The monogamy ‘league desk’ for the animal kingdom: Deer mice and wild canines prime the record…whereas people are seventh within the rankings

If you truly want to commit to someone for life, it’s worth taking notes from the California deer mouse.

This tiny rodent has topped the animal kingdom’s monogamy ‘league table’ – while humans rank seventh.

Scientists analysed the proportions of full versus half–siblings in a range of species, as well as several human populations throughout history.

Those with higher levels of monogamy are likely to produce more siblings that share both parents, while species which are more promiscuous tend to record a higher proportion of half–siblings.

Analysis revealed that the California deer mouse is the most monogamous creature, with 100 per cent of siblings sharing both parents.

Humans, meanwhile, only record 66 per cent full siblings.

This places us lower than the African wild dog, Damaraland mole rat, moustached tamarin, Ethiopian wolf and Eurasian beaver.

However, compared to our distant primate cousins, we’re much more faithful – making our preference for monogamy ‘highly unusual’, experts said.

Dr Mark Dyble, from the University of Cambridge, devised a computational model to calculate an estimated monogamy rating for each species.

The top 11 species in the rankings are considered ‘socially monogamous’, preferring long–term pair bonds.

‘There is a premier league of monogamy, in which humans sit comfortably, while the vast majority of other mammals take a far more promiscuous approach to mating,’ he said.

‘The finding that human rates of full siblings overlap with the range seen in socially monogamous mammals lends further weight to the view that monogamy is the dominant mating pattern for our species.’

The most promiscuous species, according to his analysis, is the Soay sheep – a breed that descended from a feral population that live on Scotland’s St Kilda archipelago.

Only 0.6 per cent of lambs from this breed are full siblings, Dr Dyble revealed, as each ewe mates with several rams.

Others that rank low in the table include the Celebes crested macaque, black bear, Antarctic fur seal and killer whale.

Meanwhile the red fox, grey wolf and meerkat appear in the middle of the table – and are included in the ‘socially monogamous’ category.

The only other non–human primate that appears in the top division is the moustached tamarin – a small Amazonian monkey the typically produces twins or triplets.

All other primates included in the research are known to have polygynous or polygynandrous – where both males and females have multiple partners – mating systems, and tank way down the table.

Mountain gorillas manage a six per cent full sibling rate, while chimpanzees come in at just four per cent – on a par with dolphins.

Various macaque species, from Japanese to Rhesus, sit almost at the bottom of the table.

‘Based on the mating patterns of our closest living relatives, such as chimpanzees and gorillas, human monogamy probably evolved from non–monogamous group living, a transition that is highly unusual among mammals,’ Dr Dyble said.

He added: ‘This study measures reproductive monogamy rather than sexual behaviour. In most mammals, mating and reproduction are tightly linked. In humans, birth control methods and cultural practices break that link.

‘Humans have a range of partnerships that create conditions for a mix of full and half–siblings with strong parental investment, from serial monogamy to stable polygamy.’

The findings were published in the journal Proceedings of the Royal Society B Biological Sciences.

A previous study made the controversial claim that monogamy may not be the best approach for human relationships and is based on ‘flawed science’.

In the study, researchers reviewed several earlier works and surveyed more than 2,000 people, and found that non–monogamous relationships are just as ‘functional’ as traditional ones.

They measured for trust, jealousy, passion, and overall satisfaction, and found that there were no differences in how the relationships function.

Still, non–monogamy remains somewhat taboo, and the researchers say the cultural dominance of more traditional relationships could be affecting the way intimacy is studied.