Revealed: The most monogamous animals – and where humans rank

[Buster's Uncle]

The Telegraph
Revealed: The most monogamous animals – and where humans rank
Telegraph reporters
Wed, December 10, 2025 at 9:31 AM EST
4 min read



The California deermouse ranked as the most monogamous mammal - iStockphoto


Humans are one of the most monogamous mammals, research reveals.

A study by the University of Cambridge has found that humans sit high up in the “premier league of monogamy” – between meerkats and beavers – while the vast majority of other mammals take a far more “promiscuous” approach to mating.

The league table shows humans are far closer to meerkats and beavers for levels of exclusive mating than we are to most primates.

Top of the table is the California deermouse, which stays paired for life once mated, with a 100 per cent rating, according to the findings published in the journal Proceedings of the Royal Society B Biological Sciences.

The most promiscuous species is Scotland’s Soay sheep, with a monogamy rating of 0.6 per cent, as each ewe mates with several rams, according to the study.

Previous evolutionary research used fossil records and anthropological fieldwork to infer human sexual selection while, in other species, scientists have conducted long-term observations of animal societies and used paternity tests to study mating systems.

Dr Mark Dyble, an assistant professor in evolutionary anthropology at Cambridge, has employed a new approach that analysed the proportions of full compared to half-siblings in a host of species, as well as several human populations throughout history, as a measure for monogamy.

He said species and societies with higher levels of monogamy were likely to produce more siblings that shared both parents, while those with more polygamous or promiscuous mating patterns were likely to see more half-siblings.

Dr Dyble devised a computational model that maps sibling data collected from recent genetic studies onto known reproductive strategies to calculate an estimated monogamy rating.

While still a rough guide, he argued it was a more “direct and concrete” way to gauge patterns of monogamy than many previous methods when looking at a spectrum of species over thousands of years.

Dr Dyble said: “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. 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.”



Meerkats rank almost as high as humans on the ‘sibling scale’ - RooM RF


It has long been suggested that monogamy is a “cornerstone” of the social co-operation that allowed humans to dominate the planet.

To calculate human monogamy rates, Dr Dyble used genetic data from archaeological sites, including Bronze Age burial grounds in Europe and Neolithic sites in Anatolia.

He also used ethnographic data from 94 human societies around the world: from Tanzanian hunter-gatherers the Hadza, to the rice-farming Toraja of Indonesia.

Dr Dyble said: “There is a huge amount of cross-cultural diversity in human mating and marriage practices, but even the extremes of the spectrum still sit above what we see in most non-monogamous species.”

The study has humans at an overall 66 per cent rate for full siblings, placing us seventh of 11 species considered socially monogamous and preferring long-term pair bonds.

Meerkats come in at a 60 per cent full sibling rate while beavers just beat humans for monogamy with a 73 per cent rate.



Scotland’s Soay sheep are the most promiscous - iStockphoto


The white-handed gibbon comes closest to humans in the study, with a monogamy rate of 63.5 per cent.

The only other non-human primate in the top division is the moustached tamarin, a small Amazonian monkey, which has a full sibling rate of almost 78 per cent.

All other primates in the study are known to have either polygynous or polygynandrous – where both males and females have multiple partners – mating systems, and rank way down the monogamy table.

Various macaque species, from Japanese (2.3 per cent) to Rhesus (one per cent), sit almost at the bottom of the table with the Soay sheep at the bottom.

Dr Dyble said: “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.”

The grey wolf (46 per cent) and red fox (45 per cent) sneak into the upper league with full sibling rates of almost half, while African species have much higher rates.

The only other mammal believed to live in a stable, mixed-sex, multi-adult group with several exclusive pair bonds is a large rabbit-like rodent called the Patagonian mara, which inhabits warrens containing long-term couples.

https://www.yahoo.com/news/articles/revealed-most-monogamous-animals-where-143147723.html