What are the testosterone levels of varying animals?

[paul cooper]

(12-31-2017, 08:37 AM)Polar Wrote: An average prime human male in his 20s has around 500-650 ng/dl of testosterone, and you are right that a male lion's or tiger's testosterone can be several times lower than that (180 ng/dl from captive Asian lion and 250 ng/dl from wild African lion pride leader from Kenya). Those are only two figures. I don't know any estimate for either a captive or wild tiger, but a fully-grown male black bear during both the spring and fall seasons can have anywhere from 1000-1250 ng/dl. Again, very limited data for test levels.

Whatever the case, the testosterone receptors of big cats are extremely powerful to allow them to even process that low amount of testosterone. Carnivores gain muscle and mass so much more quickly than we do. Testosterone receptors can vary in strength depending on built-in genes for testosterone regulation.

The only problems here are:

1) I am still looking hard for testosterone measurements of either captive or wild tigers. Very hard to find.

2) Tigers may vary by testosterone amount like they do in size; lions are a much more constant size. Normally, larger animals require more testosterone since they have plenty more hormone/blood pathways. So the results for tigers can vary quite a bit regarding size.

Boldchamp told me the lion and tiger have similar testosterone levels. Reply

[brotherbear]

A lion's mane is simply a physical attribute of the male lion. It's purpose is to attract females. A male lion who "rules" a pride of females - or so I understand - normally has a long thick mane. If he survives the loss of that pride to another lion, he then looses that mane. I also remember something about a lion who is a dominant male has a darker mane - a mystery to me. 
Tell me where I'm wrong here. And... is the question of testosterone relevant here? Reply

[Spalea]

@brotherbear :

About #17: The dark color of the lion's mane isn't an obligatory attribute. There are some regions where you cannot see an only one black maned-lion and other regions where they are more abundant. The testosterone that is the cause of the lion's mane is the hormone of the virility, but the fact that the mane is thick or black is only a clue of a good health. When a male lion loses his pride, leaving alone and solitary, thus having trouble regularly eating, he loses his mane too. As simple as that... Reply

[brotherbear]

Thank you Spalea, for clearing that up. Your explanation makes perfect sense. Reply

[Spalea]

(01-04-2018, 06:05 PM)brotherbear Wrote: Thank you Spalea, for clearing that up. Your explanation makes perfect sense.

You're welcome ! Sorry, I wanted to say "When a male lion loses his pride, leaving alone and weakened, thus having trouble regularly eating, he loses his mane too. As simple as that..." (and not leaving alone and solitary, stupid pleonasm)... Reply

[Shadow]

Here is something about lion manes and testosterone.

One quote: "In lions, testosterone directly affects the development of manes. Castrated males, for example, lose their ability to produce testosterone and promptly lose their mane, too."

https://www.newscientist.com/article/210...ike-males/ Reply