Though it has long been thought to be merely an incorrect assumption made on the part of early ornithologists who lacked the understanding of bird physiology and migration that we possess today, it seems that the idea that hummingbirds migrated by riding on the backs of larger birds is actually true. A recent report scheduled to be published in the next issue of the Alcid, the peer reviewed journal of the Unionized Ornithologists of America (UOA), explains not only the fact that the early assumption was correct but even goes on to detail the manner in which this “co-migration” takes place.
It seems that in preparation for the southward migration from North into Central and South America, hummingbirds gather together in small groups at apparently designated areas throughout the United States and Canada. The exact manner of the designation is not fully understood but it seems to be instinctual. Larger bird species (the researchers have termed these “commuter” species) arrive at the hummingbird gathering areas at more or less regular intervals, picking up small numbers of hummingbirds onto their backs (a process the researches named “boarding”) and fly to centrally located areas also in the U.S. (called “hubs”) where the hummingbirds from these “commuter” species transfer to still larger bird species (a process called “connecting”) in great numbers for the longer southward flights into Central and South America. From the research thus far, the largest of these “hubs” appears to be near Atlanta, Georgia, although another “hub” seems to be located in Los Angeles, California.
Further research is planned to determine just how the hummingbirds arrange themselves on the larger bird species for the trips, although it is posited that the older hummingbirds who have made the trip more often (called by the researchers “frequent flyers”) are allowed to “board” the larger birds before the rest of the assembled hummingbirds and thus select the best positions, most commonly toward the front of the larger bird. However there is also some evidence to show that hummingbirds that repeatedly travel on the same species of larger birds accumulate status and also obtain limited preferential locations.
I hope everyone enjoyed this first day of April.
Peace and good bird watching.
