin said:


> This is why I'm looking for scientific studies. :lol:
> I'm not sure what to believe!


Why not change your lighting anyway? Surely its worth a go for the cost of a bulb?

As for me... my litters are not heavy one way or another, but mine get natural light only.


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## WoodWitch

I am another to join the club of those that this has worked for!


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## The secret garden

Katie, its interesting you've said that. The study suggests that natural light produces 50/50 litters, when my mice where in a shed that what i found happened too.


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## Roland

I have three different rooms for mice, two have sunlight and one is in the cellar and has fluorescent light only. There is no difference in gender distribution and I have an overview about many mice, between 400 and 450 adults average.

It is very easy to get biased by good news. In medicine we call this a placebo effect.

Perhaps we should just start to count our babies and genders beginning at November 1st until end of April and count the numbers and different conditions together. This will give a good statistical power. But please, only true data! There is no need to be winner in a discussion, it will be helpfull for all to get good data.

Best regards, Roland
Chilloutarea Mousery - Tricolor , Splashed , Merle , Recessive Red


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## Rhasputin

That would actually be massively helpful if quite a few people agreed to report their litter gender counts, and lighting that they use.


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## SarahY

I'll do it, no problem for me as I keep ridiculously detailed records anyway. I can go back to January 2009.

Sarah xxx


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## Roland

Rhasputin said:


> That would actually be massively helpful if quite a few people agreed to report their litter gender counts, and lighting that they use.


Well, lets start with each litter born at November 1st or later and stop counting end of April. This will give us exactly 6 month. How should we define the groups? Sunlight (daylight) vs. fluorescent light versus what?


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## SarahY

Fluorescent - daylight - incandescent.

Sarah xxx


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## Roland

SarahY said:


> Fluorescent - daylight - incandescent.
> 
> Sarah xxx


what is the best day of counting, to avoid errors: just before culling / selection? Day of birth could result in many errors.


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## Jack Garcia

I will be living in a different place in April so I'm afraid my results (I use flourescent lighting by default, with roughly equal gender distribution) wouldn't be helpful.


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## SarahY

I record both! :lol: This is my diary entry for my latest litter: 
14/10/2010 Ben (dove tan) x Dove Tan Doe B: Litter born 3:8, culled 3:2, remaining 0:6 
And before that one:
12/10/2010 Ben (dove tan) x Dove Tan Doe D: Litter born 2:5:2, culled 2:0, remaining 0:5 
The reason I wrote 2:5:2 is because I found two heads so obviously had no idea what sex they were!

(for those that don't know, it's standard to write quantities as bucks:does:unknown)

Selection means nothing in our little experiment, the litter must be sexed correctly as it was born, including stillborns and 'parts' if possible. I usually cull straight after checking the nest for dead babies and sexing the live ones, this is usually 24 to 48 hours after birth.

Sarah xxx


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## Jack Garcia

SarahY said:


> Selection means nothing in our little experiment, the litter must be sexed correctly as it was born, including stillborns and 'parts' if possible. I usually cull straight after checking the nest for dead babies and sexing the live ones, this is usually 24 to 48 hours after birth.


I don't trust most people to be accurate in sexing newborn baby mice. That will heavily skew the results toward supporting the hypothesis. If any person sexes them at a couple days old and then culls them, you'll never know if they were right.


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## Jack Garcia

BTW, I say this because of the countless "what gender is this?" threads we see. Even though you and I think it's easy, it's really hard for some people to sex young babies.


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## SarahY

They can keep them in the freezer if they are unsure and post pictures? It's actually easier to sex frozen pinkies. Otherwise I don't know how we'd get round it - we can't just exclude people's data because we think they may have got it wrong, but nor can we risk the experiment by trusting those who may not be as experienced and accurate.

I don't know. I'm happy to submit my data in April and people can make what they will of it, I suppose.

Sarah xxx


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## Jack Garcia

I don't know what would be best. Either way, there are some obstacles to getting a truly unbiased result.

It'll be interesting to see what happens, regardless.


