Certain mammals mate in the context of harems, in which a dominant male monopolizes most or all of the breeding females in the group. Examples include (off the top of my head) gorillas, elk, sea lions.
Are there any birds that do this? Reptiles? Or, for that matter, do any non-mammals live in social groups in which this would be possible?
Wikipedia’s article on polygyny lists a couple. That’s a good word to search on.
Good suggestion, thanks.
Plus, right after I hit “submit” on the OP, I thought “Duh, chickens.”
There’s a species of fish where there are a bunch of females in a group and just one male. When the male dies, one of the females becomes male and takes his place.
You do realise that sea lions don’t live in social groups, right? Males stake out a territory on the breeding beach and essentially rape the females as soon as they give birth. There are plenty of birds and reptiles and even invertebrates that adopt the same strategy insofar as the males stake out a territory and have sex with all females within that territory. No social structure necessary.
I think peacocks have harems.
Good point. I obviously didn’t think things through carefully before posting.
Do most of these species have the dramatic body dimorphism we see in the mammals?
The dunnock, aka the hedge sparrow, is a case in point.
While some male-female relationships are monogamous, the female often engages the services of two or three males. Also, the male sometimes forms relationships with two or more females.
Not content with that, instances have been recorded wherein two or three males established relationships with three or more females.
Although male-female pairs are the most common breeding system in birds, there are plenty of polygynous species. Examples in North America include Red-winged Blackbirds and Meadowlarks. Some species such as House Wrens may by monogamous or polygynous.
Ostriches are also polygynous. The females in a group all lay their eggs in a communal nest, which is incubated by the male.
Although much rarer, polyandry also occurs in some species. Among the best-known are some species of jacanas. Females, which are larger than males, defend territories and have harems of up to five males. Males do all the incubation and care of nestlings. Females will even “steal” males from neighboring females, destroying the eggs in a nest and then trying to recruit the male for her own harem.
Offhand, I can’t think of any.
As has been mentioned, this happens in some fish.
The common side-blotched lizard has harems, sometimes. They have an interesting rock-paper-scissors mating setup. The males are born with orange, blue or yellow throats, and each color follows a different strategy; the oranges keep harems.