The phrase "arranging pairs" is correct and usable in written English.
It can be used in contexts where you are discussing the organization or pairing of items, people, or concepts.
Example: "The task involves arranging pairs of socks by color and size before putting them away."
Alternatives: "pairing items" or "organizing pairs".
But what was the source of the increased chick mortality for arranged pairs?
They found that males in chosen pairs had a 45percentt higher relative fitness than males in arranged pairs (Figure 3).
They found that individuals of chosen pairs stayed closer together and behaved more synchronously than did individuals in arranged pairs.
Females in chosen pairs had a 30percentt higher relative fitness than those in arranged pairs, but this difference was not significant (Figure 3).
During this time, arranged pairs tended to have a higher proportion of "disappeared" or buried eggs, and they produced significantly more infertile eggs.
Surprisingly (to me), females in arranged pairs were only slightly more likely to engage in extra-pair copulations and to produce clutches that contained eggs sired by an extra-pair male.
When they compared the two treatment groups, they found that males of arranged pairs attended their nest significantly less than did males in chosen pairs during the days when the eggs were hatching -- but males of both treatment groups showed comparable nest attendance during the entire offspring rearing period.
The arranged pairs were always left behind, along with miscellaneous spillage: a brand-new platform shoe might lie on its side in a puddle; a well-worn hiking boot might still stand, stalwart as an old dog, on the shattered sidewalk.
What's more, the nests of arranged pairs had nearly three times as many unfertilized eggs as the free-choice pairs.
Half of an aisle is devoted to multiple shelves of neatly arranged pairs.