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## Rhasputin

I don't know how my results would be helpful . . . I keep my mice in the same room as my savanna monitor, who has a heat lamp that stays on 24/7. I think that would mess up my results. :|


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## WillowDragon

And my paperwork sucks.


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## Jack Garcia

For the hypothesis that "type of lighting affects litter size in mice," it would be nice to see a controlled, formal study wherein:


all the mice had one source of light only, either florescent or incandescent (no windows or other light sources to possibly skew results)
all the mice were of the same genetic strain or background
all the mice were fed the same diet
there were enough mice (a few hundred) to make tentative conclusions
the person(s) doing the gender testing knew what they were doing (a particularly thorough way to prevent eating some of the babies would be to euthanize the mothers a day before birth and count/sex the unborn babies)

Outside of a laboratory, this isn't possible, though. I think that's why Roland was saying it's anecdotal. "Anecdotal" does not mean "bad." It means that whatever is being presented is unproven or unsupported because it's based on a limited sample. Even if it seems to work for one or ten people, there are so many other variables that it cannot be chalked up to lighting. I think most people involved in research have heard the example of crime rate and ice cream consumption. It's the same with litter size and lighting. Litter size is our crime rate, and lighting might be our ice cream. For those who haven't heard of the study, a simple overview of its basic principles is here: http://www.helium.com/items/1364808-ice ... rime-rates


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## salemouse

so, saying that this theory is correct, what would little to no light produce?

and also, although the malexfemale hypothesis may or may not be correct, the fact that animals that come into no contact with natural light tend do be of weaker constitutions that can lead to earlier death is true. is it worth it?

xP just putting that out there.


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## The secret garden

My mice are in a garage, next to no day light what so ever. They are not weak, and certainly don't die early unless i deside that they should.
Its not litter size i notice being different in the lighting its sexes as in more does than buck or vise versa. I don't keep records so i'll be no help to you but i will say that I, myself, me, Samantha Irving notice a difference in wether or not they are kept in day light or in a room lite by a bulb


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## Jack Garcia

salemouse said:


> the fact that animals that come into no contact with natural light tend do be of weaker constitutions that can lead to earlier death is true. is it worth it?


This is not a fact. Mice are crepuscular-to-nocturnal anyway.

As evidence of vertebrate animals who do fine with no natural light, there is _Amblyopsis rosae_ (cavefish), _Eurycea rathbuni_ (cave salamander), and _Condylura cristata_ (mole), all of whom receive very little or no sunlight their entire lives. As for rodents, _Heterocephalus glaber_ (the naked mole rat) is one, although there are others. You're conflating the issue of humans (a diurnal species) not receiving adequate sunlight to that of animals, and that doesn't work.


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## moustress

That study had been done and someone posted a link on it somewhere in this Forum. I think it was wither Rhasputin, or CatWoman....I could be wrong about that...maybe it was a link for a study on brown fat in meeces. Those are sitting in my inbox waiting to be read. I'm very interested in the subject myself. Don't get me wrong I loves the boyz but I don't need to get as many of them.


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## salemouse

As these experiments were made with a strain of mice in which malignancy develops in 98% of them, almost all the mice did succumb to cancer. However, those mice under natural daylight developed cancer two months later than those under the white fluorescent bulbs, and three months later than those under the pink fluorescent bulbs. An additional effect was noticed: Those mice receiving the pink light gave birth to young which were smaller in number and size than those mice receiving natural light.

Other investigations have shown that light definitely affects the pituitary gland, as well as other areas in the midbrain and hypothalamic regions. In the early 1920's, William Rowan demonstrated that the varying seasonal lengths of the daylight was responsible for the migration of birds. In other studies conducted by Bochenek, Marburg and Gudden, it was shown that light may occasion reaction on the entire endocrine system of an animal via nerve impulses originating in the retina and reaching other areas of the brain by way of accessory optic pathways. Thus, artificial light, not being of the same quality as natural light, can play havoc with the endocrine system via the nerves.

--this is from the website postedon that earlier thread with an experament of 1000 mice. Im not saying that this will happen to, probably not, but im just defending my prior statement  im just saying its a possibility.


