Desert Lions

[peter]

The remark on lion size in southwestern Africa in my previous post is not based on observations of others: it's based on information in peer-reviewed documents. The averages I found say lions in southwestern Africa are a bit larger than elsewhere.

However. I agree many underestimate long and lean animals and overestimate bulky animals. In tigers, there's a strong relation between body length and weight. This is why tigers in northern India and Nepal are heavier than elsewhere. Bulky individuals could be as heavy as they suggest, but at the level of averages it's about length in the end. The reason is length, apart from genes, is related to age. Chitwan clearly says adult tigers keep on growing after they reached adulthood. They also often get more 'dense' with growing age. This means a long animal generally has more room to express density with growing age. It also means it's expressed in more than one way. In long-lived predators, for this reason, one would expect to see a strong relation between age, length and weight: the larger the animal, the stronger the relation.

Based on what I have, I'd say this is true for most large predators. The strongest relation is seen in bears. Adult males, that is to say animals of 9-10 years of age and over, usually are much heavier than younger males of similar size. One would expect to see something similar in big cats, although less outspoken because bears are longer-lived and larger (more robust and heavier). 

Based on what I saw in skulls, I'd say this could be quite close. Skulls of old males usually are heavier, or relatively heavier, than longer skulls of younger animals. It's seen in every tiger subspecies, usually more in males than in females. The reason is females are quite a bit smaller. I didn't see it in skulls only. In one of the many leopard threads, a table was published on the relation between age, length and weight some time ago. To keep it short: the differences between the age-groups were quite pronounced. One would expect to find a stronger relation in lions and tigers, as they are larger. 

That, however, still leaves the question as to why lions living in difficult conditions are larger than lions in other parts of Africa. I'm not saying habitat and access to food have no effect on size at all, but it apparently isn't the only deciding factor. Not in lions. Reply