There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
(12-24-2018, 02:00 PM)Panther Wrote: Tigers are one of the more territorial bigcats. And are even more territorial than many bigcats. Most of the territorial battles between tigers were ended in death than that of lions or any big cats. Showing how Territorial they were, actually.
Many people think lions having more testosterone level than that of tigers, based on a study of capitive specimens. Where it gives mean of 1850 pg/ml for Asiatic lions and 1720 pg/ml for tigers.
But the other study showing other wise. The following study gives the values of 9.71 ng/ml for 4 year old males and 18.02 ng/ml for 6 year old males. That is 9710 pg/ml and 18020 pg/ml. Much higher than previously thought.
The following study, sounds familiar to that value...
"Frequent blood samples were collected to study hormonal responses to GnRH in male and female leopards and tigers. Animals were anaesthetized with ketamine-HCl and blood samples were collected every 5 min for 15 min before and 160 min after i.v. administration of GnRH (1 micrograms/kg body weight) or saline. No differences in serum cortisol concentrations were observed between sexes within species, but mean cortisol was 2-fold greater in leopards than tigers. GnRH induced a rapid rise in LH in all animals (18.3 +/- 0.9 min to peak). Net LH peak height above pretreatment levels was 3-fold greater in males than conspecific females and was also greater in tigers than leopards. Serum FSH increased after GnRH, although the magnitude of response was less than that observed for LH. Basal LH and FSH and GnRH-stimulated FSH concentrations were not influenced by sex or species. Serum testosterone increased within 30-40 min after GnRH in 3/3 leopard and 1/3 tiger males. Basal testosterone was 3-fold greater in tiger than leopard males. LH pulses (1-2 pulses/3 h) were detected in 60% of saline-treated animals, suggesting pulsatile gonadotrophin secretion; however, in males concomitant testosterone pulses were not observed. These results indicate that there are marked sex and species differences in basal and GnRH-stimulated hormonal responses between felids of the genus Panthera which may be related to differences in adrenal activity." Source: https://www.ncbi.nlm.nih.gov/m/pubmed/3123664/
While that of lions, wasn't reaching that range. When I looked up.
The following study shows the testosterone of wild male lions from Serengeti and ngorogoro crater lions.
These two sources giving the value of 2.5 ng/ml(2500 pg/ml) for wild adult male African lions.
That is almost more than 3 times lower than that observed in Bengal tigers.
These values showing that tigers posses higher level of testosterone of all big cats..
I need the opinions of you guys. No harsh "versus" debate, just a discussion about "testosterone levels"!
Unfortunately the Lion study doesn't break down group scores the way the Tiger study does.
I also wish the Tiger scores were broken down by individual instead of pooling them.
A few things I found interesting but not surprising are...
-Big Cats become fully dominate specimens around the 6-10 range, these are the ones who will have their testosterone at their peak, they'll have had many battles throughout their life and have learned what it takes to hold a territory.
-Gir Lions have a higher sperm defects than the other lions and tigers tested "girs are captive" and that means they are more susceptible to birth defects and they also have lower testosterone levels which may be the reason why they have scantly manes and aren't as physical imposing as their African Counterpart.
-Even though Serengeti and Crater Lions have very similar test. levels, their manes still are quite different and climate plays a very large role in mane size, Crater lions have thick huge manes that grow over their shoulder quite often, my guess is the fact that the Crater is 10 degrees cooler year round than the surrounding Serengeti.
