BIOLOGICAL ASPECTS 321 



ered these distances by continuous flight. While many of these birds 

 alighted exhausted on the ships there is evidently some traffic of cer- 

 tain species of land birds between America and Bermuda (600 miles) 

 which, if not regular, nevertheless occurs each year. Seasonal winds 

 had certainly influenced some of the flights, but recorded winds could 

 not be used to explain the frequent occurrence of these apparently 

 hazardous flights of lone land birds over the ocean. The repeated oc- 

 currence of these long flights demonstrates the long distance that a 

 single bird can cover without social guidance or landmarks. 



For a hummingbird to fly across the Gulf of Mexico would exceed 

 the requirements of energy which Pearson (1950) could calculate to 

 be at its disposal. Weigold (1926) reported considerable variations 

 in the weights of migrant bird species arriving at Helgoland which 

 suggested that the lighter individuals had exhausted their reserves. 

 It is certain that long oversea flights tax and at times exceed the nor- 

 mal capability of birds, but a stationary observer is more likely to 

 remark upon migrating birds which are unsuccessful than to report 

 the swift flights of normal migrants. 



Among Eskimos at Anaktuvuk it is commonly the impression that 

 migratory birds arriving in spring are in good condition and usually 

 fatter than later during the nesting season. It is also their view that 

 birds of some species become fatter again just before their departure 

 southward at the end of summer than they were at the time of arrival, 

 but the arctic people hesitate to generalize upon the condition of de- 

 parting migratory birds because the time of their departure is so 

 uncertain and the birds are then so often inconspicuous. 



After examining many birds in 1948, 1949 and 1950 it was my im- 

 pression that in general they were in good condition and commonly 

 fat during the spring season of migration. The weights of birds taken 

 for specimens had been recorded along with occasional notes on their 

 apparent fatness. After 1950 the fatness of the birds was routinely 

 recorded. The designations were based upon the amount of fat visible 

 on the birds in terms fat, medium fat, little fat, and very little fat. 

 These terms mean whatever tlie observers associate with them in re- 

 lation to their value as food. Eskimos know that the fattest ptarmi- 

 gan has hardly as much fat as a rather lean loon or duck. The great 

 differences in the characteristic amounts of fat in the various species 

 required that the birds be compared according to the amount of fat 

 appropriate for each species. Finding good agreement in the designa- 

 tions of fatness by several Eskimos I followed their usage of the 

 terms, for their judgments were based upon their established code. 



Among several thousand records of the fatness of birds which were 

 examined when taken for food or as specimens, I found fewer than 

 ten birds which were designated as lean or skinny. Wounded ducks 

 have been found after several days to be actually in emaciated con- 



