I guess I made it too easy the first time around.
quote:
Originally posted by redstang281:
So you believe the lion has an instinct to kill only cubs he does not recognize. What I want to know is how this instinct developed without the lion going through a stage where he killed every cub?
There are a few things you are apparently unfamiliar with re: lions. Perhaps if I explain a bit more about the details of this behavior, maybe you'll be able to figure out why it might have developed.
I. What is a pride?
- lions are the most sexually dimorphic of all cats
- lions are extremely territorial due to limited resources in their particular environment
- African lions (
Panthera leo) are a social species, forming a pride of up to ten+ animals
- prides consist of a group of closely-related females (mothers, daughters, sisters, nieces, etc.)
- the pride also consists of a small group of resident males - two or three is the usual number
- the males are usually related to each other but not related to the females
- this situation arises because females reaching sexual maturity remain in the pride where they were born whereas males must leave the pride upon maturity. These males form "coalitions" for survival.
- Most solitary males do not survive to reproduce because of both inefficient solitary hunting techniques and inability to takeover an existing pride
II. Lion reproductive biology
- female lions have synchronous estrus (all females in a pride come in to estrus at roughly the same time)
- it takes an average of 5 estrus cycles to produce one litter
- females (other things being equal) come into estrus once every two years
- cubs remain "immature" (i.e., cubs) for 3 (female) or 4 (male) years
- average life expectancy is 8-10 years
III. Male takeover
- males must fight and defeat the group of resident males in order to gain control of the pride. These battles will often result in severe wounding or even death for both participants.
- the average time that male lions maintain control of a pride is only about 2 years.
- because residence in the pride is the key to reproductive success of male lions, they quickly begin trying to father cubs.
- one impediment to quick fatherhood is the presence of still-nursing cubs, because females do not return to breeding condition until their cubs are weaned.
- male lions overcome this problem by killing
ANY cubs in the pride that are not weaned.
- this strategy results in females returning to breeding condition an average of 8 months earlier than they otherwise would.
- about 25% of all cub mortality in the first year is caused by infanticide and about 10% of overall lion mortality.
- once a pride is taken over, coalition males rarely if ever fight amongst themselves. All females are shared.
In other words, infanticide takes place because male lion coalitions have a very limited time to reproduce and simply can't wait for a normal estrus cycle - especially with all the females in a given pride entering estrus at roughly the same time.
Why don't females defend their cubs? They do, occasionally. However, unlike most solitary species, there is a net negative opportunity cost: males will just as quickly kill a recalcitrant female as they will cubs. The "fight-to-the-death" option is seldom exercised. If you'd like more information, see
this article for a lot of good information on lion behavior.
I hope this answers your quibble.
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