In the last post, I\u00a0embarked on an historical wild goose chase.\u00a0 I am tracing the development of our understanding of bird migration through the ages. The Barnacle Goose (this European vagrant was seen recently in Aroostook County) was the centerpiece of the last column.\u00a0 It\u2019s name came from the medieval misconception that Barnacle Geese and barnacles are different stages of the same animal.<\/p>\n
Humans did not really get a handle on bird migration until the 18th<\/sup> century, finally putting Greek myths about hibernation and transformations to rest.\u00a0 In 1749, Johannes Leche began recording the spring arrival dates of Finnish birds.\u00a0 As we will see, these types of records can be valuable in understanding migration.<\/p>\n The first published statement of bird migration appeared in Thomas Berwick\u2019s A History of British Birds in 1798.\u00a0 Berwick disputed the prevalent notion that British swallows hibernated, writing \u201cthey leave us when this country can no longer furnish them with a supply of their proper and natural food\u00a0…\u201d.<\/p>\n From around 1900, local bird clubs have been collecting arrival and departure dates for migratory birds.\u00a0 By reading these local reports, an observer could determine that Ruby-throated Hummingbirds arrive in the Gulf Coast in early March, around April 10 in Virginia but not until early May in New England.\u00a0 The wave of migration of North American birds thus becomes evident through the shared observations.<\/p>\n We have come a long way since Lemche\u2019s lonely records in Finland.\u00a0 Central depositories like ebird.org hold millions of records so the patterns of northward spread in the spring and southward withdrawal in autumn are clearly seen.\u00a0 If you haven\u2019t tried the tools under the Explore Data link on ebird, give it a try.<\/p>\n Plotting the arrival and departures of migratory birds gives us insight into bird populations but not individuals.\u00a0 Do Ruby-throated Hummingbirds that cross the Gulf of Mexico and land in Louisiana continue their migration to the Midwest while those that land in Florida migrate up the Atlantic seaboard?\u00a0 We must track individuals to answer such questions.<\/p>\n Bird banding is just the tool we need to follow individuals.\u00a0 Audubon almost certainly banded the first birds in North America.\u00a0 In 1840, he tied a silver thread around the legs of several Eastern Phoebe nestlings on his farm near Philadelphia.\u00a0 Two of the phoebes came back the following year.\u00a0 Of course, he had no idea where the phoebes went to pass the winter but he clearly established the power of banding in following individual birds<\/p>\n The North American Bird Banding Program (NABBP), begun in 1920, facilitates the banding of birds in the United States and Canada.\u00a0 After extensive training, a person is provided with a Bander\u2019s Permit and is given aluminum bands, each with a unique nine-digit number.\u00a0 Banders capture birds in nets or traps; identify the species, sex and age of each bird; take various body measurements; affix an aluminum band of the proper size to one of the legs of the bird; and release the bird.<\/p>\n If another bander captures the bird or if a banded bird is found dead, the finder contacts the biologists at the NABBP who provide the recovery data to the original bander and notifies the finder of the original date and site of the banding.\u00a0 Over the 94 years of the program, over 64 million birds have been banded and 3.5 million of them have been recovered.\u00a0 We have learned much about subpopulations of migratory species that maintain different migration routes, as well as information on fidelity to wintering and breeding sites over the years.<\/p>\n Even greater detail of migration routes can be gleaned from satellite transmitters mounted on birds\u2019 backs or from small data loggers called geolocators that track a bird\u2019s geographic position continuously.\u00a0 A geolocator has to be recovered to download the data, unlike a satellite transmitter.\u00a0 How cool is it to monitor an Osprey\u2019s migration from your computer desktop?<\/p>\n [First published on November 9, 2014]<\/p>\n\n In the last post, I\u00a0embarked on an historical wild goose chase.\u00a0 I am tracing the development of our understanding of bird migration through the ages. The Barnacle Goose (this European vagrant was seen recently in Aroostook County) was the centerpiece of the last column.\u00a0 It\u2019s name came from the medieval misconception that Barnacle Geese and […]<\/p>\n","protected":false},"author":146,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"yes","ngg_post_thumbnail":0,"footnotes":""},"categories":[921,429],"tags":[],"builder_content":"","_links":{"self":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/705"}],"collection":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/users\/146"}],"replies":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/comments?post=705"}],"version-history":[{"count":1,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/705\/revisions"}],"predecessor-version":[{"id":706,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/705\/revisions\/706"}],"wp:attachment":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/media?parent=705"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/categories?post=705"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/tags?post=705"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}