Having a harem sounds like a pretty sweet deal. After all, variety is the spice of life, no? But this breeding and social arrangement has its risks. For humans, you have the drama of sister wives. And for wild pheasants (Common, in Europe; or Ring-necked, stateside), a bigger group may actually present an existential danger.

Newly published research in the journal Animal Behaviour suggests an ideal harem size for pheasants of 2.7 female birds for every male. Scientists from the University of Exeter in England and the Game & Wildlife Conservation Trust (GWCT) found that having more females in the group makes each individual female a little less stressed about watching out for threats, and more able to forage in prep for breeding. But for the male, having more mates to watch out for decreased his ability to successfully detect and fend off rivals and predators.

So, to paraphrase an old saying, for pheasants eternal vigilance is the price of polygamy. And the intensity of that vigilance appears to correlate with the number of gals in the harem. Maybe monogamy, with just one partner to support and protect, isn’t so bad after all.

Image of male pheasant and his harem courtesy of GWCT.

Written by Meredith Mann
The lowly Red-winged Blackbirds in suburban New York triggered Meredith Mann's interest in birds. Five years later, she's explored some of the the USA's coolest hotspots, from Plum Island in Massachusetts to the Magic Hedge in Chicago to the deserts of Fallon, Nevada. She recently migrated from the Windy City (where she proudly served as a Chicago Bird Collision Monitor, rescuing migrants from skyscrapers and sidewalks) to Philadelphia, where she plans to find new editing and writing gigs; keep up her cool-finds chronicle, Blog5B; and discover which cheesesteak really is the best. And she will accept any and all invitations to bird Cape May, NJ.