Birds Go Steady Before Having Kids

Photo: flickr/USFWSmidwest Perhaps you've heard that many bird species are monogamous, including swans and whooping cranes. But have you ever wondered how these long term lovers get together? Do they "date", or is it love (and breeding) at first sight? These scientists set out to answer these questions by studying the life history of the whooping crane. They found that "a substantial portion (62%) of breeding pairs started associating at least 12 months before first breeding, with 16 of 58 breeding pairs beginning to associate over 2 years before first breeding. For most pairs, these associations with future breeding partners also became unique and distinguishable from association patterns with non-partner individuals 12 months before first breeding." Not only that, but most of the breeding pairs were childhood sweethearts, getting together "before at least one partner had reached nominal sexual maturity." Birds choose long-term partners years before breeding "Pair bonds can provide social benefits to long-term monogamous species alongside their benefits for reproduction. However, little is known about when these bonds form, in particular how long they are present before breeding. Previous studies of pair formation in long-term monogamous birds have been rather data-limited, but for many migratory birds they report pair formation on the wintering grounds. We provide the first systematic investigation of prebreeding association patterns of long-term monogamous pairs by examining entire life histories based on tracking data of migratory whooping cranes, Grus americana. We found that a substantial portion (62%) of breeding pairs started associating at least 12 months before first breeding, with 16 of 58 breeding pairs beginning to associate over 2 years before first breeding. For most pairs, these associations with future breeding partners also became unique and distinguishable from association patterns with nonpartner individuals 12 months before first breeding. In addition, 60% of pair associations began before at least one partner had reached nominal sexual maturity. Most pairs began associating in the late spring upon arrival at the summer grounds, while associations beginning at other times of the year were rare. Patterns in the associations of pairs prior to breeding can point to the potential benefits of prebreeding relationships, for instance providing support in competitive interactions or increasing partner familiarity." Related content: Scientists (finally) figure out why birds don’t crash into each other.Why do some birds lay blue eggs?When scared, baby roller birds vomit in your general direction.