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## salemouse

as to the comment about humans, i actually hadnt even thought of them xD. Plus, even if a mice is nocturnal that does not equate to living in a cave as they still recieve some rays from the sun. The night is a lot different than cave darkness.


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## Jack Garcia

salemouse said:


> im just saying its a possibility.


You also said it was a fact. Being a possibility for mice and being a fact that applies to all animals are different things. 

Interestingly, a similar thing can happen in humans called "shift worker disorder" which affects primarily sleep but a lot of other things as well, especially long-term.


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## CatWoman

Not to burst anyone's bubble, but results based simply on natural vs. incandescent vs. fluorescent light won't have any validity at all. If you look back at the original reference in the other thread, they differentiated between the color temperatures of the light:



> In an experiment conducted to determine the effects of different light on animals, 1000 mice were used and divided among three different light environments: Those receiving natural daylight produced an equal amount of male and female offspring; those under white fluorescent bulbs produced 70% females and 30% males; and those under pink fluorescent bulbs produced 30% females and 70% males. This latter group did not thrive as well as either of the two other groups. All those exposed to the pink light quit breeding two months earlier and died one month earlier than those exposed to the white light.


The color/temperature of the light is measured in Kelvins, so for the results to have any relevance, people have to know the type of bulb (incandescent vs regular fluorescent vs CFL) and _temperature_ of the light being produced by the bulb. That's why I was so particular about the bulb I'm using in my last post in that thread. I'm using a 6500K daylight balanced compact fluorescent bulb - if you go down to your local hardware store and pick up a generic "soft white" compact fluorescent bulb, it'll look "white" but it will only be about 2700K, which is a significant difference in color on the Kelvin scale. In the latter case, though your bulb is "fluorescent" you may not see any difference in gender predilection because the color is wrong.


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## Jack Garcia

That's a nice chart. I like it.

This is not particularly scientific of me, but I can't help but think that natural lighting is best for almost every purpose under the sun (under the sun, haha).


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## Roland

Jack Garcia said:


> For the hypothesis that "type of lighting affects litter size in mice," it would be nice to see a controlled, formal study wherein:
> 
> 
> all the mice had one source of light only, either florescent or incandescent (no windows or other light sources to possibly skew results)
> all the mice were of the same genetic strain or background
> all the mice were fed the same diet
> there were enough mice (a few hundred) to make tentative conclusions
> the person(s) doing the gender testing knew what they were doing (a particularly thorough way to prevent eating some of the babies would be to euthanize the mothers a day before birth and count/sex the unborn babies)
> 
> Outside of a laboratory, this isn't possible, though. I think that's why Roland was saying it's anecdotal. "Anecdotal" does not mean "bad." It means that whatever is being presented is unproven or unsupported because it's based on a limited sample. Even if it seems to work for one or ten people, there are so many other variables that it cannot be chalked up to lighting. I think most people involved in research have heard the example of crime rate and ice cream consumption. It's the same with litter size and lighting. Litter size is our crime rate, and lighting might be our ice cream. For those who haven't heard of the study, a simple overview of its basic principles is here: http://www.helium.com/items/1364808-ice ... rime-rates


Thank you very much Jack (Happy Birthday, btw.). This is exactly my problem with opinions. If we want to get valide data, we need to exclude other variables, that could have an influence. What about the protein and vitamin amount of the food? What about the different light colours? Fluorescent light can have very different spectra, and as an experienced plant breeder http://www.repage7.de/member/drofi/passiflora.html I can tell you that an normal fluorescent lamp will kill the plant, because the yellow light makes them grow long and thin, while a fluorescent lamp with blue + red light is what a plant needs. This is just an example for pitfalls. What about the mistake rate of gender determination if people look for it at day 1 after birth? 
If one wants to get good results which are valide, one needs to plan a study very well. We, the fanciers, have a huge potential together, because of the high number of animals, but there are many pitfalls.
As a director of clinical research in the pharmaceutical industry I am very familiar with these problems. I would never get a marketing authorisation for a new medical product, if I show a handfull of cases without well definded study conditions and just tell the authorities "Well, at least if worked for me". Therefor I always try to use an evidence based approach to figure out if an opinion is a fact or a biased idea only. The principle is the same for all scientific questions, not only in medicine.

