jbm@safn2.UUCP (John McClatchey) (08/03/90)
Recent discussion of Hummingbird copulation reminded me of a story I heard about Hummingbirds. It think I've heard it from several sources, but I couldn't think of a reference. The story was that some hummingbirds have been verified "riding" geese and other large birds across the Gulf of Mexico. Is this true? a joke? an old wives tale? It does seem very difficult to figure out how a hummingbird could travel across the Gulf without eating, since it has such a rapid metabolism. I would think it might "run out of gas".
sandee@sun13.scri.fsu.edu (Daan Sandee) (08/03/90)
In article <510@safn2.UUCP> jbm@safn2.UUCP (John McClatchey) writes: >.... The story was that some hummingbirds have >been verified "riding" geese and other large birds >across the Gulf of Mexico. Is this true? a joke? >an old wives tale? It does seem very difficult to >figure out how a hummingbird could travel across the >Gulf without eating, since it has such a rapid >metabolism. I would think it might "run out of gas". This is a well-known myth, and science has found no basis in fact. Actually, I can't think of any large migrant that routinely crosses the Gulf on Mexico ; but the same myth exists in Europe, where songbirds are suppose to piggyback on geese crossing the North Sea. There, also, it has remained purely a myth. While many warblers cross the Gulf non-stop (some even may fly non-stop from Maine to South America, over the Atlantic), the ruby-throated hummingbird mostly island-hops. (All other North American hummingbirds migrate by land). And apparently it can stock up enough energy to make it. Daan Sandee sandee@sun16.scri.fsu.edu Supercomputer Computations Research Institute Florida State University, Tallahassee, FL 32306-4052 (904) 644-7045
sandee@sun13.scri.fsu.edu (Daan Sandee) (08/06/90)
In article <353@sun13.scri.fsu.edu> I wrote : >In article <510@safn2.UUCP> jbm@safn2.UUCP (John McClatchey) writes: >> ... It does seem very difficult to >>figure out how a hummingbird could travel across the >>Gulf without eating, since it has such a rapid >>metabolism. I would think it might "run out of gas". > >While many warblers cross the Gulf non-stop (some even may fly non-stop >from Maine to South America, over the Atlantic), the ruby-throated >hummingbird mostly island-hops. (All other North American hummingbirds >migrate by land). And apparently it can stock up enough energy to make it. That was just me pretending to know what I was talking about. Here's the scoop from the scientific world : Long-haul migrant store extra body fat before taking off. This has long been known by comparing the body weight of the fat birds on the taking-off side with that of the emaciated birds that make it. Odum et al. measured body weights of various southward bound migrants in Florida, and found that Ruby-throated Hummingbird may increase its body weight by as much as 100% (from 2.1 grams to a heavyweight 4 grams). With a rough estimate of the physiological requirements of level flight, they arrive at a range of 2450 km (1500 miles). Thus the 600 miles across the Gulf of Mexico can be covered easily. Odum,E.L.,C.E.Connell,H.L.Stoddard, "Flight Energy and Estimated Flight Ranges of some Migratory Birds", Auk 78:515-527 (1961). See also, Lasiewski,R.C.,"The Energetics of Migratory Hummingbirds", Condor 64:324 (1962). Daan Sandee sandee@sun16.scri.fsu.edu Supercomputer Computations Research Institute Florida State University, Tallahassee, FL 32306-4052 (904) 644-7045