Do penguins really mate for life?

[Saranga]

I have recently been hearing the argument that the nuclear family is supported in nature by penguins, who “mate for life” (i.e. they are monogamous). I have also heard that this is hogwash. So which is it? Are there any animals in nature which we could call monogamous?

I did a search in GQ and was really surprised to not find a thread on this subject.

[awldune]

The Emperor penguins featured in March of the Penguins are monogamous for each mating season, but not for life.

At least, according to a featurette about the movie I saw the other day.

[John_Mace]

@Saranga

I have recently been hearing the argument that the nuclear family is supported in nature by penguins, who “mate for life” (i.e. they are monogamous). I have also heard that this is hogwash. So which is it? Are there any animals in nature which we could call monogamous?

I did a search in GQ and was really surprised to not find a thread on this subject.

Gibbons could be called monogomous, and many bird species, too. Not that there isn’t gong to be cheating now and again, but the basic structure is at least as monogomous as human pairings. I would also assume that siamangs (similar to gibbons in many respects) are mostly monogomous as well.

[elfbabe]

@Saranga

I have recently been hearing the argument that the nuclear family is supported in nature by penguins, who “mate for life” (i.e. they are monogamous).

I’m not sure I understand how this supports the nuclear family, since there are an awful lot of animals that DON’T mate for life. Bonobos, for example, are total sluts.

[Pedro]

Totally unreliable factoid: The book The Red Queen by Matt Ridley defends that there is widespread “cheating” among many monogomous bird species, the theory being that females are getting the best of both worlds (genes vs nurture) and the male behaviour is also conditioned by this to frequent copulation, etc.

Anyway the argument is crap regardless of penguin sexuality.

[MikeS]

@Pedro

Anyway the argument is crap regardless of penguin sexuality.

Yeah, somehow I don’t think the “preserve the nuclear family” types want to use penguin sexuality as their touchstone.

[shelbo]

@awldune

The Emperor penguins featured in March of the Penguins are monogamous for each mating season, but not for life.

At least, according to a featurette about the movie I saw the other day.

And according to the movie itself!

[John_Mace]

@Pedro

Totally unreliable factoid: The book The Red Queen by Matt Ridley defends that there is widespread “cheating” among many monogomous bird species, the theory being that females are getting the best of both worlds (genes vs nurture) and the male behaviour is also conditioned by this to frequent copulation, etc.

Anyway the argument is crap regardless of penguin sexuality.

Yep. There’s lots of research supporting this (bird infidelity). Good point.

[Ludy]

I was once told that loons mate for life and pick a mate by their call.

I have done loon calls, and wonder if maybe there is some love sick loon searching for me somewhere…

[Saranga]

@elfbabe

I’m not sure I understand how this supports the nuclear family, since there are an awful lot of animals that DON’T mate for life. Bonobos, for example, are total sluts.

Oh I completely agree, but at least the idea is supported somewhere in nature. One cannot then say that monogamy is totally unnatural.

So are birds monogamous or not?

[Thudlow_Boink]

Do penguins really have umbrellas and monocles and cigarette holders?

[wevets]

@Saranga

Oh I completely agree, but at least the idea is supported somewhere in nature. One cannot then say that monogamy is totally unnatural.

So are birds monogamous or not?

Birds, and especially songbirds, were once thought to be the best examples of monogamy in the animal world, but a lot has changed since then. Especially the ability to perform genetic studies has shown that many species once thought monogamous aren’t really.

From An Introduction to Behavioral Ecology, by Krebs and Davies, 1993. p. 225

…male songbirds readily desert to gain extra females if given the chance, for example by removal of a neighboring male, and they often help to provision either one of their female’s broods full-time, or several females’ broods part-time. Occasional polygyny has been reported in 39 percent of 122 well-studied European passerines.
These experiments suggest that the predominance of monogamy in many birds arises not, as Lack proposed, because each sex has the greatest success with monogamy but because of the limited opportunities for polygyny.

Another passage relevant to mammalian monogamy: (p.218)

Such obligate monogamy occurs where female ranges are small enough for a male to defend but where a male is unable to defend a large enough area to have more than one female [Rutberg 1983]. In these cases the male may then maximize his reproductive success by providing parental care. Species with obligate monogamy tend to have large litter sizes. For example this mating system is common in canids, which have large litters, and rare in felids, which have small litters.

[Blake]

@wevets

Such obligate monogamy occurs where female ranges are small enough for a male to defend but where a male is unable to defend a large enough area to have more than one female [Rutberg 1983]. In these cases the male may then maximize his reproductive success by providing parental care. Species with obligate monogamy tend to have large litter sizes. For example this mating system is common in canids, which have large litters, and rare in felids, which have small litters.

That seems an odd thing to say. Felids average a bit over 3 young to a litter, canids a bit under 5 but with more variability. Weasels are no more monogamous than any cat, and average 6 young with quite abit of variability. Wolverines and martens, which are no more monogamous than cats, average 4 young. Bears, and red panda, which are about as monogamous as the big cats, have just 2. Raccoons are also about as mongamous as big cats, but have 4 young.

It seems a stretch to say that mongamous species have larger litters. Seems that it’s simply a quirk of evolutionary history and little more. There’s certainly a lot of overlap between litter sizes that doens’t reflect pair bonding in any way.

[Jojo]

I think albatrosses have been logged as pairing for 25-30 years (so presumably for life).

[ouryL]

I read in National Geographic that DNA put the lie to the notion of animal monogamy- the DNA of the offspring not matching the “father”.

[wevets]

@Blake

That seems an odd thing to say. Felids average a bit over 3 young to a litter, canids a bit under 5 but with more variability. Weasels are no more monogamous than any cat, and average 6 young with quite abit of variability. Wolverines and martens, which are no more monogamous than cats, average 4 young. Bears, and red panda, which are about as monogamous as the big cats, have just 2. Raccoons are also about as mongamous as big cats, but have 4 young.

It seems a stretch to say that mongamous species have larger litters. Seems that it’s simply a quirk of evolutionary history and little more. There’s certainly a lot of overlap between litter sizes that doens’t reflect pair bonding in any way.

I dunno, it’s possible that Krebs & Davies got this wrong, but I’d check their references on this section:

Clutton-Brock, T.H. 1989. Mammalian Mating Systems. Proceedings of the Royal Society of London B 205: 547-65.

Rutberg, A.T. 1983. The Evolution of Monogamy in Primates. Journal of Theorhetical Biology 104: 93-112.

Before I’d toss it out with figures off the top of your head. I’m not a specialist in mating behavior or even animal behavior in general, and it may be that my training in this area is out of date, but I’m not going to dismiss it out of hand.