Best regards, Roland


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## Roland

Jack Garcia said:


> Litter size is our crime rate, and lighting might be our ice cream. For those who haven't heard of the study, a simple overview of its basic principles is here: http://www.helium.com/items/1364808-ice ... rime-rates


Have you ever heard that putting a teaspoon handle into a bottle of newly opened sparkling wine keep it fizzy? Did it work for you?
Well, a german research group has created a controlled study. They used a crossover study, where the probands where "blinded", this means they did not know when they got sparkling wine, which has been in the fridge for 4 days with a teaspoon or the same wine the same time without a teaspoon. The results were clear, no difference could be shown. The explanation is simple: Sparkling wine keeps the gas for an interesting long time in the fridge. People heard the message, that a teaspoon would help to keep it fresh, and notice the wine is still fresh. So they say "at least it works for me", and really believe it. That is not a fault of these people, they just don't understand the difference between coincidence and causality and the methods to figure it out.

Cheers!


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## Lizzle

I am so sorry, but I nearly fell over laughing after reading this thread.

Light affecting genders produced?! You sillies.. :lol: :lol: :lol: That really is all I think needs to be said..

I mean, how could that theoretically even work?


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## Jack Garcia

You're welcome, Roland!  You and I are both evidence-minded. That's why even when we disagree, we can usually give valid reasons as to why so it still works out, I think.

As a side note, even in qualitative research (which is often derided by "hard" scientists) the same scientific principles apply. I'm currently conducting a qualitative study on the effects of familial background and metaphysical beliefs on college students' self-esteem, and even though that's even more removed from mice than your medical example is, the research involved contains many of the same issues and stumbling blocks like any good research does.


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## moustress

I majored in Anthropology, and Psychological Anthro has done extensive research in the area by canvasing (using undergrads to do the legwork, of course) a set proportion of different ages, walks of life with standardized sets of questions. My college days are thirty years behind me, but I remember very clearly that my advisor, head of anthro dept,said that self-esteem was most frequently based on expectations acquired in the first ten years of life, variances in the actual outcomes. Significant variable started, in order of prevalence, first with the role you you raised to fulfill; for different socioeconomic states, for conformity to religion and mores, and so on and so forth. Variables that were common and taken into consideration include the supportive presence or lack thereof in the presence from parents, teachers, clergy, friends. People are quite plastic in their overt behaviors as conformity is one of the ways to induce the acceptance in different circles of people in different settings.

The less fulfillment of expected roles, the less self-esteem.

Of, course, a lot of anthropology and sociological studies base findings somewhat loosely by correlation and approximation. It's a problem that led me to change my major to computer science and math; while I took a LOT on anthro and soc., my degree is in math and comp sci.


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## Roland

Jack Garcia said:


> You're welcome, Roland!  You and I are both evidence-minded. That's why even when we disagree, we can usually give valid reasons as to why so it still works out, I think.


Thank you, it is true. Even when we disagree, we both know that the other one is a very honorable person and any criticism is pointed on the subject of discussion only, never directed against the person. It is nice that you always give some generosity to people, who do not speak English as their first language...


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## salemouse

i meant to say the fact of it(light other than natural) being detrimental could be true. I shouldnt have stated it as fact, I am a very very silly goose. 

I still think this is interesting whether it is fact or fiction I wonder how this idea sprang forth. So many odd rumors for things like this, yet seemingly no origin. I wonder if someone woke up one day and was just like...hmmm...I wonder how people would react if i told them mice gender is affected by light...lets try it xD


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## Rhasputin

:lol: Salemouse, that's exactly what happened with bigfoot. :lol:

Someone just woke up and said, 'Oh man! I think I'll go out in the woods today and pretend to be a giant ape man and see what happens!'

At the same time. It couldn't hurt to switch my mouse room over to fluorescent lighting just for giggles.


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## salemouse

exactalacty. :0

I think the mouse gender guy and the big foot guy should get together and make the mouse foot with odd gender specifications, when its rainy its a dude and when its sunny its a girl and when its night time its asexual.

Ive heard of stranger things xD


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