Raven poop reveals the high stress of juvenile gang life and the joys of adult relationships

Maybe mature, adult relationships really are for the birds after all. Ravens are most successful at finding food when they join large gangs of thirty or more birds, but this consistently proves to be too stressful - yes, stressful - for our feathered friends. Instead, they decide to pursue a less efficient, but much more fulfilling, relationship with just one other bird. And here's the best part - we know all this because we can read it in raven poop.

Dr. Nuria Selva has been working with fellow researchers in Poland's Bialowieza Forest to determine the deeper behavioral patterns of ravens. She says that her findings - which seem to show ravens are happier in couples - came as a shock, particularly considering its natural disadvantages:

"In the case of ravens, it is clear that food finding and sharing is easier when a group of thirty ravens is searching for a carcass, than when only two ravens do it. But our study shows that life in groups is not so heavenly as traditionally thought."

There's a lot of reasons why group living should be better for ravens. Beside food concerns, a raven in a gang - or, as a group of ravens is technically known, a congress - doesn't need to worry about defending its territory all alone. And yet when Selva and her team studied raven droppings, they discovered the younger ravens had much higher levels of the hormone corticosterone in their system than their adult counterparts. Like in many animals, corticosterone regulates the stress levels of ravens, and such high concentrations means the young ravens are dealing with some serious stress, while the adults are living relatively carefree.

So what's causing the different stress levels? Selva speculates that, while finding food might be easier for ravens in a large group, the constant fights for dominance might take their toll on the birds, forcing them to pair off and defend their own little territory instead. And, as you might well imagine, Selva sees some parallels between the maturation of these ravens and what we humans get up to:

We think that having high stress levels can be an important reason to leave the group. Somehow, we feel it has many similarities with human life - stressful life in teenage gangs versus a more peaceful live in a pair."

Biology Letters via BBC News.