What about the makhanas ? Makhanas are tusk less male elephants, what advantages do they gain by not growing tusks if tusks are secondary sexual characters that influence mate selection by females? In areas like in the northeast of India where there are an equal number of tuskers and makhanas, the makhanas are larger and more robustly built especially in the structure of the skull and the musculature of the trunk. In my observation in Nagarhole this also holds true for the south. I have also not observed any disadvantages faced by lack of tusks during interactions between makhanas and tuskers and the same factors that govern interaction between tuskers are at play here also i.e. body size , age and musth. In this regard I feel that makhanas have an advantage over tuskers due to their larger and more robust physique.
Scientific studies carried out by Dr.Raman Sukumar in Mudumalai have shown that elephants with longer tusker have fewer parasites in their dung. If this trait is inheritable then it would be advantages for a female to chose a male with longer tusks as it has a better immune system which can be passed on to her offspring. It seems that males have to make a choice between length of tusks and body size when it comes to advertising its desirability as a mate to females. And how do females really choose? There is still a lot to be understood about mate selection by female elephants and the mating game continues to enthrall me.
An important aside about long tusked elephants having less parasitical loads is what will happen to an elephant population in the long run that has been subject to ivory poaching? Poachers selectively kill elephants with long tusks thus removing the animals with better immune systems from the breeding population. Will this result in lower immune levels in the coming generations and will this make them more susceptible to epidemics? The answer is probably blowing in the wind.
Let me now take the bull by its horns and enter the realm of speculation. Are makhanas evolutionary adaptations to human predation as claimed by the Forest Departments of the South? (Yes, that is the explanation banded about for the drastic reduction in the number of tuskers in the South)
I mentioned that both musth and tusks are secondary sexual characteristics. What exactly are secondary sexual characteristics and what role do they play?
Secondary sexual characteristics are honest signals used by the male (generally with a few notable exceptions) of the species to attract females to mate with. This can take various shapes like the brighter plumages in male birds to the growth of antlers in deer. The common perception is that these tools are used as defensive weapons against predators.
Let us take the example of antlers in deer. Do antlers really help in warding off predators? If so how effective is such weaponry? And if they are so effective why are they shed? Field observations and scientific studies have shown that antlers are used chiefly between males of the same species and even then the structure of the antlers makes it very difficult for a killing thrust. They are used chiefly for fencing and pushing and are singularly useless as offensive weapons. And also after a limit large antlers become a disadvantage and that predators are quick to notice this. Wild dogs in Nagarhole show a preference for adult male chital. They realize that with a heavy load on their heads they are handicapped when running away i.e. they tire faster and also the antlers makes it difficult for them to run through the dense undergrowth of Nagarhole. Thus the wild dogs of Nagarhole prey almost exclusively on large male chital.
Let us now take the case of the peacock. The long heavy tail of the male makes him similarly more vulnerable to predation. So the question arises why do they invest so much of nutrition and undergo such risks? The obvious answer seems to be that they do so to attract females. Does that mean that females exercise some choice in mate selection? Or do they have to mate with the victor and thus have no choice?
Another factor that leads us to believe that they are used to attract females is that once the mating period is over antlers are shed as they now have no function and only serve as handicaps. Similarly the peacock sheds its tail.
Obviously there seems to be some element of female mate selection. Signals therefore play an important role. What is a male signaling? He is signaling his desirability as a mate. He advertises his superior genes vis a vis other males that can be passed on to her offspring. As the female invests more in the raising of offspring it is to her advantage that she chooses the best available genes on offer.
Let us now take a look at elephants. As only males in Asian elephants posses tusks we can be reasonably sure that they are essentially secondary sexual characters. If so what signals do large or long tusks send? I have already explained explained about musth and body condition and also about the correlation between tusk and body size as well as parasitical loads. I also touched upon the difference in the bodies of tuskers and makhanas.
It seems that in Asian elephants a male can employ various methods to send signals to females and thus influence female mate selection. A male may choose to invest more in tusks, or decide to balance the two or do away with tusks altogether and go for body size!
However elephants do not shed their tusks and they continue to grow throughout their lives. Thus long tusks do become a liability if they grow beyond a certain point. One does not know if such choice is made by individuals or is a product of genetics.
Various factors play their part and certainly evolution is of primary importance. In the northeastern states the ratio of tuskers to makhanas is roughly equal, in the south tuskers outnumber makhanas and in Sri Lanka makhanas outnumber tuskers.
One thing is sure that an expensive arms race will only come to an end when those that do not posses weapons have the same advantages as those that do posses weapons. Letís see what happens in the case of the Asian elephant. One of the biggest advantages that makhanas have over tuskers is that they do not become victims of poachers. This is a huge advantage in todayís world.
In no way am I saying that makhanas are an evolutionary adaptation against poaching. Evolution takes a very long time and it is a stupid attempt by the Forest Departments to disguise their failure in controlling poaching .However there does seems to be a a lot more to learn on the subject of makhanas and tuskers. I hope someone takes the trouble to find out more and enlighten me.
If you found this usefull , may I suggest that we start a separate forum for animal behavior ?